Inngest is a durable-execution platform for background jobs, workflows, and agents. You write functions in your own codebase with one of its SDKs and deploy them to your own infrastructure; Inngest invokes them over HTTPS whenever a triggering event arrives, and holds the queueing, state, and scheduling outside your code.
A function has three parts. Triggers are events, cron schedules, or webhook events. Flow control configures how runs are enqueued and executed — concurrency keyed on event data, throttling, debouncing, rate limiting, and prioritization. Steps are the unit of durability: each is retried on error with exponential backoff, and a completed step is memoized, so a retry skips finished work and resumes where the run left off. step.waitForEvent pauses a run for minutes or months until a matching event arrives, and other steps sleep, schedule, or throttle without holding infrastructure open.
The server is split into an Event API that authenticates SDK requests and publishes to an internal event stream, a runner that schedules runs, resumes waiting functions on matching expressions, cancels on cancelOn expressions and records events for replay, a multi-tenant queue built for fairness and flow control, an executor that runs steps and writes incremental state, a state store for pending runs, a system database, GraphQL and REST APIs, and a dashboard. The same server runs locally as a dev server with production parity, and can be self-hosted.
Features
- Durable steps: completed steps are memoized, so a retry resumes rather than restarting the function
- Automatic retries: exponential backoff on every step, without retry code of your own
- Waits: step.waitForEvent pauses a run for minutes or months and resumes when a matching event arrives
- Flow control: concurrency keys, throttling, debouncing, rate limiting, prioritization, and batching
- Idempotency: built-in keys stop the same event triggering the same work twice
- Replay: past runs re-execute against new code, using real events without resending them
- Triggers: events, cron schedules, and webhook events
- SDKs: TypeScript and JavaScript, Python, Go, and Kotlin and Java
- Local development: a CLI dev server with a dashboard on port 8288 that mirrors production behaviour
- Deployment choice: functions run on your own infrastructure and sync with either the hosted platform or a self-hosted server
