`meta.errorCode` is the mechanism this API chose for machine-readable errors, and the envelope's own description tells a client to branch on it rather than on the prose. Of the two hundred and forty-two codes in the tree, sixteen appeared anywhere in the contract. A client had to discover each one by triggering the error in testing, and had no way at all to learn that a new one had appeared. They are enumerated now, grouped by the surface that emits them, in the description of the field they belong to. The list is generated from the code and committed as a literal so it reads in a diff, and the sentence in the document is rendered from it rather than written beside it. Nothing is renamed. Four naming conventions coexist — dot.case, bare snake_case, a camelCase segment and a hyphen — and a code is a wire value a shipped client branches on, so they stay. New codes are dot.case, and the guard is what stops a fifth convention arriving unnoticed. Three families stay outside the list and say why: the assistant refusal builds its last segment from a template, the integration probes are enumerated per operation where the per-provider differences can be stated, and a route checking a credential of its own may answer 401 with no code. The guard re-derives the set from the tree and fails both ways — a code emitted and not listed, and a code listed and no longer emitted, which is the worse of the two because a client can write a branch for it and wait forever.
HealthLog API Spec
openapi.yaml is the OpenAPI 3.1 description for the HealthLog
Next.js API and the source of truth for the native iOS client's DTO
codegen. The file is generated: pnpm openapi:generate emits it
from the Zod registry under src/lib/openapi/ (registry.ts plus the
route modules in src/lib/openapi/routes/). Do not edit the YAML by
hand; the next generation overwrites it, and CI (openapi:check)
fails the build when the committed YAML drifts from the registry.
The MCP server is documented separately — it is a distinct contract over JSON-RPC, not part of the REST OpenAPI spec:
mcp-capabilities.md— the tool, resource, and prompt catalogue, the grounding contract, and the write model.mcp-skills.md— building a connector or skill on top of it.../self-hosting/mcp.md— enabling and connecting the surface (operator guide).
Preview locally
Open an interactive Redoc preview in your browser:
npx @redocly/cli preview docs/api/openapi.yaml
Generate static HTML for sharing:
npx @redocly/cli build-docs docs/api/openapi.yaml --output docs/api/index.html
Validate
npx @redocly/cli lint docs/api/openapi.yaml
The spec is expected to be lint-clean (errors = 0). Warnings such as
no-server-example.com for the localhost dev server are tolerated;
re-run the lint to see what it produces against the current file
before treating a warning as a regression.
Layout
info— title, description, andversionmirrored automatically frompackage.jsonat generation time. Never bump it by hand.servers—https://healthlog.example.comas the self-hosted placeholder plushttp://localhost:3000for local development.tags— domain groupings; the current set lives at the top of the generated file (Auth,Measurements,Medications,Mood,Analytics,Insights,Consent,Dashboard,Notifications,Devices,Export,Sync,Cycle,MeasurementReminders,Labs,Illness,Documents,Records,Admin,Meta,Retired).securitySchemes:-
bearerAuth—hlk_*API tokens. A scope grants what it names and nothing adjacent, so where a token comes from decides what it reaches:- a completed password / passkey / refresh exchange mints the
cookie-equivalent
["*"]token the native client carries; - a medication's own API-endpoint toggle mints
medication:ingestplusmedication:<id>:ingest, the pair/api/ingest/medicationgates on; POST /api/mcp/tokensmintshealth:read(optionally plushealth:write), audience-bound to/mcpand refused on REST writes;POST /api/tokens/measurementsmintsmeasurements:write, accepted byPOST /api/measurementsandPOST /api/measurements/batchonly, on the holder's own record only.
POST /api/tokensis not among them — that generic mint was removed in v1.30.17. The path still lists (GET) and revokes (DELETE /api/tokens/{id}) every token above, whichever surface issued it. - a completed password / passkey / refresh exchange mints the
cookie-equivalent
-
sessionCookie— HttpOnlyhealthlog_sessioncookie set by the password and passkey login flows. Used by the web app and any iOS client running inside a web view.
-
components.schemas— DTOs for the documented routes plus the underlying Prisma models (e.g.Measurement,Medication,MedicationIntakeEvent,MoodEntry,User,DashboardLayout,ApiEnvelope,ApiError).paths— the client-facing REST surface. Not everysrc/app/api/**/route.tsis in the contract: most/api/admin/*routes, the OAuth connect/callback legs, and the webhook surfaces are not documented here. TheRetiredtag lists removed paths that answer410 Gone.
Conventions
- Successful responses use the envelope
{ data, error: null }. - Error responses use the envelope
{ data: null, error: '<message>' }. - Pagination uses
limit+offsetquery parameters and ameta: { total, limit, offset }block on the response. - All timestamps are ISO 8601 / RFC 3339 (
format: date-time) in UTC. - IDs are CUIDs (opaque strings).
Updating the spec
When adding or changing routes:
- Update the relevant route handler under
src/app/api/**/route.ts. - Change the Zod schemas and their
.meta()registrations undersrc/lib/openapi/(registry entry plus the matching module insrc/lib/openapi/routes/). KeepoperationIdcamelCase and stable; the iOS codegen keys off it. - Run
pnpm openapi:generateand commit the regeneratedopenapi.yamlalongside the schema change. CI'sopenapi:checkfails on drift. - Never edit the YAML directly and never bump
info.versionby hand; the version followspackage.jsonat generation time.