diff --git a/libraries/overleaf-editor-core/lib/schemas.js b/libraries/overleaf-editor-core/lib/schemas.js
index c6912d9c6c..765312aa1d 100644
--- a/libraries/overleaf-editor-core/lib/schemas.js
+++ b/libraries/overleaf-editor-core/lib/schemas.js
@@ -38,7 +38,7 @@ const rawRetainOp = z.union([
 const rawScanOp = z.union([rawInsertOp, rawRemoveOp, rawRetainOp])
 
 const rawTextOperation = z.strictObject({
-  textOperation: z.array(rawScanOp).min(1),
+  textOperation: z.array(rawScanOp),
   contentHash: z.string().optional(),
 })
 
@@ -151,19 +151,27 @@ const rawBlobHash = z.string().regex(/^[0-9a-f]{40}$/, {
   message: 'invalid blob hash',
 })
 
-// file metadata is the linked-file metadata written by web, the main-file
-// marker written by the v1 history import, regular file with importedAt,
-// or an empty object (metadata cleared)
 const rawFileMetadata = z.union([
+  // doc/clear metadata
+  z.strictObject({}),
+  // regular file v2
+  z.strictObject({
+    importedAt: z.iso.datetime(),
+  }),
+  // linked-file v2
   rawLinkedFileData,
+
+  // main-file v1
   z.strictObject({
     main: z.boolean(),
     importedAt: z.iso.datetime().optional(),
   }),
+  // url import v1
   z.strictObject({
-    importedAt: z.iso.datetime(),
+    agent: z.literal('url'),
+    agentDataId: z.number(),
+    importedAt: z.iso.datetime().optional(),
   }),
-  z.strictObject({}),
 ])
 
 const rawHashFileData = z.strictObject({
diff --git a/libraries/overleaf-editor-core/test/unit/schemas.test.js b/libraries/overleaf-editor-core/test/unit/schemas.test.js
index 4936e0a33f..94f8a9fbb6 100644
--- a/libraries/overleaf-editor-core/test/unit/schemas.test.js
+++ b/libraries/overleaf-editor-core/test/unit/schemas.test.js
@@ -3,9 +3,19 @@ const {
   rawLinkedFileData,
   rawFileMetadata,
   rawRetainOp,
+  rawTextOperation,
 } = require('../../lib/schemas')
 
 describe('schemas', function () {
+  describe('rawTextOperation', function () {
+    it('accepts a no-op TextOperation', function () {
+      const result = rawTextOperation.safeParse({
+        textOperation: [],
+      })
+      expect(result.success).to.equal(true)
+    })
+  })
+
   describe('rawRetainOp', function () {
     it('accepts a bare retain length', function () {
       const result = rawRetainOp.safeParse(5)
@@ -203,6 +213,14 @@ describe('schemas', function () {
       expect(result.success).to.equal(true)
     })
 
+    it('accepts a legacy v1 url import', function () {
+      const result = rawFileMetadata.safeParse({
+        agent: 'url',
+        agentDataId: 42,
+      })
+      expect(result.success).to.equal(true)
+    })
+
     it('accepts a legacy v1 main flag with an importedAt timestamp', function () {
       const result = rawFileMetadata.safeParse({
         main: true,