GPT-5.5 API

GPT-5.5 API (openai/gpt-5.5): LLM inference via OpenAI-compatible chat completions, pay per call in USDC on Base with x402. No API key, no account. Suited for AI agents and scripts that need GPT-5.5 on demand. When listed, this request cost 30% less than the same request on BlockRun. Streaming and function calling supported. Exact price in the 402 quote before payment; automatic refund if the mode

Open endpoint ↗

Price per call: $0.001
Chain: Base
Method: POST
Paid calls · 30 days: 2

Call it from code

This API is run by its own provider and paid directly through x402. We list it so you can find it; we don't route or hold the payment.

import { x402Client, wrapFetchWithPayment } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
registerExactEvmScheme(client, { signer: agentAccount });

const pay = wrapFetchWithPayment(fetch, client);
const res = await pay("https://agent402-arb.rosariovitale0096.workers.dev/llm/gpt-5.5", { method: "POST" });
console.log(await res.json());

https://agent402-arb.rosariovitale0096.workers.dev/llm/gpt-5.5