Chat completions - auto tier · Chat Completions

by Chat completions - auto tier

POSTBaseSolanaArbitrumPolygonMonadAvalancheeip155:1329OptimismFraxtaleip155:42220stellar:pubnetalgorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=

$0.01

per call · USD Coin on Base

OpenAI-compatible chat completions with the model chosen server-side: omit model and the gateway routes the prompt to the top-ranked model for its task (code, reasoning, long-context, general) from a fixed eval-derived ranking, failing over automatically on provider errors. Flat price per call, 16k chars in, 1024 tokens out, streaming supported. Use it as a drop-in OpenAI base_url when you want good answers without picking a model.

Endpoint

POST https://agent402.tools/v1/auto/chat/completions

75

Calls / 30d

2

Unique payers / 30d

Sep 10

Last called

exact

Payment scheme

Call this service

TypeScript · @x402/fetch
import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount(process.env.PRIVATE_KEY);
const fetchWithPay = wrapFetchWithPayment(fetch, account);

const res = await fetchWithPay("https://agent402.tools/v1/auto/chat/completions", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "max_tokens": 5,
    "messages": [
      {
        "content": "Reply with exactly: OK",
        "role": "user"
      }
    ]
  }),
});
const data = await res.json();
cURL
curl -X POST \
  "https://agent402.tools/v1/auto/chat/completions" \
  -H "Content-Type: application/json" \
  -d '{"max_tokens":5,"messages":[{"content":"Reply with exactly: OK","role":"user"}]}' \
  -H "X-PAYMENT: <signed x402 payment>"

Example response

{
  "agent402_router": {
    "category": "general",
    "quality": "balanced",
    "served": "openai/gpt-4o-mini"
  },
  "choices": [
    {
      "finish_reason": "stop",
      "index": 0,
      "message": {
        "content": "OK",
        "role": "assistant"
      }
    }
  ],
  "created": 1750000000,
  "id": "gen-…",
  "model": "openai/gpt-4o-mini",
  "object": "chat.completion",
  "usage": {
    "completion_tokens": 1,
    "prompt_tokens": 12,
    "total_tokens": 13
  }
}

Payment details

Pay to0xabf4fabd7c416fb67202e5f9002389fc75e2a9d0
AssetUSD Coin · 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
NetworksBase, Solana, Arbitrum, Polygon, Monad, Avalanche, eip155:1329, Optimism, Fraxtal, eip155:42220, stellar:pubnet, algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=
Schemesexact, upto

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