Functions

Amba functions are small TypeScript HTTP handlers that run on Amba's edge runtime. Each function receives a Request and returns a Response. Use them for webhook handlers, custom mutation endpoints, queue consumers, and scheduled jobs.

Handler shape

Export a default async (req: Request) => Response:

// functions/hello.ts
export default async function (req: Request): Promise<Response> {
  const url = new URL(req.url);
  const name = url.searchParams.get('name') ?? 'world';
  return new Response(JSON.stringify({ greeting: `hello, ${name}` }), {
    headers: { 'content-type': 'application/json' },
  });
}

That's the entire surface. Standard Request / Response / Headers / URL / fetch / crypto are available at runtime.

What you can do in a function

• Custom HTTP endpoints — anything you'd put behind a server route: webhook receivers, signed-URL minters, server-only mutations.
• Reads + writes against your collections — call into your project from the handler. Server context bypasses client-side scoping, so you can implement cross-user reads when you need them.
• Queue consumers — bind a function to a queue with amba functions consume <queue> <function> and it receives one message per delivery.
• Cron jobs — register a schedule with amba functions schedule <name> "<cron>" and the runtime invokes the function on that cadence.
• Read secrets — set with amba secrets set NAME value, read with process.env.NAME. Secrets are scoped per-project and never leak cross-tenant.

Three commands you'll use most

• amba functions dev <file> — run the handler locally with hot reload while you build.
• amba functions deploy <file> — bundle and ship to production.
• amba functions logs <name> --tail — stream live logs from production.

The full command list is on the CLI reference.

Limits

• Bundle size — amba functions deploy reports the bundle size and rejects deploys over the platform cap. Use --dry-run to triage size without uploading.
• Per-function rate limits — optional, declared at deploy time with --rate-limit-window, --rate-limit-max, --rate-limit-key. The edge runtime enforces them pre-dispatch (the handler never runs for rate-limited requests).
• Runtime stdlib — standard Request/Response/Headers/URL/ crypto/fetch are provided by the platform. Node-specific built-ins (fs, child_process, net) are not.

Next

• Local dev — amba functions dev walkthrough.
• Deploy — ship to production.
• CLI reference — full command and flag list.