Roundhouse

Quant Agent Shop

Email authentication check for a domain. Returns the SPF record with its DNS lookup count and all qualifier, the DMARC policy and report addresses, MX hosts, MTA-STS and BIMI records, DKIM keys found on common selectors, a grade from A to F and a list of issues. Use to diagnose deliverability or spoofing risk. DKIM is checked on common selectors only. Typical response under 1 s. Failed calls are not charged.

SearchLiveeip155:8453Exactvia cdp
https://quantagentshop.com/v1/email-auth-check
Web-searchWeb-scrapingCompany-dataResearchCompliance
Calls · 30d
22
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far.
$0.62
Verified settled volume
264 settlements proven x402 by their on-chain EIP-3009 marker.
$0.010
Listed price
As published in the catalog. Always read the live 402 before paying.
23
Calls · 30d
Upstream's own call count for this endpoint, not ours.
5
Unique payers · 30d
Last called 2026-10-26 10:53Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x4d8d8D4f04512029172e0176744Eec4AE5238309

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

0.01USDC≈ $0.01 USD
on Base · exact scheme

Pay 0.01 USDC on Base to 0x4d8d…38309. The signed payment is good for 2 minutes.

Paid to
0x4d8d…38309
USD Coin contract
0x8335…02913
Payment window
2 minutes
As published
10000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x4d8d8D4f04512029172e0176744Eec4AE5238309",
    "amount": "10000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 120
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "domain": "example.org"
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "mx": [
            {
              "host": "smtp.google.com.",
              "preference": 1
            }
          ],
          "spf": {
            "error": null,
            "valid": true,
            "record": "v=spf1 include:_spf.google.com ~all",
            "lookups": 4,
            "all_qualifier": "~all"
          },
          "bimi": {
            "record": null
          },
          "dkim": {
            "found": [
              "google"
            ],
            "checked_selectors": [
              "google",
              "selector1",
              "selector2",
              "default",
              "k1",
              "s1",
              "s2",
              "mail",
              "dkim",
              "smtp"
            ]
          },
          "dmarc": {
            "pct": 100,
            "rua": [
              "mailto:dmarc@example.org"
            ],
            "policy": "quarantine",
            "record": "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.org",
            "subdomain_policy": null
          },
          "grade": "A",
          "domain": "example.org",
          "issues": [],
          "mta_sts": {
            "record": null
          },
          "checked_at": "2026-10-22T09:00:00+00:00"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "domain"
              ],
              "properties": {
                "domain": {
                  "type": "string",
                  "title": "Domain",
                  "maxLength": 300,
                  "minLength": 1,
                  "description": "Domain name, such as example.com."
                }
              },
              "additionalProperties": false
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST",
                "PUT",
                "PATCH"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-10-26 10:53Z
Last indexed by Roundhouse
2026-10-26 17:20Z
Last enriched (probe, favicon, geo)
2026-10-22 19:17Z
x402 version
2
Max timeout
120s
Liveness probe
HTTP 402
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service Quant Agent Shop and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=Quant%20Agent%20Shop'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://quantagentshop.com/v1/email-auth-check, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at
GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at
https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.