Surface Contract: platform API behavior and x402 pre-payment checks

Install

Works with Claude Code, VS Code, Cursor, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install connector/penny-surface-contract-penny-mcamp-workers-dev-surface-contract

About

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Permissions

What this server can do and what it asks for, from its tool list and install config. Checked Oct 25, 2026.

Tools

4 read · 1 write · 0 delete · 2 not yet classified

Secrets

None asked for

Install scripts

Nothing to install (hosted)

Runs as

Hosted (remote endpoint)

Tools (7)

As the server listed them on Oct 25, 2026. Descriptions are the server’s own words; hidden characters are shown as [U+…].

• contribute_discrepancy

  Report a platform behaviour that contradicts a published claim, or a new claim, with evidence. One-line call: POST /v1/contribute with {contractId, kind, statement, evidence[], reporter, observedAt}. Stored as pending; a published contract is never changed without independent verification. A contractId no published contract serves is accepted as a NEW-PLATFORM PROPOSAL: the 202 body carries contractExists:false (with proposal:true, proposedContractId and proposedHost), it is listed distinctly at GET /v1/contributions, and it stays pending until a second party reproduces it - it never creates o…

• get_integration_recipe

  Get a plain-text integration recipe for a platform: the order of operations to use it, and a guard clause for every behaviour we measured going wrong, each naming the contract claim behind it. Derived from the contract, so it cannot drift from it.

• get_surface_contract

  Get the machine-readable surface contract for a platform host (read/write semantics, pending states, rate limits, limits, idempotency, pagination completeness, data portability), each claim carrying its evidence and its verification status.

• list_surface_contracts

  List the platform surface contracts published in Penny's free registry, with claim counts.

• preflight_mcp_server

  Run the anonymous MCP handshake against ANY https MCP endpoint you name, right now, and get back a verdict (open / refused / unreachable / initialize-transport-error), the shape of any refusal body, whether the server is stateful (sets Mcp-Session-Id), how many tools tools/list returns, and the guard clauses that follow. Use it before wiring an MCP server into your own config. Pass `urls` (up to 5) to check a whole mcp.json in one call. When the endpoint refuses, it also reports whether the refusal advertises a credential path (an RFC 9728 resource_metadata pointer) and whether that pointer re…

• prepay_check

  Check an x402 route BEFORE you pay it. GET /v1/prepay?url=<the route> makes ONE unpaid GET with no payment header and no credential, and returns one row: the measured HTTP status, the parsed x402 v2 challenge (scheme / network / asset / amount / payTo), whether that challenge is schema-valid exact-on-Base, and whether its payTo and price agree with the seller's own card (pass `card` to read that card with one more unpaid GET). No payment is made, no credential is sent, no redirect is followed, and a transport failure on our side is reported as unknown rather than as a fact about the seller. Us…

• verify_surface

  Run the anonymous conformance checks for a contract now and return verified / failed / unknown / manual / unsupported per claim.

Signals

Last release

Oct 22, 2026 (6 days ago)

Details

Registry name

dev.workers.penny-mcamp.penny-surface-contract/surface-contract

Version

2026.10.22

Auth

Auth not stated

License

License unknown

Website

penny-surface-contract.penny-mcamp.workers.dev/

First seen

Oct 24, 2026

Last checked

Oct 24, 2026

Source

Official MCP Registry