Pay-Per-Call MCP and x402

The short answer first, because you probably came here for it: Datakoot does not implement x402. There is no wallet to fund and nothing is settled per call. Datakoot gives you 100 calls a day free without an account, and a flat monthly subscription if you need more than that. Below is what x402 actually is, why Datakoot went the other way, and what to do if x402 is genuinely what your agent needs.

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 and rather elegant:

• A client calls a paid endpoint with no payment attached.
• The server answers 402 with a PAYMENT-REQUIRED header describing its terms.
• 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.

It is chain-agnostic, and stablecoins are the primary case. The appeal for AI agents is real: an agent can buy one call, by itself, with no account, no card, and no human in the loop.

Why Datakoot does not use it

• Your agent would need a funded wallet. Claude Desktop, Claude Code, Cursor and Windsurf all speak MCP over plain HTTP. None of them carry a wallet or sign payments. Shipping x402 would mean every user had to solve a crypto problem before they could look up a single CVE.
• The free tier already solves what micropayments solve. The reason to pay per call is to use something without signing up. Datakoot’s free tier is keyless: 100 calls a day, no account, no key, no wallet. There is nothing to sign up for in the first place, so there is nothing for a micropayment to get you past.
• The payment costs more than the data. Pay-per-call wraps a 402, a signature, a verification and an on-chain settlement around a lookup that otherwise finishes in milliseconds. For sub-cent data, the payment is most of the cost and most of the latency.
• A subscription is what a finance department can approve. One invoice a month, and a flat, predictable monthly fee. A stream of on-chain micropayments is a harder thing to get signed off, and a harder thing to reconcile afterwards.

What Datakoot does instead

Free on every server — 100 keyless calls a day, no signup. Pro is $15/mo and includes 50,000 calls a month with no daily limit — one key unlocks all nine Datakoot servers. Go over and you drop to free-tier speed or top up, never cut off. See full pricing →

The free tier needs no key at all:

And a paid key is one header on the same line:

If you actually need x402

Some agent platforms are being built wallet-first, and for those x402 is exactly the right shape. If that is you, say so: email hello@datakoot.com and describe what you are building. Datakoot is a one-person company, and a real caller asking for something is what moves it up the list — far more than a guess about what people might want. The specification lives at x402.org.

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