Guides
Practical explainers on crypto payments for AI tools and agents, built from official docs and our own listing data.
What is x402? HTTP 402 payments for APIs and AI agents
x402 explained in plain English: how the HTTP 402 payment flow works, who runs it, which networks and tokens it uses, and where to find x402 APIs.
Read guide →How to accept USDC for your API (pay-per-call with x402)
Step-by-step: charge USDC per API call on Base or Solana with x402. Wallet, price, middleware, facilitator, testing and getting listed.
Read guide →AI agent payment protocols compared: x402, MPP, AP2, ACP and L402
x402 vs MPP vs AP2 vs ACP vs L402: who backs each agent payment protocol, what it is for, how it settles, with links to the official specs.
Read guide →Pay-per-call AI APIs: no account, no API key, pay in USDC
Pay-per-call AI and data APIs that charge per request in USDC via x402, with real prices from our listings and how agents pay them.
Read guide →Pay-per-call web scraper API for AI agents: URL to Markdown with WebRead (x402)
Turn a public web page into clean Markdown with one HTTP call: $0.002 USDC per successful read on Base via x402, free preview and MCP tool. Built by us.
Read guide →x402 agent verification: check an AI agent is registered and verified with AgentGate
Check an AI agent against the Concordium Agent Registry (CIS-8004) in one call: free preview, MCP tool, or $0.005 USDC per call on Base via x402. Built by us.
Read guide →Prompt injection detection API for AI agents: scan text, web pages and MCP tools (InjectScan)
Check untrusted text, web pages and MCP tool definitions for prompt injection before your agent acts on them. $0.003 USDC per scan on Base via x402, free preview and MCP tool. Built by us.
Read guide →Domain and email verification API for AI agents: DNS, SPF/DMARC, domain age and disposable checks (DomainCheck)
Check a domain or email before your agent trusts it: DNS, SPF/DMARC, domain age, disposable and parked flags, 0-100 score. $0.002 per domain, $0.001 per email in USDC on Base via x402. Built by us.
Read guide →OFAC sanctions check API for crypto wallets: screen an address before your agent pays it (PayGuard)
Screen a crypto address against the 1,050 addresses on the US Treasury OFAC SDN list: $0.001 USDC per call on Base via x402, free preview and MCP. Informational screening, not legal advice. Built by us.
Read guide →Keep exploring
Guides
- What is x402? HTTP 402 payments for APIs and AI agents
- How to accept USDC for your API (pay-per-call with x402)
- AI agent payment protocols compared: x402, MPP, AP2, ACP and L402
- Pay-per-call AI APIs: no account, no API key, pay in USDC
- Pay-per-call web scraper API for AI agents: URL to Markdown with WebRead (x402)
- x402 agent verification: check an AI agent is registered and verified with AgentGate
- Prompt injection detection API for AI agents: scan text, web pages and MCP tools (InjectScan)
- Domain and email verification API for AI agents: DNS, SPF/DMARC, domain age and disposable checks (DomainCheck)
- OFAC sanctions check API for crypto wallets: screen an address before your agent pays it (PayGuard)