prisma-composer-core-concepts

Declare the dependency with deps: { db: rawPostgres() } or postgres(dataContract) on the service, then connect it in a module's builder via provision(). At runtime the service reads the binding through service.load(), which returns { url } or { url, client }.

Use mockService from @prisma/composer/testing to substitute typed dependency doubles for isolated unit tests, or bootstrapService from @prisma/composer-prisma-cloud/testing to boot the real built entry in-process and drive it over real HTTP.

Composer mints a per-binding service key at deploy and serve() rejects any caller that is not a wired consumer with 401 before the handler runs. This is expected behavior, not a broken deploy; debug through a wired consumer or locally where nothing is enforced.

A hoisted newer effect package overrode Composer's exact pin required by the alchemy engine. Pin the whole effect constellation (effect plus @effect/sql-d1, @effect/sql-pg, @effect/vitest, and @effect/platform packages) in package.json overrides and reinstall.

Deploys are replay-only and apply only migrations committed under migrations/. After editing contract.prisma, run prisma contract emit then prisma migration plan --name <slug> to author the missing migration before deploying.

Local dev does not support Windows yet. The platform ingress buffers streaming responses, so open SSE tails time out at 60 seconds; RPC over HTTP is the only contract kind, with no gRPC, WebSocket, or streaming contracts.