DevX x402 Preflight

x402 preflight: before your agent signs a payment, fetch a paywalled URL's 402 and lint it. Parses v1 bodies and v2 PAYMENT-REQUIRED headers, then checks each accepts[] option: known network, canonical USDC, EIP-712 domain (extra.name/version) that a signature will verify against, EIP-55 payTo, zero/contract payTo, amount sanity, timeout, testnet, resource-host mismatch. Returns ok/warn/block per option, findings and the recommended option. Credit: 402 Index (MIT)

Listed · $0.003 USDC/request · 1 endpoint · Verification · base network · x402 protocol

Networks: Base (accepted)

Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.

url https://payapi.market/mcp

Listing facts

Provider

Unclaimed

Hosted at

x402-preflight.nextill-pos.workers.dev

Category

Verification

Price

$0.003 USDC per request

Endpoints

1

Payment networks

Base

Settlement-verified

Not yet. Listed, not paid for by PayAPI Market.

Listed on PayAPI Market

2026-10-30

About this API

DevX x402 Preflight is listed in the Verification category with pricing at $0.003 USDC/request.

Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.

This API exposes 1 endpoint.

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Paste this on your site. The link points at this listing. Listing is free and providers keep 100%.

Markdown

[![Listed on PayAPI Market](https://payapi.market/badge/devx-x402-preflight.svg)](https://payapi.market/api/devx-x402-preflight)

HTML

<a href="https://payapi.market/api/devx-x402-preflight"><img src="https://payapi.market/badge/devx-x402-preflight.svg" alt="Listed on PayAPI Market" height="20"></a>

What this badge means

Questions about this API

What does DevX x402 Preflight do?

x402 preflight: before your agent signs a payment, fetch a paywalled URL's 402 and lint it. Parses v1 bodies and v2 PAYMENT-REQUIRED headers, then checks each accepts[] option: known network, canonical USDC, EIP-712 domain (extra.name/version) that a signature will verify against, EIP-55 payTo, zero/contract payTo, amount sanity, timeout, testnet, resource-host mismatch. Returns ok/warn/block per option, findings and the recommended option. Credit: 402 Index (MIT) It is provided by Unclaimed.

How much does DevX x402 Preflight cost?

DevX x402 Preflight is priced at $0.003 USDC per request, paid per call with no subscription. The exact amount for each call is in the HTTP 402 response before any money moves.

Do I need an API key or account to use DevX x402 Preflight?

No. DevX x402 Preflight uses the x402 protocol, so an agent pays per request in USDC on Base and gets the response, with no API key, account or signup.

Has DevX x402 Preflight been verified?

Not yet. DevX x402 Preflight is listed and answers an x402 payment challenge, but PayAPI Market has not paid for a call to it, so it carries no settlement-verified badge.

How does an AI agent find DevX x402 Preflight?

Through the free PayAPI Market MCP server at https://payapi.market/mcp, using search_apis or get_api, or over plain HTTP at https://payapi.market/agent/search. Discovery is free; the agent pays the provider directly on the listing's own 402.

More Verification APIs · Browse the marketplace · List your own API

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