In 1992, the architects of HTTP wrote a status code into the protocol: 402 Payment Required. It sat unused for thirty years. This week, we shipped a live implementation.
The idea was elegant. Alongside 401 Unauthorized and 404 Not Found, someone at the W3C imagined a web where a server could simply say: "I have what you need. Pay me first." The original spec even described how it would work — the server would return acceptable payment schemes, and the client would retry with a ChargeTo header to authorize the transaction.
It never happened.
The web didn't get native micropayments. It got credit card forms, subscription paywalls, and an advertising economy built on surveillance. The 402 code sat in every HTTP specification for three decades, always with the same footnote: "Reserved for future use."
Mycelia Signal now serves cryptographically signed price data over both payment rails that have finally made 402 real:
Request data. Receive a 402 with a Lightning invoice. Pay 10 sats. Get a secp256k1-signed price attestation. The entire exchange takes under 2 seconds.
Same request. Same 402. Pay $0.01 USDC. Get an Ed25519-signed attestation. The USDC transfer is verified on-chain before the data is released.
Same oracle. Same canonical data format. Same independent verification. Two payment protocols that finally do what the web's designers imagined in 1992 — native, programmatic, per-request payment at the protocol level.
No API key. No subscription. No account. No intermediary deciding who gets access. A machine that can pay gets the data. A machine that can't doesn't. That's the entire access model.
You can try it right now at myceliasignal.com/demo.
The reason this matters goes beyond nostalgia for a cleaner internet. As regulators across the US, EU, and UK converge on requirements for independent, verifiable price feeds in crypto lending and collateral management, the question of how that data gets delivered and paid for becomes a real architectural decision.
Traditional API access models — keys, subscriptions, whitelists — create dependencies and single points of failure. A per-request payment model changes the relationship: you pay for exactly what you use, the oracle has no ongoing obligation to maintain your access, and there's no account to suspend or revoke. The payment is the authorization.
For AI agents specifically, this is the only model that works at scale. An autonomous agent can't fill out a sign-up form. It can't manage API key rotation. It can pay a Lightning invoice or sign a USDC transfer. The 402 model is the native payment primitive for the agentic economy — which is why it was worth waiting for the infrastructure to catch up.
402 was always the right answer. It just needed the payment infrastructure to catch up.
It caught up.
Mycelia Signal is a sovereign cryptographic oracle — 56 signed endpoints across crypto, FX, economic indicators, and commodities. Payable by AI agents via Lightning (L402) or USDC on Base (x402). Try the live demo or read the docs.