spb/skills-spboucher-ai

1# ADR-0008 — The MCP server is a thin client of the REST API, with bearer authentication23Status: accepted for V1, 2026-11-09. Describes the build contract for `apps/registry-mcp`.45## Decision67- The registry MCP server implements the Model Context Protocol with the official TypeScript SDK and exposes two transports: Streamable HTTP at `/mcp` (stateless, JSON responses) and stdio (`apps/registry-mcp/src/stdio.ts`).8- Every tool is implemented by calling the REST API through `@skills/sdk`. The server holds no database connection and no privileged credential of its own.9- For authenticated tools, the caller's `Authorization: Bearer skr_…` header is forwarded to the REST API unchanged. For stdio, the token comes from the environment.10- Archive bytes never travel through MCP. `begin_release_upload` returns an upload URL; the client sends the archive with an HTTP `PUT`, then calls `finalize_release`.11- There is no tool for shell execution, filesystem access on the server, token readback or fetching arbitrary URLs.1213## Why1415RBAC, scopes, namespace checks, rate limits, idempotency and audit already exist in the REST layer and are tested there. Reusing them through HTTP makes the two surfaces identical by construction, and a bug in an MCP tool cannot bypass authorization because the tool has no authority of its own.1617## Authentication caveat1819The MCP specification (revision 2026-07-28) makes authorization optional and, when used over HTTP, describes an OAuth 2.1 flow. It does not define static bearer tokens. Sending an API token in the `Authorization` header is common practice supported by Claude Code, Codex and Cursor, and is what V1 does. OAuth 2.1 with protected-resource metadata is Planned.2021## Consequences2223- Tool output is registry content written by third parties. Clients must treat it as untrusted data, not as instructions.24- One extra loopback HTTP hop per tool call.25- Clients that only speak the OAuth flow cannot use the authenticated tools until OAuth is implemented; public tools need no authentication.26