Pro Messages
by Messages pro in AI models & inference
Anthropic Messages API over x402 - point the Anthropic SDK (or Claude Code / the Agent SDK) at base_url https://agent402.tools/v1/pro and pay $0.10 per call in USDC, no API key, no signup. Same models, caps and price as this tier's /chat/completions route; any model here is served through the Messages wire (Claude natively, others translated). Depth: `effort` (low..max) on Claude 4.7+ and Haiku 5.5, thinking.budget_tokens on older Claude.
https://agent402.tools/v1/pro/messages- Price
- $0.1
- per call in USDC
- Uptime
- 100%
- last 30 days
- Response time
- 201 ms
- 334 ms slowest 5%
- Last check
- Passed
- 3 h ago, next any minute now
Reliability
Status and outage history · Atom feed · Watch with other listings
How to call it
POST https://agent402.tools/v1/pro/messages
Each call costs $0.1 in USDC on Polygon, paid with the request over x402.
Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.
Example request
From the listing.
POST https://agent402.tools/v1/pro/messages
content-type: application/json
{
"max_tokens": 256,
"messages": [
{
"content": "Summarize x402 in one sentence.",
"role": "user"
}
],
"model": "anthropic/claude-sonnet-5"
}Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
effort | string | No | |
max_tokens | integer | Yes | |
messages | array | Yes | |
model | string | No | |
stream | boolean | No | |
system | string | No | |
thinking | object | No | |
tools | array | No | |
zdr | boolean | No |
Example response
The provider's example. We can't check it without paying.
{
"content": [
{
"text": "x402 is an HTTP-native way for agents to pay per request with USDC.",
"type": "text"
}
],
"id": "msg_…",
"model": "anthropic/claude-sonnet-5",
"role": "assistant",
"stop_reason": "end_turn",
"type": "message",
"usage": {
"input_tokens": 14,
"output_tokens": 18
}
}Call it from code
The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.1.
curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://agent402.tools/v1/pro/messages' \
-H 'content-type: application/json' \
--data-raw '{"max_tokens":256,"messages":[{"content":"Summarize x402 in one sentence.","role":"user"}],"model":"anthropic/claude-sonnet-5"}'
# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://agent402.tools/v1/pro/messages' \
-H 'content-type: application/json' \
--data-raw '{"max_tokens":256,"messages":[{"content":"Summarize x402 in one sentence.","role":"user"}],"model":"anthropic/claude-sonnet-5"}' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
// Pays at most $0.1 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.1" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.1 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagent402.tools%2Fv1%2Fpro%2Fmessages&method=POST
const res = await pay("https://agent402.tools/v1/pro/messages", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({
"max_tokens": 256,
"messages": [
{
"content": "Summarize x402 in one sentence.",
"role": "user"
}
],
"model": "anthropic/claude-sonnet-5"
}),
});
console.log(res.status, await res.text());Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
# Pays at most $0.1 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.1"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))
with x402_requests(client) as session:
res = session.post(
"https://agent402.tools/v1/pro/messages",
json={
"max_tokens": 256,
"messages": [
{
"content": "Summarize x402 in one sentence.",
"role": "user",
},
],
"model": "anthropic/claude-sonnet-5",
},
)
print(res.status_code, res.text)Security scan
No findings
We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.
Recent checks
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 3 h ago | Passed | 402 | 923 ms | $0.1 |
| 8 h ago | Passed | 402 | 287 ms | $0.1 |
| 13 h ago | Passed | 402 | 209 ms | $0.1 |
| 17 h ago | Passed | 402 | 195 ms | $0.1 |
| 22 h ago | Passed | 402 | 328 ms | $0.1 |
Show 10 older checks
| 26 h ago | Passed | 402 | 272 ms | $0.1 |
| 30 h ago | Passed | 402 | 192 ms | $0.1 |
| 34 h ago | Passed | 402 | 265 ms | $0.1 |
| 38 h ago | Passed | 402 | 185 ms | $0.1 |
| 42 h ago | Passed | 402 | 185 ms | $0.1 |
| 46 h ago | Passed | 402 | 189 ms | $0.1 |
| 2 days ago | Passed | 402 | 260 ms | $0.1 |
| 2 days ago | Passed | 402 | 256 ms | $0.1 |
| 2 days ago | Passed | 402 | 320 ms | $0.1 |
| 3 days ago | Passed | 402 | 186 ms | $0.1 |