[flight-booking-agent] Multi-turn chat and message injection (variant B) #26
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Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
![vercel[bot]](https://avatars.githubusercontent.com/in/8329?s=60&v=4){kind=small}
| () => | ||
| new WorkflowChatTransport({ | ||
| api: '/api/chat', | ||
| onChatSendMessage: (response) => { |
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The useChat hook receives resume: false on first render even when a stored session ID exists in localStorage, causing it to start a fresh connection instead of resuming the existing session.
| await writer.write({ type: 'finish' }); | ||
| await writer.close(); |
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The writeStreamClose function acquires a WritableStream writer lock but fails to release it in a try-finally block, and is missing the writer.close() call, causing a resource leak if write() fails
| }); | ||
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| // Update messages with the agent's response | ||
| messages.push(...result.messages.slice(messages.length)); |
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Agent responses not properly added to messages on subsequent conversation turns due to incorrect array slicing logic
| // Show pending message immediately for instant feedback | ||
| setPendingMessage(text); | ||
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| try { |
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Race condition in setPendingMessage state setter inside useMemo - FIXED
| { params }: { params: Promise<{ id: string }> } | ||
| ) { | ||
| const { id: runId } = await params; | ||
| const { message } = await req.json(); |
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POST /api/chat/[id] lacks input validation for message field and runId parameter, causing client errors to return 500 instead of 400, exposing internal error details
Signed-off-by: Peter Wielander <[email protected]>
Signed-off-by: Peter Wielander <[email protected]>
…g added to conversation history in multi-turn conversations Co-authored-by: VaguelySerious <[email protected]>
This makes multi-turn session the default for the flight booking app. This is an alternative to #25, using a different pattern for user message persistence.
The docs PR vercel/workflow#759 also publishes the page on how to do chat session modeling, which includes example code snippets from this PR.
Critically, this PR also removes all
localStorageuse for persistence, with the exception of the last run ID. The durable streams serve as the main durability and storage. To do this, we also specifically persist user messages inside the stream, which wasn't done previouslyAlso see vercel/workflow#739
Difference in variants
Variant A lets
useChatnatively handle optimistic rendering of user messages, and writes custom data chunks to the stream that the client interprets as user messages.Variant B writes user messages to the actual stream as user messages, so that the stream is the source of truth and consists of 100% normally interpretable
UIMessageChunkchunks.I prefer variant B, as it's better for later processing with AI SDK, since the user messages are inside the stream as the SDK would expect them to be.
The downside with Variant B is that is requires slightly more optimistic rendering code.
Screenshots