ToolVet
75trust / 100

Transaction Assurance

by Transaction Assurance in Onchain & crypto

x402 APIPassing, checked 1 h ago

Independently verify authorization, settlement, delivery and deterministic acceptance; return a signed portable assurance receipt

POST
https://phion.systems/v1/paid/transaction-assurance
Price
$0.015
per call in USDC
Uptime
100%
last 30 days
Response time
540 ms
787 ms slowest 5%
Last check
Passed
1 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://phion.systems/v1/paid/transaction-assurance

Each call costs $0.015 in USDC on Base, 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://phion.systems/v1/paid/transaction-assurance
content-type: application/json

{
  "acceptance": [
    {
      "expected": "ok",
      "operator": "equals",
      "path": "/result"
    }
  ],
  "delivery": {
    "content_sha256": "replace-with-sha256-of-output",
    "delivered_at": 1700000060,
    "output": {
      "result": "ok"
    },
    "status": 200
  },
  "intent": {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "buyer": "agent:buyer",
    "deadline": 1700000300,
    "max_amount": "20000",
    "network": "eip155:8453",
    "requested_at": 1700000000,
    "seller": "0x0000000000000000000000000000000000000001"
  },
  "offer": {
    "amount": "15000",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "network": "eip155:8453",
    "seller": "0x0000000000000000000000000000000000000001",
    "valid_until": 1700000100
  },
  "payment": {
    "amount": "15000",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "network": "eip155:8453",
    "recipient": "0x0000000000000000000000000000000000000001",
    "settled": true,
    "settled_at": 1700000050,
    "transaction": "0xexample"
  },
  "transaction_id": "purchase-42"
}

Example response

The provider's example. We can't check it without paying.

{
  "assurance": {
    "acceptance_satisfied": true,
    "delivery_verified": true,
    "payment_settled": true,
    "verdict": "assured"
  },
  "receipt": {
    "signature": "base64url"
  }
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.015.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://phion.systems/v1/paid/transaction-assurance' \
  -H 'content-type: application/json' \
  --data-raw '{"acceptance":[{"expected":"ok","operator":"equals","path":"/result"}],"delivery":{"content_sha256":"replace-with-sha256-of-output","delivered_at":1700000060,"output":{"result":"ok"},"status":200},"intent":{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","buyer":"agent:buyer","deadline":1700000300,"max_amount":"20000","network":"eip155:8453","requested_at":1700000000,"seller":"0x0000000000000000000000000000000000000001"},"offer":{"amount":"15000","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","network":"eip155:8453","seller":"0x0000000000000000000000000000000000000001","valid_until":1700000100},"payment":{"amount":"15000","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","network":"eip155:8453","recipient":"0x0000000000000000000000000000000000000001","settled":true,"settled_at":1700000050,"transaction":"0xexample"},"transaction_id":"purchase-42"}'

# 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://phion.systems/v1/paid/transaction-assurance' \
  -H 'content-type: application/json' \
  --data-raw '{"acceptance":[{"expected":"ok","operator":"equals","path":"/result"}],"delivery":{"content_sha256":"replace-with-sha256-of-output","delivered_at":1700000060,"output":{"result":"ok"},"status":200},"intent":{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","buyer":"agent:buyer","deadline":1700000300,"max_amount":"20000","network":"eip155:8453","requested_at":1700000000,"seller":"0x0000000000000000000000000000000000000001"},"offer":{"amount":"15000","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","network":"eip155:8453","seller":"0x0000000000000000000000000000000000000001","valid_until":1700000100},"payment":{"amount":"15000","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","network":"eip155:8453","recipient":"0x0000000000000000000000000000000000000001","settled":true,"settled_at":1700000050,"transaction":"0xexample"},"transaction_id":"purchase-42"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: 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 $0.015 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.015" });
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 $0.015 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fphion.systems%2Fv1%2Fpaid%2Ftransaction-assurance&method=POST
const res = await pay("https://phion.systems/v1/paid/transaction-assurance", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "acceptance": [
      {
        "expected": "ok",
        "operator": "equals",
        "path": "/result"
      }
    ],
    "delivery": {
      "content_sha256": "replace-with-sha256-of-output",
      "delivered_at": 1700000060,
      "output": {
        "result": "ok"
      },
      "status": 200
    },
    "intent": {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "buyer": "agent:buyer",
      "deadline": 1700000300,
      "max_amount": "20000",
      "network": "eip155:8453",
      "requested_at": 1700000000,
      "seller": "0x0000000000000000000000000000000000000001"
    },
    "offer": {
      "amount": "15000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "network": "eip155:8453",
      "seller": "0x0000000000000000000000000000000000000001",
      "valid_until": 1700000100
    },
    "payment": {
      "amount": "15000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "network": "eip155:8453",
      "recipient": "0x0000000000000000000000000000000000000001",
      "settled": true,
      "settled_at": 1700000050,
      "transaction": "0xexample"
    },
    "transaction_id": "purchase-42"
  }),
});
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 $0.015 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.015"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://phion.systems/v1/paid/transaction-assurance",
        json={
            "acceptance": [
                {
                    "expected": "ok",
                    "operator": "equals",
                    "path": "/result",
                },
            ],
            "delivery": {
                "content_sha256": "replace-with-sha256-of-output",
                "delivered_at": 1700000060,
                "output": {
                    "result": "ok",
                },
                "status": 200,
            },
            "intent": {
                "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
                "buyer": "agent:buyer",
                "deadline": 1700000300,
                "max_amount": "20000",
                "network": "eip155:8453",
                "requested_at": 1700000000,
                "seller": "0x0000000000000000000000000000000000000001",
            },
            "offer": {
                "amount": "15000",
                "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
                "network": "eip155:8453",
                "seller": "0x0000000000000000000000000000000000000001",
                "valid_until": 1700000100,
            },
            "payment": {
                "amount": "15000",
                "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
                "network": "eip155:8453",
                "recipient": "0x0000000000000000000000000000000000000001",
                "settled": True,
                "settled_at": 1700000050,
                "transaction": "0xexample",
            },
            "transaction_id": "purchase-42",
        },
    )
    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

WhenResultHTTPTimePrice
1 h agoPassed402547 ms$0.015
6 h agoPassed402540 ms$0.015
12 h agoPassed402167 ms$0.015
17 h agoPassed402546 ms$0.015
22 h agoPassed402170 ms$0.015
Show 10 older checks
27 h agoPassed402634 ms$0.015
31 h agoPassed402655 ms$0.015
36 h agoPassed402589 ms$0.015
41 h agoPassed402553 ms$0.015
45 h agoPassed402787 ms$0.015
2 days agoPassed402734 ms$0.015
2 days agoPassed402616 ms$0.015
2 days agoPassed402589 ms$0.015
3 days agoPassed402549 ms$0.015
3 days agoPassed402580 ms$0.015