Remy Reference/Interface SDK/Agent chat/SendMessageCallbacks

SendMessageCallbacks

Type

Defines the named callbacks `sendMessage` invokes while a turn streams in.

The handlers sendMessage fires as a turn arrives. The named ones cover the common cases (text, thinking, tool start and result, and client tool calls), while onEvent receives every raw AgentChatEvent for logging or lower-level events like tool_input_delta. onText receives deltas to append, the opposite of the method client's accumulated onToken.

SendMessageCallbacks.ts

interface SendMessageCallbacks {
  onText?: (text: string) => void
  onThinking?: (text: string) => void
  onThinkingComplete?: (thinking: string, signature: string) => void
  onToolCallStart?: (id: string, name: string) => void
  onToolCallResult?: (id: string, output: unknown) => void
  onClientToolCall?: (name: string, input: unknown, id: string) => void
  onError?: (error: string) => void
  onEvent?: (event: AgentChatEvent) => void
  signal?: AbortSignal
}

Fields

onText?

(text: string) => void

Called with each text delta; append it, do not replace.

onThinking?

(text: string) => void

Called with each extended-thinking delta.

onThinkingComplete?

(thinking, signature) => void

Called once thinking is complete, with its full text and signature.

onToolCallStart?

(id, name) => void

Called when a tool call begins executing; show an inline activity indicator.

onToolCallResult?

(id, output) => void

Called when a tool call returns its result.

onClientToolCall?

(name, input, id) => void

Called when the agent invokes a browser-side client tool; run the on-screen action here.

onError?

(error: string) => void

Called on a stream-level error.

onEvent?

(event: AgentChatEvent) => void

Called for every event, including ones with a named callback; use it for logging or low-level events.

signal?

AbortSignal

Cancels the stream.

Wire the common handlers

chat.sendMessage(threadId, text, {
  onText: (delta) => setText((p) => p + delta),
  onToolCallStart: (id, name) => showActivity(name),
  onClientToolCall: (name, input) => runClientTool(name, input),
});