Resources and pipelines

Tapstate uses declarative *.tap.yml files with version: tapstate/v1.

If this is your first runnable pipeline, begin with the offline workspace walkthrough. For exact field shapes, use the resource grammar.

Five resource kinds

• source owns connector configuration. A read source has mode; a target connection omits it.
• transform holds reusable, input-independent logic.
• view holds reusable materialization settings for tapstate's managed state store.
• serve holds reusable external sync, query, and push declarations.
• pipeline wires sources and transforms to a view, a serve surface, or both.

source ──→ pipeline ──→ view ──→ managed state store
              │
              ├── transform (inline or reusable)
              └── serve.sync ──→ external target connection

Example relationship

version: tapstate/v1
kind: pipeline
id: active-users
source: mysql-prod
settings:
  read_mode: snapshot_and_cdc
transforms:
  - id: filter-active
    from: [users]
    type: filter
    expr: "after.status == 'active'"
view:
  id: profile-state
  from: filter-active
  primary_key: id

mysql-prod is the read source in this example. The view consumes the filter-active transform; if you add serve.sync, its source names the external target connection that receives the same pipeline result.

Declaring view is the complete instruction to materialize the current pipeline result; no serve block is required. Add serve.sync when the same result must also be delivered to a system outside tapstate. If both are declared, the view and the external serve output are independent consumers of the pipeline result.

Why use resource files

Ordinary files provide:

• reviewable changes in Git;
• stable IDs and explicit references;
• secret placeholders instead of committed credentials;
• editor assistance from the release-matched Schema;
• deterministic diagnostics;
• a common context for people, automation, and AI assistants.

What validation proves

Offline validation catches resource shape, reference, and catalog-rule errors. It does not connect to an external system, install connector artifacts, or prove that every Schema-declared feature is implemented by the current runtime.

After validation, exercise connectivity and representative data behavior in a non-production deployment. See the resource grammar for the exact validation boundary.