API reference

This section is the human-authored API reference for the runtime, store, and host adapter packages.

The generated reference for @tanstack/workflow-core still lives in Generated core reference.

Packages

Which API should I start with?

Use @tanstack/workflow-core directly when:

• you are writing tests
• you are embedding the replay engine into your own runtime
• you want to handle persistence, timers, and signals yourself

Use @tanstack/workflow-runtime when:

• you want registered workflows
• you need schedules and timer sweeps
• you need a production store contract
• you deploy to serverless or multiple workers

Use host adapters when:

• you want a provider-native cron or scheduled function entrypoint
• you want compact sweep responses
• you want deployment examples that fit the host

Stability

The runtime and adapter packages are experimental. The direction is stable:

• core stays small
• runtime owns durable execution orchestration
• stores implement a contract
• host adapters stay thin

Some names and option shapes may still change while the first production guides settle.