Files
letta-code/src/agent/message.ts
2026-01-17 20:06:36 -08:00

94 lines
3.2 KiB
TypeScript

/**
* Utilities for sending messages to an agent via conversations
**/
import type { Stream } from "@letta-ai/letta-client/core/streaming";
import type { MessageCreate } from "@letta-ai/letta-client/resources/agents/agents";
import type {
ApprovalCreate,
LettaStreamingResponse,
} from "@letta-ai/letta-client/resources/agents/messages";
import { getClientToolsFromRegistry } from "../tools/manager";
import { isTimingsEnabled } from "../utils/timing";
import { getClient } from "./client";
// Symbol to store timing info on the stream object
export const STREAM_REQUEST_START_TIME = Symbol("streamRequestStartTime");
/**
* Send a message to a conversation and return a streaming response.
* Uses the conversations API for proper message isolation per session.
*
* For the "default" conversation (agent's primary message history without
* an explicit conversation object), pass conversationId="default" and
* provide agentId in opts. This uses the agents messages API instead.
*/
export async function sendMessageStream(
conversationId: string,
messages: Array<MessageCreate | ApprovalCreate>,
opts: {
streamTokens?: boolean;
background?: boolean;
agentId?: string; // Required when conversationId is "default"
} = { streamTokens: true, background: true },
// TODO: Re-enable once issues are resolved - disabled retries were causing problems
// Disable SDK retries by default - state management happens outside the stream,
// so retries would violate idempotency and create race conditions
// requestOptions: { maxRetries?: number } = { maxRetries: 0 },
requestOptions: { maxRetries?: number } = {},
): Promise<Stream<LettaStreamingResponse>> {
// Capture request start time for TTFT measurement when timings are enabled
const requestStartTime = isTimingsEnabled() ? performance.now() : undefined;
const client = await getClient();
let stream: Stream<LettaStreamingResponse>;
if (process.env.DEBUG) {
console.log(
`[DEBUG] sendMessageStream: conversationId=${conversationId}, useAgentsRoute=${conversationId === "default"}`,
);
}
if (conversationId === "default") {
// Use agents route for default conversation (agent's primary message history)
if (!opts.agentId) {
throw new Error(
"agentId is required in opts when using default conversation",
);
}
stream = await client.agents.messages.create(
opts.agentId,
{
messages: messages,
streaming: true,
stream_tokens: opts.streamTokens ?? true,
background: opts.background ?? true,
client_tools: getClientToolsFromRegistry(),
},
requestOptions,
);
} else {
// Use conversations route for explicit conversations
stream = await client.conversations.messages.create(
conversationId,
{
messages: messages,
streaming: true,
stream_tokens: opts.streamTokens ?? true,
background: opts.background ?? true,
client_tools: getClientToolsFromRegistry(),
},
requestOptions,
);
}
// Attach start time to stream for TTFT calculation in drainStream
if (requestStartTime !== undefined) {
(stream as unknown as Record<symbol, number>)[STREAM_REQUEST_START_TIME] =
requestStartTime;
}
return stream;
}