MPCP Ecosystem Roadmap
MPCP development is tracked per-repository. Each repository has its own ROADMAP.md covering its specific implementation phases.
Repositories
| Repository | Role | Roadmap |
|---|---|---|
| mpcp-reference | Protocol core — canonical SDK, verifier, schemas, anchoring adapters, golden vectors | ROADMAP.md |
| mpcp-policy-authority | Deployable policy authority service — grant issuance, revocation, Trust Bundle issuance, on-chain anchoring | ROADMAP.md |
| mpcp-wallet-sdk | Wallet SDK — session management, SBA signing, budget enforcement (Node.js + browser) | ROADMAP.md |
| mpcp-merchant-sdk | Merchant SDK — SBA verification, revocation caching, spend tracking, framework adapters (Express / Fastify / Next.js / Edge) | ROADMAP.md |
| mpcp-gateway | Transparent payment gateway — speaks x402 externally, enforces MPCP internally; bridges non-MPCP agents to MPCP merchants | ROADMAP.md |
| mpcp-gateway-client | Agent-side fetch wrapper — GatewayClient + session.fetch(); soft-limit continuation; LangChain / Vercel AI / AutoGen adapters |
ROADMAP.md |
| mpcp-spec | Protocol specification, architecture docs, guides | this site |
Implementation status
mpcp-reference
All core phases complete.
Implemented: canonical serialization · artifact schemas · full verification engine · CLI verifier with explain mode · Hedera HCS and XRPL anchor adapters · did:xrpl resolver · XRPL NFT revocation · Trust Bundle signing and verification · resolveFromTrustBundle for key lookup · AES-256-GCM encrypted policy anchoring · golden protocol vectors · human-to-agent delegation profile · TRIP budget scope · checkRevocation utility.
mpcp-policy-authority
All phases complete. Grant issuance, policy custody, revocation endpoint, Trust Bundle issuance and signing, XRPL NFT mint/burn, persistent custody with soft-delete, audit log with webhook dispatch, multi-key admin API.
mpcp-wallet-sdk
All core and ecosystem integration phases complete. Node.js monorepo (@mpcp/core, @mpcp/agent, @mpcp/issuer, @mpcp/react).
Implemented: parseGrant · createSession(grant, opts) → Session · session.createSba({ amount, currency, rail }) · per-session budget ceiling enforcement · live revocation checking with TTL cache · session.remaining() · SQLite session persistence via Drizzle · Web Crypto signing path (CryptoKey support for browser) · @mpcp/react package (usePolicyGrant, useSession hooks) · createX402Client adapter (MPCP budget enforcement wrapping x402-gated APIs) · full integration test suite.
Deferred: React Native bundle + AsyncStorage adapter (PR7).
mpcp-merchant-sdk
All phases complete. Full Express / Fastify / Next.js / Edge (Web Crypto) adapter suite.
Implemented: verifyMpcp(sba, opts) · mpcp() Express/Fastify middleware · withMpcp() Next.js HOC · verifyMpcpEdge (zero Node.js deps) · Trust Bundle key resolution (trustBundles option) · revocation checking with TTL cache · spend tracking · verifyMpcpEdge Ed25519 + P-256 support.
mpcp-gateway
All phases (P1–P10) complete. The gateway bridges non-MPCP agents to MPCP merchants: intercepts HTTP 402, executes x402 payments, enforces session budgets/purposes/policies, and optionally attaches a signed SBA (X-Mpcp-Sba) so MPCP-aware merchants can verify the authorization chain.
Implemented:
- P1 — Core proxy + x402 interception
- P2 — Session CRUD REST API (
POST / GET / DELETE /sessions) - P3 — Ed25519-signed receipts + audit log (
GET /sessions/:id/receipts) - P4 — MPCP passthrough headers (
X-Mpcp-Sbaon 402 retry) - P5 — Production hardening: health/ready/metrics endpoints; pluggable
PaymentRail;KeyRingwith rotation; Dockerfile; SQLite session persistence (Drizzle + better-sqlite3 WAL) - P6 — Trust Bundle auto-distribution (
/.well-known/mpcp-trust-bundle.json; zero merchant env-var config) - P7 — Spend webhooks: HMAC-signed push notifications at configurable thresholds;
payment.deniedevents; dispatch log - P8 — Session policy controls: merchant allowlist/blocklist (glob); velocity limits (max payments/hour, max amount per merchant/day)
- P9 — Soft budget ceiling + continuation token: budget exhaustion pauses instead of hard-failing;
PATCH /sessions/:idraises ceiling via single-use HMAC token - P10 — x402 merchant mode:
POST /charge/GET /charge/:id/verify;/.well-known/x402-payment-info
Deferred items (each a standalone PR): PostgreSQL adapter, Redis session cache, per-owner rate limiting, OpenTelemetry traces, Prometheus text-format metrics.
mpcp-gateway-client
P1–P3 complete. P4 (receipts + audit) planned.
Implemented:
- P1 — Core client:
GatewayClient,createSession,session.fetch()wrapper, session CRUD; zero runtime deps; TypeScript + ESM - P2 — Soft-limit continuation:
onSoftLimitcallback;continueSession(); automatic retry on user approval - P3 — Framework adapters:
GatewayFetchTool(LangChain),gatewayFetchTool()(Vercel AI SDK),gatewayFetchFn()(generic function-calling / AutoGen)
Planned:
- P4 — Receipts + audit:
getReceipts(),verifyReceipt()(Ed25519),fetchGatewayKeys()
Spec roadmap
Protocol specification work is tracked via GitHub pull requests on mpcp-spec. Spec changes accompany each reference implementation PR that introduces new protocol fields or behaviors.
Upcoming spec work:
mpcp-gateway-clientP4 (receipts + audit) — spec alignment when implementedmpcp-wallet-sdkPR7 (React Native bundle) — spec alignment when implementedmpcp-referencePhase 6 pending PRs (PR21–PR25) — payment profiles, L1 evaluation, conformance badge