TensorFeed x402 Base Reader

What TensorFeed x402 Base Reader does

TensorFeed x402 Base Reader MCP server exposes read-only Base mainnet checks through MCP. Its generic chain tools cover native ETH and Circle-native bridged USDC balances, the latest block number, transaction receipts, read-only eth_call requests, and USDC transfer history for an address.

The x402-specific tools help an agent examine the payment protocol around a request. They can compare an on-chain Transfer event with an expected recipient and USDC amount, retrieve a publisher's /.well-known/x402.json manifest, find recent USDC payments received by a merchant, inspect whether an HTTPS endpoint returns a canonical paid 402 response, and decode a base64 Coinbase x402 V2 X-PAYMENT header.

TensorFeed-specific checks extend those primitives to AFTA federation certification, TensorFeed payment lookup, monitored publisher health, and the curated list of confirmed AFTA federation members.

How it works

The server reads Base mainnet through an RPC endpoint and returns structured results to the calling MCP client. Settlement verification uses a transaction hash, expected recipient, and expected USDC amount to determine whether the relevant on-chain Transfer event matches those inputs. The contract-call tool uses eth_call only; it does not submit transactions.

Manifest and endpoint tools make external HTTPS requests. The federation and TensorFeed tools call TensorFeed's documented certification, payment, monitoring, or federation surfaces. Payment-payload decoding is performed offline from the supplied header value.

TensorFeed x402 Base Reader does not manage a wallet. It has no private-key handling, signing, or transaction broadcasting. Input validation rejects malformed addresses and hashes, URL-shaped domains, and private or loopback hostnames. Returned strings are sanitized, external values are marked with an external origin, and serialized tool output is capped at 50 KB.

Setup and configuration

Install the package globally with npm:

npm install -g @tensorfeed/x402-base-mcp

For Claude Desktop, add an MCP entry that runs npx -y @tensorfeed/x402-base-mcp. Claude Code can add the same command with claude mcp add tensorfeed-x402-base -- npx -y @tensorfeed/x402-base-mcp. The README also identifies Cursor and ChatGPT as compatible MCP environments.

The default RPC is https://mainnet.base.org, which is intended for casual use. Heavier workloads can use an Alchemy or Infura Base URL through TENSORFEED_RPC_URL. The configured URL must be on the source allowlist; unsupported values fall back to the public Base endpoint and produce a warning on stderr.

Tools and capabilities

• Query ETH and USDC balances, the latest block, transaction receipts, contract calls, and recent USDC transfers.
• Verify a claimed x402 USDC settlement against the transaction's Transfer event.
• Retrieve x402 manifests and inspect x402 payment responses from HTTPS endpoints.
• Decode Coinbase x402 V2 payment headers without sending a transaction.
• Check AFTA federation status, TensorFeed wallet payments, publisher health, and federation membership.

Limitations and notes

TensorFeed x402 Base Reader is a verification and inspection server, not a payment executor. It cannot approve wallets, sign x402 payments, transfer assets, or broadcast transactions. Its chain results depend on the selected Base RPC endpoint, and the default public endpoint may be unsuitable for heavier workloads.

The server is focused on Base mainnet and USDC settlement checks described by its tools. External manifests, endpoint responses, and TensorFeed status data come from third-party or remote surfaces and should be evaluated with that provenance in mind. npm releases use GitHub Actions OIDC provenance, and the package is licensed under MIT.