Pay-Per-Call MCP and x402

The short answer first: every Datakoot tool can be paid for per call with x402. All 48 tools across all nine servers can be paid this way: $0.002 a call, or $0.01 for the security and package tools, paid in USDC on Base by your agent itself, with no account, no API key and no subscription. A call is only charged when it succeeds. If you would rather have one card and one key, Pro is $15 a month. Below is what x402 is, how Datakoot runs it, and how to connect.

What x402 is

x402 is an open payment standard, now a Linux Foundation project, that puts the long-dormant HTTP status code 402 Payment Required back to work. The flow is small:

• A client calls a paid endpoint with no payment attached.
• The server answers 402 with a PAYMENT-REQUIRED header describing its price and where to pay.
• The client signs a stablecoin payment with a wallet and retries the same request, this time carrying a PAYMENT-SIGNATURE header.
• The server has a facilitator verify and settle that payment on-chain, then returns the data.

The appeal for AI agents is that an agent can buy one call, by itself, with no account, no card, and no human in the loop.

How Datakoot runs it

• Free first. Every server still gives every caller 100 calls a day with no key at <server>.datakoot.com/mcp. When that runs out, the response points your agent to the paid options.
• Two prices. $0.002 per call for most tools (1,000 calls cost $2), and $0.01 for the security and package tools. Each tool’s 402 response states its exact price.
• Charged only on success. Datakoot verifies the payment first, runs the tool, and settles the payment only if the tool returned a result. A failed call is never charged.
• Gasless for you. Your agent signs a USDC transfer authorization (EIP-3009). The facilitator submits it, so your wallet needs USDC on Base and no ETH.
• A receipt for every call. Each paid response carries a PAYMENT-RESPONSE header with the Base transaction hash.

Endpoints

All 48 tools behind one endpoint:

Or one server at a time, for example only the security tools:

The full machine-readable catalog, with every tool, its schema and the payment requirements, is at x402.datakoot.com/discovery. The server keys are security, package, filings, economy, market, weather, domain, regulatory and base.

What your agent needs

A wallet on Base with a little USDC, and an x402-capable client. Coinbase's open-source x402 libraries handle the 402, the signing and the retry for you. Most desktop MCP clients do not carry a wallet yet; for those, the keyless free tier and Pro are the simpler path.

Payment requirements Datakoot sends, so you can check your client against them:

• Protocol: x402 version 2, scheme exact
• Network: Base mainnet (eip155:8453)
• Asset: USDC (0x833589fcd6edb6e08f4c7c32d4f71b54bda02913)
• Amount: 2000 (6 decimals, $0.002; security and package tools use 10000, $0.01)
• Facilitator: PayAI

Pay per call or Pro?

Pro ($15 a month, 50,000 calls, no daily limit) is simpler for a person: one card, one key on the same line you already use.

Pay per call suits an agent that holds its own budget and should never wait for a human to sign up. Questions either way: hello@datakoot.com. The specification lives at x402.org.

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