Inngest vs Restate

Inngest

Waits are durable and cost nothing while suspended, with runs up to 30 days on Free and 366 on Business. No reviewer inbox, Slack app or email, so the human side is your code.

Restate

An awakeable pauses a handler at no compute cost and resumes it from one HTTP request, with a durable timeout, on a free plan of 100,000 actions a month. Restate sends nothing to the approver, so the Slack message, email or inbox is the builder's code, and the published terms and privacy statement predate the paid plans.

Inngest

1. Use step.waitForSignal() when one run waits for one answer, and waitForEvent only when one answer resumes many runs
2. Register the wait before you send the approval request, or check the external state first, since early events are missed
3. Use a unique approval ID per tool call and match on it, so parallel approvals resolve independently
4. Treat null or undefined as a timeout and decide on purpose whether that rejects, approves or escalates
5. Set an event id when sending the answer, so a retried send is dropped within 24 hours

Restate

1. Create the awakeable, send its ID inside ctx.run, then await the promise, so a retry doesn't send a second approval request
2. Resolve with POST /restate/awakeables/<id>/resolve and a JSON body, or /reject with a text reason, which throws a terminal error in the handler
3. On Restate Cloud send Authorization: Bearer key_... to https://<env_id>.env.<region>.restate.cloud:8080. On a self-hosted server put an authenticating proxy in front of port 8080
4. Wrap the wait in orTimeout and decide what a timeout means. Without it the handler waits with no limit
5. Retry ingress errors only on 408, 425, 429 or 5xx, and only when x-restate-error-source isn't invocation