Sirloin

Sirloin

Responsibility

Sirloin is the main Go API. It serves gRPC and REST surfaces and owns billing, media user-facing state, credits, shop state, admin and audit state, autoscaling records, and MCP/Foxy360 runtime persistence.

Runtime

The service runs as a Go binary from apps/sirloin/cmd/app and is wired by docker-compose and apps/sirloin/railway.json.

Primary Source Paths

• apps/sirloin/cmd/app/
• apps/sirloin/internal/app/services/
• apps/sirloin/internal/app/worker/
• apps/sirloin/internal/pkg/models/
• apps/sirloin/internal/app/flankmcp/

Contracts And Generated References

• Proto contracts: proto/sirloin/v5/
• Generated Go stubs: apps/sirloin/internal/pkg/pb/
• Generated proto docs: api/server.md
• Generated Brain client consumed by sirloin: apps/sirloin/pkg/brain-client/

Related Flows

• Billing
• Media Generation
• Authentication

Related Standards

• Billing Pricing
• Media Credit Costs
• Auth Boundaries

Related Decisions

Billing and payment ADRs live under docs/src/content/docs/decisions/.

Operations

Billing docs now live under decisions, standards, flows, and operations pages. Start with Billing Operational Runbook after the operations migration lands.

Local Commands

make run-tests-all requires the sandbox or integration environment variables used by Sirloin integration tests.

• cd apps/sirloin && make lint
• cd apps/sirloin && make run-tests
• cd apps/sirloin && make run-tests-all
• cd apps/sirloin && make ci-all