Glossary

Control plane — palumb-core, the managed service that authenticates you, holds your audience and channels, receives triggers, and makes deliveries. The only component that holds your state and secrets.

Workflow — your notification logic, written as TypeScript. palumb runs it durably. Declared with workflow().

Bridge — the single signed HTTP endpoint you deploy that exposes your workflows; palumb’s engine drives it step by step. No Restate runs on your side.

palumb-engine — the durable runtime palumb runs (a Restate host) that drives your Bridge and hosts the building blocks.

workflowId routing — a trigger’s workflowId names one of your workflows directly, so there is no in-handler switch over event types.

Trigger / event — an inbound POST /v1/events that starts a workflow.

Channel — a concrete provider integration (channel = provider), e.g. email-smtp. You enable it and attach credentials, stored encrypted.

Kind — the category of a channel (email, and later slack, telegram, whatsapp). A workflow sends to a kind; palumb resolves your enabled channel of that kind.

Subscriber — a recipient, addressed by your own external_id, carrying per-kind contacts.

Topic — a pub/sub grouping; subscribers subscribe to it, and a trigger can fan out to a whole topic.

Subscription — the link between a subscriber and a topic.

Delivery / send — the egress: palumb turning your workflow’s step.send intent into a real provider call, idempotently.

Digest — a building block that accumulates many items per key and flushes them as one message after a durable window.

Building block — a reusable durable pattern palumb ships (the first is the digest) so you don’t hand-roll it.

Restate — the durable execution engine palumb runs your workflows on (inside palumb-engine). You never operate it. See Durability.

Keyed durable state — durable state addressed by a key, serialized per key. The digest is one (palumb-hosted).

Durable step (step.*) — a step palumb journals so it is not repeated on replay/retry.

Signing secret — the HMAC secret palumb generates at onboarding to sign every call to your Bridge; stored encrypted, returned once.

Idempotency key — a stable key on a delivery so retries never double-send.

Tenant — your account. API key — the opaque token that authenticates as a tenant; palumb stores only its hash.