External hosting

Most apps never need this. With hosting: { default: "coline" } everything runs on Coline. Use external hosting, per capability, when:

• a tool needs a private database or a service only your network can reach
• work runs longer than a job attempt allows, or needs your own compute
• you already run the logic and want Kairo to call it

The handler

createColineAppHandler checks signatures, timestamps and replays, then dispatches tools, renders, schedules, events, webhooks and jobs to the same code you'd run on Coline. One endpoint serves all of them.

import { createColineAppHandler } from "@colineapp/sdk/v2";
import app from "./app.config";

// Set COLINE_DELIVERY_SECRET once as a developer secret in the developer
// console, and use the same value here.
const handler = createColineAppHandler({
  app,
  secret: process.env.COLINE_DELIVERY_SECRET!,
});

// Next.js: app/coline/app/route.ts
export const POST = handler;

Then point the capabilities you want at it:

hosting: {
  default: "coline",
  overrides: { "todos.sync_crm": "external" },
  external: { baseUrl: "https://your-app.example.com" },
},

Everything not listed in overrides keeps running on Coline.

Testing deliveries

The workspace API can send a signed test delivery to your backend and replay stored ones. See apps in a workspace.