x402-protocol-integration

Request an L402 payment challenge

Vet an x402 seller before paying it: probes its live 402, reads its CDP Bazaar entry (payers, calls, last call, repeat vs evaluation usage), checks trust surfaces, returns a scored LIVE/STALE/UNLISTED/MISCONFIGURED/UNREACHABLE verdict and what changed since our last check, signed by our attestor. MUST be invoked before a first payment to an unknown resource, or on a schedule to watch it. Do NOT use to pay it. Settles $0.010 USDC; no charge on failure.

POST JSON: {"event":{id,pubkey,created_at,kind,tags,content,sig},"checkZap":false} Verifies id/sig. checkZap extracts kind-9735 bolt11; preimage proves zap settlement. Does not hit relays. Spec: https://api.major-miners.com/.well-known/l402-services

POST JSON: {"text":"hello","type":"uppercase"} type=uppercase|reverse|leetspeak|morse Demo transform. Prefer LNURL / Nostr / preimage_verify on this host. Spec: https://api.major-miners.com/.well-known/l402-services

POST JSON: {"target":"user@domain"} optional amountSats for a BOLT11. Does not pay. Lightning-native: resolve LN addresses / LNURL-pay. Spec: https://api.major-miners.com/.well-known/l402-services lnget -X POST -H "content-type: application/json" -d '{"target":"victoriousinnovation563427@getalby.com"}' https://api.major-miners.com/api/lnurl

Register an x402 endpoint so agents can find and pay it (x402scan + Coinbase Bazaar). The complete discovery path for an x402 endpoint: publish machine-readable discovery documents, pass the official validator, list on x402scan, understand what actually triggers Coinbase Bazaar indexing, and prove the listing exists from the registry's own API instead of a success toast. Written from an endpoint set that went from 0 to 11 listed resources, with the exact API payloads a registry expects today.

Web search: ranked results (title + url) for a query. ?q=x402+agent+payments&limit=8

Who actually earns on x402: 2,225 services, and 28 of them clear $100 a month. 316,517 paid calls in 30 days — x402 works. But 33% of listed services took zero calls, the median earner made $0.15 for the month, and one endpoint (8 calls at $5,000.01) is 69.8% of all gross. Both figures reported, with and without it. One payment returns the full text, and the creator is paid as it is used.

x402 is a Base/USDC monoculture: 2,803 of 2,832 services accept exactly one chain. The protocol is chain-agnostic; the market is not. 99% of x402 services accept Base only, effectively all price in USDC, and 2,829 of 2,832 accept a single chain. Plus the 24 testnet listings sitting in the production catalog waiting to take your money for nothing. One payment returns the full text, and the creator is paid as it is used.

Measure any x402 business's real revenue from the chain: the payTo address is public. Every x402 service publishes the address it wants paid at, so its settlement is countable by anyone. The eth_getLogs trick that watches every seller at once, what it returned across all 33 authors of one platform, and the two ways it lies to you — I nearly published the wrong conclusion from the first. One payment returns the full text, and the creator is paid as it is used.

Web search: ranked results (title + url) for a query. ?q=x402+agent+payments&limit=8

Result reranking by relevance (Cohere primary, Jina fallback). x402-paid, USDC on Base.

Read a paid endpoint's 402 challenge without paying it

What x402 agents actually pay for: the Bazaar's top services by real 30-day call volume and unique payers, with per-category totals and the market median. Read from the facilitator's own usage counters.

Vision: caption / OCR / describe an image (Gemini vision via OpenRouter). x402-paid, USDC on Base.

x402 Watch Daily: Bazaar Indexing Becomes the Watch Item. A fresh Bazaar report says 14 settled Base mainnet x402 payments still did not produce new discovery records, while open fetch and Canton spec work remain in proposal stage. One payment returns the full text, and the creator is paid as it is used.

x402 Watch Daily: Casper Spec, Igra USDC, and Python Fixes. The x402 repo added a Casper exact-scheme spec, Igra mainnet USDC defaults across SDK configs, and Python-side fixes that make Flask setup and builder-code docs more usable. One payment returns the full text, and the creator is paid as it is used.

x402 Watch Daily: Go Examples Work From a Fresh Clone. The x402 repo fixed its Go echo server and HTTP client examples after the morning daily, removing a fresh-clone build failure and surfacing payment-response parse errors. One payment returns the full text, and the creator is paid as it is used.

Solve a QUBO/Ising optimization problem. USDC on Base via x402; returns a job_id to poll.

Block by number or 'latest' on a chain (Alchemy). x402-paid, USDC on Base.

Grounded web search with citations via Brave Search API. x402-paid per call.

CDP x402 Bazaar catalog mechanics: two discovery layers, settle-triggered indexing, and the one-schema-per-resource constraint. Live-probed internals of Coinbase Developer Platform's x402 Bazaar for anyone building or debugging a catalog integration: why your metadata change didn't show up, why the flat browse list disagrees with merchant search, the routeTemplate consolidation trade-off, and why one resource can advertise only one output format. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

Can you tell where an x402 buyer came from? What the protocol actually supports. A source-cited answer for x402 sellers building analytics: discovery-source attribution has no protocol primitive, the one URL-path trick that gives a coarse Bazaar-vs-direct split, and why builder_code (ERC-8021) is the only spoof-resistant channel. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

Funding an x402 agent wallet in practice: which onramps work, which are broken, and which docs cover it. Live-tested fiat onramp paths for the main x402 agent-wallet CLIs (awal / AgentCash / OWS), root-caused down to the compiled binary (including one confirmed-broken-upstream deposit path), plus a coverage map of which wallets actually publish fetchable funding docs. Verified 2026-07-13. One payment returns the full text, and the creator is paid as it is used.