How to Buy a Dataset With x402
How to buy a dataset with x402: what an agent sends, what the server returns, how payment settles in USDC, and what it costs. Updated July 2026.
Buying a dataset over x402 takes one HTTP exchange. The agent requests the resource, the server replies with a price, the agent signs a payment in USDC, and the file comes back. There is no account, no API key and no checkout page anywhere in the sequence.
The exchange, step by step
1. The agent requests the dataset. A normal HTTP request to the resource URL, with no credentials attached.
2. The server answers 402. Instead of the file, it returns HTTP status 402 Payment Required, along with a machine-readable specification: the price, the accepted networks, the token, and the address to pay.
3. The agent signs a payment authorisation. Using its wallet, it produces a signed authorisation for the stated amount. On EVM chains this is an EIP-712 typed-data signature.
4. The agent repeats the request, with proof of payment attached.
5. A facilitator settles the transfer on chain and the server verifies it.
6. The server returns the dataset. The whole exchange completes inside the same request cycle, in seconds.
What you need before you start
A wallet that can sign on the network the seller accepts, most commonly Base or Solana. A USDC balance on that network. An x402 client library, available for TypeScript, Python and Rust.
That is the full list. There is no signup step, no plan to choose and no key to store.
What it costs
Prices are set by the seller and stated in the 402 response, so a buyer always sees the cost before paying. Real-time data endpoints commonly sit between $0.0001 and $0.10 per call. Curated datasets and research files are priced higher, reflecting the work behind them rather than the cost of a lookup.
Because the price arrives in the response, an agent can decide whether the resource is worth buying before committing any funds.
Why it works this way
Conventional purchasing assumes a human: an account to create, a card to enter, a subscription to choose. An agent cannot do any of that unsupervised. x402 replaces the whole sequence with a signed message, which is something software can do on its own.
The result is that a dataset becomes purchasable the moment an agent decides it needs it, rather than after a procurement process.
About Cantica
Cantica is the Fin-Tech intelligence system behind The Bright Minded. It ingests public material, and produces original derived datasets and reports on the Fin-Tech industry. Human buyers purchase through standard checkout. AI agents request a premium dataset, receive an x402 response stating the price and terms, pay in USDC, and receive the file within seconds. Cantica datasets are available at Cantica Data.