diff --git a/libraries/validation-tools/test/unit/src/zodHelpers.test.ts b/libraries/validation-tools/test/unit/src/zodHelpers.test.ts
index 0a5befff0c..b57ebfd310 100644
--- a/libraries/validation-tools/test/unit/src/zodHelpers.test.ts
+++ b/libraries/validation-tools/test/unit/src/zodHelpers.test.ts
@@ -842,40 +842,6 @@ describe('zodHelpers', () => {
     })
   })
 
-  describe('streamedBody', () => {
-    it('parses undefined (no body parser mounted) to undefined', () => {
-      const parsed = zz.streamedBody().safeParse(undefined)
-      expect(parsed.success).toBe(true)
-      expect(parsed.data).toBe(undefined)
-    })
-
-    it('parses the empty object left by a skipping body parser to undefined', () => {
-      const parsed = zz.streamedBody().safeParse({})
-      expect(parsed.success).toBe(true)
-      expect(parsed.data).toBe(undefined)
-    })
-
-    it('fails to parse a parsed JSON body', () => {
-      const parsed = zz.streamedBody().safeParse({ some: 'payload' })
-      expect(parsed.success).toBe(false)
-      expect(parsed.error?.issues).toMatchObject([
-        expect.objectContaining({
-          message: 'unexpected parsed request body on streamed endpoint',
-        }),
-      ])
-    })
-
-    it('fails to parse a raw buffer body', () => {
-      const parsed = zz.streamedBody().safeParse(Buffer.alloc(0))
-      expect(parsed.success).toBe(false)
-    })
-
-    it('fails to parse a string body', () => {
-      const parsed = zz.streamedBody().safeParse('text body')
-      expect(parsed.success).toBe(false)
-    })
-  })
-
   describe('uploadedFile', () => {
     const validFile = {
       fieldname: 'qqfile',
diff --git a/libraries/validation-tools/zodHelpers.js b/libraries/validation-tools/zodHelpers.js
index 5e14cc2376..f03b1aacee 100644
--- a/libraries/validation-tools/zodHelpers.js
+++ b/libraries/validation-tools/zodHelpers.js
@@ -206,29 +206,6 @@ const zz = {
       .min(1, { message: 'invalid event name' })
       .regex(/^[a-zA-Z0-9-_]+$/, { message: 'invalid event name' })
       .max(240, { message: 'event name is too long' }),
-  /**
-   * For endpoints that consume the request as a raw stream (e.g. blob
-   * uploads): asserts that no body parser consumed the stream before the
-   * handler. Accepts only undefined or the empty object that a skipping
-   * body parser leaves behind, and parses to undefined. If a body parser is
-   * later mounted on such a route, validation fails loudly instead of the
-   * handler silently reading an already-consumed stream.
-   */
-  streamedBody: () =>
-    z
-      .custom(
-        val => {
-          if (val === undefined) return true
-          return (
-            typeof val === 'object' &&
-            val !== null &&
-            !Buffer.isBuffer(val) &&
-            Object.keys(val).length === 0
-          )
-        },
-        { message: 'unexpected parsed request body on streamed endpoint' }
-      )
-      .transform(() => undefined),
   /**
    * A multer file object (disk storage — the only storage backend we use),
    * for validating req.file / req.files on multipart routes. The
diff --git a/package.json b/package.json
index 8c7c18a63b..34c07d3fd1 100644
--- a/package.json
+++ b/package.json
@@ -75,6 +75,7 @@
     "forwarded@npm:0.2.0": "patch:forwarded@npm%3A0.2.0#~/.yarn/patches/forwarded-npm-0.2.0.patch",
     "multer@npm:2.2.0": "patch:multer@npm%3A2.2.0#~/.yarn/patches/multer-npm-2.2.0-4ed181c78f.patch",
     "node-fetch": "patch:node-fetch@npm%3A2.7.0#~/.yarn/patches/node-fetch-npm-2.7.0.patch",
+    "passport-local": "patch:passport-local@npm%3A1.0.0#~/.yarn/patches/passport-local-npm-1.0.0-ed89961a0c.patch",
     "passport-oauth2": "patch:passport-oauth2@npm%3A1.6.1#~/.yarn/patches/passport-oauth2-npm-1.6.1.patch",
     "send": "patch:send@npm%3A0.19.0#~/.yarn/patches/send-npm-0.19.0.patch",
     "serve-static": "1.16.2",
diff --git a/services/clsi/test/acceptance/js/UrlCachingTests.js b/services/clsi/test/acceptance/js/UrlCachingTests.js
index 91cab81453..12658f95a6 100644
--- a/services/clsi/test/acceptance/js/UrlCachingTests.js
+++ b/services/clsi/test/acceptance/js/UrlCachingTests.js
@@ -32,14 +32,14 @@ const projectFileParamsSchema = z.object({
 const bucketKeyParamsSchema = z.object({
   params: z.strictObject({
     bucket: z.string(),
-    0: zz.filepath(),
+    key: zz.filepath(),
   }),
 })
 
 const staticFileParamsSchema = z.object({
   params: z.strictObject({
     random_id: z.string(),
-    0: zz.filepath(),
+    path: zz.filepath(),
   }),
 })
 
@@ -81,18 +81,18 @@ const Server = {
       res.send(`${projectId}:${fileId}`)
     })
 
-    app.get('/bucket/:bucket/key/*', (req, res, next) => {
+    app.get('/bucket/:bucket/key/:key(.+)', (req, res, next) => {
       this.getFile(req.url)
       const {
-        params: { bucket, 0: key },
+        params: { bucket, key },
       } = parseReq(req, bucketKeyParamsSchema)
       res.send(`${bucket}:${key}`)
     })
 
-    app.get('/:random_id/*', (req, res, next) => {
+    app.get('/:random_id/:path(.+)', (req, res, next) => {
       this.getFile(req.url)
       const {
-        params: { 0: path },
+        params: { path },
       } = parseReq(req, staticFileParamsSchema)
       req.url = `/${path}`
       staticServer(req, res, next)
diff --git a/services/filestore/app.js b/services/filestore/app.js
index db5b24a53f..ec55b246fc 100644
--- a/services/filestore/app.js
+++ b/services/filestore/app.js
@@ -69,13 +69,8 @@ if (settings.filestore.stores.template_files) {
   )
 }
 
-// Not a named `:key(.*)` param: Express 4.22.1's bundled path-to-regexp has a
-// bug where combining a named param with a custom (.*) regex both duplicates
-// the match under a numeric key AND corrupts the captured value (off-by-one
-// substring). The anonymous `*` wildcard doesn't have this bug, so keep it
-// and validate the numeric params[0] key directly (see schemas.js).
 app.get(
-  '/bucket/:bucket/key/*',
+  '/bucket/:bucket/key/:key(.+)',
   keyBuilder.bucketFileKeyMiddleware,
   fileController.getFile
 )
diff --git a/services/filestore/app/js/FileController.js b/services/filestore/app/js/FileController.js
index 5e00ca93dc..19336a83a3 100644
--- a/services/filestore/app/js/FileController.js
+++ b/services/filestore/app/js/FileController.js
@@ -4,11 +4,7 @@ import parseRange from 'range-parser'
 import Errors from './Errors.js'
 import { pipeline } from 'node:stream'
 import { parseReq } from '@overleaf/validation-tools'
-import {
-  getFileQuerySchema,
-  getFileQueryFallbackSchema,
-  insertFileSchema,
-} from './schemas.js'
+import { getFileQuerySchema, getFileQueryFallbackSchema } from './schemas.js'
 
 const maxSizeInBytes = 1024 * 1024 * 1024 // 1GB
 
@@ -125,7 +121,6 @@ function getFileHead(req, res, next) {
 }
 
 function insertFile(req, res, next) {
-  parseReq(req, insertFileSchema, { logOnly: true })
   metrics.inc('insertFile')
   const { key, bucket } = req
 
diff --git a/services/filestore/app/js/KeyBuilder.js b/services/filestore/app/js/KeyBuilder.js
index bdc23ae3e6..cd884d6958 100644
--- a/services/filestore/app/js/KeyBuilder.js
+++ b/services/filestore/app/js/KeyBuilder.js
@@ -44,7 +44,7 @@ function bucketFileKeyMiddleware(req, res, next) {
     logOnly: true,
   })
   req.bucket = params.bucket
-  req.key = params[0]
+  req.key = params.key
   next()
 }
 
diff --git a/services/filestore/app/js/schemas.js b/services/filestore/app/js/schemas.js
index 2a20978f96..1cefc19c3b 100644
--- a/services/filestore/app/js/schemas.js
+++ b/services/filestore/app/js/schemas.js
@@ -46,10 +46,7 @@ export const templateFileParamsFallbackSchema = z.object({
 export const bucketFileParamsSchema = z.object({
   params: z.strictObject({
     bucket: z.string().regex(/^[a-z0-9-]+$/),
-    // the anonymous `*` wildcard in app.js (kept anonymous rather than a
-    // named `:key(.*)` -- see the comment there for why); Express exposes
-    // its capture under the numeric key '0'. May contain nested segments.
-    0: zz.filepath(),
+    key: zz.filepath(),
   }),
 })
 
@@ -111,13 +108,3 @@ export const getFileQueryFallbackSchema = z.object({
     range: z.string().optional(),
   }),
 })
-
-// insertFile reads the raw request stream itself (no body parser is
-// mounted), so the body is validated as a streamed body. No fallbackSchema:
-// insertFile never reads parseReq()'s return value (FileHandler.insertFile
-// reads the stream off `req` directly), so a raw passthrough on failure
-// can't hand the handler a wrong type -- a fallback here would just
-// duplicate the primary schema.
-export const insertFileSchema = z.object({
-  body: zz.streamedBody(),
-})
diff --git a/services/filestore/test/unit/js/schemas.test.js b/services/filestore/test/unit/js/schemas.test.js
index e915592540..bdb3161337 100644
--- a/services/filestore/test/unit/js/schemas.test.js
+++ b/services/filestore/test/unit/js/schemas.test.js
@@ -5,21 +5,21 @@ describe('schemas', function () {
   describe('bucketFileParamsSchema', function () {
     it('accepts a well-formed bucket name', function () {
       const result = bucketFileParamsSchema.safeParse({
-        params: { bucket: 'my-bucket-123', 0: 'some/key' },
+        params: { bucket: 'my-bucket-123', key: 'some/key' },
       })
       expect(result.success).to.equal(true)
     })
 
     it('rejects a bucket name with disallowed characters', function () {
       const result = bucketFileParamsSchema.safeParse({
-        params: { bucket: 'My_Bucket!', 0: 'some/key' },
+        params: { bucket: 'My_Bucket!', key: 'some/key' },
       })
       expect(result.success).to.equal(false)
     })
 
     it('rejects an empty bucket name', function () {
       const result = bucketFileParamsSchema.safeParse({
-        params: { bucket: '', 0: 'some/key' },
+        params: { bucket: '', key: 'some/key' },
       })
       expect(result.success).to.equal(false)
     })
diff --git a/services/web/app/src/Features/Analytics/AnalyticsController.mjs b/services/web/app/src/Features/Analytics/AnalyticsController.mjs
index 97753be08c..46c5b9a476 100644
--- a/services/web/app/src/Features/Analytics/AnalyticsController.mjs
+++ b/services/web/app/src/Features/Analytics/AnalyticsController.mjs
@@ -5,25 +5,72 @@ import GeoIpLookup from '../../infrastructure/GeoIpLookup.mjs'
 import Features from '../../infrastructure/Features.mjs'
 import { expressify } from '@overleaf/promise-utils'
 import AccountMappingHelper from './AccountMappingHelper.mjs'
+import { z, zz, parseReq } from '../../infrastructure/Validation.mjs'
+
+// The set of segmentation/event keys is caller-supplied and dynamic (every
+// analytics event and editing session sends a different set of dimensions),
+// so it can't be enumerated up front -- treat it as a generic string-keyed
+// record (genuinely open map, mirroring SplitTestHandler's getAssignmentSchema).
+// The key regex mirrors AnalyticsManager's own _isAttributeValid, the only
+// validation applied to these keys today; values are never validated there
+// either, hence z.unknown().
+const attributeKeySchema = z.string().regex(/^[a-zA-Z0-9-_.:;,/]+$/)
+const segmentationSchema = z.record(attributeKeySchema, z.unknown())
+
+const registerSalesforceMappingSchema = z.object({
+  body: z.strictObject({
+    // sent by v1's V2RequestWorker#register_salesforce_mapping
+    createdAt: zz.datetime({ offset: true }),
+    salesforceId: z.string(),
+    v1Id: z.coerce.number().int(),
+  }),
+})
+
+// Rollout-temporary fallback (loosened primary schema; no zod validation
+// existed for this route on main); delete when this route's
+// REQ_VALIDATION_MODE instrumentation is removed.
+const registerSalesforceMappingFallbackSchema = z.object({
+  body: z.object({
+    createdAt: z.coerce.date(),
+    salesforceId: z.string(),
+    v1Id: z.coerce.number(),
+  }),
+})
 
 async function registerSalesforceMapping(req, res, next) {
   if (!Features.hasFeature('analytics')) {
     return res.sendStatus(202)
   }
-  const { createdAt, salesforceId, v1Id } = req.body
+  const { body } = parseReq(req, registerSalesforceMappingSchema, {
+    logOnly: true,
+    fallbackSchema: registerSalesforceMappingFallbackSchema,
+  })
+  const { createdAt, salesforceId, v1Id } = body
   AnalyticsManager.registerAccountMapping(
     AccountMappingHelper.generateV1Mapping(v1Id, salesforceId, createdAt)
   )
   res.sendStatus(202)
 }
 
+const updateEditingSessionSchema = z.object({
+  params: z.strictObject({
+    projectId: zz.objectId(),
+  }),
+  body: z.strictObject({
+    segmentation: segmentationSchema.optional(),
+  }),
+})
+
 async function updateEditingSession(req, res, next) {
   if (!Features.hasFeature('analytics')) {
     return res.sendStatus(202)
   }
   const userId = SessionManager.getLoggedInUserId(req.session)
-  const { projectId } = req.params
-  const segmentation = req.body.segmentation || {}
+  const { params, body } = parseReq(req, updateEditingSessionSchema, {
+    logOnly: true,
+  })
+  const { projectId } = params
+  const segmentation = body.segmentation || {}
   let countryCode = null
 
   if (userId) {
@@ -45,6 +92,13 @@ async function updateEditingSession(req, res, next) {
   res.sendStatus(202)
 }
 
+const recordEventSchema = z.object({
+  params: z.strictObject({
+    event: zz.eventName(),
+  }),
+  body: segmentationSchema,
+})
+
 // TODO: remove after clients running pre-#36315 code have drained
 function isIdleConnectionRestoredEvent(event, body) {
   if (event !== 'connection-restored') {
@@ -60,16 +114,14 @@ function recordEvent(req, res, next) {
   if (!Features.hasFeature('analytics')) {
     return res.sendStatus(202)
   }
-  if (isIdleConnectionRestoredEvent(req.params.event, req.body)) {
+  const { params, body } = parseReq(req, recordEventSchema, {
+    logOnly: true,
+  })
+  if (isIdleConnectionRestoredEvent(params.event, body)) {
     metrics.inc('analytics_idle_connection_restored_blocked')
     return res.sendStatus(202)
   }
-  delete req.body._csrf
-  AnalyticsManager.recordEventForSession(
-    req.session,
-    req.params.event,
-    req.body
-  )
+  AnalyticsManager.recordEventForSession(req.session, params.event, body)
   res.sendStatus(202)
 }
 
diff --git a/services/web/app/src/Features/Analytics/AnalyticsRegistrationSourceMiddleware.mjs b/services/web/app/src/Features/Analytics/AnalyticsRegistrationSourceMiddleware.mjs
index 36945911c0..585ac8d297 100644
--- a/services/web/app/src/Features/Analytics/AnalyticsRegistrationSourceMiddleware.mjs
+++ b/services/web/app/src/Features/Analytics/AnalyticsRegistrationSourceMiddleware.mjs
@@ -2,6 +2,8 @@ import logger from '@overleaf/logger'
 import OError from '@overleaf/o-error'
 import AnalyticsRegistrationSourceHelper from './AnalyticsRegistrationSourceHelper.mjs'
 import SessionManager from '../../Features/Authentication/SessionManager.mjs'
+import RequestHelper from './RequestHelper.mjs'
+import { parseReq } from '../../infrastructure/Validation.mjs'
 
 function setSource(medium, source) {
   return function (req, res, next) {
@@ -34,10 +36,14 @@ function setInbound() {
 
     const referrer = req.header('referrer')
     try {
+      // NOTE: The utm query flags will be removed in the next middleware.
+      const { query } = parseReq(req, RequestHelper.utmQuerySchema, {
+        logOnly: true,
+      })
       AnalyticsRegistrationSourceHelper.setInbound(
         req.session,
         req.url,
-        req.query,
+        query,
         referrer
       )
     } catch (error) {
diff --git a/services/web/app/src/Features/Analytics/AnalyticsUTMTrackingMiddleware.mjs b/services/web/app/src/Features/Analytics/AnalyticsUTMTrackingMiddleware.mjs
index 7b5d6a2b63..79b38bb3b8 100644
--- a/services/web/app/src/Features/Analytics/AnalyticsUTMTrackingMiddleware.mjs
+++ b/services/web/app/src/Features/Analytics/AnalyticsUTMTrackingMiddleware.mjs
@@ -1,16 +1,20 @@
 import RequestHelper from './RequestHelper.mjs'
 import AnalyticsManager from './AnalyticsManager.mjs'
-import { URL } from 'node:url'
 import Settings from '@overleaf/settings'
 import logger from '@overleaf/logger'
+import { parseReq, getRawReqInput } from '../../infrastructure/Validation.mjs'
 import UrlHelper from '../Helpers/UrlHelper.mjs'
 
 function recordUTMTags() {
   return function (req, res, next) {
-    const rawQuery = req.query
+    const rawQuery = getRawReqInput(req).query
 
     try {
-      const utmValues = RequestHelper.parseUtm(rawQuery)
+      const { query } = parseReq(req, RequestHelper.utmQuerySchema, {
+        logOnly: true,
+      })
+
+      const utmValues = RequestHelper.parseUtm(query)
 
       if (utmValues) {
         const path = new URL(req.url, Settings.siteUrl).pathname
diff --git a/services/web/app/src/Features/Compile/ClsiCacheController.mjs b/services/web/app/src/Features/Compile/ClsiCacheController.mjs
index 92ee7b2b20..d32dd58ba1 100644
--- a/services/web/app/src/Features/Compile/ClsiCacheController.mjs
+++ b/services/web/app/src/Features/Compile/ClsiCacheController.mjs
@@ -17,6 +17,18 @@ import { z, zz } from '@overleaf/validation-tools'
 import { parseReq } from '../../infrastructure/Validation.mjs'
 
 const downloadFromCacheSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+    editorBuildId: zz.editorBuildId(),
+    filename: zz.filepath().refine(s => ClsiCacheHandler.isAllowedFilename(s), {
+      message: 'path is not allowed',
+    }),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const downloadFromCacheFallbackSchema = z.object({
   params: z.object({
     Project_id: zz.objectId(),
     editorBuildId: zz.editorBuildId(),
@@ -26,6 +38,12 @@ const downloadFromCacheSchema = z.object({
   }),
 })
 
+const getLatestBuildFromCacheSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+})
+
 /**
  * Download a file from a specific build on the clsi-cache.
  *
@@ -36,7 +54,9 @@ const downloadFromCacheSchema = z.object({
 async function downloadFromCache(req, res) {
   const {
     params: { Project_id: projectId, editorBuildId, filename },
-  } = parseReq(req, downloadFromCacheSchema)
+  } = parseReq(req, downloadFromCacheSchema, {
+    fallbackSchema: downloadFromCacheFallbackSchema,
+  })
   return await _downloadFromCacheWithParams(
     req,
     res,
@@ -173,7 +193,10 @@ async function _downloadFromCacheWithParams(
  * @return {Promise<void>}
  */
 async function getLatestBuildFromCache(req, res) {
-  const { Project_id: projectId } = req.params
+  const { params } = parseReq(req, getLatestBuildFromCacheSchema, {
+    logOnly: true,
+  })
+  const projectId = params.Project_id
   const userId = CompileController._getUserIdForCompile(req)
   try {
     const {
diff --git a/services/web/app/src/Features/Compile/ClsiCacheManager.mjs b/services/web/app/src/Features/Compile/ClsiCacheManager.mjs
index b96d916d5d..70b4cdc83a 100644
--- a/services/web/app/src/Features/Compile/ClsiCacheManager.mjs
+++ b/services/web/app/src/Features/Compile/ClsiCacheManager.mjs
@@ -50,7 +50,9 @@ async function getLatestBuildFromCache(projectId, userId, filename, signal) {
       ? lastUpdatedInRedis
       : lastUpdatedInMongo
   const isUpToDate = lastCompiled >= lastUpdated
-  const imageName = Path.basename(fullImageName)
+  // fullImageName is unset for projects outside SaaS (no
+  // Settings.currentImageName to default from on creation)
+  const imageName = fullImageName ? Path.basename(fullImageName) : undefined
 
   return {
     internal: {
diff --git a/services/web/app/src/Features/Compile/CompileController.mjs b/services/web/app/src/Features/Compile/CompileController.mjs
index 2dc538d622..b94f794ecc 100644
--- a/services/web/app/src/Features/Compile/CompileController.mjs
+++ b/services/web/app/src/Features/Compile/CompileController.mjs
@@ -45,7 +45,25 @@ function getOutputFilesArchiveSpecification(projectId, userId, buildId) {
   }
 }
 
+// Only reads the one query field this helper itself consumes -- the route
+// handlers that call this (compile, ClsiCacheController.getLatestBuildFromCache)
+// separately validate their own full query/params/body with their own schema.
+const splitTestOptionsQuerySchema = z.object({
+  body: z.object({
+    png2pdf: z.boolean().optional(),
+  }),
+  query: z.object({
+    // presence-based flag: the frontend only ever sets this to "true" or
+    // omits it (see compiler.ts buildCompileParams), so a bare optional
+    // string preserves the existing truthy check below
+    enable_pdf_caching: z.string().optional(),
+  }),
+})
+
 async function _getSplitTestOptions(req, res) {
+  const { body, query } = parseReq(req, splitTestOptionsQuerySchema, {
+    logOnly: true,
+  })
   const compileFromHistory = await SplitTestHandler.promises.featureFlagEnabled(
     req,
     res,
@@ -58,7 +76,7 @@ async function _getSplitTestOptions(req, res) {
   const pdfCachingMinChunkSize = Settings.pdfCachingMinChunkSize
 
   const pdfCachingOptions =
-    !enablePdfCaching || !req.query.enable_pdf_caching
+    !enablePdfCaching || !query.enable_pdf_caching
       ? // The frontend does not want to do pdf caching.
         { enablePdfCaching: false }
       : { enablePdfCaching, pdfCachingMinChunkSize }
@@ -78,7 +96,7 @@ async function _getSplitTestOptions(req, res) {
   )
 
   const png2PdfOptions =
-    !enablePng2Pdf || !req.body.png2pdf
+    !enablePng2Pdf || !body.png2pdf
       ? { enablePng2Pdf: false }
       : { enablePng2Pdf }
 
@@ -91,12 +109,21 @@ async function _getSplitTestOptions(req, res) {
   }
 }
 
-async function _syncTeX(req, res, direction, validatedOptions) {
-  const projectId = req.params.Project_id
-  const { editorId, buildId, clsiserverid: clsiServerId } = req.query
-  if (!editorId?.match(/^[a-f0-9-]+$/)) throw new Error('invalid ?editorId')
-  if (!buildId?.match(/^[a-f0-9-]+$/)) throw new Error('invalid ?buildId')
-
+// buildId in syncTeXBaseQuery below is validated with zz.buildId(), which
+// requires a hyphen-separated pair of hex runs (/^[0-9a-f]+-[0-9a-f]+$/) --
+// stricter than the bare hex-ish regex the manual guards restored below
+// check editorId/buildId against. Both layers run: the schema during this
+// rollout's logOnly phase, and the manual guards unconditionally.
+async function _syncTeX(
+  req,
+  res,
+  projectId,
+  editorId,
+  buildId,
+  clsiServerId,
+  direction,
+  validatedOptions
+) {
   const userId = CompileController._getUserIdForCompile(req)
   try {
     const body = await CompileManager.promises.syncTeX(projectId, userId, {
@@ -116,7 +143,77 @@ async function _syncTeX(req, res, direction, validatedOptions) {
   }
 }
 
+const compileSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+  query: z.object({
+    // presence-based flags: the frontend only ever sets these to "true" or
+    // omits them (see compiler.ts buildCompileParams); bare optional
+    // strings preserve the existing truthy checks below rather than
+    // z.stringbool(), which would treat an (unused-in-practice) explicit
+    // "false" value differently than the current code does
+    auto_compile: z.string().optional(),
+    file_line_errors: z.string().optional(),
+    enable_pdf_caching: z.string().optional(),
+  }),
+  body: z.strictObject({
+    stopOnFirstError: z.boolean().optional(),
+    editorId: z.uuid().optional(),
+    rootResourcePath: zz.filepath().optional(),
+    rootDoc_id: zz.objectId().nullish(),
+    // legacy nested duplicate of rootDoc_id, only sent by old cached
+    // frontend bundles during a deploy transition -- can be removed once
+    // that's no longer a concern. Deliberately non-strict: this object's
+    // shape before that cleanup isn't fully known here, and the only field
+    // ever read from it is rootDoc_id.
+    settingsOverride: z
+      .object({ rootDoc_id: zz.objectId().nullish() })
+      .optional(),
+    compiler: z.string().optional(),
+    draft: z.boolean().optional(),
+    png2pdf: z.boolean().optional(),
+    // silently ignored (not rejected) when not one of these three, to
+    // match the existing .includes() check below
+    check: z.string().optional(),
+    incrementalCompilesEnabled: z.boolean().optional(),
+  }),
+})
+
+const stopCompileSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+})
+
+const compileSubmissionSchema = z.object({
+  params: z.strictObject({
+    submission_id: zz.submissionId(),
+  }),
+  // This is the public compile-submission API used by external callers (see
+  // modules/publish-modal/app/src/PublishModalRouter.mjs): the body is a
+  // whole CLSI compile job spec ("resources" etc.) forwarded verbatim to
+  // ClsiManager.sendExternalRequest -- CLSI's own compileSchema
+  // (services/clsi/app/js/CompileController.js) is what actually validates
+  // that job spec, so this is treated as a genuinely open map, letting the
+  // few option flags below still be read out named without stripping the
+  // rest of the payload before it's forwarded (a non-strict z.object() would
+  // strip unrecognized keys from the parsed result, breaking the forward).
+  body: z.record(z.string(), z.unknown()),
+})
+
 const deleteAuxFilesSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+  query: z.object({
+    clsiserverid: zz.clsiServerId().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const deleteAuxFilesFallbackSchema = z.object({
   params: z.object({
     Project_id: zz.objectId(),
   }),
@@ -126,6 +223,18 @@ const deleteAuxFilesSchema = z.object({
 })
 
 const wordCountSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+  query: z.object({
+    clsiserverid: zz.clsiServerId().optional(),
+    file: z.string().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const wordCountFallbackSchema = z.object({
   params: z.object({
     Project_id: zz.objectId(),
   }),
@@ -136,6 +245,26 @@ const wordCountSchema = z.object({
 })
 
 const getFileForSubmissionFromClsiSchema = z.object({
+  params: z.strictObject({
+    submissionId: zz.submissionId(),
+    build_id: zz.buildId(),
+    file: zz.filepath(),
+  }),
+  query: z.object({
+    clsiserverid: zz.clsiServerId().optional(),
+    // V1's CLSI::Response#v2_api_url always appends this (from the
+    // compile response's compileGroup field, which compileSubmission below
+    // never populates -- see its res.json()), so it arrives here blank
+    // rather than one of zz.compileGroup()'s enum values. Unread by the
+    // handler either way; accept the real enum plus that one specific
+    // blank case, rather than opening this up to an arbitrary string.
+    compileGroup: zz.compileGroup().or(z.literal('')).optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const getFileForSubmissionFromClsiFallbackSchema = z.object({
   params: z.object({
     submissionId: zz.submissionId(),
     build_id: zz.buildId(),
@@ -146,7 +275,33 @@ const getFileForSubmissionFromClsiSchema = z.object({
   }),
 })
 
+// getFileFromClsi/getOutputZipFromClsi below (not downloadPdf, which only
+// has one route) are each mounted on two routes: one plain, and one with an
+// extra (unused by the handler) :user_id segment for a specific user's
+// build -- see router.mjs. user_id is declared but never read, purely so
+// the strict params schema still accepts the second route's extra segment.
 const getFileFromClsiSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+    user_id: zz.objectId().optional(),
+    build_id: zz.buildId(),
+    file: zz.filepath(),
+  }),
+  query: z.object({
+    clsiserverid: zz.clsiServerId().optional(),
+    editorId: z.uuid().optional(),
+    // frontend's buildFileList always appends this to every per-file
+    // download link it builds for the "Other logs and files" menu
+    // (services/web/frontend/js/features/pdf-preview/util/file-list.ts)
+    compileGroup: zz.compileGroup().optional(),
+    // not consumed, traffic tag
+    enable_pdf_caching: z.stringbool().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const getFileFromClsiFallbackSchema = z.object({
   params: z.object({
     Project_id: zz.objectId(),
     build_id: zz.buildId(),
@@ -155,10 +310,32 @@ const getFileFromClsiSchema = z.object({
   query: z.object({
     clsiserverid: zz.clsiServerId().optional(),
     editorId: z.uuid().optional(),
+    // not consumed, traffic tag
+    enable_pdf_caching: z.string().optional(),
   }),
 })
 
 const getOutputPDFFromClsiSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+    build_id: zz.buildId(),
+  }),
+  query: z.object({
+    clsiserverid: zz.clsiServerId().optional(),
+    editorId: z.uuid().optional(),
+    // presence-based flag, see compile()'s query fields above
+    popupDownload: z.string().optional(),
+    // the PDF download link is built from the same query params as the
+    // preview's pdfUrl (see output-files.ts), which includes compileGroup
+    compileGroup: zz.compileGroup().optional(),
+    // not consumed, traffic tag
+    enable_pdf_caching: z.stringbool().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const getOutputPDFFromClsiFallbackSchema = z.object({
   params: z.object({
     Project_id: zz.objectId(),
     build_id: zz.buildId(),
@@ -166,54 +343,123 @@ const getOutputPDFFromClsiSchema = z.object({
   query: z.object({
     clsiserverid: zz.clsiServerId().optional(),
     editorId: z.uuid().optional(),
+    // not consumed, traffic tag
+    enable_pdf_caching: z.string().optional(),
   }),
 })
 
 const getOutputZipFromClsiSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+    user_id: zz.objectId().optional(),
+    build_id: zz.buildId(),
+  }),
+  query: z.object({
+    clsiserverid: zz.clsiServerId().optional(),
+    // frontend's buildFileList always appends editorId/compileGroup, and
+    // (for the "Download all" archive link specifically) one `files` entry
+    // per output file, to the query string it builds
+    // (services/web/frontend/js/features/pdf-preview/util/file-list.ts).
+    // None of these three are read by the handler below -- the backend
+    // already knows the build's full file list -- they're carried along
+    // only because the archive URL is built from the same query-params
+    // object as the per-file download links.
+    editorId: z.uuid().optional(),
+    compileGroup: zz.compileGroup().optional(),
+    // a single file in the archive arrives as a bare string, not a
+    // one-element array -- Express's query parser only produces an array
+    // once a query key repeats
+    files: z.union([z.string(), z.array(z.string())]).optional(),
+    // not consumed, traffic tag
+    enable_pdf_caching: z.stringbool().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const getOutputZipFromClsiFallbackSchema = z.object({
   params: z.object({
     Project_id: zz.objectId(),
     build_id: zz.buildId(),
   }),
   query: z.object({
     clsiserverid: zz.clsiServerId().optional(),
+    // not consumed, traffic tag
+    enable_pdf_caching: z.string().optional(),
+  }),
+})
+
+const compileAndDownloadPdfSchema = z.object({
+  params: z.strictObject({
+    project_id: zz.objectId(),
+  }),
+})
+
+const syncTeXBaseQuery = {
+  editorId: z.uuid().optional(),
+  buildId: zz.buildId(),
+  clsiserverid: zz.clsiServerId().optional(),
+}
+
+const proxySyncPdfSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+  query: z.object({
+    page: z.string().regex(/^\d+$/),
+    h: z.string().regex(/^-?\d+\.\d+$/),
+    v: z.string().regex(/^-?\d+\.\d+$/),
+    ...syncTeXBaseQuery,
+  }),
+})
+
+const proxySyncCodeSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+  query: z.object({
+    file: zz.filepath(),
+    line: z.string().regex(/^\d+$/),
+    column: z.string().regex(/^\d+$/),
+    ...syncTeXBaseQuery,
   }),
 })
 
 const _CompileController = {
   async compile(req, res) {
     res.setTimeout(COMPILE_TIMEOUT_MS)
-    const projectId = req.params.Project_id
-    const isAutoCompile = !!req.query.auto_compile
-    const fileLineErrors = !!req.query.file_line_errors
-    const stopOnFirstError = !!req.body.stopOnFirstError
+    const { params, query, body } = parseReq(req, compileSchema, {
+      logOnly: true,
+    })
+    const projectId = params.Project_id
+    const isAutoCompile = !!query.auto_compile
+    const fileLineErrors = !!query.file_line_errors
+    const stopOnFirstError = !!body.stopOnFirstError
     const userId = SessionManager.getLoggedInUserId(req.session)
     const options = {
       isAutoCompile,
       fileLineErrors,
       stopOnFirstError,
-      editorId: req.body.editorId,
-      rootResourcePath: req.body.rootResourcePath,
+      editorId: body.editorId,
+      rootResourcePath: body.rootResourcePath,
     }
 
-    if (req.body.rootDoc_id) {
-      options.rootDoc_id = req.body.rootDoc_id
-    } else if (
-      req.body.settingsOverride &&
-      req.body.settingsOverride.rootDoc_id
-    ) {
+    if (body.rootDoc_id) {
+      options.rootDoc_id = body.rootDoc_id
+    } else if (body.settingsOverride && body.settingsOverride.rootDoc_id) {
       // Can be removed after deploy
-      options.rootDoc_id = req.body.settingsOverride.rootDoc_id
+      options.rootDoc_id = body.settingsOverride.rootDoc_id
     }
-    if (req.body.compiler) {
-      options.compiler = req.body.compiler
+    if (body.compiler) {
+      options.compiler = body.compiler
     }
-    if (req.body.draft) {
-      options.draft = req.body.draft
+    if (body.draft) {
+      options.draft = body.draft
     }
-    if (['validate', 'error', 'silent'].includes(req.body.check)) {
-      options.check = req.body.check
+    if (['validate', 'error', 'silent'].includes(body.check)) {
+      options.check = body.check
     }
-    if (req.body.incrementalCompilesEnabled) {
+    if (body.incrementalCompilesEnabled) {
       options.incrementalCompilesEnabled = true
     }
 
@@ -363,7 +609,8 @@ const _CompileController = {
   },
 
   async stopCompile(req, res) {
-    const projectId = req.params.Project_id
+    const { params } = parseReq(req, stopCompileSchema, { logOnly: true })
+    const projectId = params.Project_id
     const userId = SessionManager.getLoggedInUserId(req.session)
     await CompileManager.promises.stopCompile(projectId, userId)
     res.sendStatus(200)
@@ -372,30 +619,32 @@ const _CompileController = {
   // Used for submissions through the public API
   async compileSubmission(req, res) {
     res.setTimeout(COMPILE_TIMEOUT_MS)
-    const submissionId = req.params.submission_id
+    const { params, body } = parseReq(req, compileSubmissionSchema, {
+      logOnly: true,
+    })
+    const submissionId = params.submission_id
     const options = {}
-    if (req.body?.rootResourcePath != null) {
-      options.rootResourcePath = req.body.rootResourcePath
+    if (body?.rootResourcePath != null) {
+      options.rootResourcePath = body.rootResourcePath
     }
-    if (req.body?.compiler) {
-      options.compiler = req.body.compiler
+    if (body?.compiler) {
+      options.compiler = body.compiler
     }
-    if (req.body?.draft) {
-      options.draft = req.body.draft
+    if (body?.draft) {
+      options.draft = body.draft
     }
-    if (['validate', 'error', 'silent'].includes(req.body?.check)) {
-      options.check = req.body.check
+    if (['validate', 'error', 'silent'].includes(body?.check)) {
+      options.check = body.check
     }
     options.compileGroup =
-      req.body?.compileGroup || Settings.defaultFeatures.compileGroup
+      body?.compileGroup || Settings.defaultFeatures.compileGroup
     options.compileBackendClass =
       Settings.apis.clsi.submissionCompileBackendClass
-    options.timeout =
-      req.body?.timeout || Settings.defaultFeatures.compileTimeout
+    options.timeout = body?.timeout || Settings.defaultFeatures.compileTimeout
     const { status, outputFiles, clsiServerId, validationProblems } =
       await ClsiManager.promises.sendExternalRequest(
         submissionId,
-        req.body,
+        body,
         options
       )
     res.json({
@@ -416,8 +665,10 @@ const _CompileController = {
   async downloadPdf(req, res) {
     const {
       params: { Project_id: projectId, build_id: buildId },
-      query: { clsiserverid: clsiServerId, editorId },
-    } = parseReq(req, getOutputPDFFromClsiSchema)
+      query: { clsiserverid: clsiServerId, editorId, popupDownload },
+    } = parseReq(req, getOutputPDFFromClsiSchema, {
+      fallbackSchema: getOutputPDFFromClsiFallbackSchema,
+    })
     Metrics.inc('pdf-downloads')
     try {
       await pdfDownloadRateLimiter.consume(req.ip, 1, { method: 'ip' })
@@ -439,7 +690,7 @@ const _CompileController = {
     res.contentType('application/pdf')
     const filename = `${_CompileController._getSafeProjectName(project)}.pdf`
 
-    if (req.query.popupDownload) {
+    if (popupDownload) {
       res.setContentDisposition('attachment', { filename })
     } else {
       res.setContentDisposition('inline', { filename })
@@ -468,7 +719,9 @@ const _CompileController = {
     const {
       params: { Project_id: projectId },
       query: { clsiserverid },
-    } = parseReq(req, deleteAuxFilesSchema)
+    } = parseReq(req, deleteAuxFilesSchema, {
+      fallbackSchema: deleteAuxFilesFallbackSchema,
+    })
     const userId = CompileController._getUserIdForCompile(req)
     await CompileManager.promises.deleteAuxFiles(
       projectId,
@@ -480,7 +733,10 @@ const _CompileController = {
 
   // this is only used by templates, so is not called with a userId
   async compileAndDownloadPdf(req, res) {
-    const projectId = req.params.project_id
+    const { params } = parseReq(req, compileAndDownloadPdfSchema, {
+      logOnly: true,
+    })
+    const projectId = params.project_id
 
     let outputFiles, clsiServerId, buildId
     try {
@@ -522,7 +778,9 @@ const _CompileController = {
     const {
       params: { Project_id: projectId, build_id: buildId },
       query: { clsiserverid: clsiServerId },
-    } = parseReq(req, getOutputZipFromClsiSchema)
+    } = parseReq(req, getOutputZipFromClsiSchema, {
+      fallbackSchema: getOutputZipFromClsiFallbackSchema,
+    })
 
     const project = await ProjectGetter.promises.getProject(projectId, {
       name: 1,
@@ -548,7 +806,9 @@ const _CompileController = {
     const {
       params: { Project_id: projectId, build_id: buildId, file },
       query: { clsiserverid: clsiServerId, editorId },
-    } = parseReq(req, getFileFromClsiSchema)
+    } = parseReq(req, getFileFromClsiSchema, {
+      fallbackSchema: getFileFromClsiFallbackSchema,
+    })
 
     await _downloadFromClsiNginx(
       projectId,
@@ -567,7 +827,9 @@ const _CompileController = {
     const {
       params: { submissionId, build_id: buildId, file },
       query: { clsiserverid: clsiServerId },
-    } = parseReq(req, getFileForSubmissionFromClsiSchema)
+    } = parseReq(req, getFileForSubmissionFromClsiSchema, {
+      fallbackSchema: getFileForSubmissionFromClsiFallbackSchema,
+    })
     await _downloadFromClsiNginx(
       submissionId,
       null,
@@ -582,7 +844,12 @@ const _CompileController = {
   },
 
   async proxySyncPdf(req, res) {
-    const { page, h, v } = req.query
+    const {
+      params: { Project_id: projectId },
+      query: { page, h, v, editorId, buildId, clsiserverid: clsiServerId },
+    } = parseReq(req, proxySyncPdfSchema, { logOnly: true })
+    if (!editorId?.match(/^[a-f0-9-]+$/)) throw new Error('invalid ?editorId')
+    if (!buildId?.match(/^[a-f0-9-]+$/)) throw new Error('invalid ?buildId')
     if (!page?.match(/^\d+$/)) {
       throw new Error('invalid page parameter')
     }
@@ -592,11 +859,32 @@ const _CompileController = {
     if (!v?.match(/^-?\d+\.\d+$/)) {
       throw new Error('invalid v parameter')
     }
-    await _syncTeX(req, res, 'pdf', { page, h, v })
+    await _syncTeX(
+      req,
+      res,
+      projectId,
+      editorId,
+      buildId,
+      clsiServerId,
+      'pdf',
+      { page, h, v }
+    )
   },
 
   async proxySyncCode(req, res) {
-    const { file, line, column } = req.query
+    const {
+      params: { Project_id: projectId },
+      query: {
+        file,
+        line,
+        column,
+        editorId,
+        buildId,
+        clsiserverid: clsiServerId,
+      },
+    } = parseReq(req, proxySyncCodeSchema, { logOnly: true })
+    if (!editorId?.match(/^[a-f0-9-]+$/)) throw new Error('invalid ?editorId')
+    if (!buildId?.match(/^[a-f0-9-]+$/)) throw new Error('invalid ?buildId')
     if (!file) {
       throw new Error('missing file parameter')
     }
@@ -615,11 +903,22 @@ const _CompileController = {
     if (!column?.match(/^\d+$/)) {
       throw new Error('invalid column parameter')
     }
-    await _syncTeX(req, res, 'code', { file, line, column })
+    await _syncTeX(
+      req,
+      res,
+      projectId,
+      editorId,
+      buildId,
+      clsiServerId,
+      'code',
+      { file, line, column }
+    )
   },
 
   async wordCount(req, res) {
-    const { params, query } = parseReq(req, wordCountSchema)
+    const { params, query } = parseReq(req, wordCountSchema, {
+      fallbackSchema: wordCountFallbackSchema,
+    })
     const projectId = params.Project_id
     const file = query.file || false
     const { clsiserverid } = query
diff --git a/services/web/app/src/Features/Documents/DocumentController.mjs b/services/web/app/src/Features/Documents/DocumentController.mjs
index 1c325e5ad2..d5b1bbbec8 100644
--- a/services/web/app/src/Features/Documents/DocumentController.mjs
+++ b/services/web/app/src/Features/Documents/DocumentController.mjs
@@ -27,12 +27,14 @@ const insertOp = z.strictObject({
   i: z.string(),
   p: z.number().int().min(0),
   u: z.boolean().optional(),
+  fixedRemoveChange: z.boolean().optional(),
 })
 
 const deleteOp = z.strictObject({
   d: z.string(),
   p: z.number().int().min(0),
   u: z.boolean().optional(),
+  fixedRemoveChange: z.boolean().optional(),
 })
 
 const commentOp = z.strictObject({
diff --git a/services/web/app/src/Features/FileStore/FileStoreController.mjs b/services/web/app/src/Features/FileStore/FileStoreController.mjs
index ab5e4f014b..174b4f057b 100644
--- a/services/web/app/src/Features/FileStore/FileStoreController.mjs
+++ b/services/web/app/src/Features/FileStore/FileStoreController.mjs
@@ -8,15 +8,34 @@ import ProjectLocator from '../Project/ProjectLocator.mjs'
 import HistoryManager from '../History/HistoryManager.mjs'
 import Errors from '../Errors/Errors.js'
 import { preparePlainTextResponse } from '../../infrastructure/Response.mjs'
+import { z, zz, parseReq } from '../../infrastructure/Validation.mjs'
+
+const getFileSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+    File_id: zz.objectId(),
+  }),
+  // the query string isn't read for any decision-making -- only logged
+  // verbatim for debugging, so treat it as a generic open map
+  query: z.record(z.string(), z.unknown()),
+})
+
+const getFileHeadSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+    File_id: zz.objectId(),
+  }),
+})
 
 /**
  * @param {any} req
  * @param {any} res
  */
 async function getFile(req, res) {
-  const projectId = req.params.Project_id
-  const fileId = req.params.File_id
-  const queryString = req.query
+  const { params, query } = parseReq(req, getFileSchema, { logOnly: true })
+  const projectId = params.Project_id
+  const fileId = params.File_id
+  const queryString = query
   const userAgent = req.get('User-Agent')
   req.logger.addFields({ projectId, fileId, queryString })
 
@@ -110,8 +129,9 @@ async function getFile(req, res) {
  * @param {any} res
  */
 async function getFileHead(req, res) {
-  const projectId = req.params.Project_id
-  const fileId = req.params.File_id
+  const { params } = parseReq(req, getFileHeadSchema, { logOnly: true })
+  const projectId = params.Project_id
+  const fileId = params.File_id
 
   let file
   try {
diff --git a/services/web/app/src/Features/InactiveData/InactiveProjectController.mjs b/services/web/app/src/Features/InactiveData/InactiveProjectController.mjs
index 825845acc8..6c32cf6c73 100644
--- a/services/web/app/src/Features/InactiveData/InactiveProjectController.mjs
+++ b/services/web/app/src/Features/InactiveData/InactiveProjectController.mjs
@@ -10,14 +10,38 @@
  * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
  */
 import InactiveProjectManager from './InactiveProjectManager.mjs'
+import { z, zz, parseReq } from '../../infrastructure/Validation.mjs'
+
+const deactivateOldProjectsSchema = z.object({
+  body: z.strictObject({
+    numberOfProjectsToArchive: z.coerce.number().int().optional(),
+    ageOfProjects: z.coerce.number().int().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (loosened primary schema; no zod validation
+// existed for this route on main); delete when this route's
+// REQ_VALIDATION_MODE instrumentation is removed.
+const deactivateOldProjectsFallbackSchema = z.object({
+  body: z.object({
+    numberOfProjectsToArchive: z.coerce.number().optional(),
+    ageOfProjects: z.coerce.number().optional(),
+  }),
+})
+
+const deactivateProjectSchema = z.object({
+  params: z.strictObject({
+    project_id: zz.objectId(),
+  }),
+})
 
 export default {
   deactivateOldProjects(req, res) {
-    const numberOfProjectsToArchive = parseInt(
-      req.body.numberOfProjectsToArchive,
-      10
-    )
-    const { ageOfProjects } = req.body
+    const { body } = parseReq(req, deactivateOldProjectsSchema, {
+      logOnly: true,
+      fallbackSchema: deactivateOldProjectsFallbackSchema,
+    })
+    const { numberOfProjectsToArchive, ageOfProjects } = body
     return InactiveProjectManager.deactivateOldProjects(
       numberOfProjectsToArchive,
       ageOfProjects,
@@ -32,7 +56,10 @@ export default {
   },
 
   deactivateProject(req, res) {
-    const { project_id: projectId } = req.params
+    const { params } = parseReq(req, deactivateProjectSchema, {
+      logOnly: true,
+    })
+    const { project_id: projectId } = params
     return InactiveProjectManager.deactivateProject(projectId, function (err) {
       if (err != null) {
         return res.sendStatus(500)
diff --git a/services/web/app/src/Features/LinkedFiles/LinkedFilesController.mjs b/services/web/app/src/Features/LinkedFiles/LinkedFilesController.mjs
index ee9d5c0dbf..daf01bd782 100644
--- a/services/web/app/src/Features/LinkedFiles/LinkedFilesController.mjs
+++ b/services/web/app/src/Features/LinkedFiles/LinkedFilesController.mjs
@@ -48,7 +48,84 @@ const {
 
 let LinkedFilesController
 
+// Per-provider shape of the client-submitted `data` object. This mirrors
+// overleaf-editor-core's `rawLinkedFileData` discriminated union (the
+// *stored* linkedFileData shape), but is not identical to it: `provider`
+// lives as a sibling of `data` here rather than inside it, `importedAt` is
+// never client-submitted (set server-side after validation), and a couple
+// of fields are intentionally looser than the stored shape because the
+// agents apply defaults/coercions between validation and storage --
+// `zotero`'s `format` defaults to 'bibtex' when absent (ZoteroAgent
+// `_getFormat`), and `project_file`/`project_output_file`'s
+// `v1_source_doc_id` may arrive as a number (existing callers do this; the
+// agent's `_canCreate` check rejects v1 ids with its own 403, so this must
+// not be intercepted by validation first).
 const createLinkedFileSchema = z.object({
+  params: z.strictObject({
+    project_id: zz.objectId(),
+  }),
+  body: z.discriminatedUnion('provider', [
+    z.strictObject({
+      name: z.string(),
+      parent_folder_id: zz.objectId(),
+      provider: z.literal('url'),
+      data: z.strictObject({
+        url: z.string(),
+      }),
+    }),
+    z.strictObject({
+      name: z.string(),
+      parent_folder_id: zz.objectId(),
+      provider: z.literal('project_file'),
+      data: z.strictObject({
+        source_project_id: zz.objectId().optional(),
+        v1_source_doc_id: z.union([z.string(), z.number()]).optional(),
+        source_entity_path: z.string(),
+      }),
+    }),
+    z.strictObject({
+      name: z.string(),
+      parent_folder_id: zz.objectId(),
+      provider: z.literal('project_output_file'),
+      data: z.strictObject({
+        source_project_id: zz.objectId().optional(),
+        v1_source_doc_id: z.union([z.string(), z.number()]).optional(),
+        source_output_file_path: z.string(),
+        build_id: zz.buildId().optional(),
+        clsiServerId: z.string().optional(),
+      }),
+    }),
+    z.strictObject({
+      name: z.string(),
+      parent_folder_id: zz.objectId(),
+      provider: z.literal('mendeley'),
+      data: z.strictObject({
+        group_id: zz.routeSegment().optional(),
+      }),
+    }),
+    z.strictObject({
+      name: z.string(),
+      parent_folder_id: zz.objectId(),
+      provider: z.literal('zotero'),
+      data: z.strictObject({
+        format: z.enum(['bibtex', 'biblatex']).optional(),
+        group_id: zz.routeSegment().optional(),
+      }),
+    }),
+    z.strictObject({
+      name: z.string(),
+      parent_folder_id: zz.objectId(),
+      provider: z.literal('papers'),
+      data: z.strictObject({
+        group_id: zz.routeSegment().optional(),
+      }),
+    }),
+  ]),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const createLinkedFileFallbackSchema = z.object({
   params: z.object({
     project_id: zz.objectId(),
   }),
@@ -61,6 +138,19 @@ const createLinkedFileSchema = z.object({
 })
 
 const refreshLinkedFileSchema = z.object({
+  params: z.strictObject({
+    project_id: zz.objectId(),
+    file_id: zz.objectId(),
+  }),
+  body: z.strictObject({
+    clientId: z.string().optional(),
+    shouldReindexReferences: z.boolean().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const refreshLinkedFileFallbackSchema = z.object({
   params: z.object({
     project_id: zz.objectId(),
     file_id: zz.objectId(),
@@ -72,7 +162,9 @@ const refreshLinkedFileSchema = z.object({
 })
 
 async function createLinkedFile(req, res, next) {
-  const { params, body } = parseReq(req, createLinkedFileSchema)
+  const { params, body } = parseReq(req, createLinkedFileSchema, {
+    fallbackSchema: createLinkedFileFallbackSchema,
+  })
   const { project_id: projectId } = params
   const { name, provider, data, parent_folder_id: parentFolderId } = body
   const userId = SessionManager.getLoggedInUserId(req.session)
@@ -105,7 +197,9 @@ async function createLinkedFile(req, res, next) {
 }
 
 async function refreshLinkedFile(req, res, next) {
-  const { params, body } = parseReq(req, refreshLinkedFileSchema)
+  const { params, body } = parseReq(req, refreshLinkedFileSchema, {
+    fallbackSchema: refreshLinkedFileFallbackSchema,
+  })
   const { project_id: projectId, file_id: fileId } = params
   const { clientId, shouldReindexReferences } = body
   const userId = SessionManager.getLoggedInUserId(req.session)
diff --git a/services/web/app/src/Features/PasswordReset/PasswordResetController.mjs b/services/web/app/src/Features/PasswordReset/PasswordResetController.mjs
index 8079e54187..4d52bcd775 100644
--- a/services/web/app/src/Features/PasswordReset/PasswordResetController.mjs
+++ b/services/web/app/src/Features/PasswordReset/PasswordResetController.mjs
@@ -12,6 +12,15 @@ import { z, parseReq } from '../../infrastructure/Validation.mjs'
 import Features from '../../infrastructure/Features.mjs'
 
 const setNewUserPasswordSchema = z.object({
+  body: z.strictObject({
+    email: z.string().optional(),
+    password: z.string(),
+    passwordResetToken: z.string(),
+  }),
+})
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const setNewUserPasswordFallbackSchema = z.object({
   body: z.object({
     email: z.string().optional(),
     password: z.string(),
@@ -21,7 +30,9 @@ const setNewUserPasswordSchema = z.object({
 
 async function setNewUserPassword(req, res, next) {
   let user
-  const { body } = parseReq(req, setNewUserPasswordSchema)
+  const { body } = parseReq(req, setNewUserPasswordSchema, {
+    fallbackSchema: setNewUserPasswordFallbackSchema,
+  })
   let { passwordResetToken, password, email } = body
   if (!passwordResetToken || !password) {
     return res.status(400).json({
@@ -114,13 +125,22 @@ async function setNewUserPassword(req, res, next) {
 }
 
 const requestResetSchema = z.object({
+  body: z.strictObject({
+    email: z.string(),
+  }),
+})
+// Rollout-temporary fallback (pre-refinement schema from main); delete
+// when this route's REQ_VALIDATION_MODE instrumentation is removed.
+const requestResetFallbackSchema = z.object({
   body: z.object({
     email: z.string(),
   }),
 })
 
 async function requestReset(req, res, next) {
-  const { body } = parseReq(req, requestResetSchema)
+  const { body } = parseReq(req, requestResetSchema, {
+    fallbackSchema: requestResetFallbackSchema,
+  })
   const email = EmailsHelper.parseEmail(body.email)
   if (!email) {
     return res.status(400).json({
diff --git a/services/web/app/src/Features/ServerAdmin/AdminController.mjs b/services/web/app/src/Features/ServerAdmin/AdminController.mjs
index 76bf71143e..fb16871654 100644
--- a/services/web/app/src/Features/ServerAdmin/AdminController.mjs
+++ b/services/web/app/src/Features/ServerAdmin/AdminController.mjs
@@ -10,6 +10,52 @@ import ProjectGetter from '../Project/ProjectGetter.mjs'
 import Modules from '../../infrastructure/Modules.mjs'
 import Features from '../../infrastructure/Features.mjs'
 import { expressify } from '@overleaf/promise-utils'
+import { z, zz, parseReq } from '../../infrastructure/Validation.mjs'
+
+const closeEditorSchema = z.object({
+  body: z.strictObject({
+    // the real form (views/admin/index.pug) never actually sends this
+    // field; a falsy/missing value is treated as "closed"
+    isOpen: z.boolean().optional(),
+  }),
+})
+
+const disconnectAllUsersSchema = z.object({
+  query: z.object({
+    delay: z.coerce.number().optional(),
+  }),
+})
+
+// Rollout-temporary fallback (loosened primary schema; no zod validation
+// existed for this route on main); delete when this route's
+// REQ_VALIDATION_MODE instrumentation is removed. `delay` is used
+// numerically below, so a raw passthrough still needs to coerce it.
+const disconnectAllUsersFallbackSchema = z.object({
+  query: z.object({
+    delay: z
+      .unknown()
+      .optional()
+      .transform(v => (v === undefined ? undefined : Number(v))),
+  }),
+})
+
+const flushProjectToTpdsSchema = z.object({
+  body: z.strictObject({
+    project_id: zz.objectId(),
+  }),
+})
+
+const pollDropboxForUserSchema = z.object({
+  body: z.strictObject({
+    user_id: zz.objectId(),
+  }),
+})
+
+const createMessageSchema = z.object({
+  body: z.strictObject({
+    content: z.string(),
+  }),
+})
 
 const AdminController = {
   _sendDisconnectAllUsersMessage: delay => {
@@ -61,7 +107,11 @@ const AdminController = {
 
   disconnectAllUsers: (req, res) => {
     logger.warn('disconecting everyone')
-    const delay = (req.query && req.query.delay) > 0 ? req.query.delay : 10
+    const { query } = parseReq(req, disconnectAllUsersSchema, {
+      logOnly: true,
+      fallbackSchema: disconnectAllUsersFallbackSchema,
+    })
+    const delay = query.delay > 0 ? query.delay : 10
     AdminController._sendDisconnectAllUsersMessage(delay)
     res.redirect('/admin#open-close-editor')
   },
@@ -74,12 +124,16 @@ const AdminController = {
 
   closeEditor(req, res) {
     logger.warn('closing editor')
-    Settings.editorIsOpen = req.body.isOpen
+    const { body } = parseReq(req, closeEditorSchema, { logOnly: true })
+    Settings.editorIsOpen = body.isOpen
     res.redirect('/admin#open-close-editor')
   },
 
   flushProjectToTpds(req, res, next) {
-    TpdsProjectFlusher.flushProjectToTpds(req.body.project_id, error => {
+    const { body } = parseReq(req, flushProjectToTpdsSchema, {
+      logOnly: true,
+    })
+    TpdsProjectFlusher.flushProjectToTpds(body.project_id, error => {
       if (error) {
         return next(error)
       }
@@ -88,12 +142,15 @@ const AdminController = {
   },
 
   pollDropboxForUser(req, res) {
-    const { user_id: userId } = req.body
-    TpdsUpdateSender.pollDropboxForUser(userId, () => res.sendStatus(200))
+    const { body } = parseReq(req, pollDropboxForUserSchema, {
+      logOnly: true,
+    })
+    TpdsUpdateSender.pollDropboxForUser(body.user_id, () => res.sendStatus(200))
   },
 
   createMessage(req, res, next) {
-    SystemMessageManager.createMessage(req.body.content, function (error) {
+    const { body } = parseReq(req, createMessageSchema, { logOnly: true })
+    SystemMessageManager.createMessage(body.content, function (error) {
       if (error) {
         return next(error)
       }
diff --git a/services/web/app/src/Features/SplitTests/SplitTestHandler.mjs b/services/web/app/src/Features/SplitTests/SplitTestHandler.mjs
index e9ecb612ec..93a041bb13 100644
--- a/services/web/app/src/Features/SplitTests/SplitTestHandler.mjs
+++ b/services/web/app/src/Features/SplitTests/SplitTestHandler.mjs
@@ -15,6 +15,7 @@ import SessionManager from '../Authentication/SessionManager.mjs'
 import logger from '@overleaf/logger'
 import SplitTestSessionHandler from './SplitTestSessionHandler.mjs'
 import SplitTestUserGetter from './SplitTestUserGetter.mjs'
+import { getRawReqInput } from '../../infrastructure/Validation.mjs'
 
 /**
  * @import { Assignment } from "./types"
@@ -69,7 +70,10 @@ async function getAssignment(
       await _loadSplitTestInfoInLocals(res.locals, splitTestName, req.session)
 
       if (!ignoreOverrides) {
-        let query = req.query || {}
+        // query keys are caller-supplied and dynamic (one per split test
+        // name), so this is read raw rather than by name (case 1: verbatim
+        // forwarding)
+        let query = getRawReqInput(req).query || {}
         if (includeReferer && req.headers.referer) {
           // Pick up the query of the top-level page, i.e. what's in the browsers address bar, from ajax requests.
           // E.g. /project/:id?split-test=foo -> ajax /project/:id/compile should see split-test=foo.
@@ -200,7 +204,10 @@ async function hasUserBeenAssignedToVariant(
   ignoreVersion = false
 ) {
   try {
-    const { session = {}, query = {} } = req
+    const { session = {} } = req
+    // same dynamic caller-supplied key as getAssignment() above (case 1:
+    // verbatim forwarding)
+    const { query } = getRawReqInput(req)
 
     const splitTest = await _getSplitTest(splitTestName)
     const currentVersion = SplitTestUtils.getCurrentVersion(splitTest)
diff --git a/services/web/app/src/Features/TokenAccess/TokenAccessController.mjs b/services/web/app/src/Features/TokenAccess/TokenAccessController.mjs
index ae7a670949..d832818a5a 100644
--- a/services/web/app/src/Features/TokenAccess/TokenAccessController.mjs
+++ b/services/web/app/src/Features/TokenAccess/TokenAccessController.mjs
@@ -23,6 +23,7 @@ import UserGetter from '../User/UserGetter.mjs'
 import Settings from '@overleaf/settings'
 import LimitationsManager from '../Subscription/LimitationsManager.mjs'
 import SplitTestHandler from '../SplitTests/SplitTestHandler.mjs'
+import { z, zz, parseReq } from '../../infrastructure/Validation.mjs'
 
 const { getSafeAdminDomainRedirect } = UrlHelper
 const { canRedirectToAdminDomain } = AdminAuthorizationHelper
@@ -91,8 +92,18 @@ async function _isOverleafStaff(userId) {
   )
 }
 
+const tokenAccessPageSchema = z.object({
+  // the router constrains :token to READ_ONLY_TOKEN_PATTERN /
+  // READ_AND_WRITE_TOKEN_PATTERN already, so a bare string is sufficient
+  // here -- Express never invokes this handler for a non-matching token.
+  params: z.strictObject({
+    token: z.string(),
+  }),
+})
+
 async function tokenAccessPage(req, res, next) {
-  const { token } = req.params
+  const { params } = parseReq(req, tokenAccessPageSchema, { logOnly: true })
+  const { token } = params
   if (!TokenAccessHandler.isValidToken(token)) {
     return next(new Errors.NotFoundError())
   }
@@ -285,9 +296,29 @@ async function checkAndGetProjectOrResponseAction(
   return [project, null, { projectId, action: 'continue' }]
 }
 
+const grantTokenAccessSchema = z.object({
+  // the router constrains :token to READ_ONLY_TOKEN_PATTERN /
+  // READ_AND_WRITE_TOKEN_PATTERN already, so a bare string is sufficient
+  // here -- Express never invokes this handler for a non-matching token.
+  params: z.strictObject({
+    token: z.string(),
+  }),
+  body: z.strictObject({
+    // sent as a genuine JSON boolean by the frontend (postJSON), not a
+    // query-string value -- z.stringbool() would reject it.
+    confirmedByUser: z.boolean().optional(),
+    // opaque: only ever compared for equality / logged, never used as a
+    // path or query value (see TokenAccessHandler.checkTokenHashPrefix).
+    tokenHashPrefix: z.string().optional(),
+  }),
+})
+
 async function grantTokenAccessReadAndWrite(req, res, next) {
-  const { token } = req.params
-  const { confirmedByUser, tokenHashPrefix } = req.body
+  const { params, body } = parseReq(req, grantTokenAccessSchema, {
+    logOnly: true,
+  })
+  const { token } = params
+  const { confirmedByUser, tokenHashPrefix } = body
   const userId = SessionManager.getLoggedInUserId(req.session)
   if (!TokenAccessHandler.isReadAndWriteToken(token)) {
     return res.sendStatus(400)
@@ -391,8 +422,11 @@ async function grantTokenAccessReadAndWrite(req, res, next) {
 }
 
 async function grantTokenAccessReadOnly(req, res, next) {
-  const { token } = req.params
-  const { confirmedByUser, tokenHashPrefix } = req.body
+  const { params, body } = parseReq(req, grantTokenAccessSchema, {
+    logOnly: true,
+  })
+  const { token } = params
+  const { confirmedByUser, tokenHashPrefix } = body
   const userId = SessionManager.getLoggedInUserId(req.session)
   if (!TokenAccessHandler.isReadOnlyToken(token)) {
     return res.sendStatus(400)
@@ -469,8 +503,22 @@ async function grantTokenAccessReadOnly(req, res, next) {
   }
 }
 
+// non-strict: this is middleware, chained before sharingUpdatesConsent /
+// moveReadWriteToCollaborators / moveReadWriteToReadOnly, which apply their
+// own strict schemas to the same params.
+const ensureUserCanUseSharingUpdatesConsentPageSchema = z.object({
+  params: z.object({
+    Project_id: zz.objectId(),
+  }),
+})
+
 async function ensureUserCanUseSharingUpdatesConsentPage(req, res, next) {
-  const { Project_id: projectId } = req.params
+  const { params } = parseReq(
+    req,
+    ensureUserCanUseSharingUpdatesConsentPageSchema,
+    { logOnly: true }
+  )
+  const { Project_id: projectId } = params
   const userId = SessionManager.getLoggedInUserId(req.session)
   const project = await ProjectGetter.promises.getProject(projectId, {
     owner_ref: 1,
@@ -499,8 +547,17 @@ async function ensureUserCanUseSharingUpdatesConsentPage(req, res, next) {
   next()
 }
 
+const sharingUpdatesConsentSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+})
+
 async function sharingUpdatesConsent(req, res, next) {
-  const { Project_id: projectId } = req.params
+  const { params } = parseReq(req, sharingUpdatesConsentSchema, {
+    logOnly: true,
+  })
+  const { Project_id: projectId } = params
   AnalyticsManager.recordEventForSession(req.session, 'notification-prompt', {
     page: req.path,
     name: 'link-sharing-collaborator',
@@ -510,8 +567,17 @@ async function sharingUpdatesConsent(req, res, next) {
   })
 }
 
+const moveReadWriteToCollaboratorsSchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+})
+
 async function moveReadWriteToCollaborators(req, res, next) {
-  const { Project_id: projectId } = req.params
+  const { params } = parseReq(req, moveReadWriteToCollaboratorsSchema, {
+    logOnly: true,
+  })
+  const { Project_id: projectId } = params
   const userId = SessionManager.getLoggedInUserId(req.session)
   const project = await ProjectGetter.promises.getProject(projectId, {
     owner_ref: 1,
@@ -579,8 +645,17 @@ async function moveReadWriteToCollaborators(req, res, next) {
   res.sendStatus(204)
 }
 
+const moveReadWriteToReadOnlySchema = z.object({
+  params: z.strictObject({
+    Project_id: zz.objectId(),
+  }),
+})
+
 async function moveReadWriteToReadOnly(req, res, next) {
-  const { Project_id: projectId } = req.params
+  const { params } = parseReq(req, moveReadWriteToReadOnlySchema, {
+    logOnly: true,
+  })
+  const { Project_id: projectId } = params
   const userId = SessionManager.getLoggedInUserId(req.session)
   await ProjectAuditLogHandler.promises.addEntry(
     projectId,
diff --git a/services/web/app/src/Features/TokenAccess/TokenAccessHandler.mjs b/services/web/app/src/Features/TokenAccess/TokenAccessHandler.mjs
index c76d572e5d..2614ea374b 100644
--- a/services/web/app/src/Features/TokenAccess/TokenAccessHandler.mjs
+++ b/services/web/app/src/Features/TokenAccess/TokenAccessHandler.mjs
@@ -13,8 +13,8 @@ import Features from '../../infrastructure/Features.mjs'
 
 const { ObjectId } = mongodb
 
-const READ_AND_WRITE_TOKEN_PATTERN = '([0-9]+[a-z]{6,12})'
-const READ_ONLY_TOKEN_PATTERN = '([a-z]{12})'
+const READ_AND_WRITE_TOKEN_PATTERN = '[0-9]+[a-z]{6,12}'
+const READ_ONLY_TOKEN_PATTERN = '[a-z]{12}'
 
 const TokenAccessHandler = {
   TOKEN_TYPES: {
diff --git a/services/web/app/src/router.mjs b/services/web/app/src/router.mjs
index 263076b570..84cddfd079 100644
--- a/services/web/app/src/router.mjs
+++ b/services/web/app/src/router.mjs
@@ -643,7 +643,7 @@ async function initialize(webRouter, privateApiRouter, publicApiRouter) {
   )
 
   webRouter.get(
-    '/download/project/:Project_id/build/:editorBuildId/output/cached/:filename(.*)',
+    '/download/project/:Project_id/build/:editorBuildId/output/cached/:filename',
     AuthorizationMiddleware.ensureUserCanReadProject,
     ClsiCacheController.downloadFromCache
   )
@@ -677,7 +677,7 @@ async function initialize(webRouter, privateApiRouter, publicApiRouter) {
 
   // direct url access to output files for a specific build
   webRouter.get(
-    '/project/:Project_id/build/:build_id/output/:file(.*)',
+    '/project/:Project_id/build/:build_id/output/:file(.+)',
     rateLimiterMiddlewareOutputFiles,
     AuthorizationMiddleware.ensureUserCanReadProject,
     CompileController.getFileFromClsi
@@ -685,7 +685,7 @@ async function initialize(webRouter, privateApiRouter, publicApiRouter) {
 
   // direct url access to output files for a specific user and build
   webRouter.get(
-    '/project/:Project_id/user/:user_id/build/:build_id/output/:file(.*)',
+    '/project/:Project_id/user/:user_id/build/:build_id/output/:file(.+)',
     rateLimiterMiddlewareOutputFiles,
     AuthorizationMiddleware.ensureUserCanReadProject,
     CompileController.getFileFromClsi
@@ -791,7 +791,7 @@ async function initialize(webRouter, privateApiRouter, publicApiRouter) {
       ProjectDownloadsController.exportProjectConversion
     )
     webRouter.get(
-      '/project/:Project_id/download/conversion/:conversionId/:type/build/:buildId/output/:file(.*)',
+      '/project/:Project_id/download/conversion/:conversionId/:type/build/:buildId/output/:file(.+)',
       AuthenticationController.requireLogin(),
       RateLimiterMiddleware.rateLimit(rateLimiters.documentExportDownload, {
         params: ['Project_id'],
@@ -1003,33 +1003,33 @@ async function initialize(webRouter, privateApiRouter, publicApiRouter) {
     TpdsController.updateFolder
   )
   privateApiRouter.post(
-    '/user/:user_id/update/*',
+    '/user/:user_id/update/:path(.+)',
     AuthenticationController.requirePrivateApiAuth(),
     TpdsController.mergeUpdate
   )
   privateApiRouter.delete(
-    '/user/:user_id/update/*',
+    '/user/:user_id/update/:path(.+)',
     AuthenticationController.requirePrivateApiAuth(),
     TpdsController.deleteUpdate
   )
   privateApiRouter.post(
-    '/project/:project_id/user/:user_id/update/*',
+    '/project/:project_id/user/:user_id/update/:path(.+)',
     AuthenticationController.requirePrivateApiAuth(),
     TpdsController.mergeUpdate
   )
   privateApiRouter.delete(
-    '/project/:project_id/user/:user_id/update/*',
+    '/project/:project_id/user/:user_id/update/:path(.+)',
     AuthenticationController.requirePrivateApiAuth(),
     TpdsController.deleteUpdate
   )
 
   privateApiRouter.post(
-    '/project/:project_id/contents/*',
+    '/project/:project_id/contents/:path(.+)',
     AuthenticationController.requirePrivateApiAuth(),
     TpdsController.updateProjectContents
   )
   privateApiRouter.delete(
-    '/project/:project_id/contents/*',
+    '/project/:project_id/contents/:path(.+)',
     AuthenticationController.requirePrivateApiAuth(),
     TpdsController.deleteProjectContents
   )
diff --git a/services/web/modules/user-activate/app/src/UserActivateController.mjs b/services/web/modules/user-activate/app/src/UserActivateController.mjs
index 6bee167e03..616450d5ed 100644
--- a/services/web/modules/user-activate/app/src/UserActivateController.mjs
+++ b/services/web/modules/user-activate/app/src/UserActivateController.mjs
@@ -4,15 +4,23 @@ import UserGetter from '../../../../app/src/Features/User/UserGetter.mjs'
 import UserRegistrationHandler from '../../../../app/src/Features/User/UserRegistrationHandler.mjs'
 import ErrorController from '../../../../app/src/Features/Errors/ErrorController.mjs'
 import { expressify } from '@overleaf/promise-utils'
+import { z, parseReq } from '../../../../app/src/infrastructure/Validation.mjs'
 
 const __dirname = Path.dirname(fileURLToPath(import.meta.url))
 
+const registerSchema = z.object({
+  body: z.strictObject({
+    email: z.string().optional(),
+  }),
+})
+
 function registerNewUser(req, res, next) {
   res.render(Path.resolve(__dirname, '../views/user/register'))
 }
 
 async function register(req, res, next) {
-  const { email } = req.body
+  const { body } = parseReq(req, registerSchema, { logOnly: true })
+  const { email } = body
   if (email == null || email === '') {
     return res.sendStatus(422) // Unprocessable Entity
   }
@@ -26,18 +34,43 @@ async function register(req, res, next) {
   })
 }
 
+const activateAccountPageSchema = z.object({
+  // Non-strict: this link is emailed out and may get sent back through an
+  // email gateway/link-rewriter that appends its own tracking query params
+  // (e.g. utm_* or a click-tracking id) -- rejecting the whole request over
+  // an unrecognized key would turn a legitimate activation click into a 400
+  // for the user, so extra params are tolerated rather than named/rejected.
+  query: z.object({
+    // A legitimate activation link only ever carries a bare user_id string,
+    // but a tampered URL can turn it into a nested object via qs bracket
+    // notation (`?user_id[x]=y`), which the handler below explicitly
+    // detects (the `typeof` check) and turns into its own rendered 403
+    // page -- not the generic JSON 400 that handleValidationError would
+    // produce for a value rejected by the schema itself. So this stays a
+    // loose union rather than zz.objectId(), leaving the type check (and
+    // its response) to the handler.
+    user_id: z
+      .union([z.string(), z.record(z.string(), z.unknown())])
+      .optional(),
+    token: z.string().optional(),
+  }),
+})
+
 async function activateAccountPage(req, res, next) {
+  const { query } = parseReq(req, activateAccountPageSchema, {
+    logOnly: true,
+  })
   // An 'activation' is actually just a password reset on an account that
   // was set with a random password originally.
-  if (req.query.user_id == null || req.query.token == null) {
+  if (query.user_id == null || query.token == null) {
     return ErrorController.notFound(req, res)
   }
 
-  if (typeof req.query.user_id !== 'string') {
+  if (typeof query.user_id !== 'string') {
     return ErrorController.forbidden(req, res)
   }
 
-  const user = await UserGetter.promises.getUser(req.query.user_id, {
+  const user = await UserGetter.promises.getUser(query.user_id, {
     email: 1,
     loginCount: 1,
   })
@@ -58,7 +91,7 @@ async function activateAccountPage(req, res, next) {
   res.render(Path.resolve(__dirname, '../views/user/activate'), {
     title: 'activate_account',
     email: user.email,
-    token: req.query.token,
+    token: query.token,
   })
 }
 
diff --git a/services/web/modules/user-activate/test/unit/src/UserActivateController.test.mjs b/services/web/modules/user-activate/test/unit/src/UserActivateController.test.mjs
index 54dfca5b46..47468f4aba 100644
--- a/services/web/modules/user-activate/test/unit/src/UserActivateController.test.mjs
+++ b/services/web/modules/user-activate/test/unit/src/UserActivateController.test.mjs
@@ -162,4 +162,38 @@ describe('UserActivateController', function () {
         .should.equal(true)
     })
   })
+
+  describe('register with a missing email', function () {
+    beforeEach(function (ctx) {
+      ctx.req.body = {}
+      ctx.res.sendStatus = sinon.stub()
+      ctx.UserRegistrationHandler.promises.registerNewUserAndSendActivationEmail =
+        sinon.stub().resolves({ user: ctx.user, setNewPasswordUrl: 'mock/url' })
+    })
+
+    it('should return 422', async function (ctx) {
+      await ctx.UserActivateController.register(ctx.req, ctx.res)
+      ctx.res.sendStatus.calledWith(422).should.equal(true)
+    })
+
+    it('should not register a user', async function (ctx) {
+      await ctx.UserActivateController.register(ctx.req, ctx.res)
+      sinon.assert.notCalled(
+        ctx.UserRegistrationHandler.promises
+          .registerNewUserAndSendActivationEmail
+      )
+    })
+  })
+
+  describe('register with an empty email', function () {
+    beforeEach(function (ctx) {
+      ctx.req.body = { email: '' }
+      ctx.res.sendStatus = sinon.stub()
+    })
+
+    it('should return 422', async function (ctx) {
+      await ctx.UserActivateController.register(ctx.req, ctx.res)
+      ctx.res.sendStatus.calledWith(422).should.equal(true)
+    })
+  })
 })
diff --git a/services/web/test/acceptance/config/settings.test.defaults.js b/services/web/test/acceptance/config/settings.test.defaults.js
index 8f32bb9b08..33ed4f88fc 100644
--- a/services/web/test/acceptance/config/settings.test.defaults.js
+++ b/services/web/test/acceptance/config/settings.test.defaults.js
@@ -71,6 +71,9 @@ module.exports = {
       url: 'http://127.0.0.1:23013',
       downloadHost: 'http://127.0.0.1:23080',
     },
+    clsiCache: {
+      instances: [{ url: 'http://127.0.0.1:23081', shard: 'cache' }],
+    },
     realTime: {
       url: 'http://127.0.0.1:23026',
     },
diff --git a/services/web/test/acceptance/src/AdminControllerTests.mjs b/services/web/test/acceptance/src/AdminControllerTests.mjs
new file mode 100644
index 0000000000..dc6a901585
--- /dev/null
+++ b/services/web/test/acceptance/src/AdminControllerTests.mjs
@@ -0,0 +1,180 @@
+import { expect } from 'chai'
+import Settings from '@overleaf/settings'
+import UserHelper from './helpers/User.mjs'
+import Features from '../../../app/src/infrastructure/Features.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+
+describe('AdminController', function () {
+  let admin
+
+  beforeEach(async function () {
+    admin = new User()
+    await admin.login()
+    await admin.ensureAdmin()
+    await admin.login()
+  })
+
+  describe('GET /admin', function () {
+    it('should render the admin page', async function () {
+      const { response, body } = await admin.doRequest('get', {
+        url: '/admin',
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.include('System Admin')
+    })
+  })
+
+  describe('POST /admin/closeEditor', function () {
+    before(function () {
+      // only mounted in Server CE/Pro; see router.mjs
+      if (Features.hasFeature('saas')) {
+        this.skip()
+      }
+    })
+
+    // closeEditor flips the site-wide Settings.editorIsOpen flag, which
+    // gates every non-/admin route (see checkIfEditorClosed in Server.mjs);
+    // reset it directly (not via an HTTP round-trip, which could itself
+    // fail) so a closed site doesn't leak into whatever runs next.
+    afterEach(function () {
+      Settings.editorIsOpen = true
+    })
+
+    it('should reject an unexpected field with 400', async function () {
+      const { response, body } = await admin.doRequest('post', {
+        url: '/admin/closeEditor',
+        json: { notAField: true },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'notAField'
+      )
+    })
+
+    it('should close the editor and redirect', async function () {
+      const { response } = await admin.doRequest('post', {
+        url: '/admin/closeEditor',
+        json: {},
+      })
+      expect(response.statusCode).to.equal(302)
+      expect(response.headers.location).to.equal('/admin#open-close-editor')
+    })
+
+    it('should block a non-admin route while closed, then restore access via openEditor', async function () {
+      await admin.doRequest('post', { url: '/admin/closeEditor', json: {} })
+
+      const closed = await admin.doRequest('get', {
+        url: '/login',
+        json: true,
+      })
+      expect(closed.response.statusCode).to.equal(503)
+      expect(closed.body.message).to.include('maintenance')
+
+      const { response } = await admin.doRequest('post', {
+        url: '/admin/openEditor',
+        json: {},
+      })
+      expect(response.statusCode).to.equal(302)
+      expect(response.headers.location).to.equal('/admin#open-close-editor')
+
+      const reopened = await admin.doRequest('get', {
+        url: '/login',
+        json: true,
+      })
+      expect(reopened.response.statusCode).to.equal(200)
+    })
+  })
+
+  describe('POST /admin/disconnectAllUsers', function () {
+    before(function () {
+      // only mounted in Server CE/Pro; see router.mjs
+      if (Features.hasFeature('saas')) {
+        this.skip()
+      }
+    })
+
+    it('should reject a non-numeric delay with 400', async function () {
+      const { response, body } = await admin.doRequest('post', {
+        url: '/admin/disconnectAllUsers?delay=not-a-number',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'delay'
+      )
+    })
+
+    it('should disconnect users and redirect', async function () {
+      const { response } = await admin.doRequest('post', {
+        url: '/admin/disconnectAllUsers?delay=1',
+      })
+      expect(response.statusCode).to.equal(302)
+      expect(response.headers.location).to.equal('/admin#open-close-editor')
+    })
+  })
+
+  describe('POST /admin/flushProjectToTpds', function () {
+    it('should reject a malformed project_id with 400', async function () {
+      const { response, body } = await admin.doRequest('post', {
+        url: '/admin/flushProjectToTpds',
+        json: { project_id: 'not-an-object-id' },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'project_id'
+      )
+    })
+  })
+
+  describe('POST /admin/pollDropboxForUser', function () {
+    it('should reject a malformed user_id with 400', async function () {
+      const { response, body } = await admin.doRequest('post', {
+        url: '/admin/pollDropboxForUser',
+        json: { user_id: 'not-an-object-id' },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'user_id'
+      )
+    })
+  })
+
+  describe('POST /admin/messages', function () {
+    it('should reject a missing content field with 400', async function () {
+      const { response, body } = await admin.doRequest('post', {
+        url: '/admin/messages',
+        json: {},
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'content'
+      )
+    })
+
+    it('should create the message and redirect', async function () {
+      const { response } = await admin.doRequest('post', {
+        url: '/admin/messages',
+        json: { content: 'a system message' },
+      })
+      expect(response.statusCode).to.equal(302)
+      expect(response.headers.location).to.equal('/admin#system-messages')
+    })
+  })
+
+  describe('POST /admin/messages/clear', function () {
+    it('should clear messages and redirect', async function () {
+      const { response } = await admin.doRequest('post', {
+        url: '/admin/messages/clear',
+        json: {},
+      })
+      expect(response.statusCode).to.equal(302)
+      expect(response.headers.location).to.equal('/admin#system-messages')
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/AnalyticsControllerTests.mjs b/services/web/test/acceptance/src/AnalyticsControllerTests.mjs
new file mode 100644
index 0000000000..01a014e133
--- /dev/null
+++ b/services/web/test/acceptance/src/AnalyticsControllerTests.mjs
@@ -0,0 +1,124 @@
+import { expect } from 'chai'
+import UserHelper from './helpers/User.mjs'
+import request from './helpers/request.js'
+import Features from '../../../app/src/infrastructure/Features.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+const authedRequest = request.promises
+
+const auth = Buffer.from('overleaf:password').toString('base64')
+function privateApiRequest(options) {
+  return authedRequest.request({
+    ...options,
+    json: options.json === undefined ? true : options.json,
+    headers: {
+      ...options.headers,
+      Authorization: `Basic ${auth}`,
+    },
+  })
+}
+
+describe('AnalyticsController', function () {
+  let owner
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+  })
+
+  describe('POST /event/:event', function () {
+    it('should accept a well-formed event', async function () {
+      const { response } = await owner.doRequest('post', {
+        url: '/event/i-did-something',
+        json: { editorType: 'abc' },
+      })
+      expect(response.statusCode).to.equal(202)
+    })
+
+    it('should reject a segmentation key with disallowed characters', async function () {
+      if (!Features.hasFeature('analytics')) {
+        this.skip()
+      }
+      const { response, body } = await owner.doRequest('post', {
+        url: '/event/i-did-something',
+        json: { 'bad key!': 'x' },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'bad key!'
+      )
+    })
+
+    it('should reject an event name with disallowed characters', async function () {
+      // AnalyticsRouter's `:event([a-z0-9-_]+)` route pattern rejects this
+      // before the request ever reaches the controller/schema, so this holds
+      // regardless of the analytics feature flag.
+      const { response } = await owner.doRequest('post', {
+        url: '/event/Bad!Event',
+        json: { editorType: 'abc' },
+      })
+      expect(response.statusCode).to.equal(404)
+    })
+
+    it('should not match the route for an event name containing a dot', async function () {
+      const { response } = await owner.doRequest('post', {
+        url: '/event/foo.bar',
+        json: { editorType: 'abc' },
+      })
+      expect(response.statusCode).to.equal(404)
+    })
+  })
+
+  describe('PUT /editingSession/:projectId', function () {
+    it('should reject a malformed project id with 404', async function () {
+      if (!Features.hasFeature('analytics')) {
+        this.skip()
+      }
+      const { response, body } = await owner.doRequest('put', {
+        url: '/editingSession/not-an-object-id',
+        json: { segmentation: { editorType: 'abc' } },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'projectId'
+      )
+    })
+  })
+
+  describe('POST /analytics/register-v-1-salesforce-mapping', function () {
+    it('should accept a well-formed mapping', async function () {
+      if (!Features.hasFeature('analytics')) {
+        this.skip()
+      }
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/analytics/register-v-1-salesforce-mapping',
+        json: {
+          createdAt: new Date().toISOString(),
+          salesforceId: '000000000000A0aaaA',
+          v1Id: 42,
+        },
+      })
+      expect(response.statusCode).to.equal(202)
+    })
+
+    it('should reject a non-numeric v1Id', async function () {
+      if (!Features.hasFeature('analytics')) {
+        this.skip()
+      }
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/analytics/register-v-1-salesforce-mapping',
+        json: {
+          createdAt: new Date().toISOString(),
+          salesforceId: '000000000000A0aaaA',
+          v1Id: 'not-a-number',
+        },
+      })
+      expectValidationErrorRaw(response, 400, 'v1Id')
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/AuthenticationTests.mjs b/services/web/test/acceptance/src/AuthenticationTests.mjs
index 16f8c1a704..a8aa18f73f 100644
--- a/services/web/test/acceptance/src/AuthenticationTests.mjs
+++ b/services/web/test/acceptance/src/AuthenticationTests.mjs
@@ -50,6 +50,31 @@ describe('Authentication', function () {
     })
   })
 
+  describe('logout', function () {
+    beforeEach('login', async function () {
+      await user.login()
+    })
+
+    it('should accept a genuine native HTML form submission (form-encoded body, no CSRF header)', async function () {
+      // The real "Log Out" menu item is a plain HTML form (see
+      // account-menu-items.tsx): no JS involved, so the token only ever
+      // travels as a hidden _csrf form field, never as a header. With no
+      // Accept header favouring JSON, logoutSchema's handler redirects
+      // the browser directly rather than returning a JSON body.
+      const { response } = await user.submitNativeForm('/logout')
+      expect(response.statusCode).to.equal(302)
+      expect(response.headers.location).to.equal('/login')
+    })
+
+    it('should still reject an unrecognized field in the body', async function () {
+      const { response } = await user.doRequest('POST', {
+        url: '/logout',
+        json: { _csrf: user.csrfToken, notARealField: 'nope' },
+      })
+      expect(response.statusCode).to.equal(400)
+    })
+  })
+
   describe('login', function () {
     beforeEach('doLogin', async function () {
       await user.login()
diff --git a/services/web/test/acceptance/src/ClsiCacheControllerTests.mjs b/services/web/test/acceptance/src/ClsiCacheControllerTests.mjs
new file mode 100644
index 0000000000..3185023a8a
--- /dev/null
+++ b/services/web/test/acceptance/src/ClsiCacheControllerTests.mjs
@@ -0,0 +1,142 @@
+import { expect } from 'chai'
+import UserHelper from './helpers/User.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+import MockClsiCacheClass from './mocks/MockClsiCache.mjs'
+
+const User = UserHelper.promises
+
+let MockClsiCache
+
+before(function () {
+  MockClsiCache = MockClsiCacheClass.instance()
+})
+
+describe('ClsiCacheController', function () {
+  let owner, projectId
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+    projectId = await owner.createProject('clsi-cache-controller-test', {
+      template: 'blank',
+    })
+  })
+
+  describe('GET /project/:Project_id/output/cached/output.overleaf.json', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/project/not-an-object-id/output/cached/output.overleaf.json',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+
+    it('should return 404 when nothing is cached', async function () {
+      // getLatestBuildFromCache uses res.sendStatus(), unlike
+      // downloadFromCache's res.status().end() -- sendStatus fills the
+      // body with the status text, so this is genuinely different from
+      // (and not to be confused with) an empty-body response.
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/output/cached/output.overleaf.json`,
+      })
+      expect(response.statusCode).to.equal(404)
+      expect(body).to.equal('Not Found')
+    })
+
+    it('should return 410 when the cached build is stale', async function () {
+      // isUpToDate compares this X-Last-Modified against the project's own
+      // lastUpdated timestamp (always "now", since the project was just
+      // created) -- an ancient date always loses that comparison.
+      MockClsiCache.addEntry(
+        `/project/${projectId}/user/${owner.id}/latest/output/output.overleaf.json`,
+        {
+          content: '{}',
+          contentType: 'application/json',
+          lastModified: new Date(0),
+        }
+      )
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/output/cached/output.overleaf.json`,
+      })
+      expect(response.statusCode).to.equal(410)
+      expect(body).to.equal('Gone')
+    })
+  })
+
+  describe('GET /download/project/:Project_id/build/:editorBuildId/output/cached/:filename', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/download/project/not-an-object-id/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/output/cached/output.pdf',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+
+    it('should reject a malformed editorBuildId with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/not-a-valid-build-id/output/cached/output.pdf`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'editorBuildId'
+      )
+    })
+
+    it('should reject a path traversal filename with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/output/cached/..%2F..%2F..%2F..%2Fetc%2Fpasswd`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'filename'
+      )
+    })
+
+    it('should return 404 when nothing is cached for this build', async function () {
+      // Asserting the empty body (rather than just the status code) is what
+      // distinguishes "reached the handler and the real cache genuinely has
+      // nothing" from "rejected by the schema", which also 404s but with a
+      // JSON `{ error, statusCode }` body.
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/output/cached/output.pdf`,
+      })
+      expect(response.statusCode).to.equal(404)
+      expect(body).to.equal('')
+    })
+
+    it('should return the cached file when the build is genuinely cached', async function () {
+      MockClsiCache.addEntry(
+        `/project/${projectId}/user/${owner.id}/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/search/output/output.pdf`,
+        { content: 'mock-pdf-bytes', contentType: 'application/pdf' }
+      )
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/output/cached/output.pdf`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.equal('mock-pdf-bytes')
+    })
+
+    it('should return a nested filename when the build is genuinely cached', async function () {
+      // some.blg is allowed by isAllowedFilename's `.blg` suffix branch
+      // rather than its list of literal names -- proves that branch reaches
+      // the cache lookup and back.
+      MockClsiCache.addEntry(
+        `/project/${projectId}/user/${owner.id}/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/search/output/some.blg`,
+        { content: 'mock-blg-bytes', contentType: 'text/plain' }
+      )
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222/output/cached/some.blg`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.equal('mock-blg-bytes')
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/CompileControllerTests.mjs b/services/web/test/acceptance/src/CompileControllerTests.mjs
new file mode 100644
index 0000000000..1295ebcb1f
--- /dev/null
+++ b/services/web/test/acceptance/src/CompileControllerTests.mjs
@@ -0,0 +1,278 @@
+import { expect } from 'chai'
+import UserHelper from './helpers/User.mjs'
+import request from './helpers/request.js'
+import settings from '@overleaf/settings'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+const authedRequest = request.promises
+
+const auth = Buffer.from('overleaf:password').toString('base64')
+function privateApiRequest(options) {
+  return authedRequest.request({
+    ...options,
+    json: options.json === undefined ? true : options.json,
+    headers: {
+      ...options.headers,
+      Authorization: `Basic ${auth}`,
+    },
+  })
+}
+
+describe('CompileController', function () {
+  let owner, projectId
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+    projectId = await owner.createProject('compile-controller-test', {
+      template: 'blank',
+    })
+  })
+
+  describe('POST /project/:Project_id/compile', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: '/project/not-an-object-id/compile',
+        json: {},
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+
+    it('should reject a non-boolean draft flag with 400', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: `/project/${projectId}/compile`,
+        json: { draft: 'not-a-boolean' },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'draft'
+      )
+    })
+  })
+
+  describe('POST /project/:Project_id/compile/stop', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: '/project/not-an-object-id/compile/stop',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+  })
+
+  describe('DELETE /project/:Project_id/output', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('delete', {
+        url: '/project/not-an-object-id/output',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+  })
+
+  describe('GET /project/:Project_id/wordcount', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/project/not-an-object-id/wordcount',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+  })
+
+  describe('GET /download/project/:Project_id/build/:build_id/output/output.pdf', function () {
+    it('should reject a malformed build id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/not-a-build-id/output/output.pdf`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'build_id'
+      )
+    })
+
+    it('should accept an enable_pdf_caching query param and proxy to CLSI', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/download/project/${projectId}/build/18fbe9e7564-30dcb2f71250c690/output/output.pdf?enable_pdf_caching=true`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.equal('hello')
+    })
+  })
+
+  describe('GET /project/:Project_id/build/:build_id/output/output.zip', function () {
+    it('should reject a malformed build id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/build/not-a-build-id/output/output.zip`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'build_id'
+      )
+    })
+
+    it('should accept an enable_pdf_caching query param and proxy to CLSI', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/build/18fbe9e7564-30dcb2f71250c690/output/output.zip?enable_pdf_caching=true`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.equal('mock-zip: 18fbe9e7564-30dcb2f71250c690')
+    })
+  })
+
+  describe('GET /project/:Project_id/build/:build_id/output/:file', function () {
+    it('should reject a path traversal filename with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/build/18fbe9e7564-30dcb2f71250c690/output/../../../../etc/passwd`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'file'
+      )
+    })
+
+    it('should accept a genuine filename and proxy to CLSI', async function () {
+      // This route resolves to a per-user build path (see
+      // CompileController._getUserIdForCompile), which MockClsiNginxApi
+      // (this test environment's stand-in CLSI) handles with an
+      // unconditional 200 ("hello") -- proving the request reached CLSI,
+      // rather than being rejected by the schema.
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/build/18fbe9e7564-30dcb2f71250c690/output/nested.txt`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.equal('hello')
+    })
+
+    it('should accept an enable_pdf_caching query param and proxy to CLSI', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/build/18fbe9e7564-30dcb2f71250c690/output/nested.txt?enable_pdf_caching=true`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(body).to.equal('hello')
+    })
+  })
+
+  describe('GET /project/:Project_id/sync/code', function () {
+    it('should reject a non-numeric line with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/sync/code?file=main.tex&line=not-a-number&column=1&editorId=abc123&buildId=abc-123`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'line'
+      )
+    })
+
+    it('should reject a buildId that does not match the hex-hyphen-hex shape with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/sync/code?file=main.tex&line=1&column=1&editorId=abc123&buildId=not-a-valid-build-id`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'buildId'
+      )
+    })
+  })
+
+  describe('GET /project/:Project_id/sync/pdf', function () {
+    it('should reject a non-numeric page with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/sync/pdf?page=not-a-number&h=1.0&v=1.0&editorId=abc123&buildId=abc-123`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'page'
+      )
+    })
+
+    it('should reject a buildId that does not match the hex-hyphen-hex shape with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/project/${projectId}/sync/pdf?page=1&h=1.0&v=1.0&editorId=abc123&buildId=not-a-valid-build-id`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'buildId'
+      )
+    })
+  })
+
+  describe('GET /internal/project/:project_id/compile/pdf', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'get',
+        url: '/internal/project/not-an-object-id/compile/pdf',
+      })
+      expectValidationErrorRaw(response, 404, 'project_id')
+    })
+  })
+
+  describe('POST /api/clsi/compile/:submission_id', function () {
+    beforeEach(function () {
+      // route is only registered by the publish-modal module (SaaS-only)
+      if (!settings.moduleImportSequence.includes('publish-modal')) {
+        this.skip()
+      }
+    })
+
+    it('should reject a malformed submission_id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/api/clsi/compile/invalid submission id!',
+        json: {},
+      })
+      expectValidationErrorRaw(response, 404, 'submission_id')
+    })
+  })
+
+  describe('GET /api/clsi/compile/:submissionId/build/:build_id/output/:file', function () {
+    beforeEach(function () {
+      // route is only registered by the publish-modal module (SaaS-only)
+      if (!settings.moduleImportSequence.includes('publish-modal')) {
+        this.skip()
+      }
+    })
+
+    it('should reject a malformed build_id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'get',
+        url: '/api/clsi/compile/sub-1234/build/not-a-build-id/output/output.pdf',
+      })
+      expectValidationErrorRaw(response, 404, 'build_id')
+    })
+
+    it('should accept a blank compileGroup and proxy to CLSI', async function () {
+      // V1's CLSI::Response#v2_api_url always appends compileGroup (taken
+      // from the compile response); compileSubmission (above) never
+      // populates that field, so it arrives here blank rather than one of
+      // zz.compileGroup()'s enum values.
+      const response = await privateApiRequest({
+        method: 'get',
+        url: '/api/clsi/compile/sub-1234/build/18fbe9e7564-30dcb2f71250c690/output/output.pdf?compileGroup=',
+      })
+      expect(response.statusCode).to.equal(200)
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/ConfirmEmailTests.mjs b/services/web/test/acceptance/src/ConfirmEmailTests.mjs
new file mode 100644
index 0000000000..afd79e0231
--- /dev/null
+++ b/services/web/test/acceptance/src/ConfirmEmailTests.mjs
@@ -0,0 +1,89 @@
+import { expect } from 'chai'
+import UserHelper from './helpers/User.mjs'
+import OneTimeTokenHandler from '../../../app/src/Features/Security/OneTimeTokenHandler.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+
+describe('Confirm email via link/token (UserEmailsController.confirm)', function () {
+  let user
+
+  beforeEach('login', async function () {
+    user = new User()
+    await user.login()
+  })
+
+  async function getTokenForUser() {
+    return OneTimeTokenHandler.promises.getNewToken(
+      'email_confirmation',
+      { user_id: user.id, email: user.email },
+      { expiresIn: 24 * 60 * 60 }
+    )
+  }
+
+  it('should accept the redundant _csrf field the async-form helper packs into the body', async function () {
+    // views/user/confirm_email.pug's confirmEmailForm carries
+    // data-ol-async-form: hydrate-form.ts's async-form helper packs all
+    // FormData -- including the hidden _csrf input -- into the JSON body
+    // on top of the X-Csrf-Token header it sets, so confirmEmailSchema
+    // must tolerate _csrf turning up in the body too.
+    const token = await getTokenForUser()
+    const { response } = await user.doRequest('POST', {
+      url: '/user/emails/confirm',
+      json: { token, _csrf: user.csrfToken },
+    })
+    expect(response.statusCode).to.equal(200)
+  })
+
+  it('should still reject a non-string token', async function () {
+    const { response, body } = await user.doRequest('POST', {
+      url: '/user/emails/confirm',
+      json: { token: ['not', 'a', 'string'], _csrf: user.csrfToken },
+    })
+    expectValidationErrorRaw(
+      { statusCode: response.statusCode, body },
+      400,
+      'token'
+    )
+  })
+
+  it('should 404 for an invalid token (proving the request reaches the handler, not blocked by the schema)', async function () {
+    const { response, body } = await user.doRequest('POST', {
+      url: '/user/emails/confirm',
+      json: { token: 'not-a-real-token', _csrf: user.csrfToken },
+    })
+    expect(response.statusCode).to.equal(404)
+    expect(body.message).to.equal(
+      'Sorry, your confirmation token is invalid or has expired. Please request a new email confirmation link.'
+    )
+  })
+})
+
+describe('Show confirm email page (UserEmailsController.showConfirm)', function () {
+  let user
+
+  beforeEach('login', async function () {
+    user = new User()
+    await user.login()
+  })
+
+  it('should render the page with the token from the query string', async function () {
+    const { response, body } = await user.doRequest('GET', {
+      url: '/user/emails/confirm?token=mock-confirm-token',
+    })
+    expect(response.statusCode).to.equal(200)
+    expect(body).to.include('value="mock-confirm-token"')
+  })
+
+  it('should reject an invalid token query value', async function () {
+    const { response, body } = await user.doRequest('GET', {
+      url: '/user/emails/confirm?token[foo]=bar',
+      json: true,
+    })
+    expectValidationErrorRaw(
+      { statusCode: response.statusCode, body },
+      400,
+      'token'
+    )
+  })
+})
diff --git a/services/web/test/acceptance/src/DocumentControllerTests.mjs b/services/web/test/acceptance/src/DocumentControllerTests.mjs
new file mode 100644
index 0000000000..8ab139aae5
--- /dev/null
+++ b/services/web/test/acceptance/src/DocumentControllerTests.mjs
@@ -0,0 +1,167 @@
+import { expect } from 'chai'
+import UserHelper from './helpers/User.mjs'
+import request from './helpers/request.js'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+const authedRequest = request.promises
+
+const auth = Buffer.from('overleaf:password').toString('base64')
+function privateApiRequest(options) {
+  return authedRequest.request({
+    ...options,
+    json: options.json === undefined ? true : options.json,
+    headers: {
+      ...options.headers,
+      Authorization: `Basic ${auth}`,
+    },
+  })
+}
+
+describe('DocumentController', function () {
+  let owner, projectId, docId
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+    projectId = await owner.createProject('document-controller-test', {
+      template: 'blank',
+    })
+    const project = await owner.getProject(projectId)
+    docId = project.rootFolder[0].docs[0]._id.toString()
+  })
+
+  describe('GET /project/:Project_id/doc/:doc_id', function () {
+    it('should return the document as json', async function () {
+      const response = await privateApiRequest({
+        method: 'get',
+        url: `/project/${projectId}/doc/${docId}`,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(response.body.lines).to.be.an('array')
+      expect(response.body.version).to.be.a('number')
+      expect(response.body.pathname).to.equal('/main.tex')
+    })
+
+    it('should return the document as plain text when plain=true', async function () {
+      const response = await privateApiRequest({
+        method: 'get',
+        url: `/project/${projectId}/doc/${docId}?plain=true`,
+        json: false,
+      })
+      expect(response.statusCode).to.equal(200)
+      expect(response.body).to.be.a('string')
+    })
+
+    it('should reject a malformed project id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'get',
+        url: `/project/not-an-object-id/doc/${docId}`,
+      })
+      expectValidationErrorRaw(response, 404, 'Project_id')
+    })
+
+    it('should reject a malformed doc id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'get',
+        url: `/project/${projectId}/doc/not-an-object-id`,
+      })
+      expectValidationErrorRaw(response, 404, 'doc_id')
+    })
+  })
+
+  describe('POST /project/:Project_id/doc/:doc_id', function () {
+    it('should update the document lines and version', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/project/${projectId}/doc/${docId}`,
+        json: {
+          lines: ['new content', 'second line'],
+          version: 2,
+          ranges: {},
+          lastUpdatedAt: String(Date.now()),
+          lastUpdatedBy: owner._id.toString(),
+        },
+      })
+      expect(response.statusCode).to.equal(200)
+
+      const getResponse = await privateApiRequest({
+        method: 'get',
+        url: `/project/${projectId}/doc/${docId}`,
+      })
+      expect(getResponse.body.lines).to.deep.equal([
+        'new content',
+        'second line',
+      ])
+      expect(getResponse.body.version).to.equal(2)
+    })
+
+    it('should accept a null lastUpdatedBy for system-initiated updates', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/project/${projectId}/doc/${docId}`,
+        json: {
+          lines: ['content'],
+          version: 2,
+          ranges: {},
+          lastUpdatedAt: String(Date.now()),
+          lastUpdatedBy: null,
+        },
+      })
+      expect(response.statusCode).to.equal(200)
+    })
+
+    it('should reject a non-array lines field', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/project/${projectId}/doc/${docId}`,
+        json: {
+          lines: 'not-an-array',
+          version: 2,
+          ranges: {},
+        },
+      })
+      expectValidationErrorRaw(response, 400, 'lines')
+    })
+
+    it('should reject a malformed lastUpdatedAt', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/project/${projectId}/doc/${docId}`,
+        json: {
+          lines: ['content'],
+          version: 2,
+          ranges: {},
+          lastUpdatedAt: 'not-a-number',
+          lastUpdatedBy: owner._id.toString(),
+        },
+      })
+      expectValidationErrorRaw(response, 400, 'lastUpdatedAt')
+    })
+  })
+
+  describe('POST /project/:Project_id/doc/:doc_id/changes/reject', function () {
+    it('should accept the request and return 204', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/project/${projectId}/doc/${docId}/changes/reject`,
+        json: {
+          rejectedChangeAuthorIds: [owner._id.toString()],
+          userId: owner._id.toString(),
+        },
+      })
+      expect(response.statusCode).to.equal(204)
+    })
+
+    it('should reject a non-ObjectId rejectedChangeAuthorIds entry', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/project/${projectId}/doc/${docId}/changes/reject`,
+        json: {
+          rejectedChangeAuthorIds: ['not-an-object-id'],
+        },
+      })
+      expectValidationErrorRaw(response, 400, 'rejectedChangeAuthorIds')
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/DocumentUpdaterControllerTests.mjs b/services/web/test/acceptance/src/DocumentUpdaterControllerTests.mjs
new file mode 100644
index 0000000000..76dcec7ccb
--- /dev/null
+++ b/services/web/test/acceptance/src/DocumentUpdaterControllerTests.mjs
@@ -0,0 +1,40 @@
+import UserHelper from './helpers/User.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+
+describe('DocumentUpdaterController', function () {
+  let owner, projectId
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+    projectId = await owner.createProject('document-updater-controller-test', {
+      template: 'blank',
+    })
+  })
+
+  describe('GET /Project/:Project_id/doc/:Doc_id/download', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/Project/not-an-object-id/doc/${projectId}/download`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+
+    it('should reject a malformed doc id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/Project/${projectId}/doc/not-an-object-id/download`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Doc_id'
+      )
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/FileStoreControllerTests.mjs b/services/web/test/acceptance/src/FileStoreControllerTests.mjs
new file mode 100644
index 0000000000..f7308515b8
--- /dev/null
+++ b/services/web/test/acceptance/src/FileStoreControllerTests.mjs
@@ -0,0 +1,51 @@
+import { expect } from 'chai'
+import UserHelper from './helpers/User.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+
+describe('FileStoreController', function () {
+  let owner, projectId
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+    projectId = await owner.createProject('filestore-controller-test', {
+      template: 'blank',
+    })
+  })
+
+  describe('GET /Project/:Project_id/file/:File_id', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/Project/not-an-object-id/file/${projectId}`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Project_id'
+      )
+    })
+
+    it('should reject a malformed file id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: `/Project/${projectId}/file/not-an-object-id`,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'File_id'
+      )
+    })
+  })
+
+  describe('HEAD /Project/:Project_id/file/:File_id', function () {
+    it('should reject a malformed project id with 404', async function () {
+      const { response } = await owner.doRequest('head', {
+        url: `/Project/not-an-object-id/file/${projectId}`,
+      })
+      // HEAD responses carry no body to assert a validation message against
+      expect(response.statusCode).to.equal(404)
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/InactiveProjectControllerTests.mjs b/services/web/test/acceptance/src/InactiveProjectControllerTests.mjs
new file mode 100644
index 0000000000..7b990fc061
--- /dev/null
+++ b/services/web/test/acceptance/src/InactiveProjectControllerTests.mjs
@@ -0,0 +1,44 @@
+import request from './helpers/request.js'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const authedRequest = request.promises
+
+const auth = Buffer.from('overleaf:password').toString('base64')
+function privateApiRequest(options) {
+  return authedRequest.request({
+    ...options,
+    json: options.json === undefined ? true : options.json,
+    headers: {
+      ...options.headers,
+      Authorization: `Basic ${auth}`,
+    },
+  })
+}
+
+describe('InactiveProjectController', function () {
+  describe('POST /internal/project/:project_id/deactivate', function () {
+    // The happy path (real archiving via docstore) isn't exercised here:
+    // MockDocstoreApi doesn't implement the archive endpoint this hits, so a
+    // full round trip 500s regardless of request validation. That behavior
+    // (mocked-manager only) is covered at the unit level instead; this file
+    // covers the request-validation wiring.
+    it('should reject a malformed project id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: `/internal/project/not-an-object-id/deactivate`,
+      })
+      expectValidationErrorRaw(response, 404, 'project_id')
+    })
+  })
+
+  describe('POST /internal/deactivateOldProjects', function () {
+    it('should reject a non-numeric numberOfProjectsToArchive', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/internal/deactivateOldProjects',
+        json: { numberOfProjectsToArchive: 'not-a-number' },
+      })
+      expectValidationErrorRaw(response, 400, 'numberOfProjectsToArchive')
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/LinkedFilesTests.mjs b/services/web/test/acceptance/src/LinkedFilesTests.mjs
index 5afe3b5d6a..14fb5faa87 100644
--- a/services/web/test/acceptance/src/LinkedFilesTests.mjs
+++ b/services/web/test/acceptance/src/LinkedFilesTests.mjs
@@ -5,21 +5,31 @@ import Settings from '@overleaf/settings'
 import UserHelper from './helpers/User.mjs'
 import express from 'express'
 import { plainTextResponse } from '../../../app/src/infrastructure/Response.mjs'
+import { parseReq, z, handleValidationError } from '@overleaf/validation-tools'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
 
 const User = UserHelper.promises
 
+const linkedUrlProxySchema = z.object({
+  query: z.object({
+    url: z.string(),
+  }),
+})
+
 const LinkedUrlProxy = express()
 LinkedUrlProxy.get('/', (req, res, next) => {
-  if (req.query.url === 'http://example.com/foo') {
+  const { query } = parseReq(req, linkedUrlProxySchema)
+  if (query.url === 'http://example.com/foo') {
     return plainTextResponse(res, 'foo foo foo')
-  } else if (req.query.url === 'http://example.com/bar') {
+  } else if (query.url === 'http://example.com/bar') {
     return plainTextResponse(res, 'bar bar bar')
-  } else if (req.query.url === 'http://example.com/large') {
+  } else if (query.url === 'http://example.com/large') {
     return plainTextResponse(res, 'x'.repeat(Settings.maxUploadSize + 1))
   } else {
     return res.sendStatus(404)
   }
 })
+LinkedUrlProxy.use(handleValidationError)
 
 describe('LinkedFiles', function () {
   before(function () {
@@ -207,6 +217,38 @@ describe('LinkedFiles', function () {
       expect(response.statusCode).to.equal(404)
       expect(body).to.equal('Source file not found')
     })
+
+    it('should reject a malformed file id when refreshing a linked file', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: `/project/${projectOneId}/linked_file/not-an-object-id/refresh`,
+        json: true,
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'file_id'
+      )
+    })
+
+    it('should reject a malformed source_project_id when creating a project_file linked file', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: `/project/${projectOneId}/linked_file`,
+        json: {
+          name: 'test-link.txt',
+          parent_folder_id: projectOneRootFolderId,
+          provider: 'project_file',
+          data: {
+            source_project_id: 'not-an-object-id',
+            source_entity_path: `/${sourceDocName}`,
+          },
+        },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'source_project_id'
+      )
+    })
   })
 
   describe('with a linked project_file from a v1 project that has not been imported', function () {
@@ -423,6 +465,26 @@ describe('LinkedFiles', function () {
       expect(response.statusCode).to.equal(200)
       expect(body).to.equal('foo foo foo')
     })
+
+    it('should reject an unrecognized field in the linked file data', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: `/project/${projectOneId}/linked_file`,
+        json: {
+          provider: 'url',
+          data: {
+            url: 'http://example.com/foo',
+            notARealField: 'nope',
+          },
+          parent_folder_id: projectOneRootFolderId,
+          name: 'url-test-file-invalid',
+        },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'notARealField'
+      )
+    })
   })
 
   // TODO: Add test for asking for host that return ENOTFOUND
@@ -489,6 +551,48 @@ describe('LinkedFiles', function () {
       expect(refreshedFile._id.toString()).to.equal(refreshedFileId.toString())
       expect(refreshedFile.name).to.equal('test.pdf')
     })
+
+    it('should reject a malformed source_project_id when creating a project_output_file linked file', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: `/project/${projectOneId}/linked_file`,
+        json: {
+          name: 'test.pdf',
+          parent_folder_id: projectOneRootFolderId,
+          provider: 'project_output_file',
+          data: {
+            source_project_id: 'not-an-object-id',
+            source_output_file_path: 'output.pdf',
+            build_id: '1234-abcd',
+          },
+        },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'source_project_id'
+      )
+    })
+
+    it('should reject a malformed build_id when creating a project_output_file linked file', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: `/project/${projectOneId}/linked_file`,
+        json: {
+          name: 'test.pdf',
+          parent_folder_id: projectOneRootFolderId,
+          provider: 'project_output_file',
+          data: {
+            source_project_id: projectTwoId,
+            source_output_file_path: 'output.pdf',
+            build_id: 'not-a-valid-build-id',
+          },
+        },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'build_id'
+      )
+    })
   })
 
   describe('with a linked project_output_file from a v1 project that has not been imported', function () {
diff --git a/services/web/test/acceptance/src/TemplatesControllerTests.mjs b/services/web/test/acceptance/src/TemplatesControllerTests.mjs
new file mode 100644
index 0000000000..2e06991147
--- /dev/null
+++ b/services/web/test/acceptance/src/TemplatesControllerTests.mjs
@@ -0,0 +1,92 @@
+import UserHelper from './helpers/User.mjs'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const User = UserHelper.promises
+
+describe('TemplatesController', function () {
+  let owner
+
+  beforeEach(async function () {
+    owner = new User()
+    await owner.login()
+  })
+
+  describe('GET /project/new/template/:Template_version_id', function () {
+    it('should reject a non-numeric Template_version_id with 404', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/project/new/template/not-a-number?id=123',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        404,
+        'Template_version_id'
+      )
+    })
+
+    it('should reject a non-numeric id query param with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/project/new/template/456?id=not-a-number',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'id'
+      )
+    })
+
+    it('should reject a non-string templateName query param with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/project/new/template/456?id=123&templateName=a&templateName=b',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'templateName'
+      )
+    })
+
+    it('should reject a path-traversal-shaped brandVariationId query param with 400', async function () {
+      const { response, body } = await owner.doRequest('get', {
+        url: '/project/new/template/456?id=123&brandVariationId=1%2F..%2F..%2Fv1%2Fx',
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'brandVariationId'
+      )
+    })
+  })
+
+  describe('POST /project/new/template', function () {
+    it('should reject a non-numeric templateId with 400', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: '/project/new/template',
+        json: {
+          templateId: 'not-a-number',
+          templateVersionId: '456',
+        },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'templateId'
+      )
+    })
+
+    it('should reject a path-traversal-shaped brandVariationId with 400', async function () {
+      const { response, body } = await owner.doRequest('post', {
+        url: '/project/new/template',
+        json: {
+          templateId: '123',
+          templateVersionId: '456',
+          brandVariationId: '1/../../v1/x',
+        },
+      })
+      expectValidationErrorRaw(
+        { statusCode: response.statusCode, body },
+        400,
+        'brandVariationId'
+      )
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/TokenAccessTests.mjs b/services/web/test/acceptance/src/TokenAccessTests.mjs
index eb66c9ef2e..7d27f101bc 100644
--- a/services/web/test/acceptance/src/TokenAccessTests.mjs
+++ b/services/web/test/acceptance/src/TokenAccessTests.mjs
@@ -7,6 +7,7 @@ import { db } from '../../../app/src/infrastructure/mongodb.mjs'
 import expectErrorResponse from './helpers/expectErrorResponse.mjs'
 import logger from '@overleaf/logger'
 import sinon from 'sinon'
+import TokenAccessHandler from '../../../app/src/Features/TokenAccess/TokenAccessHandler.mjs'
 
 const tryEditorAccess = (user, projectId, test, callback) =>
   async.series(
@@ -85,8 +86,11 @@ const _doTryTokenAccess = (
       return callback()
     }
     user.request.post(
+      // `token` here is a route param, not a body field -- the grant
+      // endpoints only read confirmedByUser/tokenHashPrefix from the body
+      // (see TokenAccessController.mjs's grantTokenAccessSchema).
       `${url}/grant`,
-      { json: { token } },
+      { json: {} },
       (err, response, body) => {
         if (err) {
           return callback(err)
@@ -132,8 +136,10 @@ const _doTryTokenAccept = (
       return callback()
     }
     user.request.post(
+      // `token` here is a route param, not a body field -- see the same
+      // note in _doTryTokenAccess above.
       `${url}/grant`,
-      { json: { token, confirmedByUser: true } },
+      { json: { confirmedByUser: true } },
       (err, response, body) => {
         if (err) {
           return callback(err)
@@ -1057,7 +1063,6 @@ describe('TokenAccess', function () {
                   `${this.tokens.readAndWrite}/grant`,
                   {
                     json: {
-                      token: this.tokens.readAndWrite,
                       tokenHashPrefix: urlFragment,
                     },
                   },
@@ -1099,6 +1104,98 @@ describe('TokenAccess', function () {
     })
   })
 
+  describe('anonymous read-and-write token, enabled', function () {
+    let previousAnonymousReadAndWriteEnabled
+    beforeEach(function () {
+      previousAnonymousReadAndWriteEnabled =
+        TokenAccessHandler.ANONYMOUS_READ_AND_WRITE_ENABLED
+      // ANONYMOUS_READ_AND_WRITE_ENABLED is spread onto the default export
+      // (a copy) as well as kept on `promises` (the original object) --
+      // both need to be flipped for the flag to take effect everywhere.
+      TokenAccessHandler.ANONYMOUS_READ_AND_WRITE_ENABLED = true
+      TokenAccessHandler.promises.ANONYMOUS_READ_AND_WRITE_ENABLED = true
+    })
+    afterEach(function () {
+      TokenAccessHandler.ANONYMOUS_READ_AND_WRITE_ENABLED =
+        previousAnonymousReadAndWriteEnabled
+      TokenAccessHandler.promises.ANONYMOUS_READ_AND_WRITE_ENABLED =
+        previousAnonymousReadAndWriteEnabled
+    })
+
+    beforeEach(function (done) {
+      this.owner.createProject(
+        `token-anon-rw-enabled-test${Math.random()}`,
+        (err, projectId) => {
+          if (err != null) {
+            return done(err)
+          }
+          this.projectId = projectId
+          this.owner.makeTokenBased(this.projectId, err => {
+            if (err != null) {
+              return done(err)
+            }
+            this.owner.getProject(this.projectId, (err, project) => {
+              if (err != null) {
+                return done(err)
+              }
+              this.tokens = project.tokens
+              done()
+            })
+          })
+        }
+      )
+    })
+
+    it('should grant the anonymous user read-and-write access and let them load the editor', function (done) {
+      async.series(
+        [
+          cb =>
+            tryEditorAccess(
+              this.anon,
+              this.projectId,
+              expectErrorResponse.restricted.html,
+              cb
+            ),
+          cb =>
+            tryReadAndWriteTokenAccess(
+              this.anon,
+              this.tokens.readAndWrite,
+              (response, body) => {
+                expect(response.statusCode).to.equal(200)
+              },
+              (response, body) => {
+                expect(response.statusCode).to.equal(200)
+                expect(body.redirect).to.equal(`/project/${this.projectId}`)
+                expect(body.grantAnonymousAccess).to.equal('readAndWrite')
+              },
+              cb
+            ),
+          cb =>
+            tryEditorAccess(
+              this.anon,
+              this.projectId,
+              (response, body) => {
+                expect(response.statusCode).to.equal(200)
+              },
+              cb
+            ),
+          cb =>
+            tryAnonContentAccess(
+              this.anon,
+              this.projectId,
+              this.tokens.readAndWrite,
+              (response, body) => {
+                expect(body.privilegeLevel).to.equal('readAndWrite')
+                expect(body.isRestrictedUser).to.equal(false)
+              },
+              cb
+            ),
+        ],
+        done
+      )
+    })
+  })
+
   describe('private overleaf project', function () {
     beforeEach(function (done) {
       this.owner.createProject('overleaf-import', (err, projectId) => {
diff --git a/services/web/test/acceptance/src/TpdsControllerTests.mjs b/services/web/test/acceptance/src/TpdsControllerTests.mjs
new file mode 100644
index 0000000000..a51d151090
--- /dev/null
+++ b/services/web/test/acceptance/src/TpdsControllerTests.mjs
@@ -0,0 +1,79 @@
+import request from './helpers/request.js'
+import { expectValidationErrorRaw } from '@overleaf/validation-tools/testUtils.js'
+
+const authedRequest = request.promises
+
+const auth = Buffer.from('overleaf:password').toString('base64')
+function privateApiRequest(options) {
+  return authedRequest.request({
+    ...options,
+    json: options.json === undefined ? true : options.json,
+    headers: {
+      ...options.headers,
+      Authorization: `Basic ${auth}`,
+    },
+  })
+}
+
+describe('TpdsController', function () {
+  describe('POST /user/:user_id/project/new', function () {
+    it('should reject a malformed user_id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/user/not-an-object-id/project/new',
+        json: { projectName: 'foo' },
+      })
+      expectValidationErrorRaw(response, 404, 'user_id')
+    })
+  })
+
+  describe('POST /user/:user_id/project/resolve', function () {
+    it('should reject a malformed user_id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/user/not-an-object-id/project/resolve',
+        json: { projectName: 'foo' },
+      })
+      expectValidationErrorRaw(response, 404, 'user_id')
+    })
+  })
+
+  describe('POST /tpds/folder-update', function () {
+    it('should reject a malformed userId with 400', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/tpds/folder-update',
+        json: { userId: 'not-an-object-id', path: '/a/b' },
+      })
+      expectValidationErrorRaw(response, 400, 'userId')
+    })
+  })
+
+  describe('POST /user/:user_id/update/:path(.+)', function () {
+    it('should reject a malformed user_id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/user/not-an-object-id/update/project-name/file.tex',
+      })
+      expectValidationErrorRaw(response, 404, 'user_id')
+    })
+  })
+
+  describe('POST /project/:project_id/contents/:path(.+)', function () {
+    it('should reject a malformed project_id with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/project/not-an-object-id/contents/chapters/main.tex',
+      })
+      expectValidationErrorRaw(response, 404, 'project_id')
+    })
+
+    it('should reject a path traversal payload with 404', async function () {
+      const response = await privateApiRequest({
+        method: 'post',
+        url: '/project/507f191e810c19729de860ea/contents/../../../../etc/passwd',
+      })
+      expectValidationErrorRaw(response, 404, 'params.path')
+    })
+  })
+})
diff --git a/services/web/test/acceptance/src/mocks/MockDocUpdaterApi.mjs b/services/web/test/acceptance/src/mocks/MockDocUpdaterApi.mjs
index 2926dd3d21..229439fec8 100644
--- a/services/web/test/acceptance/src/mocks/MockDocUpdaterApi.mjs
+++ b/services/web/test/acceptance/src/mocks/MockDocUpdaterApi.mjs
@@ -34,11 +34,13 @@ const insertOp = z.strictObject({
   i: z.string(),
   p: z.number().int().min(0),
   u: z.boolean().optional(),
+  fixedRemoveChange: z.boolean().optional(),
 })
 const deleteOp = z.strictObject({
   d: z.string(),
   p: z.number().int().min(0),
   u: z.boolean().optional(),
+  fixedRemoveChange: z.boolean().optional(),
 })
 const commentOp = z.strictObject({
   c: z.string(),
diff --git a/services/web/test/acceptance/src/mocks/MockDocstoreApi.mjs b/services/web/test/acceptance/src/mocks/MockDocstoreApi.mjs
index 3e85876b8e..461ae260df 100644
--- a/services/web/test/acceptance/src/mocks/MockDocstoreApi.mjs
+++ b/services/web/test/acceptance/src/mocks/MockDocstoreApi.mjs
@@ -8,11 +8,13 @@ const insertOp = z.strictObject({
   i: z.string(),
   p: z.number().int().min(0),
   u: z.boolean().optional(),
+  fixedRemoveChange: z.boolean().optional(),
 })
 const deleteOp = z.strictObject({
   d: z.string(),
   p: z.number().int().min(0),
   u: z.boolean().optional(),
+  fixedRemoveChange: z.boolean().optional(),
 })
 const commentOp = z.strictObject({
   c: z.string().optional(),
diff --git a/services/web/test/unit/src/Analytics/AnalyticsController.test.mjs b/services/web/test/unit/src/Analytics/AnalyticsController.test.mjs
index 1f67da7cdb..b6539f369a 100644
--- a/services/web/test/unit/src/Analytics/AnalyticsController.test.mjs
+++ b/services/web/test/unit/src/Analytics/AnalyticsController.test.mjs
@@ -1,5 +1,6 @@
-import { beforeEach, describe, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import sinon from 'sinon'
+import { setReqValidationModeForTests } from '@overleaf/validation-tools'
 import MockResponse from '../helpers/MockResponse.mjs'
 const modulePath = new URL(
   '../../../../app/src/Features/Analytics/AnalyticsController.mjs',
@@ -50,11 +51,17 @@ describe('AnalyticsController', function () {
     ctx.res = new MockResponse(vi)
   })
 
+  afterEach(function () {
+    setReqValidationModeForTests(null)
+  })
+
   describe('updateEditingSession', function () {
     beforeEach(function (ctx) {
+      // projectId is validated as a Mongo ObjectId
+      ctx.projectId = '507f191e810c19729de860ea'
       ctx.req = {
         params: {
-          projectId: 'a project id',
+          projectId: ctx.projectId,
         },
         session: {},
         body: {
@@ -75,7 +82,7 @@ describe('AnalyticsController', function () {
           sinon.assert.calledWith(
             ctx.AnalyticsManager.updateEditingSession,
             '1234',
-            'a project id',
+            ctx.projectId,
             'XY',
             { editorType: 'abc' }
           )
@@ -90,7 +97,6 @@ describe('AnalyticsController', function () {
     beforeEach(function (ctx) {
       const body = {
         foo: 'stuff',
-        _csrf: 'atoken123',
       }
       ctx.req = {
         params: {
@@ -100,9 +106,6 @@ describe('AnalyticsController', function () {
         sessionID: 'sessionIDHere',
         session: {},
       }
-
-      ctx.expectedData = Object.assign({}, body)
-      delete ctx.expectedData._csrf
     })
 
     it('should use the session', async function (ctx) {
@@ -112,23 +115,24 @@ describe('AnalyticsController', function () {
           ctx.AnalyticsManager.recordEventForSession,
           ctx.req.session,
           ctx.req.params.event,
-          ctx.expectedData
+          ctx.req.body
         )
         resolve()
       })
     })
 
-    it('should remove the CSRF token before sending to the manager', async function (ctx) {
-      await new Promise(resolve => {
-        ctx.controller.recordEvent(ctx.req, ctx.res)
-        sinon.assert.calledWith(
-          ctx.AnalyticsManager.recordEventForSession,
-          ctx.req.session,
-          ctx.req.params.event,
-          ctx.expectedData
-        )
-        resolve()
-      })
+    it('should reject an event name containing characters outside [a-z0-9-_]', function (ctx) {
+      setReqValidationModeForTests('enforce')
+      ctx.req.params.event = 'I.did:something,here/now;too'
+      expect(() => ctx.controller.recordEvent(ctx.req, ctx.res)).to.throw()
+      sinon.assert.notCalled(ctx.AnalyticsManager.recordEventForSession)
+    })
+
+    it('should reject an event name containing a disallowed character', function (ctx) {
+      setReqValidationModeForTests('enforce')
+      ctx.req.params.event = 'bad event!'
+      expect(() => ctx.controller.recordEvent(ctx.req, ctx.res)).to.throw()
+      sinon.assert.notCalled(ctx.AnalyticsManager.recordEventForSession)
     })
   })
 })
diff --git a/services/web/test/unit/src/Analytics/AnalyticsRegistrationSourceMiddleware.test.mjs b/services/web/test/unit/src/Analytics/AnalyticsRegistrationSourceMiddleware.test.mjs
new file mode 100644
index 0000000000..42dc453f0e
--- /dev/null
+++ b/services/web/test/unit/src/Analytics/AnalyticsRegistrationSourceMiddleware.test.mjs
@@ -0,0 +1,152 @@
+import { afterEach, beforeEach, describe, it, vi } from 'vitest'
+import sinon from 'sinon'
+import { setReqValidationModeForTests } from '@overleaf/validation-tools'
+import MockRequest from '../helpers/MockRequest.mjs'
+import MockResponse from '../helpers/MockResponse.mjs'
+
+const MODULE_PATH = new URL(
+  '../../../../app/src/Features/Analytics/AnalyticsRegistrationSourceMiddleware',
+  import.meta.url
+).pathname
+
+describe('AnalyticsRegistrationSourceMiddleware', function () {
+  beforeEach(async function (ctx) {
+    ctx.req = new MockRequest(vi)
+    ctx.req.header = name => ctx.req.headers[name]
+    ctx.res = new MockResponse(vi)
+    ctx.next = sinon.stub()
+
+    ctx.AnalyticsRegistrationSourceHelper = {
+      clearSource: sinon.stub(),
+      setInbound: sinon.stub(),
+    }
+    vi.doMock(
+      '../../../../app/src/Features/Analytics/AnalyticsRegistrationSourceHelper.mjs',
+      () => ({ default: ctx.AnalyticsRegistrationSourceHelper })
+    )
+
+    ctx.SessionManager = {
+      isUserLoggedIn: sinon.stub().returns(false),
+    }
+    vi.doMock(
+      '../../../../app/src/Features/Authentication/SessionManager.mjs',
+      () => ({ default: ctx.SessionManager })
+    )
+
+    ctx.AnalyticsRegistrationSourceMiddleware = (
+      await import(MODULE_PATH)
+    ).default
+  })
+
+  afterEach(function () {
+    setReqValidationModeForTests(null)
+  })
+
+  describe('setInbound', function () {
+    beforeEach(function (ctx) {
+      ctx.req.url = '/project'
+      ctx.req.session = {}
+      ctx.middleware = ctx.AnalyticsRegistrationSourceMiddleware.setInbound()
+    })
+
+    describe('when the session already has an inbound referrer', function () {
+      beforeEach(function (ctx) {
+        ctx.req.session.inbound = { referrer: { medium: 'direct' } }
+        ctx.middleware(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('does not overwrite it', function (ctx) {
+        sinon.assert.notCalled(ctx.AnalyticsRegistrationSourceHelper.setInbound)
+      })
+
+      it('calls next', function (ctx) {
+        sinon.assert.calledOnce(ctx.next)
+      })
+    })
+
+    describe('when the user is already logged in', function () {
+      beforeEach(function (ctx) {
+        ctx.SessionManager.isUserLoggedIn.returns(true)
+        ctx.req.query = { utm_campaign: 'spring-sale' }
+        ctx.middleware(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('does not record a referrer', function (ctx) {
+        sinon.assert.notCalled(ctx.AnalyticsRegistrationSourceHelper.setInbound)
+      })
+
+      it('calls next', function (ctx) {
+        sinon.assert.calledOnce(ctx.next)
+      })
+    })
+
+    describe('with well-formed utm query params', function () {
+      beforeEach(function (ctx) {
+        ctx.req.query = {
+          utm_campaign: 'spring-sale',
+          utm_source: 'newsletter',
+        }
+        ctx.req.headers.referrer = 'https://example.com'
+        ctx.middleware(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('forwards the parsed utm query to the helper', function (ctx) {
+        sinon.assert.calledWith(
+          ctx.AnalyticsRegistrationSourceHelper.setInbound,
+          ctx.req.session,
+          ctx.req.url,
+          { utm_campaign: 'spring-sale', utm_source: 'newsletter' },
+          'https://example.com'
+        )
+      })
+
+      it('calls next', function (ctx) {
+        sinon.assert.calledOnce(ctx.next)
+      })
+    })
+
+    describe('with a malformed utm query value', function () {
+      beforeEach(function (ctx) {
+        ctx.req.query = { utm_campaign: ['spring-sale', 'other'] }
+      })
+
+      describe('in the default log-only validation mode', function () {
+        beforeEach(function (ctx) {
+          setReqValidationModeForTests('log')
+          ctx.middleware(ctx.req, ctx.res, ctx.next)
+        })
+
+        it('falls back to the raw, unvalidated query', function (ctx) {
+          sinon.assert.calledWith(
+            ctx.AnalyticsRegistrationSourceHelper.setInbound,
+            ctx.req.session,
+            ctx.req.url,
+            ctx.req.query,
+            undefined
+          )
+        })
+
+        it('calls next', function (ctx) {
+          sinon.assert.calledOnce(ctx.next)
+        })
+      })
+
+      describe('with request validation enforced', function () {
+        beforeEach(function (ctx) {
+          setReqValidationModeForTests('enforce')
+          ctx.middleware(ctx.req, ctx.res, ctx.next)
+        })
+
+        it('fails silently without recording a referrer', function (ctx) {
+          sinon.assert.notCalled(
+            ctx.AnalyticsRegistrationSourceHelper.setInbound
+          )
+        })
+
+        it('still calls next', function (ctx) {
+          sinon.assert.calledOnce(ctx.next)
+        })
+      })
+    })
+  })
+})
diff --git a/services/web/test/unit/src/Analytics/AnalyticsUTMTrackingMiddleware.test.mjs b/services/web/test/unit/src/Analytics/AnalyticsUTMTrackingMiddleware.test.mjs
index 4efcc835e4..7c63f11425 100644
--- a/services/web/test/unit/src/Analytics/AnalyticsUTMTrackingMiddleware.test.mjs
+++ b/services/web/test/unit/src/Analytics/AnalyticsUTMTrackingMiddleware.test.mjs
@@ -1,5 +1,6 @@
-import { assert, beforeEach, describe, it, vi } from 'vitest'
+import { afterEach, assert, beforeEach, describe, it, vi } from 'vitest'
 import sinon from 'sinon'
+import { setReqValidationModeForTests } from '@overleaf/validation-tools'
 import MockRequest from '../helpers/MockRequest.mjs'
 import MockResponse from '../helpers/MockResponse.mjs'
 
@@ -44,6 +45,10 @@ describe('AnalyticsUTMTrackingMiddleware', function () {
     ctx.middleware = ctx.AnalyticsUTMTrackingMiddleware.recordUTMTags()
   })
 
+  afterEach(function () {
+    setReqValidationModeForTests(null)
+  })
+
   describe('without UTM tags in query', function () {
     beforeEach(function (ctx) {
       ctx.req.url = '/project'
@@ -216,4 +221,50 @@ describe('AnalyticsUTMTrackingMiddleware', function () {
       )
     })
   })
+
+  describe('with a non-string UTM parameter', function () {
+    beforeEach(function (ctx) {
+      ctx.req.url = '/project?utm_source=Organic&utm_source=Direct'
+      ctx.req.query = {
+        utm_source: ['Organic', 'Direct'],
+      }
+      ctx.req.headers = {
+        host: 'test-domain.overleaf.com',
+      }
+    })
+
+    it('still processes the request without throwing', function (ctx) {
+      setReqValidationModeForTests('log')
+      ctx.middleware(ctx.req, ctx.res, ctx.next)
+
+      assert.isTrue(ctx.res.redirected)
+      assert.equal('/project', ctx.res.redirectedTo)
+      sinon.assert.calledWith(
+        ctx.AnalyticsManager.recordEventForSession,
+        ctx.req.session,
+        'page-view',
+        {
+          path: '/project',
+          utm_source: ['Organic', 'Direct'],
+          domain: 'test-domain',
+        }
+      )
+    })
+
+    describe('request validation', function () {
+      beforeEach(function (ctx) {
+        setReqValidationModeForTests('enforce')
+      })
+
+      it('does not throw', function (ctx) {
+        assert.doesNotThrow(() => {
+          ctx.middleware(ctx.req, ctx.res, ctx.next)
+        })
+
+        assert.isTrue(ctx.res.redirected)
+        assert.equal('/project', ctx.res.redirectedTo)
+        sinon.assert.notCalled(ctx.AnalyticsManager.recordEventForSession)
+      })
+    })
+  })
 })
diff --git a/services/web/test/unit/src/Compile/ClsiCacheController.test.mjs b/services/web/test/unit/src/Compile/ClsiCacheController.test.mjs
new file mode 100644
index 0000000000..0e591f995f
--- /dev/null
+++ b/services/web/test/unit/src/Compile/ClsiCacheController.test.mjs
@@ -0,0 +1,155 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import sinon from 'sinon'
+import MockRequest from '../helpers/MockRequest.mjs'
+import MockResponse from '../helpers/MockResponse.mjs'
+import {
+  NotFoundError,
+  ResourceGoneError,
+} from '../../../../app/src/Features/Errors/Errors.js'
+
+const MODULE_PATH =
+  '../../../../app/src/Features/Compile/ClsiCacheController.mjs'
+
+// pin Errors.js to a single module instance so `instanceof` checks in the
+// controller (loaded dynamically below, after other modules are mocked)
+// see the same error classes this file imports statically
+vi.mock('../../../../app/src/Features/Errors/Errors.js', () =>
+  vi.importActual('../../../../app/src/Features/Errors/Errors.js')
+)
+
+describe('ClsiCacheController', function () {
+  beforeEach(async function (ctx) {
+    // Project_id/editorBuildId are validated by the schema
+    ctx.projectId = '507f191e810c19729de860ea'
+    ctx.userId = '507f191e810c19729de860eb'
+    ctx.editorBuildId = 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa-1111111-2222222'
+
+    ctx.ClsiCacheHandler = {
+      isAllowedFilename: sinon.stub().returns(true),
+      getOutputFile: sinon.stub(),
+      getEgressLabel: sinon.stub().returns('output.pdf'),
+    }
+    ctx.ClsiCacheManager = { getLatestCompileResult: sinon.stub() }
+    ctx.CompileController = {
+      _getUserIdForCompile: sinon.stub().returns(ctx.userId),
+      _getSafeProjectName: sinon.stub().returns('project-name'),
+      _getSplitTestOptions: sinon.stub().resolves({
+        pdfCachingMinChunkSize: 100,
+        pdfDownloadDomain: 'https://example.com',
+      }),
+    }
+    ctx.ProjectGetter = {
+      promises: { getProject: sinon.stub().resolves({ name: 'project' }) },
+    }
+
+    vi.doMock('../../../../app/src/Features/Compile/ClsiCacheHandler', () => ({
+      default: ctx.ClsiCacheHandler,
+    }))
+    vi.doMock('../../../../app/src/Features/Compile/ClsiCacheManager', () => ({
+      default: ctx.ClsiCacheManager,
+    }))
+    vi.doMock('../../../../app/src/Features/Compile/CompileController', () => ({
+      default: ctx.CompileController,
+    }))
+    vi.doMock('../../../../app/src/Features/Project/ProjectGetter', () => ({
+      default: ctx.ProjectGetter,
+    }))
+
+    ctx.controller = (await import(MODULE_PATH)).default
+    ctx.req = new MockRequest(vi)
+    ctx.req.params = { Project_id: ctx.projectId }
+    ctx.res = new MockResponse(vi)
+    ctx.res.json = sinon.stub()
+    ctx.res.sendStatus = sinon.stub()
+  })
+
+  describe('getLatestBuildFromCache', function () {
+    beforeEach(function (ctx) {
+      ctx.result = {
+        zone: 'a',
+        outputFiles: [],
+        compileGroup: 'standard',
+        clsiServerId: 'server-1',
+        clsiCacheShard: 'shard-1',
+        options: {},
+        stats: {},
+        timings: {},
+      }
+    })
+
+    it('should return the cached compile result as json', async function (ctx) {
+      ctx.ClsiCacheManager.getLatestCompileResult.resolves(ctx.result)
+      await ctx.controller.getLatestBuildFromCache(ctx.req, ctx.res)
+      ctx.ClsiCacheManager.getLatestCompileResult
+        .calledWith(ctx.projectId, ctx.userId)
+        .should.equal(true)
+      ctx.res.json
+        .calledWithMatch({
+          fromCache: true,
+          status: 'success',
+          clsiServerId: 'server-1',
+          pdfDownloadDomain: 'https://example.com/zone/a',
+        })
+        .should.equal(true)
+    })
+
+    it('should return 404 when the compile result is not found', async function (ctx) {
+      ctx.ClsiCacheManager.getLatestCompileResult.rejects(new NotFoundError())
+      await ctx.controller.getLatestBuildFromCache(ctx.req, ctx.res)
+      ctx.res.sendStatus.calledWith(404).should.equal(true)
+    })
+
+    it('should return 410 when the compile result is gone', async function (ctx) {
+      ctx.ClsiCacheManager.getLatestCompileResult.rejects(
+        new ResourceGoneError()
+      )
+      await ctx.controller.getLatestBuildFromCache(ctx.req, ctx.res)
+      ctx.res.sendStatus.calledWith(410).should.equal(true)
+    })
+
+    it('should reject a malformed project id', async function (ctx) {
+      ctx.req.params = { Project_id: 'not-an-object-id' }
+      await expect(ctx.controller.getLatestBuildFromCache(ctx.req, ctx.res)).to
+        .be.rejected
+      ctx.ClsiCacheManager.getLatestCompileResult.called.should.equal(false)
+    })
+  })
+
+  describe('downloadFromCache', function () {
+    beforeEach(function (ctx) {
+      ctx.req.params = {
+        Project_id: ctx.projectId,
+        editorBuildId: ctx.editorBuildId,
+        filename: 'output.pdf',
+      }
+    })
+
+    it('should reject a malformed project id', async function (ctx) {
+      ctx.req.params.Project_id = 'not-an-object-id'
+      await expect(ctx.controller.downloadFromCache(ctx.req, ctx.res)).to.be
+        .rejected
+      ctx.ClsiCacheHandler.getOutputFile.called.should.equal(false)
+    })
+
+    it('should reject a malformed editorBuildId', async function (ctx) {
+      ctx.req.params.editorBuildId = 'not-a-valid-build-id'
+      await expect(ctx.controller.downloadFromCache(ctx.req, ctx.res)).to.be
+        .rejected
+      ctx.ClsiCacheHandler.getOutputFile.called.should.equal(false)
+    })
+
+    it('should reject a path traversal filename', async function (ctx) {
+      ctx.req.params.filename = '../../../etc/passwd'
+      await expect(ctx.controller.downloadFromCache(ctx.req, ctx.res)).to.be
+        .rejected
+      ctx.ClsiCacheHandler.getOutputFile.called.should.equal(false)
+    })
+
+    it('should reject a filename rejected by ClsiCacheHandler', async function (ctx) {
+      ctx.ClsiCacheHandler.isAllowedFilename.returns(false)
+      await expect(ctx.controller.downloadFromCache(ctx.req, ctx.res)).to.be
+        .rejected
+      ctx.ClsiCacheHandler.getOutputFile.called.should.equal(false)
+    })
+  })
+})
diff --git a/services/web/test/unit/src/Compile/CompileController.test.mjs b/services/web/test/unit/src/Compile/CompileController.test.mjs
index 5bf92e2b00..8fcfdb80a4 100644
--- a/services/web/test/unit/src/Compile/CompileController.test.mjs
+++ b/services/web/test/unit/src/Compile/CompileController.test.mjs
@@ -1,10 +1,11 @@
-import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import sinon from 'sinon'
 import MockRequest from '../helpers/MockRequest.mjs'
 import MockResponse from '../helpers/MockResponse.mjs'
 import { Headers } from 'node-fetch'
 import { ReadableString } from '@overleaf/stream-utils'
 import { RequestFailedError } from '@overleaf/fetch-utils'
+import { setReqValidationModeForTests } from '@overleaf/validation-tools'
 import { asZodError } from '@overleaf/validation-tools/testUtils.js'
 
 const modulePath = '../../../../app/src/Features/Compile/CompileController.mjs'
@@ -390,7 +391,7 @@ describe('CompileController', function () {
 
     describe('with an editor id', function () {
       beforeEach(async function (ctx) {
-        ctx.req.body = { editorId: 'the-editor-id' }
+        ctx.req.body = { editorId: '550e8400-e29b-41d4-a716-446655440000' }
         await ctx.CompileController.compile(ctx.req, ctx.res, ctx.next)
       })
 
@@ -406,7 +407,7 @@ describe('CompileController', function () {
             enablePdfCaching: false,
             fileLineErrors: false,
             stopOnFirstError: false,
-            editorId: 'the-editor-id',
+            editorId: '550e8400-e29b-41d4-a716-446655440000',
             rootResourcePath: undefined,
           }
         )
@@ -657,6 +658,26 @@ describe('CompileController', function () {
     })
   })
 
+  describe('stopCompile', function () {
+    beforeEach(async function (ctx) {
+      ctx.CompileManager.promises.stopCompile = sinon.stub().resolves()
+      ctx.req.params = { Project_id: ctx.projectId }
+      ctx.req.session = {}
+      ctx.res.sendStatus = sinon.stub()
+      await ctx.CompileController.stopCompile(ctx.req, ctx.res, ctx.next)
+    })
+
+    it('should stop the compile for the project', function (ctx) {
+      ctx.CompileManager.promises.stopCompile
+        .calledWith(ctx.projectId, ctx.user_id)
+        .should.equal(true)
+    })
+
+    it('should return a 200', function (ctx) {
+      ctx.res.sendStatus.calledWith(200).should.equal(true)
+    })
+  })
+
   describe('compileSubmission', function () {
     beforeEach(function (ctx) {
       ctx.submission_id = 'sub-1234'
@@ -785,6 +806,22 @@ describe('CompileController', function () {
       })
     })
 
+    describe('with popupDownload', function () {
+      beforeEach(async function (ctx) {
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          popupDownload: 'true',
+        }
+        await ctx.CompileController.downloadPdf(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('should set the content-disposition to attachment', function (ctx) {
+        expect(ctx.res.setContentDisposition).toBeCalledWith('attachment', {
+          filename: 'test_namè__1.pdf',
+        })
+      })
+    })
+
     describe('anon', function () {
       beforeEach(async function (ctx) {
         ctx.SessionManager.getLoggedInUserId.returns(null)
@@ -798,6 +835,26 @@ describe('CompileController', function () {
       })
     })
 
+    describe('with an enable_pdf_caching query param', function () {
+      beforeEach(async function (ctx) {
+        // output-files.ts appends this to the PDF download link whenever
+        // pdf caching is enabled.
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          enable_pdf_caching: 'true',
+        }
+        await ctx.CompileController.downloadPdf(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('should not reject the request', function (ctx) {
+        ctx.next.should.not.have.been.called
+      })
+
+      it('should proxy the PDF from the CLSI', function (ctx) {
+        ctx.fetchUtils.fetchStreamWithResponse.should.have.been.called
+      })
+    })
+
     describe('when rate-limited', function () {
       beforeEach(async function (ctx) {
         ctx.rateLimiter.consume.rejects({
@@ -892,6 +949,55 @@ describe('CompileController', function () {
         )
       })
     })
+
+    describe('with the full query string buildFileList sends for the archive link', function () {
+      beforeEach(async function (ctx) {
+        // services/web/frontend/js/features/pdf-preview/util/file-list.ts
+        // appends editorId/compileGroup to the shared params object, then
+        // one `files` entry per archived file -- a single file arrives as
+        // a bare string, not a one-element array. enable_pdf_caching is
+        // appended separately (see output-files.ts) whenever pdf caching is
+        // enabled.
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          editorId: 'e58b482a-3c9e-4de1-9a05-d5e2f1c8f8f0',
+          compileGroup: 'priority',
+          files: 'output.pdf',
+          enable_pdf_caching: 'true',
+        }
+        await ctx.CompileController.getOutputZipFromClsi(
+          ctx.req,
+          ctx.res,
+          ctx.next
+        )
+      })
+
+      it('should not reject the request', function (ctx) {
+        ctx.next.should.not.have.been.called
+      })
+
+      it('should proxy to the CLSI', function (ctx) {
+        ctx.fetchUtils.fetchStreamWithResponse.should.have.been.called
+      })
+    })
+
+    describe('with multiple files in the query string', function () {
+      beforeEach(async function (ctx) {
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          files: ['output.pdf', 'output.log'],
+        }
+        await ctx.CompileController.getOutputZipFromClsi(
+          ctx.req,
+          ctx.res,
+          ctx.next
+        )
+      })
+
+      it('should not reject the request', function (ctx) {
+        ctx.next.should.not.have.been.called
+      })
+    })
   })
 
   describe('getFileForSubmissionFromClsi', function () {
@@ -973,6 +1079,54 @@ describe('CompileController', function () {
         }
       )
     })
+
+    it('should reject a buildId that does not match the hex-hyphen-hex shape', async function (ctx) {
+      ctx.req.query.buildId = 'not-a-valid-build-id'
+      ctx.next = sinon.stub()
+      await ctx.CompileController.proxySyncCode(ctx.req, ctx.res, ctx.next)
+      ctx.next.should.have.been.calledWithMatch({
+        name: 'InvalidRequestError',
+        zodError: asZodError({
+          origin: 'string',
+          code: 'invalid_format',
+          format: 'regex',
+          pattern: '/^[0-9a-f]+-[0-9a-f]+$/',
+          path: ['query', 'buildId'],
+          message: 'invalid buildId',
+        }),
+      })
+      ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+    })
+
+    describe('when the schema is in log-only mode', function () {
+      beforeEach(function () {
+        setReqValidationModeForTests('log')
+      })
+
+      afterEach(function () {
+        setReqValidationModeForTests(null)
+      })
+
+      it('should still reject a non-numeric line via the manual guard', async function (ctx) {
+        ctx.req.query.line = 'not-a-number'
+        ctx.next = sinon.stub()
+        await ctx.CompileController.proxySyncCode(ctx.req, ctx.res, ctx.next)
+        ctx.next.should.have.been.calledWithMatch({
+          message: 'invalid line parameter',
+        })
+        ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+      })
+
+      it('should still reject a non-numeric column via the manual guard', async function (ctx) {
+        ctx.req.query.column = 'not-a-number'
+        ctx.next = sinon.stub()
+        await ctx.CompileController.proxySyncCode(ctx.req, ctx.res, ctx.next)
+        ctx.next.should.have.been.calledWithMatch({
+          message: 'invalid column parameter',
+        })
+        ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+      })
+    })
   })
 
   describe('proxySyncPdf', function () {
@@ -1023,6 +1177,64 @@ describe('CompileController', function () {
         }
       )
     })
+
+    it('should reject a buildId that does not match the hex-hyphen-hex shape', async function (ctx) {
+      ctx.req.query.buildId = 'not-a-valid-build-id'
+      ctx.next = sinon.stub()
+      await ctx.CompileController.proxySyncPdf(ctx.req, ctx.res, ctx.next)
+      ctx.next.should.have.been.calledWithMatch({
+        name: 'InvalidRequestError',
+        zodError: asZodError({
+          origin: 'string',
+          code: 'invalid_format',
+          format: 'regex',
+          pattern: '/^[0-9a-f]+-[0-9a-f]+$/',
+          path: ['query', 'buildId'],
+          message: 'invalid buildId',
+        }),
+      })
+      ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+    })
+
+    describe('when the schema is in log-only mode', function () {
+      beforeEach(function () {
+        setReqValidationModeForTests('log')
+      })
+
+      afterEach(function () {
+        setReqValidationModeForTests(null)
+      })
+
+      it('should still reject a non-numeric page via the manual guard', async function (ctx) {
+        ctx.req.query.page = 'not-a-number'
+        ctx.next = sinon.stub()
+        await ctx.CompileController.proxySyncPdf(ctx.req, ctx.res, ctx.next)
+        ctx.next.should.have.been.calledWithMatch({
+          message: 'invalid page parameter',
+        })
+        ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+      })
+
+      it('should still reject a non-numeric h via the manual guard', async function (ctx) {
+        ctx.req.query.h = 'not-a-number'
+        ctx.next = sinon.stub()
+        await ctx.CompileController.proxySyncPdf(ctx.req, ctx.res, ctx.next)
+        ctx.next.should.have.been.calledWithMatch({
+          message: 'invalid h parameter',
+        })
+        ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+      })
+
+      it('should still reject a non-numeric v via the manual guard', async function (ctx) {
+        ctx.req.query.v = 'not-a-number'
+        ctx.next = sinon.stub()
+        await ctx.CompileController.proxySyncPdf(ctx.req, ctx.res, ctx.next)
+        ctx.next.should.have.been.calledWithMatch({
+          message: 'invalid v parameter',
+        })
+        ctx.CompileManager.promises.syncTeX.should.have.been.calledOnce
+      })
+    })
   })
 
   describe('getFileFromClsi', function () {
@@ -1169,6 +1381,89 @@ describe('CompileController', function () {
         expect(ctx.res.statusCode).to.equal(404)
       })
     })
+
+    describe('with a compileGroup query param', function () {
+      beforeEach(async function (ctx) {
+        // buildFileList (see file-list.ts) always appends this to every
+        // per-file download link it builds
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          compileGroup: 'priority',
+        }
+        await ctx.CompileController.getFileFromClsi(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('should not reject the request', function (ctx) {
+        ctx.next.should.not.have.been.called
+      })
+
+      it('should proxy to the CLSI', function (ctx) {
+        ctx.fetchUtils.fetchStreamWithResponse.should.have.been.called
+      })
+    })
+
+    describe('with an enable_pdf_caching query param', function () {
+      beforeEach(async function (ctx) {
+        // output-files.ts appends this to per-file download links whenever
+        // pdf caching is enabled.
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          enable_pdf_caching: 'true',
+        }
+        await ctx.CompileController.getFileFromClsi(ctx.req, ctx.res, ctx.next)
+      })
+
+      it('should not reject the request', function (ctx) {
+        ctx.next.should.not.have.been.called
+      })
+
+      it('should proxy to the CLSI', function (ctx) {
+        ctx.fetchUtils.fetchStreamWithResponse.should.have.been.called
+      })
+    })
+
+    describe('with an invalid enable_pdf_caching query param', function () {
+      beforeEach(function (ctx) {
+        ctx.req.query = {
+          clsiserverid: ctx.clsiServerId,
+          enable_pdf_caching: 'notabool',
+        }
+        ctx.next = sinon.stub()
+      })
+
+      it('should reject the request', async function (ctx) {
+        await ctx.CompileController.getFileFromClsi(ctx.req, ctx.res, ctx.next)
+        ctx.next.should.have.been.calledWithMatch({
+          name: 'InvalidRequestError',
+          zodError: asZodError({
+            code: 'invalid_value',
+            expected: 'stringbool',
+            values: [
+              'true',
+              '1',
+              'yes',
+              'on',
+              'y',
+              'enabled',
+              'false',
+              '0',
+              'no',
+              'off',
+              'n',
+              'disabled',
+            ],
+            path: ['query', 'enable_pdf_caching'],
+            message:
+              'Invalid option: expected one of "true"|"1"|"yes"|"on"|"y"|"enabled"|"false"|"0"|"no"|"off"|"n"|"disabled"',
+          }),
+        })
+      })
+
+      it('should not open a request to CLSI', async function (ctx) {
+        await ctx.CompileController.getFileFromClsi(ctx.req, ctx.res, ctx.next)
+        ctx.fetchUtils.fetchStreamWithResponse.should.not.have.been.called
+      })
+    })
   })
 
   describe('deleteAuxFiles', function () {
diff --git a/services/web/test/unit/src/FileStore/FileStoreController.test.mjs b/services/web/test/unit/src/FileStore/FileStoreController.test.mjs
index 228bdb9950..1f38bda9c5 100644
--- a/services/web/test/unit/src/FileStore/FileStoreController.test.mjs
+++ b/services/web/test/unit/src/FileStore/FileStoreController.test.mjs
@@ -38,14 +38,15 @@ describe('FileStoreController', function () {
 
     ctx.controller = (await import(MODULE_PATH)).default
     ctx.stream = {}
-    ctx.projectId = '2k3j1lk3j21lk3j'
-    ctx.fileId = '12321kklj1lk3jk12'
+    // Project_id/File_id are validated as Mongo ObjectIds
+    ctx.projectId = '507f191e810c19729de860ea'
+    ctx.fileId = '507f191e810c19729de860eb'
     ctx.req = {
       params: {
         Project_id: ctx.projectId,
         File_id: ctx.fileId,
       },
-      query: 'query string here',
+      query: { foo: 'bar' },
       get(key) {
         return undefined
       },
diff --git a/services/web/test/unit/src/HelperFiles/UrlHelper.test.mjs b/services/web/test/unit/src/HelperFiles/UrlHelper.test.mjs
index 688fbe931b..665af3ad8b 100644
--- a/services/web/test/unit/src/HelperFiles/UrlHelper.test.mjs
+++ b/services/web/test/unit/src/HelperFiles/UrlHelper.test.mjs
@@ -45,4 +45,26 @@ describe('UrlHelper', function () {
       )
     })
   })
+
+  describe('getCanonicalURL', function () {
+    it('strips the query string and hash', function (ctx) {
+      const req = {
+        headers: { host: '127.0.0.1:3000' },
+        originalUrl: '/blog/some-post?foo=bar#section',
+      }
+      expect(ctx.UrlHelper.getCanonicalURL(req)).to.equal(
+        'http://127.0.0.1:3000/blog/some-post'
+      )
+    })
+
+    it('strips a trailing slash', function (ctx) {
+      const req = {
+        headers: { host: '127.0.0.1:3000' },
+        originalUrl: '/blog/some-post/',
+      }
+      expect(ctx.UrlHelper.getCanonicalURL(req)).to.equal(
+        'http://127.0.0.1:3000/blog/some-post'
+      )
+    })
+  })
 })
diff --git a/services/web/test/unit/src/InactiveData/InactiveProjectController.test.mjs b/services/web/test/unit/src/InactiveData/InactiveProjectController.test.mjs
new file mode 100644
index 0000000000..bb276a253a
--- /dev/null
+++ b/services/web/test/unit/src/InactiveData/InactiveProjectController.test.mjs
@@ -0,0 +1,100 @@
+import { beforeEach, describe, it, vi } from 'vitest'
+import sinon from 'sinon'
+import MockRequest from '../helpers/MockRequest.mjs'
+import MockResponse from '../helpers/MockResponse.mjs'
+
+const modulePath =
+  '../../../../app/src/Features/InactiveData/InactiveProjectController'
+
+describe('InactiveProjectController', function () {
+  beforeEach(async function (ctx) {
+    ctx.InactiveProjectManager = {
+      deactivateOldProjects: sinon.stub(),
+      deactivateProject: sinon.stub(),
+    }
+    vi.doMock(
+      '../../../../app/src/Features/InactiveData/InactiveProjectManager',
+      () => ({
+        default: ctx.InactiveProjectManager,
+      })
+    )
+    ctx.controller = (await import(modulePath)).default
+    ctx.req = new MockRequest(vi)
+    ctx.res = new MockResponse(vi)
+    ctx.res.json = sinon.stub()
+    ctx.res.sendStatus = sinon.stub()
+  })
+
+  describe('deactivateOldProjects', function () {
+    it('should call the manager with the parsed numeric values', function (ctx) {
+      ctx.req.body = { numberOfProjectsToArchive: 5, ageOfProjects: 30 }
+      ctx.InactiveProjectManager.deactivateOldProjects.callsFake(
+        (limit, daysOld, cb) => cb(null, ['project-1'])
+      )
+      ctx.controller.deactivateOldProjects(ctx.req, ctx.res)
+      ctx.InactiveProjectManager.deactivateOldProjects
+        .calledWith(5, 30)
+        .should.equal(true)
+      ctx.res.json.calledWith(['project-1']).should.equal(true)
+    })
+
+    it('should coerce numeric-looking strings sent as the body', function (ctx) {
+      // some private-API callers post numbers as strings
+      ctx.req.body = { numberOfProjectsToArchive: '5', ageOfProjects: '30' }
+      ctx.InactiveProjectManager.deactivateOldProjects.callsFake(
+        (limit, daysOld, cb) => cb(null, [])
+      )
+      ctx.controller.deactivateOldProjects(ctx.req, ctx.res)
+      ctx.InactiveProjectManager.deactivateOldProjects
+        .calledWith(5, 30)
+        .should.equal(true)
+    })
+
+    it('should work without any body fields', function (ctx) {
+      ctx.req.body = {}
+      ctx.InactiveProjectManager.deactivateOldProjects.callsFake(
+        (limit, daysOld, cb) => cb(null, [])
+      )
+      ctx.controller.deactivateOldProjects(ctx.req, ctx.res)
+      ctx.InactiveProjectManager.deactivateOldProjects
+        .calledWith(undefined, undefined)
+        .should.equal(true)
+    })
+
+    it('should return a 500 when the manager errors', function (ctx) {
+      ctx.req.body = {}
+      ctx.InactiveProjectManager.deactivateOldProjects.callsFake(
+        (limit, daysOld, cb) => cb(new Error('failed'))
+      )
+      ctx.controller.deactivateOldProjects(ctx.req, ctx.res)
+      ctx.res.sendStatus.calledWith(500).should.equal(true)
+    })
+  })
+
+  describe('deactivateProject', function () {
+    beforeEach(function (ctx) {
+      // project_id is validated as a Mongo ObjectId
+      ctx.projectId = '507f191e810c19729de860ea'
+      ctx.req.params = { project_id: ctx.projectId }
+    })
+
+    it('should call the manager and return 200', function (ctx) {
+      ctx.InactiveProjectManager.deactivateProject.callsFake((id, cb) =>
+        cb(null)
+      )
+      ctx.controller.deactivateProject(ctx.req, ctx.res)
+      ctx.InactiveProjectManager.deactivateProject
+        .calledWith(ctx.projectId)
+        .should.equal(true)
+      ctx.res.sendStatus.calledWith(200).should.equal(true)
+    })
+
+    it('should return a 500 when the manager errors', function (ctx) {
+      ctx.InactiveProjectManager.deactivateProject.callsFake((id, cb) =>
+        cb(new Error('failed'))
+      )
+      ctx.controller.deactivateProject(ctx.req, ctx.res)
+      ctx.res.sendStatus.calledWith(500).should.equal(true)
+    })
+  })
+})
diff --git a/services/web/test/unit/src/LinkedFiles/LinkedFilesController.test.mjs b/services/web/test/unit/src/LinkedFiles/LinkedFilesController.test.mjs
index b2ae3749cc..d8cd4077ee 100644
--- a/services/web/test/unit/src/LinkedFiles/LinkedFilesController.test.mjs
+++ b/services/web/test/unit/src/LinkedFiles/LinkedFilesController.test.mjs
@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import sinon from 'sinon'
+import { setReqValidationModeForTests } from '@overleaf/validation-tools'
 const modulePath =
   '../../../../app/src/Features/LinkedFiles/LinkedFilesController.mjs'
 
@@ -13,6 +14,10 @@ describe('LinkedFilesController', function () {
     ctx.clock.restore()
   })
 
+  afterEach(function () {
+    setReqValidationModeForTests(null)
+  })
+
   beforeEach(async function (ctx) {
     ctx.userId = 'user-id'
     ctx.Agent = {
@@ -25,9 +30,11 @@ describe('LinkedFilesController', function () {
     // ObjectIds, so use well-formed values throughout.
     ctx.projectId = '507f1f77bcf86cd799439011'
     ctx.parentFolderId = '507f191e810c19729de860eb'
-    ctx.provider = 'provider'
+    // must be one of the real, schema-validated provider literals; 'url' is
+    // the simplest shape (a single required `url` field in `data`).
+    ctx.provider = 'url'
     ctx.fileName = 'linked-file-name'
-    ctx.data = { customAgentData: 'foo' }
+    ctx.data = { url: 'https://example.com/foo' }
     ctx.LinkedFilesHandler = {
       promises: {
         getFileById: sinon.stub(),
@@ -140,7 +147,7 @@ describe('LinkedFilesController', function () {
             expect(ctx.Agent.promises.createLinkedFile).to.have.been.calledWith(
               ctx.projectId,
               {
-                customAgentData: 'foo',
+                url: 'https://example.com/foo',
                 provider: ctx.provider,
                 importedAt: ctx.fakeTime.toISOString(),
               },
@@ -154,6 +161,43 @@ describe('LinkedFilesController', function () {
         ctx.LinkedFilesController.createLinkedFile(ctx.req, ctx.res, ctx.next)
       })
     })
+
+    it('rejects a mendeley group_id containing a path separator without calling the agent', async function (ctx) {
+      setReqValidationModeForTests('enforce')
+      ctx.req.body.provider = 'mendeley'
+      ctx.req.body.data = { group_id: 'abcd/../../etc' }
+      await new Promise(resolve => {
+        ctx.next = sinon.stub().callsFake(() => resolve())
+        ctx.res = {
+          json: () => resolve(),
+          sendStatus: () => resolve(),
+        }
+        ctx.LinkedFilesController.createLinkedFile(ctx.req, ctx.res, ctx.next)
+      })
+      expect(ctx.next).to.have.been.calledOnce
+      expect(ctx.next.firstCall.args[0]?.name).to.equal('InvalidRequestError')
+      expect(ctx.Agent.promises.createLinkedFile).to.not.have.been.called
+    })
+
+    it('rejects a project_output_file build_id that is not in the hex-hyphen-hex shape without calling the agent', async function (ctx) {
+      setReqValidationModeForTests('enforce')
+      ctx.req.body.provider = 'project_output_file'
+      ctx.req.body.data = {
+        source_output_file_path: 'output.pdf',
+        build_id: 'not-a-valid-build-id',
+      }
+      await new Promise(resolve => {
+        ctx.next = sinon.stub().callsFake(() => resolve())
+        ctx.res = {
+          json: () => resolve(),
+          sendStatus: () => resolve(),
+        }
+        ctx.LinkedFilesController.createLinkedFile(ctx.req, ctx.res, ctx.next)
+      })
+      expect(ctx.next).to.have.been.calledOnce
+      expect(ctx.next.firstCall.args[0]?.name).to.equal('InvalidRequestError')
+      expect(ctx.Agent.promises.createLinkedFile).to.not.have.been.called
+    })
   })
   describe('refreshLinkedFiles', function () {
     beforeEach(function (ctx) {
@@ -211,6 +255,7 @@ describe('LinkedFilesController', function () {
     })
 
     it('rejects invalid params without calling the agent', async function (ctx) {
+      setReqValidationModeForTests('enforce')
       ctx.req.params.file_id = 'not-an-object-id'
       await new Promise(resolve => {
         ctx.next = sinon.stub().callsFake(() => resolve())
diff --git a/services/web/test/unit/src/PasswordReset/PasswordResetController.test.mjs b/services/web/test/unit/src/PasswordReset/PasswordResetController.test.mjs
index e8db5c0af4..0645872447 100644
--- a/services/web/test/unit/src/PasswordReset/PasswordResetController.test.mjs
+++ b/services/web/test/unit/src/PasswordReset/PasswordResetController.test.mjs
@@ -121,6 +121,10 @@ describe('PasswordResetController', function () {
   })
 
   describe('requestReset', function () {
+    beforeEach(function (ctx) {
+      ctx.req.body = { email: ctx.req.body.email }
+    })
+
     it('should tell the handler to process that email', async function (ctx) {
       ctx.PasswordResetHandler.promises.generateAndEmailResetToken.resolves(
         'primary'
diff --git a/services/web/test/unit/src/ServerAdmin/AdminController.test.mjs b/services/web/test/unit/src/ServerAdmin/AdminController.test.mjs
new file mode 100644
index 0000000000..5edff686e4
--- /dev/null
+++ b/services/web/test/unit/src/ServerAdmin/AdminController.test.mjs
@@ -0,0 +1,177 @@
+import { beforeEach, describe, it, vi } from 'vitest'
+import sinon from 'sinon'
+import MockRequest from '../helpers/MockRequest.mjs'
+import MockResponse from '../helpers/MockResponse.mjs'
+
+const modulePath =
+  '../../../../app/src/Features/ServerAdmin/AdminController.mjs'
+
+describe('AdminController', function () {
+  beforeEach(async function (ctx) {
+    ctx.Settings = {}
+    ctx.TpdsUpdateSender = { pollDropboxForUser: sinon.stub() }
+    ctx.TpdsProjectFlusher = { flushProjectToTpds: sinon.stub() }
+    ctx.EditorRealTimeController = { emitToAll: sinon.stub() }
+    ctx.SystemMessageManager = {
+      createMessage: sinon.stub(),
+      clearMessages: sinon.stub(),
+      promises: {
+        getMessagesFromDB: sinon.stub().resolves([]),
+      },
+    }
+    ctx.ProjectGetter = {
+      promises: { findAllDebugProjects: sinon.stub().resolves([]) },
+    }
+    ctx.Modules = {
+      promises: { hooks: { fire: sinon.stub().resolves([null]) } },
+    }
+    ctx.Features = { hasFeature: sinon.stub().returns(false) }
+
+    vi.doMock('@overleaf/settings', () => ({ default: ctx.Settings }))
+    vi.doMock(
+      '../../../../app/src/Features/ThirdPartyDataStore/TpdsUpdateSender',
+      () => ({ default: ctx.TpdsUpdateSender })
+    )
+    vi.doMock(
+      '../../../../app/src/Features/ThirdPartyDataStore/TpdsProjectFlusher',
+      () => ({ default: ctx.TpdsProjectFlusher })
+    )
+    vi.doMock(
+      '../../../../app/src/Features/Editor/EditorRealTimeController',
+      () => ({ default: ctx.EditorRealTimeController })
+    )
+    vi.doMock(
+      '../../../../app/src/Features/SystemMessages/SystemMessageManager',
+      () => ({ default: ctx.SystemMessageManager })
+    )
+    vi.doMock('../../../../app/src/Features/Project/ProjectGetter', () => ({
+      default: ctx.ProjectGetter,
+    }))
+    vi.doMock('../../../../app/src/infrastructure/Modules', () => ({
+      default: ctx.Modules,
+    }))
+    vi.doMock('../../../../app/src/infrastructure/Features', () => ({
+      default: ctx.Features,
+    }))
+
+    ctx.controller = (await import(modulePath)).default
+    ctx.req = new MockRequest(vi)
+    ctx.res = new MockResponse(vi)
+    ctx.res.redirect = sinon.stub()
+    ctx.res.sendStatus = sinon.stub()
+    ctx.res.render = sinon.stub()
+    ctx.next = sinon.stub()
+  })
+
+  describe('index', function () {
+    it('should render the admin page', async function (ctx) {
+      await ctx.controller.index(ctx.req, ctx.res, ctx.next)
+      ctx.res.render.calledWith('admin/index').should.equal(true)
+    })
+
+    it('should include debug projects when saas is enabled', async function (ctx) {
+      ctx.Features.hasFeature.returns(true)
+      await ctx.controller.index(ctx.req, ctx.res, ctx.next)
+      ctx.ProjectGetter.promises.findAllDebugProjects.called.should.equal(true)
+      ctx.res.render
+        .calledWithMatch('admin/index', {
+          debugProjects: [],
+        })
+        .should.equal(true)
+    })
+  })
+
+  describe('disconnectAllUsers', function () {
+    it('should use the default delay when none is given', function (ctx) {
+      ctx.req.query = {}
+      ctx.controller.disconnectAllUsers(ctx.req, ctx.res)
+      ctx.EditorRealTimeController.emitToAll
+        .calledWith('forceDisconnect', sinon.match.string, 10)
+        .should.equal(true)
+      ctx.res.redirect.calledWith('/admin#open-close-editor').should.equal(true)
+    })
+
+    it('should use the given delay', function (ctx) {
+      ctx.req.query = { delay: '5000' }
+      ctx.controller.disconnectAllUsers(ctx.req, ctx.res)
+      ctx.EditorRealTimeController.emitToAll
+        .calledWith('forceDisconnect', sinon.match.string, 5000)
+        .should.equal(true)
+    })
+  })
+
+  describe('openEditor', function () {
+    it('should open the editor and redirect', function (ctx) {
+      ctx.controller.openEditor(ctx.req, ctx.res)
+      ctx.Settings.editorIsOpen.should.equal(true)
+      ctx.res.redirect.calledWith('/admin#open-close-editor').should.equal(true)
+    })
+  })
+
+  describe('closeEditor', function () {
+    it('should close the editor and redirect', function (ctx) {
+      ctx.req.body = {}
+      ctx.controller.closeEditor(ctx.req, ctx.res)
+      Boolean(ctx.Settings.editorIsOpen).should.equal(false)
+      ctx.res.redirect.calledWith('/admin#open-close-editor').should.equal(true)
+    })
+  })
+
+  describe('flushProjectToTpds', function () {
+    beforeEach(function (ctx) {
+      // project_id is validated as a Mongo ObjectId
+      ctx.projectId = '507f191e810c19729de860ea'
+      ctx.req.body = { project_id: ctx.projectId }
+    })
+
+    it('should flush the project and return 200', function (ctx) {
+      ctx.TpdsProjectFlusher.flushProjectToTpds.callsFake((id, cb) => cb())
+      ctx.controller.flushProjectToTpds(ctx.req, ctx.res, ctx.next)
+      ctx.TpdsProjectFlusher.flushProjectToTpds
+        .calledWith(ctx.projectId)
+        .should.equal(true)
+      ctx.res.sendStatus.calledWith(200).should.equal(true)
+    })
+
+    it('should call next with an error on failure', function (ctx) {
+      const error = new Error('failed')
+      ctx.TpdsProjectFlusher.flushProjectToTpds.callsFake((id, cb) => cb(error))
+      ctx.controller.flushProjectToTpds(ctx.req, ctx.res, ctx.next)
+      ctx.next.calledWith(error).should.equal(true)
+    })
+  })
+
+  describe('pollDropboxForUser', function () {
+    it('should poll dropbox for the user', function (ctx) {
+      // user_id is validated as a Mongo ObjectId
+      ctx.userId = '507f191e810c19729de860eb'
+      ctx.req.body = { user_id: ctx.userId }
+      ctx.TpdsUpdateSender.pollDropboxForUser.callsFake((id, cb) => cb())
+      ctx.controller.pollDropboxForUser(ctx.req, ctx.res)
+      ctx.TpdsUpdateSender.pollDropboxForUser
+        .calledWith(ctx.userId)
+        .should.equal(true)
+      ctx.res.sendStatus.calledWith(200).should.equal(true)
+    })
+  })
+
+  describe('createMessage', function () {
+    it('should create the message and redirect', function (ctx) {
+      ctx.req.body = { content: 'a system message' }
+      ctx.SystemMessageManager.createMessage.callsFake((content, cb) => cb())
+      ctx.controller.createMessage(ctx.req, ctx.res, ctx.next)
+      ctx.SystemMessageManager.createMessage
+        .calledWith('a system message')
+        .should.equal(true)
+      ctx.res.redirect.calledWith('/admin#system-messages').should.equal(true)
+    })
+  })
+
+  describe('clearMessages', function () {
+    it('should clear messages and redirect', function (ctx) {
+      ctx.SystemMessageManager.clearMessages.callsFake(cb => cb())
+      ctx.controller.clearMessages(ctx.req, ctx.res, ctx.next)
+      ctx.res.redirect.calledWith('/admin#system-messages').should.equal(true)
+    })
+  })
+})
diff --git a/services/web/test/unit/src/SplitTests/SplitTestHandler.test.mjs b/services/web/test/unit/src/SplitTests/SplitTestHandler.test.mjs
index c974020ed9..a91eb9bf6c 100644
--- a/services/web/test/unit/src/SplitTests/SplitTestHandler.test.mjs
+++ b/services/web/test/unit/src/SplitTests/SplitTestHandler.test.mjs
@@ -543,6 +543,57 @@ describe('SplitTestHandler', function () {
     })
   })
 
+  describe('malformed query override values', function () {
+    describe('getAssignment', function () {
+      beforeEach(function (ctx) {
+        ctx.AnalyticsManager.getIdsFromSession.returns({
+          userId: 'abc123abc123',
+        })
+        ctx.req.query = { 'active-test': { nested: 'oops' } }
+      })
+
+      it('falls through to the computed assignment', async function (ctx) {
+        const { variant } = await ctx.SplitTestHandler.promises.getAssignment(
+          ctx.req,
+          ctx.res,
+          'active-test'
+        )
+        expect(variant).to.equal('variant-1')
+      })
+    })
+
+    describe('hasUserBeenAssignedToVariant', function () {
+      beforeEach(function (ctx) {
+        ctx.user = {
+          _id: new ObjectId(),
+          analyticsId: 'analytics-id',
+          splitTests: {
+            'active-test': [
+              {
+                variantName: 'variant-1',
+                versionNumber: 2,
+                assignedAt: 'active-test-assigned-at',
+              },
+            ],
+          },
+        }
+        ctx.SplitTestUserGetter.promises.getUser.resolves(ctx.user)
+        ctx.req.query = { 'active-test': { nested: 'oops' } }
+      })
+
+      it('still resolves the recorded assignment', async function (ctx) {
+        const assigned =
+          await ctx.SplitTestHandler.promises.hasUserBeenAssignedToVariant(
+            ctx.req,
+            ctx.user._id,
+            'active-test',
+            'variant-1'
+          )
+        expect(assigned).to.be.true
+      })
+    })
+  })
+
   describe('variant user limits', function () {
     beforeEach(function (ctx) {
       ctx.AnalyticsManager.getIdsFromSession.returns({
diff --git a/services/web/test/unit/src/TokenAccess/TokenAccessController.test.mjs b/services/web/test/unit/src/TokenAccess/TokenAccessController.test.mjs
index 22367c02dc..1d4d55a79d 100644
--- a/services/web/test/unit/src/TokenAccess/TokenAccessController.test.mjs
+++ b/services/web/test/unit/src/TokenAccess/TokenAccessController.test.mjs
@@ -1,6 +1,11 @@
-import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import sinon from 'sinon'
 import mongodb from 'mongodb-legacy'
+import {
+  InvalidParamsError,
+  InvalidRequestError,
+  setReqValidationModeForTests,
+} from '@overleaf/validation-tools'
 import MockRequest from '../helpers/MockRequest.mjs'
 import MockResponse from '../helpers/MockResponse.mjs'
 import PrivilegeLevels from '../../../../app/src/Features/Authorization/PrivilegeLevels.mjs'
@@ -277,6 +282,10 @@ describe('TokenAccessController', function () {
     ctx.TokenAccessController = (await import(MODULE_PATH)).default
   })
 
+  afterEach(function () {
+    setReqValidationModeForTests(null)
+  })
+
   describe('grantTokenAccessReadAndWrite', function () {
     beforeEach(function (ctx) {
       ctx.LimitationsManager.promises.canAcceptEditCollaboratorInvite.resolves(
@@ -1029,7 +1038,7 @@ describe('TokenAccessController', function () {
 
   describe('ensureUserCanUseSharingUpdatesConsentPage', function () {
     beforeEach(function (ctx) {
-      ctx.req.params = { Project_id: ctx.project._id }
+      ctx.req.params = { Project_id: ctx.project._id.toString() }
     })
 
     describe('when not in link sharing changes test', function () {
@@ -1082,10 +1091,10 @@ describe('TokenAccessController', function () {
           expect(
             ctx.CollaboratorsGetter.promises
               .isUserInvitedReadWriteMemberOfProject
-          ).to.have.been.calledWith(ctx.user._id, ctx.project._id)
+          ).to.have.been.calledWith(ctx.user._id, ctx.project._id.toString())
           expect(
             ctx.CollaboratorsGetter.promises.userIsReadWriteTokenMember
-          ).to.have.been.calledWith(ctx.user._id, ctx.project._id)
+          ).to.have.been.calledWith(ctx.user._id, ctx.project._id.toString())
           expect(ctx.next).to.have.been.calledOnce
           expect(ctx.next.firstCall.args[0]).to.not.exist
         })
@@ -1147,7 +1156,7 @@ describe('TokenAccessController', function () {
 
   describe('moveReadWriteToCollaborators', function () {
     beforeEach(function (ctx) {
-      ctx.req.params = { Project_id: ctx.project._id }
+      ctx.req.params = { Project_id: ctx.project._id.toString() }
     })
 
     describe('when there are collaborator slots available', function () {
@@ -1175,11 +1184,11 @@ describe('TokenAccessController', function () {
         it('sets the privilege level to read and write for the invited viewer', function (ctx) {
           expect(
             ctx.TokenAccessHandler.promises.removeReadAndWriteUserFromProject
-          ).to.have.been.calledWith(ctx.user._id, ctx.project._id)
+          ).to.have.been.calledWith(ctx.user._id, ctx.project._id.toString())
           expect(
             ctx.CollaboratorsHandler.promises.addUserIdToProject
           ).to.have.been.calledWith(
-            ctx.project._id,
+            ctx.project._id.toString(),
             undefined,
             ctx.user._id,
             PrivilegeLevels.READ_AND_WRITE
@@ -1214,11 +1223,11 @@ describe('TokenAccessController', function () {
         it('sets the privilege level to read only for the invited viewer (pendingEditor)', function (ctx) {
           expect(
             ctx.TokenAccessHandler.promises.removeReadAndWriteUserFromProject
-          ).to.have.been.calledWith(ctx.user._id, ctx.project._id)
+          ).to.have.been.calledWith(ctx.user._id, ctx.project._id.toString())
           expect(
             ctx.CollaboratorsHandler.promises.addUserIdToProject
           ).to.have.been.calledWith(
-            ctx.project._id,
+            ctx.project._id.toString(),
             undefined,
             ctx.user._id,
             PrivilegeLevels.READ_ONLY,
@@ -1232,7 +1241,7 @@ describe('TokenAccessController', function () {
 
   describe('moveReadWriteToReadOnly', function () {
     beforeEach(function (ctx) {
-      ctx.req.params = { Project_id: ctx.project._id }
+      ctx.req.params = { Project_id: ctx.project._id.toString() }
     })
 
     describe('previously joined token access user moving to anonymous viewer', function () {
@@ -1250,7 +1259,7 @@ describe('TokenAccessController', function () {
       it('removes them from read write token access refs and adds them to read only token access refs', function (ctx) {
         expect(
           ctx.TokenAccessHandler.promises.moveReadAndWriteUserToReadOnly
-        ).to.have.been.calledWith(ctx.user._id, ctx.project._id)
+        ).to.have.been.calledWith(ctx.user._id, ctx.project._id.toString())
         expect(ctx.res.sendStatus).toHaveBeenCalledWith(204)
       })
 
@@ -1258,7 +1267,7 @@ describe('TokenAccessController', function () {
         expect(
           ctx.ProjectAuditLogHandler.promises.addEntry
         ).to.have.been.calledWith(
-          ctx.project._id,
+          ctx.project._id.toString(),
           'readonly-via-sharing-updates',
           ctx.user._id,
           ctx.req.ip
@@ -1266,4 +1275,96 @@ describe('TokenAccessController', function () {
       })
     })
   })
+
+  describe('request validation', function () {
+    beforeEach(function () {
+      setReqValidationModeForTests('enforce')
+    })
+
+    it('rejects a grant read-and-write request body with an unrecognized field', async function (ctx) {
+      ctx.req.params = { token: ctx.token }
+      ctx.req.body = { confirmedByUser: true, extraField: 'nope' }
+      await new Promise(resolve => {
+        ctx.TokenAccessController.grantTokenAccessReadAndWrite(
+          ctx.req,
+          ctx.res,
+          err => {
+            expect(err).to.be.instanceof(InvalidRequestError)
+            resolve()
+          }
+        )
+      })
+    })
+
+    it('rejects a grant read-only request body with an unrecognized field', async function (ctx) {
+      ctx.req.params = { token: ctx.token }
+      ctx.req.body = { confirmedByUser: true, extraField: 'nope' }
+      await new Promise(resolve => {
+        ctx.TokenAccessController.grantTokenAccessReadOnly(
+          ctx.req,
+          ctx.res,
+          err => {
+            expect(err).to.be.instanceof(InvalidRequestError)
+            resolve()
+          }
+        )
+      })
+    })
+
+    it('rejects a malformed Project_id when checking sharing-updates consent eligibility', async function (ctx) {
+      ctx.req.params = { Project_id: 'not-an-object-id' }
+      await new Promise(resolve => {
+        ctx.TokenAccessController.ensureUserCanUseSharingUpdatesConsentPage(
+          ctx.req,
+          ctx.res,
+          err => {
+            expect(err).to.be.instanceof(InvalidParamsError)
+            resolve()
+          }
+        )
+      })
+    })
+
+    it('rejects a malformed Project_id on the sharing-updates consent page', async function (ctx) {
+      ctx.req.params = { Project_id: 'not-an-object-id' }
+      await new Promise(resolve => {
+        ctx.TokenAccessController.sharingUpdatesConsent(
+          ctx.req,
+          ctx.res,
+          err => {
+            expect(err).to.be.instanceof(InvalidParamsError)
+            resolve()
+          }
+        )
+      })
+    })
+
+    it('rejects a malformed Project_id when moving to collaborators', async function (ctx) {
+      ctx.req.params = { Project_id: 'not-an-object-id' }
+      await new Promise(resolve => {
+        ctx.TokenAccessController.moveReadWriteToCollaborators(
+          ctx.req,
+          ctx.res,
+          err => {
+            expect(err).to.be.instanceof(InvalidParamsError)
+            resolve()
+          }
+        )
+      })
+    })
+
+    it('rejects a malformed Project_id when moving to read-only', async function (ctx) {
+      ctx.req.params = { Project_id: 'not-an-object-id' }
+      await new Promise(resolve => {
+        ctx.TokenAccessController.moveReadWriteToReadOnly(
+          ctx.req,
+          ctx.res,
+          err => {
+            expect(err).to.be.instanceof(InvalidParamsError)
+            resolve()
+          }
+        )
+      })
+    })
+  })
 })
diff --git a/yarn.lock b/yarn.lock
index 2e46c284af..1270c18561 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -26527,7 +26527,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"passport-local@npm:^1.0.0":
+"passport-local@npm:1.0.0":
   version: 1.0.0
   resolution: "passport-local@npm:1.0.0"
   dependencies:
@@ -26536,6 +26536,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"passport-local@patch:passport-local@npm%3A1.0.0#~/.yarn/patches/passport-local-npm-1.0.0-ed89961a0c.patch":
+  version: 1.0.0
+  resolution: "passport-local@patch:passport-local@npm%3A1.0.0#~/.yarn/patches/passport-local-npm-1.0.0-ed89961a0c.patch::version=1.0.0&hash=35e215"
+  dependencies:
+    passport-strategy: "npm:1.x.x"
+  checksum: 10c0/9b8275673fb4f0edb31a82553c9901413c857669dd9e75df26de0958ab3760391ae762fa7596cd28956510b45cb37c05eb8c95f07c75e8fe6e07a77b9a89e988
+  languageName: node
+  linkType: hard
+
 "passport-oauth2@npm:1.6.1":
   version: 1.6.1
   resolution: "passport-oauth2@npm:1.6.1"