Blockchain Data · x402

Validate an email address before you accept a signup or send to it: RFC 5322 syntax, wh…

by 402utils.com · discovered, not yet claimed by its owner · updated 2026-09-02

Not responding. This endpoint did not answer its last liveness check (2026-10-13). It may be temporarily down.

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Validate an email address before you accept a signup or send to it: RFC 5322 syntax, whether the domain resolves and its MX records, whether it is a disposable/throwaway domain (community blocklist), and whether it is a role account (info@, support@…). DNS is checked over DoH. No SMTP probing (intrusive and spammy), so a true 'domainExists' does not guarantee the mailbox exists.

Tags: bazaar

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/5895.json for the price and payment options.
Pay. Call GET https://402utils.com/v1/email-check. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.003 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Uptime: 0 of the last 1 checks answered
Calls (30d): 3 · 2 unique payers (third-party data from the public x402 Bazaar)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.003	0xc55A2D530b53CBaD1001e4AfD4720B7E71f9C291	60s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xc55A2D530b53CBaD1001e4AfD4720B7E71f9C291",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "3000",
    "amountUsd": 0.003,
    "maxTimeoutSeconds": 60
  }
]

Schemas

Output schema (JSON Schema)

{
  "bazaar": {
    "info": {
      "input": {
        "method": "GET",
        "queryParams": {
          "email": "[email protected]"
        },
        "type": "http"
      },
      "output": {
        "example": {
          "checkedAt": "2026-07-04T00:00:00.000Z",
          "disposable": false,
          "domainExists": true,
          "email": "[email protected]",
          "mxRecords": [
            "mx1.example.com"
          ],
          "roleAccount": false,
          "syntaxValid": true
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "description": "Query string only.",
              "properties": {
                "email": {
                  "description": "The email address to validate (required).",
                  "format": "email",
                  "type": "string"
                }
              },
              "required": [
                "email"
              ],
              "type": "object"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "properties": {
                "checkedAt": {
                  "format": "date-time",
                  "type": "string"
                },
                "disposable": {
                  "description": "Domain is on the disposable-email blocklist.",
                  "type": "boolean"
                },
                "domainExists": {
                  "description": "Best-effort: domain has MX or A records (DoH).",
                  "type": "boolean"
                },
                "email": {
                  "type": "string"
                },
                "mxRecords": {
                  "items": {
                    "type": "string"
                  },
                  "type": "array"
                },
                "roleAccount": {
                  "description": "Local part is a role address (info, support…).",
                  "type": "boolean"
                },
                "syntaxValid": {
                  "type": "boolean"
                }
              },
              "required": [
                "email",
                "syntaxValid",
                "domainExists",
                "mxRecords",
                "disposable",
                "roleAccount",
                "checkedAt"
              ],
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

Example shape — generated from the schema, not a captured live response

null

Examples

curl

curl "https://402utils.com/v1/email-check"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://402utils.com/v1/email-check");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://402utils.com/v1/email-check")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: 402utils.com
Endpoint: https://402utils.com/v1/email-check
Machine-readable: /resources/5895.json