toolgrep / Testing & QA / x402 Preflight
Alternatives to x402 Preflight
x402 Preflight: Launch diagnostics for x402 API developers. 8 products similar to x402 Preflight, compared on pricing, free tier, API, MCP server, SDK and open source. 8 of 8 have a free tier, 8 of 8 have an API, 8 of 8 offer an MCP server.
- SpendPreflight
Trust and verification tools for stablecoin payments, built for AI agents and the people who run them.
- Lumière PayCheck
Trust scores for x402 payment endpoints, checked before an AI agent pays
- nohumans.directory
A machine-readable registry of paid x402 APIs and datasets, verified by paying endpoints with real USDC and publishing purchase outcomes.
- 402registry
Pay-per-check discoverability audit that shows what an AI crawler actually sees on your site
- Settlens
x402 security and testing for agentic payments
- minia2a.uk
Marketplace of 1,600+ pay-per-call API services for AI agents, settled in USDC on Base via the x402 protocol.
- PayAPI Market
x402 marketplace for AI agents
- 402MCP.org
The Open Registry for Agentic Commerce & HTTP 402
Side by side
| Product | Pricing | Free tier | API | MCP server | SDK | Open source |
|---|---|---|---|---|---|---|
| x402 Preflight | Freemium | yes | yes | yes | no | no |
| SpendPreflight | Usage-based · from 0.001 USDC per check | yes | yes | yes | yes | — |
| Lumière PayCheck | Freemium | yes | yes | yes | yes | — |
| nohumans.directory | Free | yes | yes | yes | — | — |
| 402registry | Usage-based | yes | yes | yes | no | no |
| Settlens | Usage-based | yes | yes | yes | no | no |
| minia2a.uk | Usage-based | yes | yes | yes | no | — |
| PayAPI Market | Free | yes | yes | yes | yes | — |
| 402MCP.org | Free | yes | yes | yes | no | — |
Facts come from each product's own website, or from its verified owner when they have edited the listing. Each product page shows when it was last verified and how it was extracted. Similarity comes from the products' descriptions.
API
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