Replaces the M5.1-skeleton handler set with the M4.2 spec from
IMPLEMENTATION_PLAN.md:
Endpoints (authoritative shape in openapi.yaml):
POST /v1/tenants
GET /v1/tenants/{id}
GET /v1/tenants/by-slug/{slug}
POST /v1/tenants/{id}/activate
POST /v1/tenants/{id}/cancel
GET /v1/entitlements?tenant_id=...
GET /v1/catalog
POST /v1/catalog/request
POST /v1/catalog/trial-request
POST /v1/api-keys returns plaintext ONCE
GET /v1/api-keys?tenant_id=...
DELETE /v1/api-keys/{id}
POST /v1/internal/api-keys/verify always 200; valid: bool
POST /v1/audit
GET /v1/audit?{tenant_id,product,actor_id,action,since,until,limit,cursor}
Architecture:
internal/store/store.go Store interface (CRUD + audit + ping)
internal/store/memory.go in-process impl, used when DATABASE_URL
is empty (seed acme tenant, no migrations)
internal/store/postgres.go pgxpool impl against the M4.1 schema
internal/server/server.go router + healthz/readyz
internal/server/{tenants,catalog,apikeys,audit}.go
per-concern handlers (≤250 LoC each)
internal/server/helpers.go writeJSON/writeError/error mapping/log mw
openapi.yaml 3.1 spec; openapi_test.go is the contract gate
API keys:
Plaintext format 'bp_<22-char base64>'. Prefix bp_<8> stored for UI.
Hash is argon2id(salt, time=1, mem=64MB, threads=4, len=32) encoded as
'argon2id|<salt-b64>|<hash-b64>'. Format-tagged so we can rotate
parameters without re-keying. Verify is constant-time.
Store selection:
cmd/server picks Postgres when DATABASE_URL is set, otherwise Memory.
Both implementations are exercised by the same eachStore test harness —
parity is enforced.
Audit:
Every state-changing endpoint emits via s.emitAudit() (fire-and-forget).
audit_log uses ON DELETE SET NULL on tenant_id so forensic history
outlives tenant deletes (per M4.1 schema).
Routing constraint:
Go 1.22 ServeMux can't disambiguate /v1/tenants/{id}/products from
/v1/tenants/by-slug/{slug=products}. Per-tenant subresources moved to
query-param top-level paths: /v1/entitlements?tenant_id=… and
/v1/api-keys?tenant_id=….
Tests:
Every endpoint exercised against both Memory and Postgres via the
eachStore harness. Includes happy paths, validation errors, conflicts,
404s, auto-audit-emit assertion. testcontainers-go for the postgres
harness; gated by -short.
TestOpenAPISpec is the contract gate: every documented operation must
resolve against the router. (kin-openapi v0.138.0.)
Refs: M4.2
Minimal Go service: /healthz + /v1/tenants/by-slug/:slug + /v1/tenants/:id with an in-memory store seeded with the acme tenant. Stdlib-only; pgx + JWT validation land in M4.1 follow-up.
sharang