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71trust / 100

A2a

by TariffMonkee in Onchain & crypto

x402 APIPassing, checked 2 h ago

Agent2Agent (A2A) protocol JSON-RPC endpoint supporting SendMessage. Authorizes up to $0.75, the highest skill price; settlement charges the invoked skill's actual price. Base (EVM) only. The skill catalog and per-skill pricing are in /.well-known/agent-card.json.

POST
https://tariffmonkee.com/paid/a2a
Price
$0.75
per call in USDC
Uptime
100%
last 30 days
Response time
1.3 s
2.4 s slowest 5%
Last check
Passed
2 h ago, next any minute now

Run a free test callHow to call it

Reliability

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

How to call it

POST https://tariffmonkee.com/paid/a2a

Each call costs $0.75 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://tariffmonkee.com/paid/a2a
content-type: application/json

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "SendMessage",
  "params": {
    "message": {
      "parts": [
        {
          "data": {
            "params": {
              "email": "[email protected]"
            },
            "skill": "tariffmonkee-email-verify"
          }
        }
      ]
    }
  }
}

Parameters

ParameterTypeRequiredDescription
idstring or numberYesCaller-chosen request id, echoed in the response.
jsonrpcstringYesJSON-RPC protocol version, always the string 2.0.
methodstringYesThe only supported A2A method.
paramsobjectYesA2A SendMessage parameters.

Example response

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

Example response, 35 lines
{
  "id": 1,
  "jsonrpc": "2.0",
  "result": {
    "task": {
      "artifacts": [
        {
          "artifactId": "34c898fa-c378-495f-abda-8bb848955456",
          "name": "email-verify",
          "parts": [
            {
              "data": {
                "dmarc": {},
                "domain": "mozilla.org",
                "email": "[email protected]",
                "hasMxRecord": true,
                "isDisposableDomain": false,
                "reasons": [],
                "spf": {},
                "syntaxValid": true,
                "verdict": "deliverable"
              }
            }
          ]
        }
      ],
      "contextId": "307e9e69-bcb5-4741-a8be-d7615079c4c7",
      "id": "23d268aa-d294-463f-b6a8-d81151fb2259",
      "status": {
        "state": "TASK_STATE_COMPLETED",
        "timestamp": "2026-10-18T13:04:48.500Z"
      }
    }
  }
}

Call it from code

The curl command shows the payment challenge.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://tariffmonkee.com/paid/a2a' \
  -H 'content-type: application/json' \
  --data-raw '{"id":1,"jsonrpc":"2.0","method":"SendMessage","params":{"message":{"parts":[{"data":{"params":{"email":"[email protected]"},"skill":"tariffmonkee-email-verify"}}]}}}'

# 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://tariffmonkee.com/paid/a2a' \
  -H 'content-type: application/json' \
  --data-raw '{"id":1,"jsonrpc":"2.0","method":"SendMessage","params":{"message":{"parts":[{"data":{"params":{"email":"[email protected]"},"skill":"tariffmonkee-email-verify"}}]}}}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

We don't show code that pays this service: it uses a payment scheme other than exact, which needs a different client setup.

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
2 h agoPassed4022.0 s$0.75
6 h agoPassed4021.9 s$0.75
10 h agoPassed40252 ms$0.75
14 h agoPassed4022.4 s$0.75
18 h agoPassed4021.3 s$0.75
Show 5 older checks
22 h agoPassed402965 ms$0.75
26 h agoPassed4021.9 s$0.75
29 h agoPassed4022.2 s$0.75
32 h agoPassed4021.3 s$0.75
35 h agoPassed4021.3 s$0.75