Anvia

Protocol and state ​

The public stream protocol is always framed as anvia.client.v3. createHttpClientTransport() validates the response protocol header, frame sequence, stream identity, and monotonically increasing event IDs before yielding application events.

Request union ​

ts
type ClientStreamRequest =
  | {
      type: 'messages'
      messages: readonly Message[]
      metadata?: JsonObject
      resume?: ClientStreamCursor
    }
  | {
      type: 'interaction_response'
      interactionId: string
      response: AgentInteractionResponse
      metadata?: JsonObject
      resume?: ClientStreamCursor
    }

UIMessage[] is client state; it does not cross the server boundary. Convert deliberately with uiMessagesToMessages() and messagesToUIMessages().

Interactions ​

ClientInteraction records the public interaction request, originating run ID, and pending, responded, or cancelled status. A response addresses the interaction by ID. The server owns the continuation, verifies the caller, claims it once, and rejects unknown, expired, already-used, or mismatched responses.

State reduction ​

applyClientStreamEvent(messages, event) applies canonical events to UIMessage[]. Runtime status, usage, context usage, and trace correlation live in UIMessage.generation; app-owned metadata round-trips separately.

Errors are masked by default. Use mapError only at the trusted adapter boundary when the application intentionally exposes a safe public shape.

Built for Anvia.