One-shot health probe for any endpoint: HTTP status and latency, TLS certificate issuer and days-to-expiry, response size, security-header audit (HSTS, CSP, X-Content-Type-Options, X-Frame-Options) and named issues (SLOW_RESPONSE, CERTIFICATE_EXPIRING, SERVER_ERROR_STATUS). Call it on a schedule and

Complete DNS inspection in one call over DNS-over-HTTPS: A, AAAA, MX, TXT, NS, CNAME, SOA and CAA records with TTLs — plus a derived email posture analysis (SPF present and policy, DMARC present and policy, MX count, overall assessment) that raw lookup tools don't do.

Buyer-intelligence API for ranking x402 services, auditing endpoint risk, and building provider dossiers before agents pay. Supports free previews, paid x402 routes on Base USDC, OpenAPI, and MCP discovery. ([Discovery](https://x402-market-intel-mcp.mtree.workers.dev/.well-known/x402) | [OpenAPI](https://x402-market-intel-mcp.mtree.workers.dev/openapi.yaml))

ZK-private HTTP payments for x402. Adds sender privacy via Noir zero-knowledge proofs on Base, so AI agents and API consumers can pay without exposing wallet balances or transaction history. ([GitHub](https://github.com/BermudaBay/sdk))

52-service x402-wired agent fleet on Base mainnet (treasury 0x15184bf50b3d3f52b60434f8942b7d52f2eb436e, USDC EIP-3009 settlement). Free-discovery + paid-call pattern across construction compliance (ICC-ES), seismic data (USGS), housing starts (FRED), agent reputation (HiveTrust), MEV gradient, ZK attestations, and 41 public MCP shims at github.com/srotzin (all v1.0.0). 51 entries on Anthropic MCP Registry. Public MEV leaderboard ([hive-a2amev](https://hive-a2amev.onrender.com/leaderboard)) and verifiable Spectral receipts. ([GitHub](https://github.com/srotzin)) | ([@hivecivilization/x402-helpers](https://github.com/srotzin/x402-helpers))

Payment gateway for agentic commerce with x402 support. SDKs for TypeScript, Python, and Java. Two-layer architecture: Prism (orchestration — API, SDKs, middleware) and Spectrum (on-chain stablecoin settlement across Base, Ethereum, Arbitrum, and BSC). ([Docs](https://developers.fd.xyz))

AI agent transaction framework.

Open payment protocol for AI agents. Add one JSON file to any skill to accept x402 payments. Gasless for both providers and clients. Multi-chain (Base, Polygon, Solana, BNB, Tempo). CLI, TypeScript/Python SDKs, testnet faucet. ([GitHub](https://github.com/Yaqing2023/moltspay)) | ([Docs](https://moltspay.com/docs))

Machine-first API discovery for AI agents. Ranked, verified x402 endpoints across 110+ capabilities with semantic intent resolution, continuous 402 verification probes, and quality ranking. MCP server, TypeScript SDK, and REST API. ([GitHub](https://github.com/entroute/mcp-server)) | ([npm](https://www.npmjs.com/package/@entroute/mcp-server)) | ([Docs](https://entroute.com/docs))

x402-gated Goldilocks NTT (forward and inverse) compute service. Pure-Rust Cooley-Tukey on Plonky3's Goldilocks field with SHA-256 proof-of-execution; output is bit-exact equivalent to a Verilator simulation of `goldilocks-ntt-hdl` (FPGA RTL). $0.01 USDC per call on Solana Devnet, log2(n) ≤ 12 on the free tier. ([Discovery manifest](https://ntt-x402.isurvivable.workers.dev/.well-known/x402) | [Service descriptor](https://ntt-x402.isurvivable.workers.dev/) | [Source](https://github.com/MavenRain/goldilocks-ntt-hdl-x402))

Credit identity layer for AI agents on Base. Public deterministic Tessera Score (0–100) computed from on-chain activity via a published formula — no ML, no proprietary model, anyone can reproduce. Paid x402 endpoints: `GET /api/x402/score/[address]` ($0.001 USDC) returns score + tier + percentile + credit-line estimate + five-input breakdown; `GET /api/x402/agent/[address]` ($0.002 USDC) returns the combined Score + verified Agent Directory profile in one call. Free SDK variants also available. Settlement via Coinbase facilitator on Base mainnet, EIP-3009 transferWithAuthorization. ([Docs](https://www.tesseracredit.com/docs#x402-payments)) | ([SDK](https://github.com/cmxdev1/Tessera/tree/main/sdk)) | ([GitHub](https://github.com/cmxdev1/Tessera))

Agent identity verification and authorization layer for x402 endpoints. ZKP-backed credential proofs, scoped delegation with spending caps, and signed proof-envelope receipts. TypeScript SDK, Python SDK, CLI, gateway, and Circom circuits. ([GitHub](https://github.com/bolyra/bolyra)) ([npm](https://www.npmjs.com/package/@bolyra/sdk)) ([PyPI](https://pypi.org/project/bolyra/)) ([Demo](https://bolyra.ai/playground))

Agent economy infrastructure with 48 x402-monetized endpoints across 8 Cloudflare Workers on Base. ERC-8004 on-chain agent identity (Avalanche #1770), DeFi intelligence, LP position analytics with shape detection, agent search & discovery, fleet monitoring, human feedback layers, and a 16-endpoint AI-powered gateway. All pay-per-call via USDC, no API keys required. ([Landing](https://gentechlabs.net) | [x402 Gateway](https://gentech-x402-gateway.jordanjones0902.workers.dev) | [AgentScan](https://agentscan.info/agents/c455a06e-0d72-4847-8175-ece7f7daa3e3))

x402 payment gateway and facilitator for monetizing digital content, APIs, and AI agent resources. Per-settlement pricing, seller dashboard, SDKs (Go, TypeScript, Python), and React paywall. Supports major stablecoins on EVM-based networks including Base, Neo X, and others.

Payment-to-access infrastructure for x402 V2 challenge and retry flows on Solana USDC, with settlement verification, receipts, entitlements, atomic usage consumption, webhooks, SDKs, MCP, and A2A discovery.

Machine-to-machine invoicing: issue a signed invoice now, let the payer settle it later at its own dynamically-priced /pay sub-resource instead of paying synchronously.

13 pay-per-request APIs for autonomous agents on Base (USDC, x402 v2 with v1 body compatibility, self-hosted facilitator). GPU media rendering (image/video/audio, 16 kinds, async job handle with free polling), verifiable randomness with ed25519 attestation, commit-reveal randomness with a free public reveal, bulk chain exports and indexed address history for the Animica L1. Every product except commit-reveal has a FREE TRIAL at <paid path>/trial - same code, same response shape, no payment, capped per client per day - and the 402 challenge itself carries a freeTrial field. Availability is gated live: a product that cannot be served reports available:false and returns 503 without requesting payment.

Choose the best x402 provider before spending using recent paid performance evidence, with independent fallbacks.

Hosted facilitator service with enterprise-grade reliability and instant settlement.

Decentralized proof-of-stake blockchain with x402 payment integration for AI agent micropayments. Features attestation-based consensus, hardware-bound validators, and RTC token economy with native x402 support for autonomous agent transactions. ([Docs](https://github.com/Scottcjn/rustchain-bounties))

Non-custodial protocol translation layer bridging x402, MPP, and AP2. One integration, every AI agent payment protocol. Atomic fee-split settlement via on-chain FeeSplit contract on Base. ([GitHub](https://github.com/xyncpay/xyncpay))