---
title: "x402 endpoint preflight"
method: POST
path: "/v1/developer/x402-preflight"
tags: ["developer"]
---

# x402 endpoint preflight

`POST /v1/developer/x402-preflight`

## Request

- Base URL: `https://apiacre.com`
- URL: `https://apiacre.com/v1/developer/x402-preflight`
- Auth: none required

Probe a public endpoint without paying, grade its x402 v2 challenge, check exact-host x402-list presence and traction, and optionally rank licensed market matches with buyer-concentration caveats.

Price: **$0.05 USDC** via x402 exact payment on Base and Solana.

## Request body

- X402PreflightInput
  - `url` string, uri, required
  - `method` 'GET' | 'POST'
  - `body` object, nullable
  - `market_query` string, nullable
  - `market_limit` integer

## Response `200`

Successful Response

- ServiceResponse
  - `request_id` string, required
  - `service` string, required
  - `version` string
  - `data` object, required
  - `meta` ServiceMeta, required
    - `duration_ms` integer, required
    - `cached` boolean
    - `sources` string[]
    - `warnings` string[]
    - `next_actions` ServiceNextAction[]
      - `service` string, required
      - `title` string, required
      - `reason` string, required
      - `method` 'POST'
      - `path` string, required
      - `price` string, required
      - `input_template` object, required
      - `use_output` string, required
      - `handoff_path` string, required
      - `checkout_path` string, required
      - `sample_path` string, nullable, required
      - `maximum_atomic_usdc` string, required
      - `handoff_payment_required` false
      - `executes_automatically` false
      - `authorization_required` boolean

## Other responses

- `402`: Payment Required. Decode PAYMENT-REQUIRED, satisfy the x402 requirement, and retry with PAYMENT-SIGNATURE.
- `422`: Validation Error

---

[API](https://skmtc.dev/apiacre/apis/api-acre.md) · [All operations](https://skmtc.dev/apiacre/apis/api-acre/llms.txt) · [OpenAPI document](https://skmtc.dev/apiacre/apis/api-acre/revisions/0ba942b920ad?raw)