diff --git a/services/track-changes/app.coffee b/services/track-changes/app.coffee
index 68e11cc486..c8c0be3c56 100644
--- a/services/track-changes/app.coffee
+++ b/services/track-changes/app.coffee
@@ -12,6 +12,8 @@ app.use express.logger()
 
 app.post "/doc/:doc_id/flush", HttpController.flushUpdatesWithLock
 
+app.get "/project/:project_id/doc/:doc_id/diff", HttpController.getDiff
+
 app.get "/status", (req, res, next) ->
 	res.send "track-changes is alive"
 
diff --git a/services/track-changes/app/coffee/DiffManager.coffee b/services/track-changes/app/coffee/DiffManager.coffee
index 4c45661aa3..eddb461c53 100644
--- a/services/track-changes/app/coffee/DiffManager.coffee
+++ b/services/track-changes/app/coffee/DiffManager.coffee
@@ -2,6 +2,7 @@ HistoryManager = require "./HistoryManager"
 DocumentUpdaterManager = require "./DocumentUpdaterManager"
 MongoManager = require "./MongoManager"
 DiffGenerator = require "./DiffGenerator"
+logger = require "logger-sharelatex"
 
 module.exports = DiffManager =
 	getLatestDocAndUpdates: (project_id, doc_id, fromDate, toDate, callback = (error, lines, version, updates) ->) ->
@@ -14,20 +15,26 @@ module.exports = DiffManager =
 					callback(null, lines, version, updates)
 	
 	getDiff: (project_id, doc_id, fromDate, toDate, callback = (error, diff) ->) ->
+		logger.log project_id: project_id, doc_id: doc_id, from: fromDate, to: toDate, "getting diff"
 		DiffManager.getLatestDocAndUpdates project_id, doc_id, fromDate, null, (error, lines, version, updates) ->
 			return callback(error) if error?
-			lastUpdate = updates[updates.length - 1]
+
+			logger.log lines: lines, version: version, updates: updates, "got doc and updates"
+
+			lastUpdate = updates[0]
 			if lastUpdate? and lastUpdate.v != version
 				return callback new Error("latest update version, #{lastUpdate.v}, does not match doc version, #{version}")
-			
 
 			updatesToApply = []
-			for update in updates
-				if update.meta.end_ts <= toDate
+			for update in updates.reverse()
+				if update.meta.start_ts <= toDate
 					updatesToApply.push update
 
+			logger.log project_id: project_id, doc_id: doc_id, updatesToApply: updatesToApply, "got updates to apply"
+
 			try
 				startingContent = DiffGenerator.rewindUpdates lines.join("\n"), updates
+				logger.log project_id: project_id, doc_id: doc_id, startingContent: startingContent, "rewound doc"
 				diff = DiffGenerator.buildDiff startingContent, updatesToApply
 			catch e
 				return callback(e)
diff --git a/services/track-changes/app/coffee/HttpController.coffee b/services/track-changes/app/coffee/HttpController.coffee
index 1fd1926317..5b742e8891 100644
--- a/services/track-changes/app/coffee/HttpController.coffee
+++ b/services/track-changes/app/coffee/HttpController.coffee
@@ -1,4 +1,5 @@
 HistoryManager = require "./HistoryManager"
+DiffManager = require "./DiffManager"
 logger = require "logger-sharelatex"
 
 module.exports = HttpController =
@@ -7,5 +8,23 @@ module.exports = HttpController =
 		logger.log doc_id: doc_id, "compressing doc history"
 		HistoryManager.processUncompressedUpdatesWithLock doc_id, (error) ->
 			return next(error) if error?
-			logger.log "done http request"
 			res.send 204
+
+	getDiff: (req, res, next = (error) ->) ->
+		doc_id = req.params.doc_id
+		project_id = req.params.project_id
+
+		if req.query.from?
+			from = parseInt(req.query.from, 10)
+		else
+			from = null
+		if req.query.to?
+			to = parseInt(req.query.to, 10)
+		else
+			to = null
+
+		logger.log project_id, doc_id: doc_id, from: from, to: to, "getting diff"
+		DiffManager.getDiff project_id, doc_id, from, to, (error, diff) ->
+			return next(error) if error?
+			res.send JSON.stringify(diff: diff)
+
diff --git a/services/track-changes/config/settings.development.coffee b/services/track-changes/config/settings.development.coffee
index 56d0a90eb8..d3cf2978ec 100755
--- a/services/track-changes/config/settings.development.coffee
+++ b/services/track-changes/config/settings.development.coffee
@@ -5,3 +5,6 @@ module.exports =
 		trackchanges:
 			port: 3015
 			host: "localhost"
+	apis:
+		documentupdater:
+			url: "http://localhost:3003"
diff --git a/services/track-changes/test/acceptance/coffee/AppendingUpdatesTests.coffee b/services/track-changes/test/acceptance/coffee/AppendingUpdatesTests.coffee
index 31c4a012eb..031659f24b 100644
--- a/services/track-changes/test/acceptance/coffee/AppendingUpdatesTests.coffee
+++ b/services/track-changes/test/acceptance/coffee/AppendingUpdatesTests.coffee
@@ -3,31 +3,19 @@ chai = require("chai")
 chai.should()
 expect = chai.expect
 mongojs = require "../../../app/js/mongojs"
-db = mongojs.db
 ObjectId = mongojs.ObjectId
 Settings = require "settings-sharelatex"
 request = require "request"
 rclient = require("redis").createClient() # Only works locally for now
 
-flushAndGetCompressedUpdates = (doc_id, callback = (error, updates) ->) ->
-	request.post {
-		url: "http://localhost:3015/doc/#{doc_id}/flush"
-	}, (error, response, body) =>
-		response.statusCode.should.equal 204
-		db.docHistory
-			.find(doc_id: ObjectId(doc_id))
-			.sort("meta.end_ts": 1)
-			.toArray callback
-
-pushRawUpdates = (doc_id, updates, callback = (error) ->) ->
-	rclient.rpush "UncompressedHistoryOps:#{doc_id}", (JSON.stringify(u) for u in updates)..., callback
+TrackChangesClient = require "./helpers/TrackChangesClient"
 
 describe "Appending doc ops to the history", ->
 	describe "when the history does not exist yet", ->
 		before (done) ->
 			@doc_id = ObjectId().toString()
 			@user_id = ObjectId().toString()
-			pushRawUpdates @doc_id, [{
+			TrackChangesClient.pushRawUpdates @doc_id, [{
 				op: [{ i: "f", p: 3 }]
 				meta: { ts: Date.now(), user_id: @user_id }
 				v: 3
@@ -41,7 +29,7 @@ describe "Appending doc ops to the history", ->
 				v: 5
 			}], (error) =>
 				throw error if error?
-				flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
+				TrackChangesClient.flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
 					throw error if error?
 					done()
 
@@ -57,7 +45,7 @@ describe "Appending doc ops to the history", ->
 		beforeEach (done) ->
 			@doc_id = ObjectId().toString()
 			@user_id = ObjectId().toString()
-			pushRawUpdates @doc_id, [{
+			TrackChangesClient.pushRawUpdates @doc_id, [{
 				op: [{ i: "f", p: 3 }]
 				meta: { ts: Date.now(), user_id: @user_id }
 				v: 3
@@ -71,13 +59,13 @@ describe "Appending doc ops to the history", ->
 				v: 5
 			}], (error) =>
 				throw error if error?
-				flushAndGetCompressedUpdates @doc_id, (error, updates) =>
+				TrackChangesClient.flushAndGetCompressedUpdates @doc_id, (error, updates) =>
 					throw error if error?
 					done()
 
 		describe "when the updates are recent and from the same user", ->
 			beforeEach (done) ->
-				pushRawUpdates @doc_id, [{
+				TrackChangesClient.pushRawUpdates @doc_id, [{
 					op: [{ i: "b", p: 6 }]
 					meta: { ts: Date.now(), user_id: @user_id }
 					v: 6
@@ -91,7 +79,7 @@ describe "Appending doc ops to the history", ->
 					v: 8
 				}], (error) =>
 					throw error if error?
-					flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
+					TrackChangesClient.flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
 						throw error if error?
 						done()
 
@@ -107,7 +95,7 @@ describe "Appending doc ops to the history", ->
 		describe "when the updates are far apart", ->
 			beforeEach (done) ->
 				oneDay = 24 * 60 * 60 * 1000
-				pushRawUpdates @doc_id, [{
+				TrackChangesClient.pushRawUpdates @doc_id, [{
 					op: [{ i: "b", p: 6 }]
 					meta: { ts: Date.now() + oneDay, user_id: @user_id }
 					v: 6
@@ -121,7 +109,7 @@ describe "Appending doc ops to the history", ->
 					v: 8
 				}], (error) =>
 					throw error if error?
-					flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
+					TrackChangesClient.flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
 						throw error if error?
 						done()
 
@@ -147,9 +135,9 @@ describe "Appending doc ops to the history", ->
 				}
 				@expectedOp.i = "a" + @expectedOp.i
 
-			pushRawUpdates @doc_id, updates, (error) =>
+			TrackChangesClient.pushRawUpdates @doc_id, updates, (error) =>
 				throw error if error?
-				flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
+				TrackChangesClient.flushAndGetCompressedUpdates @doc_id, (error, @updates) =>
 					throw error if error?
 					done()
 
diff --git a/services/track-changes/test/acceptance/coffee/GettingADiffTests.coffee b/services/track-changes/test/acceptance/coffee/GettingADiffTests.coffee
new file mode 100644
index 0000000000..02d83f0044
--- /dev/null
+++ b/services/track-changes/test/acceptance/coffee/GettingADiffTests.coffee
@@ -0,0 +1,70 @@
+sinon = require "sinon"
+chai = require("chai")
+chai.should()
+expect = chai.expect
+mongojs = require "../../../app/js/mongojs"
+db = mongojs.db
+ObjectId = mongojs.ObjectId
+Settings = require "settings-sharelatex"
+
+TrackChangesClient = require "./helpers/TrackChangesClient"
+MockDocUpdaterApi = require "./helpers/MockDocUpdaterApi"
+
+describe "Getting a diff", ->
+	before (done) ->
+		sinon.spy MockDocUpdaterApi, "getDoc"
+
+		@now = Date.now()
+		@from = @now - 100000000
+		@to = @now
+		@user_id = ObjectId().toString()
+		@doc_id = ObjectId().toString()
+		@project_id = ObjectId().toString()
+
+		twoMinutes = 2 * 60 * 1000
+
+		@updates = [{
+			op: [{ i: "one ", p: 0 }]
+			meta: { ts: @from - twoMinutes, user_id: @user_id }
+			v: 3
+		}, {
+			op: [{ i: "two ", p: 4 }]
+			meta: { ts: @from + twoMinutes, user_id: @user_id }
+			v: 4
+		}, {
+			op: [{ i: "three ", p: 8 }]
+			meta: { ts: @to - twoMinutes, user_id: @user_id }
+			v: 5
+		}, {
+			op: [{ i: "four", p: 14 }]
+			meta: { ts: @to + twoMinutes, user_id: @user_id }
+			v: 6
+		}]
+		@lines = ["one two three four"]
+		@expected_diff = [
+			{ u: "one " }
+			{ i: "two ", meta: { start_ts: @from + twoMinutes, end_ts: @from + twoMinutes, user_id: @user_id } }
+			{ i: "three ", meta: { start_ts: @to - twoMinutes, end_ts: @to - twoMinutes, user_id: @user_id } }
+		]
+
+		MockDocUpdaterApi.docs[@doc_id] =
+			lines: @lines
+			version: 6
+
+		TrackChangesClient.pushRawUpdates @doc_id, @updates, (error) =>
+			throw error if error?
+			TrackChangesClient.getDiff @project_id, @doc_id, @from, @to, (error, diff) =>
+				throw error if error?
+				@diff = diff.diff
+				done()
+
+	after () ->
+		MockDocUpdaterApi.getDoc.restore()
+
+	it "should return the diff", ->
+		expect(@diff).to.deep.equal @expected_diff
+
+	it "should get the doc from the doc updater", ->
+		MockDocUpdaterApi.getDoc
+			.calledWith(@project_id, @doc_id)
+			.should.equal true
diff --git a/services/track-changes/test/acceptance/coffee/helpers/MockDocUpdaterApi.coffee b/services/track-changes/test/acceptance/coffee/helpers/MockDocUpdaterApi.coffee
new file mode 100644
index 0000000000..a64098503c
--- /dev/null
+++ b/services/track-changes/test/acceptance/coffee/helpers/MockDocUpdaterApi.coffee
@@ -0,0 +1,24 @@
+express = require("express")
+app = express()
+
+module.exports = MockDocUpdaterApi =
+	docs: {}
+
+	getDoc: (project_id, doc_id, callback = (error) ->) ->
+		callback null, @docs[doc_id]
+
+	run: () ->
+		app.get "/project/:project_id/doc/:doc_id", (req, res, next) =>
+			@getDoc req.params.project_id, req.params.doc_id, (error, doc) ->
+				if error?
+					res.send 500
+				if !doc?
+					res.send 404
+				else
+					res.send JSON.stringify doc
+
+		app.listen 3003, (error) ->
+			throw error if error?
+
+MockDocUpdaterApi.run()
+
diff --git a/services/track-changes/test/acceptance/coffee/helpers/TrackChangesClient.coffee b/services/track-changes/test/acceptance/coffee/helpers/TrackChangesClient.coffee
new file mode 100644
index 0000000000..52a5552dd6
--- /dev/null
+++ b/services/track-changes/test/acceptance/coffee/helpers/TrackChangesClient.coffee
@@ -0,0 +1,24 @@
+request = require "request"
+rclient = require("redis").createClient() # Only works locally for now
+{db, ObjectId} = require "../../../../app/js/mongojs"
+
+module.exports = TrackChangesClient =
+	flushAndGetCompressedUpdates: (doc_id, callback = (error, updates) ->) ->
+		request.post {
+			url: "http://localhost:3015/doc/#{doc_id}/flush"
+		}, (error, response, body) =>
+			response.statusCode.should.equal 204
+			db.docHistory
+				.find(doc_id: ObjectId(doc_id))
+				.sort("meta.end_ts": 1)
+				.toArray callback
+
+	pushRawUpdates: (doc_id, updates, callback = (error) ->) ->
+		rclient.rpush "UncompressedHistoryOps:#{doc_id}", (JSON.stringify(u) for u in updates)..., callback
+
+	getDiff: (project_id, doc_id, from, to, callback = (error, diff) ->) ->
+		request.get {
+			url: "http://localhost:3015/project/#{project_id}/doc/#{doc_id}/diff?from=#{from}&to=#{to}"
+		}, (error, response, body) =>
+			response.statusCode.should.equal 200
+			callback null, JSON.parse(body)
\ No newline at end of file
diff --git a/services/track-changes/test/unit/coffee/DiffManager/DiffManagerTests.coffee b/services/track-changes/test/unit/coffee/DiffManager/DiffManagerTests.coffee
index 332a73120d..391ad138cb 100644
--- a/services/track-changes/test/unit/coffee/DiffManager/DiffManagerTests.coffee
+++ b/services/track-changes/test/unit/coffee/DiffManager/DiffManagerTests.coffee
@@ -53,10 +53,12 @@ describe "DiffManager", ->
 			@lines = [ "hello", "world" ]
 			@version = 42
 			@updates = [
-				{ op: "mock-1", v: 41, meta: { end_ts: new Date(@to.getTime() - 10)} }
-				{ op: "mock-2", v: 42, meta: { end_ts: new Date(@to.getTime() + 10)} }
+				{ op: "mock-4", v: 42, meta: { start_ts: new Date(@to.getTime() + 20)} }
+				{ op: "mock-3", v: 41, meta: { start_ts: new Date(@to.getTime() + 10)} }
+				{ op: "mock-2", v: 40, meta: { start_ts: new Date(@to.getTime() - 10)} }
+				{ op: "mock-1", v: 39, meta: { start_ts: new Date(@to.getTime() - 20)} }
 			]
-			@diffed_updates = @updates.slice(0,1)
+			@diffed_updates = @updates.slice(2)
 			@rewound_content = "rewound-content"
 			@diff = [ u: "mock-diff" ]
 			
@@ -79,7 +81,7 @@ describe "DiffManager", ->
 
 			it "should generate the diff", ->
 				@DiffGenerator.buildDiff
-					.calledWith(@rewound_content, @diffed_updates)
+					.calledWith(@rewound_content, @diffed_updates.reverse())
 					.should.equal true
 
 			it "should call the callback with the diff", ->
@@ -88,7 +90,7 @@ describe "DiffManager", ->
 		describe "with mismatching versions", ->
 			beforeEach ->
 				@version = 42
-				@updates = [ { op: "mock-1", v: 39 }, { op: "mock-1", v: 40 } ]
+				@updates = [ { op: "mock-1", v: 40 }, { op: "mock-1", v: 39 } ]
 				@DiffManager.getLatestDocAndUpdates = sinon.stub().callsArgWith(4, null, @lines, @version, @updates)
 				@DiffManager.getDiff @project_id, @doc_id, @from, @to, @callback
 
diff --git a/services/track-changes/test/unit/coffee/HttpController/HttpControllerTests.coffee b/services/track-changes/test/unit/coffee/HttpController/HttpControllerTests.coffee
index a0d7c23166..89e03ff6ea 100644
--- a/services/track-changes/test/unit/coffee/HttpController/HttpControllerTests.coffee
+++ b/services/track-changes/test/unit/coffee/HttpController/HttpControllerTests.coffee
@@ -10,7 +10,9 @@ describe "HttpController", ->
 		@HttpController = SandboxedModule.require modulePath, requires:
 			"logger-sharelatex": { log: sinon.stub() }
 			"./HistoryManager": @HistoryManager = {}
+			"./DiffManager": @DiffManager = {}
 		@doc_id = "doc-id-123"
+		@project_id = "project-id-123"
 		@version = 42
 		@next = sinon.stub()
 
@@ -30,4 +32,29 @@ describe "HttpController", ->
 				.should.equal true
 
 		it "should return a success code", ->
-			@res.send.calledWith(204).should.equal true
\ No newline at end of file
+			@res.send.calledWith(204).should.equal true
+
+	describe "getDiff", ->
+		beforeEach ->
+			@from = Date.now() - 10000
+			@to = Date.now()
+			@req =
+				params:
+					doc_id: @doc_id
+					project_id: @project_id
+				query:
+					from: @from.toString()
+					to: @to.toString()
+			@res =
+				send: sinon.stub()
+			@diff = [ u: "mock-diff" ]
+			@DiffManager.getDiff = sinon.stub().callsArgWith(4, null, @diff)
+			@HttpController.getDiff @req, @res, @next
+
+		it "should get the diff", ->
+			@DiffManager.getDiff
+				.calledWith(@project_id, @doc_id, parseInt(@from, 10), parseInt(@to, 10))
+				.should.equal true
+
+		it "should return the diff", ->
+			@res.send.calledWith(JSON.stringify(diff: @diff)).should.equal true