ToolVet
78trust / 100

Provenance Certificate

by MimirAPI in Onchain & crypto

x402 APIPassing, checked 51 min ago

Chain-of-custody license certificate for any digital asset: a SHA-256 content hash bound to issuer, subject, and license terms under an HMAC-SHA-256 signature. Deterministic, portable, and verifiable through the issuer while the current HMAC v1 profile is active — a receipt an agent can carry to record what it licensed, from whom, and on what terms.

POST
https://mimirapi.com/v1/provenance/certificate
Price
$0.25
per call in USDC
Uptime
100%
last 30 days
Response time
224 ms
389 ms slowest 5%
Last check
Passed
51 min 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://mimirapi.com/v1/provenance/certificate

Each call costs $0.25 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://mimirapi.com/v1/provenance/certificate
content-type: application/json

{
  "contentHash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "license": "CC-BY-4.0",
  "subject": "did:web:agent.example.com"
}

Parameters

ParameterTypeRequiredDescription
contentHashstringYesSHA-256 hex of the asset
licensestringYes
subjectstringYes

Example response

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

{
  "certificate": {
    "alg": "HMAC-SHA-256",
    "contentHash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    "issuedAt": "2026-07-21T00:00:00.000Z",
    "issuer": "MimirAPI",
    "license": "CC-BY-4.0",
    "signature": "9b1a…hex HMAC-SHA-256…",
    "subject": "did:web:agent.example.com"
  }
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.25.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://mimirapi.com/v1/provenance/certificate' \
  -H 'content-type: application/json' \
  --data-raw '{"contentHash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855","license":"CC-BY-4.0","subject":"did:web:agent.example.com"}'

# 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://mimirapi.com/v1/provenance/certificate' \
  -H 'content-type: application/json' \
  --data-raw '{"contentHash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855","license":"CC-BY-4.0","subject":"did:web:agent.example.com"}' \
  | 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 $0.25 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.25" });
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 $0.25 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmimirapi.com%2Fv1%2Fprovenance%2Fcertificate&method=POST
const res = await pay("https://mimirapi.com/v1/provenance/certificate", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "contentHash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    "license": "CC-BY-4.0",
    "subject": "did:web:agent.example.com"
  }),
});
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 $0.25 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.25"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://mimirapi.com/v1/provenance/certificate",
        json={
            "contentHash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
            "license": "CC-BY-4.0",
            "subject": "did:web:agent.example.com",
        },
    )
    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
51 min agoPassed402321 ms$0.25
6 h agoPassed402287 ms$0.25
10 h agoPassed402224 ms$0.25
15 h agoPassed402211 ms$0.25
19 h agoPassed402389 ms$0.25
Show 10 older checks
23 h agoPassed402249 ms$0.25
27 h agoPassed402365 ms$0.25
31 h agoPassed402294 ms$0.25
36 h agoPassed402277 ms$0.25
40 h agoPassed40251 ms$0.25
44 h agoPassed402322 ms$0.25
2 days agoPassed402329 ms$0.25
2 days agoPassed402218 ms$0.25
2 days agoPassed402386 ms$0.25
3 days agoPassed402171 ms$0.25