Inngest

Inngest replaces the queue, the state store and the scheduler that usually sit behind background work. Developers write durable step functions in their own application code, and the infrastructure that normally has to be assembled and watched over disappears from the job.

A function has three parts, triggers from events, cron schedules or webhooks, flow control that governs how runs are enqueued and executed, and steps. Wrapping code in a step makes it retry on failure independently, which lets one workflow run for months and recover from errors as it goes.

The self-hosted server is worth understanding before you run it.

• Event API: receives events over HTTP, authenticates them with event keys and publishes to an internal stream.
• Runner: schedules runs, resumes paused functions on matching events and cancels others by expression.
• Queue: multi-tenant and multi-tier, handling concurrency, throttling, prioritization, debouncing, rate limiting and batching.
• Executor: executes steps, writes incremental run state and retries after failures.
• Dashboard and APIs: GraphQL and REST access plus a UI for apps, functions and run history.

SDKs cover TypeScript and JavaScript, Python, Go and Kotlin or Java, all under Apache 2.0, while the server and CLI carry the Server Side Public License with delayed open source publication. Local development runs the Dev Server from one npx command with production parity, then functions deploy to your own infrastructure and sync with the hosted platform or a self-hosted server, which invokes them over HTTPS when triggering events arrive.