Code402 · Verification infrastructure

Find protocol gaps before agents find them.

Free structural preflight for UCP, ACP, MCP, AP2, x402, A2A and Code402 Micro-AST. Submit a redacted JSON document and receive specific findings you can share with your integration team.

Machine-readable coverage · OpenAPI · Discuss an integration audit

Seven protocols. Explicit checks.

UCP: profile envelope, version, registries, transport endpoints and capability schema pointers.
ACP: selected checkout-response fields, status, currency shape and integer totals.
MCP: initialize and tool-list response structure, versions, names and input schemas.
AP2: exact versioned type on a decoded mandate claim, open constraints and expiry shape.
x402: v2 requirements, atomic amounts, EVM addresses and expected payout comparison.
A2A: agent card identity, capabilities and skill declarations.
Micro-AST: custom catalogue counts, tool IDs, target URLs and prices, including free tools.

Call from your agent

Send JSON to POST /v1/protocols/check:

{"protocol":"mcp","document":{"jsonrpc":"2.0","id":1,"result":{"tools":[]}}}

Connect an MCP client to https://hcrb.in/protocols/mcp and call protocol_preflight. The same input works over REST.

Know what a result means

This is selected structural preflight, not certification. It does not verify signatures, identity, delegated authority, live settlement, fulfillment or complete protocol compliance. AP2 results must never authorize spending. No payment is required.

Submit redacted documents. Responses omit submitted field values. The checker does not fetch supplied URLs, persist submitted documents or move funds.

For production integration work, request an audit scoped to your protocol and implementation. Existing paid validation and signed receipts are available through the core MCP integration; receipt verification remains free.