AURON MCP — v1 (read-only, multi-tenant, production-lean)

MCP gateway between AI hosts/agents and the AURON Suite backend (api_peluqueria). Identity, tenancy, and RBAC are resolved from the real AURON REST API — the model can never steer them.

What this is

• Read-only: every tool is a GET against a verified AURON endpoint. No create/update/delete is exposed.

• Real identity: resolves the authenticated AURON principal via GET /api/auth/verify/ + GET /api/tenants/current/ (Bearer token or the httpOnly auth cookies that /api/auth/login/ issues).

• Fail-closed RBAC: role → permission mirror (policy/roles.py) derived from AURON's canonical roles. Unknown roles get zero permissions; AURON's own authorization (403) still overrides the table.

• Tenancy delegated to AURON: the adapter NEVER sends tenant_id or an X-Auron-Tenant header. The upstream derives the tenant from the session via its TenantMiddleware, exactly like AURON's own clients.

• Error boundary: nothing internal (messages, tokens, upstream bodies, stack traces) reaches the model — see errors/normalize_error.

• Per-call audit: every tool call (success or denied) is written to an append-only JSONL audit log and stdout.

• Rate limiting: per-(user, tool) sliding-window limiter checked before policy on every call.

Related MCP server: FinOps AI Copilot MCP Server

Tools

Plus a auron://context/current resource and a daily_business_review prompt.

Quick start

python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

Copy .env.example to .env and set the real values:

AURON_ADAPTER=http
AURON_API_BASE_URL=http://localhost:8000

Authenticate once (this stores AURON's httpOnly auth cookies for the gateway):

auron-manage login --email caja@salon.test --subdomain salon-uno
auron-manage status        # verify the resolved identity/role

Run the server:

auron-mcp          # stdio (default; what local MCP hosts expect)

Run over Streamable HTTP (spec 2026-07-28) instead:

AURON_MCP_TRANSPORT=streamable-http \
AURON_MCP_HTTP_HOST=127.0.0.1 \
AURON_MCP_HTTP_PORT=8765 \
auron-mcp          # serves the MCP endpoint at http://127.0.0.1:8765/mcp

The HTTP deployment validates the MCP-Protocol-Version / Mcp-Method / Mcp-Name request headers against the JSON-RPC body (400 + -32020 HeaderMismatch), rejects non-POST with 405, and enables DNS-rebinding protection. See docs/CONNECTING.md for the full endpoint contract and src/auron_mcp/http_app.py for the spec layer on top of the SDK transport.

With AURON_ADAPTER=mock (default) the server works offline with a fixed dev identity (u-mock-1 / t-mock-1 / CLIENT_ADMIN) for development and testing only.

Tests

pytest -q          # 78 tests: policy, rbac, audit, ratelimit, adapters,
                   # identity provider, tools, MCP stdio handshake, and the
                   # 2026-07-28 Streamable HTTP header rules
ruff check src tests

Layout

src/auron_mcp/
  auth/          identity.py (AuronIdentity) + provider.py (resolve via AURON)
  policy/        roles.py (RBAC mirror) + engine.py (PolicyEngine, fail-closed)
  audit/         AuditLogger (JSONL + stdout)
  adapters/      base.py (interface) / http.py (httpx2 + cookies) / mock.py
  tools/         AuronTools (policy + rate-limit + audit around every read)
  errors/        normalize_error (model-safe error boundary)
  server.py      MCPServer wiring (stdio / streamable-http / sse)
  http_app.py    Streamable HTTP deployment: 2026-07-28 header validation,
                 DNS-rebinding settings, optional bearer token
  manage.py      operator CLI: login / status / clean

Security principles

1. Never trust a tenant ID supplied by an LLM as an authorization boundary.

2. Resolve tenant/scope from authenticated identity and server-side policy.

3. Tools are read-only; side effects are intentionally out of scope for v1.

4. Every sensitive action is auditable — including denied attempts.

5. MCP calls stable AURON application APIs, never raw SQL.

6. Never expose secrets, JWTs, upstream response bodies, or stack traces to the model.

7. A tool call has a cost — rate-limit it.

See docs/mcp-integration-audit.md (audit of the real AURON backend), docs/ARCHITECTURE.md, docs/CONNECTING.md, and docs/ROADMAP.md.