---
title: "OPENAI-COMPATIBLE chat completions, PRO tier — frontier models at one flat price, no API key, no account"
method: POST
path: "/v1/pro/chat/completions"
tags: ["Inference"]
---

# OPENAI-COMPATIBLE chat completions, PRO tier — frontier models at one flat price, no API key, no account

`POST /v1/pro/chat/completions`

## Request

- Base URL: `https://api.webbersites.com`
- URL: `https://api.webbersites.com/v1/pro/chat/completions`
- Auth: API key in header `X-PAYMENT`

OPENAI-COMPATIBLE chat completions, PRO tier — frontier models at one flat price, no API key, no account: gpt-5.2 (default), gpt-5.5, claude-sonnet-5, gemini-3.1-pro, gemini-3.5-flash. Same dialect as OpenAI — base_url https://api.webbersites.com/v1/pro works with any OpenAI SDK. Caps: 24,000 input chars, 1,024 output tokens, text-only, no streaming. The x402 payment IS the auth.

Price: $0.05 per call, paid in USDC via the x402 protocol (see the x402 security scheme).

## Request body

- object
  - `model` string: gpt-5.2 (default), gpt-5.5, claude-sonnet-5, gemini-3.1-pro, gemini-3.5-flash
  - `messages` unknown[], required: OpenAI-style messages: [{role, content}], text content only, 24,000 chars total
    - unknown
  - `max_tokens` number: output cap, clamped to 1,024

## Response `200`

Success

- object
  - `choices` unknown[]: OpenAI-shape choices; the answer is choices[0].message.content
    - unknown
  - `usage` object

## Other responses

- `402`: Payment required — the response body lists accepted payment methods (amount, asset, network, pay-to address). Retry the request with a signed X-PAYMENT header.

---

[API](https://skmtc.dev/webbersites/apis/webbersites-x402-data-api.md) · [All operations](https://skmtc.dev/webbersites/apis/webbersites-x402-data-api/llms.txt) · [OpenAPI document](https://skmtc.dev/webbersites/apis/webbersites-x402-data-api/revisions/c14a76c67a94?raw)