Integrations

The packages under jdlib.integrations are edges: each one translates a transport into the same collaborators and the same chain. None of them implements a security mechanism of its own — an edge that implemented one would be a second answer to a question the library has already answered.

Integration	Package	Extra	What it is for
FastAPI	jdlib.integrations.fastapi	fastapi	the HTTP surface: middleware, the guard, the error envelope, the composition root
MCP	jdlib.integrations.mcp	mcp	the model-facing surface: tools and resources over the same chain
CLI	jdlib.integrations.cli	cli	the operator commands: migrations, tenants, isolation policies, schema lint
pytest	jdlib.integrations.pytest_plugin, jdlib.testing	dev	the fixtures and helpers the example suites are built on

The stores are integrated the same way — a provider implements a protocol the library defines:

Store	Module	Extra	What it is for
PostgreSQL	jdlib.data.postgres, jdlib.persistence	—	the control plane and the tenant plane
Neo4j	jdlib.graph	graph	the derived graph plane
Redis	jdlib.caching.redis	redis	a shared cache provider
S3	jdlib.storage.s3	s3	object storage
Cerbos	jdlib.security.authz.cerbos	—	the reference decision point

The rule an integration follows

1. It composes, it does not decide. The edge builds the authenticator, the resolver chain, the context factory, the PEP and the unit of work from configuration, and then gets out of the way.
2. Its optional dependency is optional. Importing jdlib never imports fastapi, mcp, redis, boto3 or neo4j; a missing extra is a refusal that names the extra, not an ImportError at process start.
3. It answers with the library's envelope. A failure on any edge is the same ErrorResponse shape, with the same stable codes, so a client does not need per-surface handling.
4. It is measured like a surface. The enterprise example runs its HTTP and MCP surfaces through the same security assertions, and the differences between them are documented rather than smoothed over.