Effect v4 backbone
Shared Effect services, schemas, errors, and HTTP contracts.
effectcapabilities
Shared Effect services, schemas, errors, and HTTP contracts.
packages/capabilities owns application behavior as Effect v4 services,
schemas, and tagged errors. The web, API, and background Workers compose these
services instead of implementing separate use cases.
Services use Context.Service. Live adapters read and write D1; Seed adapters
implement the same contracts in memory for tests and fixture-backed execution.
Tests can provide a Seed layer without starting a Worker.
Effect Schema defines capability values and HTTP payloads. packages/api
composes those schemas into HttpApi groups, which drive server routing,
OpenAPI, and the typed client.
Tagged errors distinguish expected refusals from unexpected failures. HTTP
annotations assign statuses such as WorkspaceNotFound 404,
AuthorizationDenied 403, and RateLimited 429. MCP handlers return expected
operation refusals as tool errors. Web handlers translate allowlisted errors
into safe UI messages.
The web app loads server state through TanStack Start loaders and server functions. Browser modules must not import server adapters or their runtime dependencies.