diff --git a/services/web/app/coffee/Features/Compile/ClsiManager.coffee b/services/web/app/coffee/Features/Compile/ClsiManager.coffee
index 77c2dc3dd8..2341129481 100755
--- a/services/web/app/coffee/Features/Compile/ClsiManager.coffee
+++ b/services/web/app/coffee/Features/Compile/ClsiManager.coffee
@@ -128,10 +128,9 @@ module.exports = ClsiManager =
 			if project.compiler not in ClsiManager.VALID_COMPILERS
 				project.compiler = "pdflatex"
 
-			ClsiStateManager.checkState project_id, project, (error, stateOk, state) ->
+			ClsiStateManager.checkProjectStateMatch project_id, project, (error, stateOk, projectState) ->
 				return callback(error) if error?
 				logger.log project_id: project_id, checkState: stateOk, "checked project state"
-				console.log "OPTIONS ARE", options
 				if stateOk and not options.state? # incremental
 					ClsiManager._getContentFromDocUpdater project_id, (error, docUpdaterDocs) ->
 						return callback(error) if error?
@@ -145,18 +144,18 @@ module.exports = ClsiManager =
 								path = docPath[doc._id]
 								docs[path] = doc
 							console.log "MAPPED DOCS", docs
-							options.incremental = state
+							options.incremental = projectState
 							ClsiManager._finaliseRequest project_id, options, project, docs, [], callback
 				else
 					ClsiManager._getContentFromMongo project_id, (error, docs, files) ->
 						return callback(error) if error?
 						console.log "DOCS", docs
 						# FIXME want to store state after project has been sent to clsi
-						ClsiStateManager.setState project_id, project, (error, state) ->
+						ClsiStateManager.setProjectState project_id, project, (error, projectState) ->
 							if error?
 								logger.err err:error, project_id:project_id, "error storing state in redis"
 								#return callback(error)
-							options.state = state
+							options.state = projectState
 							ClsiManager._finaliseRequest project_id, options, project, docs, files, callback
 
 	_getContentFromDocUpdater: (project_id, callback = (error, docs) ->) ->
diff --git a/services/web/app/coffee/Features/Compile/ClsiStateManager.coffee b/services/web/app/coffee/Features/Compile/ClsiStateManager.coffee
index 9f4c558eb6..8347e9348b 100644
--- a/services/web/app/coffee/Features/Compile/ClsiStateManager.coffee
+++ b/services/web/app/coffee/Features/Compile/ClsiStateManager.coffee
@@ -7,8 +7,19 @@ crypto = require "crypto"
 buildKey = (project_id)->
 	return "clsistate:#{project_id}"  # FIXME: should we cluster these on project??
 
+# the "state" of a project is a hash of the relevant attributes in the
+# project object in this case we only need the rootFolder.
+#
+# When it changes the full set of files on the CLSI will need to be
+# updated.  If it doesn't change then we can overwrite changed docs in
+# place on the clsi, getting them from the docupdater.
+#
+# The docupdater is also responsible for unsetting the key in redis if
+# it removes any documents from the doc updater.
+
 buildState = (project) ->
-	JSON.stringify project
+	json = JSON.stringify(project.rootFolder)
+	return crypto.createHash('sha1').update(json, 'utf8').digest('hex')
 
 clsiStateEnabled = Settings.clsiState
 
@@ -16,26 +27,19 @@ OneHour = 3600 * 1000
 
 module.exports = ClsiStateManager =
 
-	checkState: (project_id, project, callback = (err, ok) ->) ->
+	checkProjectStateMatch: (project_id, project, callback = (err, ok) ->) ->
 		newState = buildState(project)
-		@getState project_id, (err, oldState) ->
+		rclient.get buildKey(project_id), (err, oldState) ->
 			return callback(err) if err?
+			logger.log project_id: project_id, new_state: newState, old_state: oldState, "got project state from redis"
 			if newState is oldState
-				hash = crypto.createHash('sha1').update(newState, 'utf8').digest('hex')
-				callback(null,true,hash)
+				callback(null,true,oldState)
 			else
 				callback(null,false)
 
-	getState: (project_id, callback = (err, state)->)->
-		rclient.get buildKey(project_id), (err, state)->
-			return callback(err) if err?
-			logger.log project_id: project_id, state: state, "got project state from redis"
-			return callback(null, state)
-
-	setState: (project_id, project, callback = (err)->)->
-		projectState = buildState project
+	setProjectState: (project_id, project, callback = (err)->)->
+		projectState = buildState(project)
 		logger.log project_id: project_id, projectState: projectState, "setting project state in redis"
 		rclient.set buildKey(project_id), projectState, "PX", OneHour, (err) ->
 			return callback(err) if err?
-			hash = crypto.createHash('sha1').update(projectState, 'utf8').digest('hex')
-			callback(null,hash)
+			callback(null,projectState)