chat-adapter-linq

Vercel Chat SDK adapter for Linq. Send and receive iMessage / SMS / RCS through real devices via the Linq Partner API.

Install

bun add chat-adapter-linq chat

Quick start

import { Chat } from "chat";
import { createMemoryState } from "@chat-adapter/state-memory";
import { createLinqAdapter } from "chat-adapter-linq";

const linq = createLinqAdapter({
  defaultFrom: "+12025551234",
  // apiKey: "...",            // or set LINQ_API_KEY env var
  // signingSecret: "...", // or set LINQ_WEBHOOK_SECRET env var
});

const chat = new Chat({
  userName: "linq-bot",
  adapters: { linq },
  state: createMemoryState(),
});

chat.onDirectMessage(async (thread, message) => {
  await thread.startTyping();
  await thread.post(`You said: ${message.text}`);
});

await chat.initialize();

// Wire chat.webhooks.linq to a public HTTPS endpoint that Linq POSTs to.

Configuration

Environment variables

Variable	Description
LINQ_API_KEY	Linq Partner API bearer token (overridden by config.apiKey).
LINQ_WEBHOOK_SECRET	HMAC-SHA256 webhook signing secret (overridden by config.signingSecret).
LINQ_FROM	E.164 phone number this bot sends from (overridden by config.defaultFrom).

LinqAdapterConfig

interface LinqAdapterConfig {
  /** Linq Partner API bearer token. */
  apiKey: string;
  /** HMAC-SHA256 webhook signing secret. Returned only when the subscription is created — store it. */
  signingSecret: string;
  /** E.164 phone number to send from (e.g. "+12025551234"). */
  defaultFrom: string;
  /** Override base URL. Default: "https://api.linqapp.com/api/partner". */
  baseUrl?: string;
  /** Bot username surfaced in handler context. Default: `linq:{defaultFrom}`. */
  userName?: string;
  /** Custom logger. */
  logger?: Logger;
  /** Override fetch (testing). */
  fetch?: typeof fetch;
  /** Reject webhooks older than this many seconds. Default: 300. */
  webhookToleranceSec?: number;
}

Webhook setup

POST /v3/webhook-subscriptions with ?version=2026-02-03 on your target URL. The adapter only parses the 2026-02-03 payload format. The signing secret is returned exactly once — copy it into LINQ_WEBHOOK_SECRET immediately.

Features

• Inbound messages (1:1 routes to onDirectMessage; group to onSubscribedMessage after subscribe).
• Outbound text, markdown, and Card postables (cards render as fallback text — iMessage has no rich card surface).
• Attachments via URL (≤10MB) or pre-upload (POST /v3/attachments, ≤100MB).
• Reactions: native tapbacks (love, like, dislike, laugh, emphasize, question) plus arbitrary emoji via custom_emoji.
• Edit (PATCH /v3/messages/{id}) and delete (DELETE /v3/messages/{id} — Linq-side only, not unsend).
• Typing indicator (DMs only; group chats silently no-op).
• openDM(handle) reuses an existing 1:1 chat or lazy-creates one on first post().

Unsupported

• Buttons, modals, slash commands, scheduled messages — iMessage doesn't have them.
• v2025-01-01 webhook payload format.
• @bot mentions — iMessage has no syntax for them. Use onDirectMessage for 1:1 and onNewMessage(/.*/) to opt into group threads.

License

MIT