Q chat is blocked until vector indexing completes

[justinmk3]

Describe the bug

Chat does not show an answer until after Context index built successfully.

• Possibly related commit: 6d4280d

Tried to bisect as far back as dd9c2b5 , but still can repro with that commit.

To reproduce

1. start vscode or jetbrains in a medium/large-sized workspace
2. enter a Q chat prompt
3. the chat shows Thinking...
4. chat will not respond with an answer until after the Q lsp server logs print Context index built successfully log message.

logs:

[Info  - 12:07:52] [2025-06-11T16:07:52.429Z] Indexing 4 workspace folders...
[2025-06-11T16:07:52.432Z] Attached new listener and notified of current config.
[Info  - 12:07:52] [2025-06-11T16:07:52.432Z] Local context server has been initialized
[Info  - 12:07:52] [2025-06-11T16:07:52.570Z] Indexing 4 workspace folders...
[Info  - 12:07:52] [VSCode Client]  Received {"command":"telemetry/event","params":{"name":"enterFocus"}} from chat
[Info  - 12:07:52] [VSCode Client]  Received {"command":"ui-is-ready"} from chat
[Info  - 12:07:52] [VSCode Client]  Received {"command":"aws/chat/ready"} from chat
[Info  - 12:07:52] [VSCode Client]  Received {"command":"aws/chat/tabAdd","params":{"tabId":"fjjwax"}} from chat
[Info  - 12:07:52] [VSCode Client]  Received {"command":"telemetry/event","params":{"triggerType":"click","tabId":"fjjwax","name":"tabAdd"}} from chat
[Info  - 12:07:54] [Telemetry] Emitting amazonq_enterFocusChat telemetry: {"credentialStartUrl":"https://amzn.awsapps.com/start","result":"Succeeded"}
[2025-06-11T16:07:54.372Z] Received ready notification
[Info  - 12:07:54] [VSCode Client]  Received {"command":"aws/chat/tabAdd","params":{"tabId":"tnn43q"}} from chat
[Info  - 12:07:54] [VSCode Client]  Received {"command":"telemetry/event","params":{"triggerType":"click","tabId":"tnn43q","name":"tabAdd"}} from chat
[Info  - 12:07:54] [VSCode Client]  Received {"requestId":"cb0caaeb-61c7-46d7-83c4-d9a2020bb0df","command":"aws/chat/openTab","params":{"success":true,"result":{"tabId":"tnn43q"}}} from chat
[2025-06-11T16:07:54.966Z] Adding tab: fjjwax
[2025-06-11T16:07:56.725Z] Adding tab: tnn43q
[2025-06-11T16:07:57.852Z] Setting historyIdMapping: tabId=tnn43q, historyId=637eba77-96ed-4330-bdf3-ee7e4d92dbf3
[2025-06-11T16:07:57.852Z] Updating tab open state: historyId=637eba77-96ed-4330-bdf3-ee7e4d92dbf3, isOpen=true
[Info  - 12:07:58] [Telemetry] Emitting amazonq_loadHistory telemetry: {"amazonqTimeToLoadHistory":861,"amazonqHistoryFileSize":624213,"openTabCount":1,"languageServerVersion":"1.11.0","result":"Succeeded"}
[2025-06-11T16:07:58.581Z] {"featureEvaluations":[{"feature":"ServiceSideWorkspaceContext","variation":"CONTROL","value":{"stringValue":"CONTROL"}},{"feature":"customizationArnOverride","variation":"NGDE-Chat-Enabled-Customization-V1","value":{"stringValue":"arn:aws:codewhisperer:us-east-1:011528293760:customization/XMAXDH7RXN44"}},{"feature":"highlightCommand","variation":"Ask questions about Amazon Wiki, BuilderHub, and Sage documentation.","value":{"stringValue":"@sage"}}]}
[Info  - 12:07:58] [2025-06-11T16:07:58.581Z] A/B testing enabled: false
[Info  - 12:07:59] [2025-06-11T16:07:59.140Z] Indexing complete: found 15637 files.
[Info  - 12:07:59] [2025-06-11T16:07:59.770Z] Indexing complete: found 15637 files.
[Info  - 12:08:44] [VSCode Client]  Received {"command":"aws/chat/sendChatQuickAction","params":{"quickAction":"/help","prompt":"What can Amazon Q help me with?","tabId":"fjjwax"}} from chat
[Info  - 12:09:11] [VSCode Client]  Received {"command":"telemetry/event","params":{"name":"exitFocus"}} from chat
[Info  - 12:09:13] [VSCode Client]  Received {"command":"telemetry/event","params":{"name":"enterFocus"}} from chat
[Info  - 12:09:21] [VSCode Client]  Received {"command":"telemetry/event","params":{"name":"exitFocus"}} from chat
[Info  - 12:10:03] [Telemetry] Emitting amazonq_exitFocusChat telemetry: {"credentialStartUrl":"https://amzn.awsapps.com/start","result":"Succeeded"}
[Info  - 12:10:03] [2025-06-11T16:10:03.471Z] Context index built successfully

Expected behavior

vector indexing should happen asynchronously. chat should respond even if vector indexing is pending.

Screenshots

Your Environment

• OS: macos
• Flare version: 48b996d

[justinmk3]

via @shruti0085 :

So something I noticed in logic with uiready with VS/Eclipse vs JB, we do not wait for uiReady handler of language server to finish before we unblock our handling of processing events from language server to the UI.

JB does block it:

• https://github.com/aws/aws-toolkit-jetbrains/blob/9e4d9101e9c7ed233826c41e303613180e99b1a7/plugins/amazonq/shared/jetbrains-community/src/software/aws/toolkits/jetbrains/services/amazonq/lsp/flareChat/ChatCommunicationManager.kt#L54
• https://github.com/aws/aws-toolkit-jetbrains/blob/9e4d9101e9c7ed233826c41e303613180e99b1a7/plugins/amazonq/chat/jetbrains-community/src/software/aws/toolkits/jetbrains/services/amazonq/webview/BrowserConnector.kt#L300

In case of VS/Eclipse ready is treated as a fire and forget event to the server. Our UI is ready for interaction as soon as chat sends uiready and we do not wait for server handling to finish for that.

I haven't looked at VSC code, but that could be the cause of atleast some delay in JB