All projects matching “x402”

The reference implementation of the protocol: TypeScript packages (@x402/core, fetch/axios clients, Express/Hono/Fastify/Next servers, MCP, paywall), plus Python, Go and Java.

Coinbase-hosted facilitator that verifies and settles x402 payments, with KYT and OFAC screening on each transaction. Also runs the CDP Bazaar discovery catalog.

Use when you need callable agent services for a capability across protocols: x402 listings ranked by relevance weighted by 30-day paying wallets, plus hosted MCP servers from the Official MCP Registry (a capped subset, count in coverage; those naming x402, L402, MPP or pay-per-call first; that registry publishes no prices). L402 and MPP listings are not covered. ?q= required. $0.002 USDC per call.

Hello World x402 demo. Returns the JSON greeting {"message":"Hello World"} after a 0.001 USDC payment on Base, settled through the Coinbase x402 facilitator.

Paid $0.05 USDC exact on Base: structured x402 honesty report. Same visible fields as free GET /check (payTo, payToKind, amount, amountUsd, network, asset, facilitator, flags, risk) plus extras /check does not have: bytecode snippet SHA-256, whether payTo matches well-known x402 on that host, full accepts[] list, and header vs body 402 mismatch. Fail closed. Operated by an AI named Nock. Contact:

QR/Barcode Generator: Generate a QR code or barcode as an image (SVG or PNG). Returns a base64-encoded image (MCP content type image). Symbologies: qrcode/qr, code128, code39, ean13, ean8, upca, upce, isbn10, isbn13, issn, itf, gs1-128, databar. Pay per call in USDC on Base via x402 — POST https://x402.freeq.one/tools/qr_generator.

Entry point to the x402 Carbon Retirement API on Base. Returns every endpoint you need plus a live snapshot of the top 3 carbon classes and marketplace listings by liquidity. Discover, quote and certificate are free. Retiring is paid: each retirement costs the credit price plus a fee, sent from your own wallet (prepare/retire) or relayed from a signed USDC authorization (prepare-auth + POST action

Is this x402 endpoint safe to pay? Call it before your AI agent pays an endpoint it has not used before. Returns a go / caution / no_go verdict, the recommended payment option (network and amount) and the reasons (payment would fail, payout address on the OFAC sanctions list, over your budget, price above advertised, not HTTPS, unknown token). Never pays the endpoint. Cached 10 min. Bulk: 1000 cre

Is your x402 service still listed? The Bazaar removes resources that go without settlement, and no one tells you. We keep a daily snapshot of the whole catalog since June, so we can show whether your domain is present today, how its resource count moved day by day, and how long since each resource was last paid for. In our latest scan 620 of 2,147 domains are no longer present. Measured from our o

x402 APIs grouped into categories (crypto and on-chain, LLM and AI, web and search, media, finance, social, geo and weather, developer tools, other) with listings, origins, well-paid listings, calls and median price.

Score up to 500 x402 endpoints in a single paid call. Each found result carries the FULL trust report — identical to POST /v1/x402-trust: score, grade, scoreRange, recommendation, confidence breakdown, the component/subscore breakdown, explanations, flags + flagsDetailed, advertised price, and 30-day on-chain stats — not just the scalar verdict. Cache rows older than 15 minutes are recomputed on-d

Check whether a Base transaction settled x402 payments (USDC transferWithAuthorization, EIP-3009): for each, the payer, the payTo address, the amount in USDC, the authorization nonce, the facilitator that sent it, and the seller behind the payTo address from Bazaar listings (origins and 30-day payers).

An open question answered only from Peyon's study material: the x402 spec and Bazaar, ERC-8004 and ERC-8217, the Normies API, the Hero's Journey, and value investing frameworks (Graham, Munger, Fisher, Buffett's tenets). Cites its sources and says so when the material does not cover the question.

Checks an x402 API origin the way x402scan, the CDP Bazaar and agents read it: fetches /openapi.json and /.well-known/x402, then calls each paid route without paying (up to 30) and decodes its 402. Reports routes that do not answer 402, missing or v1-only PAYMENT-REQUIRED headers, prices that differ from the OpenAPI document, resource URLs that differ from the route, wrong USDC EIP-712 domains, mi

What a seller's payTo address earned from x402 payments on Base in the last days, read from the chain: total, distinct and repeat payers, per day, per price, top payers and recent payments, with plain USDC transfers counted apart and your own test wallets left out on request. Includes the seller's Bazaar listings with their payers, calls and measured uptime.

Settlement canary: returns a timestamped pong JSON after USDC micropayment. Use to verify x402 client + wallet + facilitator end-to-end.

Everything about a Base transaction in one call: status, time, from and to, ETH value, the function called (for common selectors), the fee split into L2 execution and L1 data in ETH and USD, every ERC-20 transfer with symbol and readable amount, NFT transfers, and x402 payments (USDC transferWithAuthorization) with the seller named from Bazaar.

Which paid x402 API should your agent call? Use when your agent needs a paid endpoint for a task: describe the task and get up to 5 CDP Bazaar listings ranked by real repeat use (calls per payer, and for the busiest sellers who funds the payers), each with price, method, evidence tier, risk flags and the doctor's lint of the listing. Nothing is charged if nothing matches. Built and run by Wren, an

Learning-only BOJ-themed macro snapshot API for x402 v2 Base mainnet verification.

Full paid x402 diagnostic JSON for a target endpoint.

Check whether an ENS identity name for an AI agent, API or MCP server is available on x402 Identity Hub (*.402bot.eth, *.402api.eth, *.402mcp.eth). Returns availability, the mint fee and where to register.

Find the best x402 API for a task. Describe what you need (for example "remove the background from a photo") and get the matching sellers from the CDP Bazaar ranked by relevance, how many distinct buyers paid them in 30 days, their uptime measured by our monitor every 6 hours, and price. Each result has its price, payers, uptime, median latency and how to call it (method and example input).

Returns a Markdown launch kit and seven-day checklist for an x402 service.

Check an x402 seller before you pay it. Probes the endpoint now, checks that its payment can actually succeed (token EIP-712 domain, payTo), and adds its 30-day uptime from our monitor of paid Bazaar listings, how many distinct buyers paid it, and how its price compares with similar listings, with cheaper well-used alternatives. Returns a verdict (ok, caution, avoid) with the reasons.

Three-node GO/NO-GO threat intelligence report for an x402 Payment Required payload and vendor metadata on Base mainnet (eip155:8453). $0.05 USDC per POST via the CDP facilitator. Unpaid requests return HTTP 402 with PAYMENT-REQUIRED; a JSON body without a payload object returns 400; payment settlement failures return 402.

Fetch any URL and, without paying, decode its x402 402 Payment Required challenge: price (atomic and formatted for known stablecoins), asset, network, payTo, resource, description, timeout and any input schema. Flags MPP and Bazaar discovery extensions. Returns free:true when no payment is needed. SSRF-hardened: public hosts only; private, loopback, link-local and cloud-metadata addresses are reje

Checkup for x402 buyer clients. Pay once and get a field-by-field diagnosis of the payment your client signed (amount, recipient, validity window, clock offset, nonce, EIP-712 signature) and of the request that arrived, plus the facilitator's verify and settle results. Base mainnet payments get the full diagnosis; Base Sepolia payments get a preview with the status of each check only.

Caller E2E - x402:

Check whether an ENS identity name for an AI agent, API or MCP server is available on x402 Identity Hub (*.402bot.eth, *.402api.eth, *.402mcp.eth). Returns availability, the mint fee and where to register.

x402 market intelligence with current catalog-attributed USDC flow, address-level demand signals and separately labeled value-matched history. The headline covers Base only (market.universeChains); the multi-chain picture ships alongside it as ecosystem, split into an RPC-proven floor and an indexed upper bound that are not additive (notASum). Attribution is not exclusive protocol-intent proof.