Paxaver MCP Server
AI-facing adapter over the Paxaver school community platform.
Implements the Model Context Protocol (MCP) on Cloudflare Workers with RS256 JWT
validation, capability-first authorization, and Streamable HTTP transport.

What this is
The Paxaver MCP server lets AI assistants (ChatGPT, Claude, Perplexity, and any
MCP-compatible client) act on behalf of a Paxaver user: check a lunch menu, order
lunch, register for fundraising events, volunteer, and — for school administrators
— manage restaurants, menu items,
events, and daily orders.
It is a thin adapter. It contains no business logic and never touches the
database, Stripe, or email directly. Every action is delegated to the private
Paxaver backend API over a Cloudflare service binding (same region, no public
network hop). The MCP server's only responsibilities are:
- MCP protocol handling (JSON-RPC 2.0, Streamable HTTP)
- RS256 JWT validation via JWKS from the centralized Paxaver auth worker
- Per-tool capability policy and role gating
- Sanitized, user-safe error mapping
Authentication is handled by the Paxaver auth worker (auth.paxaver.com), which
serves as the OAuth 2.0 / OIDC authorization server. The MCP server validates
the resulting RS256 JWTs and forwards them to the backend. The MCP server itself
is not an authorization server.
Architecture
┌───────────────┐ MCP (Streamable HTTP) ┌──────────────────────┐
│ AI Client │ ─────────────────────────────▶ │ Paxaver MCP Worker │
│ ChatGPT/Claude│ ◀───────────────────────────── │ (this repo) │
│ /Perplexity │ RS256 JWT + JSON-RPC 2.0 │ Hono + jose │
└───────────────┘ └──────────┬───────────┘
│
Cloudflare service binding
(PAXAVER_API, same region)
│
▼
┌──────────────────────┐
│ Paxaver API Worker │
│ (private backend) │
│ D1 · Stripe · SES │
└──────────────────────┘
The MCP worker never binds D1, Stripe, or SES. The service binding carries a
short-lived JWT (120s TTL, audience paxaver-internal) that the backend trusts as
an internal call while still attributing the action to the authenticated Paxaver
user. See docs/architecture.md for the full picture.
Quick start
Install
Develop locally
npm install
npm run dev
npm run typecheck
npm run lint
npm test
The local dev server starts on http://localhost:8787. Discovery endpoints live
under /.well-known/; the MCP endpoint is POST /mcp.
Note: Local development without the PAXAVER_API_* service bindings falls
back to authenticated HTTPS against API_BASE_URL_CA, API_BASE_URL_US, and
API_BASE_URL_MX (default http://localhost:8787). For full integration
testing, run the Paxaver backend worker locally; the defaults already point at
it.
Deployment
Two environments, each a separate Worker with its own custom domain:
| Environment | Worker name | Domain |
|---|
staging | paxaver-mcp-staging | mcp.paxaver.dev |
production | paxaver-mcp | mcp.paxaver.com |
The production worker serves both CA and US users through a single endpoint
(mcp.paxaver.com). User region is resolved from the JWT tenant_id claim,
and the worker routes to the correct regional backend via service bindings
(PAXAVER_API_CA, PAXAVER_API_US). Currency is determined by the user's
school, not by the MCP endpoint.
Docker
The Dockerfile runs the worker locally via wrangler dev, proxying the
production backends over HTTPS:
docker build -t paxaver-mcp .
docker run -p 8787:8787 paxaver-mcp
npm run deploy:staging
npm run deploy:prod
The worker requires no secrets. See
docs/deployment.md.
The server exposes 26 tools grouped into five categories. Visibility in
tools/list is filtered by the caller's roles; every call is re-authorized
before dispatch, and the backend re-checks data-level access (defense-in-depth).
| Category | Tools |
|---|
| User / account | get_my_context, get_my_wallet_balance |
| Lunch ordering | get_lunch_menu, list_my_lunch_orders, create_lunch_order_draft, update_lunch_order_draft, discard_lunch_order_draft, pay_lunch_order_draft, cancel_my_lunch_order |
| Events & volunteering | list_school_events, register_for_event, list_my_event_registrations, cancel_my_event_registration, list_my_volunteer_signups, sign_up_for_volunteer_shift, cancel_my_volunteer_signup |
| Event administration | create_school_event, update_school_event, cancel_school_event |
| Restaurant / menu admin | list_school_restaurants, create_school_restaurant, list_restaurant_menu_items, create_restaurant_menu_item, update_restaurant_menu_item, archive_restaurant_menu_item, schedule_lunch_menu_item |
Ordering is draft → review → payment: create_lunch_order_draft, adjust
with update_lunch_order_draft, then pay_lunch_order_draft.
Compatibility: pre-2.5 tool names (get_menu, register_event,
create_menu_item, …) still work — they resolve to the canonical tools —
but are no longer advertised. order_lunch also remains callable for
existing integrations. See docs/tools.md for the full
legacy-name mapping.
Financial and destructive tools are labeled and require user confirmation. Full
reference: docs/tools.md. Authorization policy:
docs/authorization.md.
Privacy
No personal contact information (email, phone, address) is collected or
returned through MCP tools. The get_my_context tool returns only the user's
name, school, students, and roles. Student data is limited to IDs, names, and
school slugs. Allergies, notes, birthday, and other PII are not exposed in
read responses. The MCP server does not log user data.
Documentation
| Document | Topic |
|---|
| docs/architecture.md | System architecture, service binding boundary, regional isolation |
| docs/authentication.md | JWT validation, JWKS, auth worker delegation, token format |
| docs/authorization.md | Capability policy table, role gating, defense-in-depth |
| docs/tools.md | Full tool reference with input schemas and classifications |
| docs/deployment.md | Wrangler config, environments, secrets, custom domains |
| docs/security.md | Security model, CORS, CSRF, error sanitization, headers |
| docs/compatibility.md | MCP protocol version, transports, supported AI clients |
| docs/migration.md | Migration from the legacy mcp-server/ in the private monorepo |
| CHANGELOG.md | Release history |
| SECURITY.md | Vulnerability reporting policy |
| CONTRIBUTING.md | Development setup and contribution process |
Tech stack
- Runtime: Cloudflare Workers (
compatibility_date: 2026-09-15)
- Framework: Hono v4
- JWT: jose v6 (RS256 via JWKS)
- Protocol: MCP
2025-06-18, Streamable HTTP
- Auth: RS256 JWT validation via centralized auth worker (
auth.paxaver.com)
- Build/deploy: Wrangler v4
- Test: Vitest v2 (Workers pool + Node pool)
License
Apache-2.0. Copyright (c) 2026 Smartoire. See LICENSE.