assistant-ui Streaming

Always consult assistant-ui.com/llms.txt for the latest API.

assistant-stream is the wire layer underneath assistant-ui's chat runtimes. It normalizes every backend into one stream of AssistantStreamChunk values, ships encoders and decoders for three wire formats, and adds a resumable-stream layer on top of any of them. If your backend already speaks the Vercel AI SDK, you rarely touch this package directly (streamText plus toUIMessageStream is enough); reach for it when you write a custom endpoint, need to decode a stream yourself, or want resumable streams.

References

• ./references/data-stream.md -- the Data Stream protocol, useDataStreamRuntime, and its wire format
• ./references/assistant-transport.md -- the Assistant Transport SSE format and the useAssistantTransportRuntime state-snapshot runtime
• ./references/encoders.md -- the encoder and decoder catalog, PlainTextEncoder, UIMessageStreamDecoder, accumulators, and debugging
• ./references/resumable.md -- assistant-stream/resumable: context, stores, and client wiring

When to use it