AirnodeHub is exposing its API catalogue through a single Streamable HTTP MCP endpoint that does not require a client account or API key. A live search-listings request on September 28 returned 36 listings, spanning crypto markets, blockchain data, finance, transport, health, weather and public statistics. AirnodeHub MCP documentation.
The endpoint gives MCP clients four main steps: search the catalogue, inspect a listing, call a declared operation and verify the response attestation. That common interface means a client can move from a CoinGecko price request to an ECB data query or a Hyperliquid market lookup without integrating a separate authentication flow for each listing. The catalogue count is a current snapshot and can change as listings are added or removed.
Keyless access has a limited meaning here. The client does not supply an AirnodeHub account or API key, while the Airnode deployment can hold credentials needed by the upstream API. Free operations can be called directly. If an operation is priced, the MCP server does not pay on the caller's behalf. It returns the x402 payment requirements so a wallet-enabled client can settle the request directly. API consumer documentation.
Successful calls return the upstream data with an Airnode address, request hash, timestamp and EIP-191 signature. The request hash binds the attestation to the operation, parameters and any response projection used by the caller. The verify-attestation tool checks the expected listing address, rebuilds that request hash and recovers the signer from the signature. Attestation specification.
The signature proves which listed Airnode signed a particular response and whether the signed material was altered. It does not independently prove that the upstream value was accurate, and a third-party listing attests to relaying a response rather than originating the underlying data. Developers can see the verification sequence in the earlier AirnodeHub ETH response walkthrough.
Explore AirnodeHub to browse the current API catalogue.