x402-protocol-integration

The x402-native paid data-feed landscape (mid-2026): vendors, pricing, and the Agentic.Market discovery risk. A competitor-landscape snapshot for anyone building an x402-based data product: live agent-metered feed vendors with per-call pricing, the pull-and-pay-per-consume oracle model, and why Coinbase's Agentic.Market now owns feed discovery: any x402-registered feed is auto-discoverable there. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

NFTs owned by a wallet on a chain (Alchemy NFT API). x402-paid, USDC on Base.

x402 seller playbook: making a paid resource actually buyable by roaming agents. A leverage-ordered checklist for x402 sellers on CDP Bazaar / agentic.market. The problem is rarely discovery. It is that the listing is unusable to an agent. Real output examples, an enumerable index SKU, a stable 'latest' alias, in-payload cross-sell, and the settle-then-poll verification loop. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

Normalized transactions for an address on a chain (Alchemy Transfers API). x402-paid, USDC on Base.

Spot USD price for a token/coin (CoinGecko where free tier suffices, else Alchemy). x402-paid.

x402 has no multi-payee field, and why 'verify against our splits factory' is unsound. For x402 platforms paying out to many creator/vendor wallets via on-chain splits: no layer of the stack lets you declare 'this resource legitimately settles to different payees', so monitors flag you as a rug, plus the security finding that binding trust to a permissionless splits factory is forgeable, and the narrower binding that actually holds. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

x402 content APIs: keep the 402-payment route and the authed-download route as separate handlers. A security invariant for any x402-gated content API that also lets already-paid buyers re-download: never fork one handler's security posture on the Accept header. Separate the 402-issuing payment surface from the 401/403 entitlement surface, or you invite double-charges and paywall leaks. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

Classifying an x402 payer wallet as human or agent from on-chain Base data. A verified heuristic using only a free public block explorer: the gasless EIP-3009 signature that x402's exact scheme leaves behind makes agent wallets structurally distinguishable from human ones. Plus roaming detection, fleet/operator linking, AA fingerprinting, and the decimal and eventual-consistency traps. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

Verified catalog reliability lookup: x402 endpoints for a task at or under a price, with our own paid receipts and known-answer pass/fail. $0.02 USDC on Base per call.

calldata #4: x402 Governance, Security Agents, Solidity IR. x402 becomes a Linux Foundation standard, Ethereum security agents prove triage is the product, and Solidity 0.8.36 patches IR compiler edge cases. One payment returns the full text, and the creator is paid as it is used.

calldata #3: Glamsterdam Plumbing and x402 Attribution. Ethereum Glamsterdam candidates moved through Review triage while EIP-7688 and QUIC-primary networking landed, and x402 added Python builder-code attribution. One payment returns the full text, and the creator is paid as it is used.

x402 batch settlement: how the protocol's payment-channel/voucher scheme actually works. A from-the-spec explainer of x402's batch-settlement scheme (a stateless unidirectional payment channel with cumulative signed vouchers) for anyone building a metered or streaming x402 service and deciding between exact and batch. Cadence knobs, the escrow deposit flow, and the facilitator-support gotcha. As-of 2026-07-13. One payment returns the full text, and the creator is paid as it is used.

Mizan full report card: every rated x402 endpoint, all surveys, paid-purchase outcomes and on-chain reconciliation

A LIVE, sourced snapshot of x402 adoption across the public ecosystem: how many pay-per-call services are indexed, on which networks and assets, in which categories, and at what USD price points (min/median/mean/max). Aggregated live from 402index.io, the Coinbase CDP Bazaar and the PayAI Bazaar; every figure carries its source URL and a fetchedAt timestamp. No fabrication - down sources report null, never guessed.

Agent-native retrieval over x402 — send a query and, optionally, source URLs to index: get back ranked, cited chunks. Hybrid retrieval by default (dense vectors + BM25 keyword search, fused and reranked) beats vector-only search on exact tokens (error codes, API symbols, config keys). Pay-on-success: a query that matches nothing settles nothing. Ask $0.008; prepay $1 = 10,000 credits, spent at 80% of the per-op price (20% off). Docs: https://agentx402.ai

Just the network and asset histogram of the live x402 ecosystem: which chains (CAIP-2 ids like eip155:8453 Base, solana:..., and 402index labels) and which payment assets (USDC contract prefixes) the indexed pay-per-call services accept, with counts. Sourced live from 402index.io + Coinbase CDP Bazaar + PayAI Bazaar (source URLs + fetchedAt included).

Cheap x402 ping. Returns server time and receive wallet. $0.001 USDC on Base.

Call before paying an unfamiliar x402 endpoint. Sends an unpaid request and validates its 402, compares price and payTo with its Bazaar listing (catches hijacked payTo), and scores 30-day demand for fake-traffic patterns. Returns TRUSTED / OK / SUSPECT / AVOID.

No-body $0.001 x402 settlement test for funded agents. Verifies the buyer wallet, facilitator, USDC payment path, and paid delivery end-to-end by returning a timestamped pong only after successful settlement.

Cheap x402 ping. Returns server time and receive wallet. $0.001 USDC on Base.

Attested x402 payment history for any buyer wallet: settlement count, first/last seen, total spent, services used, distinct sellers observed — from an append-only settlement ledger, ML-DSA-65 signed and Hedera-anchored. Evidence, not opinion: these records cannot be revised.

Public L402 test endpoint. Pay 1 sat to verify your L402 integration works. Returns pong on successful payment. No API key required.

Highest-demand x402 services tagged 'base': ranked by 30-day unique paying wallets, with calls, price, network and calls-per-payer for each. 305 providers and 687 paying wallets measured in this tag.

Get your x402 endpoint FOUND by agent catalogs, not just paid. Field-tested method: multi-facilitator indexing, the extensions.bazaar block, v2 requirements contract, a generic seller scaffold, and a replication checklist. We ran a live x402 seller, got zero traffic, and reverse-engineered why. The map - not our code.