Webhooks

Preview — sandbox webhooks are newly available and still evolving; the shape may change. We’d love your feedback.

Register a destination and OpenComputer delivers a sandbox’s lifecycle events to it as a small, signed delivery envelope — signed, retried, and redeliverable. Use it to react when a sandbox boots, hibernates, stops, or scales, without polling. The envelope is camelCase, with top-level routing fields and the full event nested under event:

{
  "type": "sandbox.stopped",
  "sandboxId": "sb-3f9a…",
  "eventId": "sb-3f9a…:3:142",
  "event": {
    "id": "sb-3f9a…:3:142", "ts": "2026-06-24T12:00:00Z",
    "orgId": "…", "sandboxId": "sb-3f9a…",
    "type": "sandbox.stopped", "data": { "reason": "user_requested" }
  }
}

Dedupe on deliveryId — verifyWebhook sets it from the svix-id header (stable across retries and redelivery). Need to route on your own metadata? Attach metadata when you register the destination and it rides as custom HTTP headers on every request — there’s no metadata in the body.

Events

Subscribe to all events, or filter with eventTypes (exact like sandbox.stopped, or a prefix like sandbox.*).

Event	When	`event.data`
`sandbox.created`	the sandbox resource is accepted	`template`
`sandbox.ready`	the VM has booted and can run commands	—
`sandbox.hibernated`	the sandbox was paused (disk persisted)	—
`sandbox.resumed`	a hibernated sandbox woke	—
`sandbox.stopped`	the sandbox stopped	`reason`: `user_requested` \| `expired` \| `crash`
`sandbox.migrated`	the sandbox moved to new infrastructure	—
`sandbox.checkpoint.created`	a checkpoint was taken	`checkpointId`
`sandbox.forked`	a sandbox was forked from a checkpoint	`parentId`
`sandbox.scaled`	the sandbox’s resources changed	`cpuCount`, `memoryMB`
`sandbox.preview_url.changed`	a preview-URL port mapping was added or removed	`port`, `url` (`url` is `null` when the mapping was removed)

Destinations

A destination is org-scoped by default (all your sandboxes), or pinned to one sandbox with sandboxId. Set enabled: false to pause a destination — it stops receiving deliveries until you re-enable it; events that occur while it’s paused aren’t backfilled.

import { Webhooks } from "@opencomputer/sdk";

const webhooks = new Webhooks({ apiKey: process.env.OPENCOMPUTER_API_KEY! });

const { id, secret } = await webhooks.create({
  url: "https://app.example.com/oc-webhook",
  eventTypes: ["sandbox.stopped", "sandbox.ready"],
  name: "prod",            // optional display name
});
// `secret` (whsec_…) verifies deliveries — returned here and re-fetchable via webhooks.getSecret(id).

POST https://app.opencomputer.dev/api/webhooks
X-API-Key: $OPENCOMPUTER_API_KEY
Content-Type: application/json

{
  "url": "https://app.example.com/oc-webhook",
  "eventTypes": ["sandbox.stopped", "sandbox.ready"],
  "name": "prod"
}

Every destination is signed. If you don’t pass a secret, OpenComputer generates one (whsec_…) and returns it on create. The secret is re-fetchable any time via webhooks.getSecret(id) (GET /api/webhooks/:id/secret), and rotatable via webhooks.update(id, { rotateSecret: true }).

TypeScript SDK
REST API

Call	Purpose
`webhooks.create(params)`	Register a new destination (returns the `secret`).
`webhooks.list()`	List destinations.
`webhooks.get(id)`	Fetch one (`hasSecret`, not the secret value).
`webhooks.getSecret(id)`	Fetch the current signing secret (`whsec_…`).
`webhooks.update(id, params)`	Pause/resume (`enabled`), retune `eventTypes`, change `url`, or `rotateSecret`.
`webhooks.delete(id)`	Delete — removes the endpoint; deleted history isn’t queryable.
`webhooks.test(id)`	Enqueue a sample event (delivered asynchronously).

Method · Path	Purpose
`POST /api/webhooks`	Register a new destination.
`GET /api/webhooks`	List destinations.
`GET /api/webhooks/:id`	Fetch one.
`GET /api/webhooks/:id/secret`	Fetch the current signing secret.
`PATCH /api/webhooks/:id`	Pause/resume, retune `eventTypes`, change `url`, or `rotateSecret`.
`DELETE /api/webhooks/:id`	Delete (history not queryable afterward).
`POST /api/webhooks/:id/test`	Enqueue a sample event (delivered asynchronously).

sandbox.created and sandbox.ready fire before a separate webhooks.create call could know the sandbox id. To capture a sandbox’s full lifecycle, register the webhook with the sandbox — it’s pinned to that sandbox and gets every event from created on:

import { Sandbox } from "@opencomputer/sdk";

const sandbox = await Sandbox.create({
  webhooks: [{ url: "https://app.example.com/oc-webhook" }],
});
// the generated signing secret is on the create response: sandbox.webhooks[0].secret

POST https://app.opencomputer.dev/api/sandboxes
X-API-Key: $OPENCOMPUTER_API_KEY
Content-Type: application/json

{ "template": "base", "webhooks": [{ "url": "https://app.example.com/oc-webhook" }] }

Deliveries

Every send and its outcome — the data behind a deliveries dashboard.

TypeScript SDK
REST API

Call	Purpose
`webhooks.deliveries.list(id)`	List recent delivery attempts (up to 50).
`webhooks.deliveries.get(id, messageId)`	One delivered message, in detail.
`webhooks.deliveries.redeliver(id, messageId)`	Re-send a message (same `svix-id`).

Method · Path	Purpose
`GET /api/webhooks/:id/deliveries`	List recent attempts (up to 50).
`GET /api/webhooks/:id/deliveries/:messageId`	One delivered message, in detail.
`POST /api/webhooks/:id/deliveries/:messageId/redeliver`	Re-send a message.

Each record is a Svix delivery attempt with its status and the consumer’s responseStatusCode; Svix retries failed attempts on its managed schedule and retains recent attempt history (the attempt index lags a send by a few seconds). A deleted destination’s history is no longer queryable.

Delivery = { id, status: "success" | "pending" | "failed", responseStatusCode?, timestamp }

Redelivery re-sends the same message to the endpoint (same svix-id) — for when the original never landed. A receiver that dedupes on svix-id treats it as the same message.

Signing, retries, and dedupe

HTTPS only, checked at registration. The delivery layer (Svix) additionally blocks private, loopback, link-local, and cloud-metadata addresses at send time.
Always signed with Standard Webhooks (delivery is by Svix). Every request carries svix-id, svix-timestamp, and svix-signature = v1,<base64(HMAC-SHA256(secret, "{svix-id}.{svix-timestamp}.{rawBody}"))>. Verify against the raw request body, before parsing it; the timestamp guards replay. Any custom headers you attached as destination metadata ride along too. Your signing secret is re-fetchable any time via GET /api/webhooks/{id}/secret and rotatable via update (rotateSecret: true).
At-least-once. Once an event is handed off it’s retried until it succeeds or the delivery layer gives up. A duplicate can still arrive, so dedupe on svix-id (the verifier exposes it as both deliveryId and dedupeId).
Not strictly ordered. Events for one sandbox can arrive out of order (e.g. sandbox.ready before sandbox.created). Treat each event independently and key off event.type; don’t assume an ordering.
Success / retry / give-up. A delivery succeeds on HTTP 2xx. Failures are retried on Svix’s managed backoff (immediately, then 5s, 5m, 30m, 2h, 5h, 10h, 10h); an endpoint that keeps failing for ~5 days is auto-disabled. Inspect attempts and recover failed messages via the deliveries API. Unsafe targets (private / loopback / cloud-metadata addresses) are blocked by the delivery layer.

Verify a webhook

The SDK ships a verifier — no extra dependency, runs in Node / Cloudflare Workers / browsers — that checks the signature and returns the parsed envelope. It’s the same verifyWebhook used for session webhooks; pass SandboxLifecycleEvent to type the nested event:

import { verifyWebhook, type SandboxLifecycleEvent } from "@opencomputer/sdk";

// rawBody = the RAW request body string, read BEFORE JSON.parse.
// Throws on a missing / expired / invalid signature.
const delivery = await verifyWebhook<SandboxLifecycleEvent>(rawBody, request.headers, process.env.OC_WEBHOOK_SECRET!);

if (delivery.type === "sandbox.stopped") {
  console.log(delivery.sandboxId, delivery.event.data.reason); // event.data is typed per event
}

Or verify with any Standard Webhooks / Svix library directly, against the raw body and the svix-id / svix-timestamp / svix-signature headers.

Webhooks here cover sandbox lifecycle. To deliver an agent’s session events (turns, messages, results), see Agent Sessions webhooks — verified with the same verifyWebhook helper. Session webhooks differ in a couple of specifics today: their webhook-id is the event id, and signing is opt-in (set a secret).

Getting Started

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Reserved Capacity

CLI

Guides

TypeScript SDK

Python SDK

CLI Reference

API Reference

Resources

Events

Destinations

Deliveries

Signing, retries, and dedupe

Verify a webhook

​Events

​Destinations

​Subscribe at create

​Deliveries

​Signing, retries, and dedupe

​Verify a webhook

Events

Destinations

Subscribe at create

Deliveries

Signing, retries, and dedupe

Verify a webhook