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PaywallWatch

payment-readyonline

payment-ready until 2026-11-05

Use when an agent needs email validation, screening only, for an address from a form, a scrape or a CRM and must decide whether it is worth sending to.

Compare: all web scraping APIs · all email verification APIs · all WHOIS and domain APIs

paywallwatch.com ↗

Call it x402 v2

x402 v2

Base URL
https://api.paywallwatch.com
Payment
x402 v2, header channel
$ curl -i 'https://api.paywallwatch.com/v1/email/verify'

An unpaid request returns HTTP 402 with the payment terms. Sign a payment authorization, then retry with the PAYMENT-SIGNATURE header.

Endpoints 2 paid routes on api.paywallwatch.com

GET/v1/email/verifyBase+Sol$0.003since 10-29
GET/v1/pingBase+Sol$0.01since 10-29

Prices as captured in the 402 response: median $0.0065 across the 2 endpoints, unchanged since first capture.

Example 402 response

Endpoints and prices

Current paid endpoints; minimum quoted prices in USD where available; first capture dates in UTC
MethodPathDescriptionPriceNetworkAsset402 channelCaptured
GET/v1/email/verifyUse when an agent needs email validation, screening only, for an address from a form, a scrape or a CRM and must decide whether it is worth sending to. Screens the address: syntax, DNS mail exchanger, disposable domain, role account, free provider and common typos. It does not verify that the mailbox exists. A DNS failure answers 503 and is not charged.$0.003Base+SolUSDCheadersince 10-29
GET/v1/pingUse when testing an x402 client end to end. Returns ok and the server time; costs one cent.$0.01Base+SolUSDCheadersince 10-29

Payment evidence

402 payload captured at . Check evidence JSON · Measurement methodology.

First of 2 payloads captured by the monitor.

222 lines, scroll inside

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xAE71740237442f5f1a2A7b4f59A201e9a4350C0C",
      "amount": "3000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "BENrLoUbndxoNMUS5JXApGMtNykLjFXXixMtpDwDR9SP"
      },
      "payTo": "8DH2FPfSPydYXvXSxrG3tLdzDVpyJDyKG5pKkXpwK1rn",
      "amount": "3000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://api.paywallwatch.com/v1/email/verify",
    "tags": [
      "email",
      "email-validation",
      "email-screening",
      "lead",
      "crm",
      "disposable-email",
      "email-check",
      "mx",
      "dns",
      "deliverability"
    ],
    "iconUrl": "https://paywallwatch.com/icon.png",
    "mimeType": "application/json",
    "description": "Use when an agent needs email validation, screening only, for an address from a form, a scrape or a CRM and must decide whether it is worth sending to. Screens the address: syntax, DNS mail exchanger, disposable domain, role account, free provider and common typos. It does not verify that the mailbox exists. A DNS failure answers 503 and is not charged.",
    "serviceName": "PaywallWatch"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "email": "[email protected]"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "email": "[email protected]",
            "has_mx": true,
            "reasons": [],
            "verdict": "domain_accepts_mail",
            "checked_at": "2026-10-20T09:12:00Z",
            "disposable": false,
            "dns_status": "ok",
            "suggestion": null,
            "role_account": false,
            "valid_syntax": true,
            "free_provider": false,
            "screening_note": "Screening only: syntax, DNS mail exchanger, disposable-domain list, role-account and typo heuristics. It does not verify that the mailbox exists or that mail will be delivered.",
            "mailbox_verified": false
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "email"
                ],
                "properties": {
                  "email": {
                    "type": "string",
                    "description": "The address to screen"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "email",
                  "valid_syntax",
                  "dns_status",
                  "has_mx",
                  "disposable",
                  "role_account",
                  "free_provider",
                  "suggestion",
                  "verdict",
                  "reasons",
                  "mailbox_verified",
                  "screening_note",
                  "checked_at"
                ],
                "properties": {
                  "email": {
                    "type": "string"
                  },
                  "has_mx": {
                    "type": "boolean"
                  },
                  "reasons": {
                    "type": "array",
                    "items": {
                      "enum": [
                        "invalid_syntax",
                        "domain_not_found",
                        "null_mx",
                        "no_mail_exchanger",
                        "no_mx_record_only_a_record",
                        "disposable_domain",
                        "typo_suspected"
                      ],
                      "type": "string"
                    }
                  },
                  "verdict": {
                    "enum": [
                      "domain_accepts_mail",
                      "risky",
                      "disposable",
                      "undeliverable"
                    ],
                    "type": "string"
                  },
                  "checked_at": {
                    "type": "string",
                    "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(\\.\\d+)?Z$"
                  },
                  "disposable": {
                    "type": "boolean"
                  },
                  "dns_status": {
                    "enum": [
                      "ok",
                      "implicit",
                      "null_mx",
                      "nomx",
                      "nxdomain",
                      "not_checked"
                    ],
                    "type": "string"
                  },
                  "suggestion": {
                    "type": [
                      "string",
                      "null"
                    ]
                  },
                  "role_account": {
                    "type": "boolean"
                  },
                  "valid_syntax": {
                    "type": "boolean"
                  },
                  "free_provider": {
                    "type": "boolean"
                  },
                  "screening_note": {
                    "type": "string"
                  },
                  "mailbox_verified": {
                    "type": "boolean",
                    "const": false
                  }
                },
                "additionalProperties": false
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}
Other captured 402 responses (1)

Captured payload 2 of 2

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xAE71740237442f5f1a2A7b4f59A201e9a4350C0C",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM"
      },
      "payTo": "8DH2FPfSPydYXvXSxrG3tLdzDVpyJDyKG5pKkXpwK1rn",
      "amount": "10000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://api.paywallwatch.com/v1/ping",
    "tags": [
      "x402",
      "ping",
      "test",
      "health-check"
    ],
    "iconUrl": "https://paywallwatch.com/icon.png",
    "mimeType": "application/json",
    "description": "Use when testing an x402 client end to end. Returns ok and the server time; costs one cent.",
    "serviceName": "PaywallWatch"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "at": "2026-10-20T09:12:00Z",
            "ok": true
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "properties": {}
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "ok",
                  "at"
                ],
                "properties": {
                  "at": {
                    "type": "string",
                    "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(\\.\\d+)?Z$"
                  },
                  "ok": {
                    "type": "boolean",
                    "const": true
                  }
                },
                "additionalProperties": false
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Can I trust it score from our own monitoring

score from our own monitoring

95/100 Strong

#6 of 177 in Verification. Bands: strong 93+, solid 75+, mixed 55+, weak below 55.

Reliability
100% uptime since 10-29
Compliance
A 14/14 checks pass
Price
$0.003 to $0.01 p21 in Verification
Risk
clean no risk flag
Traction
---
14/14 compliance checks
  • 402 payload captured
  • accepts[] array present
  • payTo address recoverable
  • payTo at accepts[0].payTo (conformant shape)
  • payTo is a valid on-chain address
  • atomic price declared
  • atomic price in a sane range
  • asset (token) address declared
  • network resolves to CAIP-2
  • payment scheme declared
  • served over HTTPS
  • declares the current x402 version (2)
  • EIP-712 domain parameters present on every EVM entry
  • x402 v2 envelope delivered in the payment-required header

402 terms unchanged since 2026-10-29. Last up 2026-10-29.

── Site signals

  • homepage reachable
  • openapi doc
  • pricing page
  • llms.txt
  • robots.txt
  • terms page
How the score works

What the score read on this service: status online, 100% uptime, latest daily rollup (no 30d window yet), 968ms response p95, x402 compliance 14 of 14, $0.003 price against the category. Each of those is measured, and each is published in full below.

The score comes from our own monitoring, never from reviews, operator claims, or a language model: reliability, x402 compliance, price against the category, a deterministic risk flag, and a small on-chain traction term, weighted by ranking generation 3. It is not placement anyone can buy: the paid verify tier is reported beside it and is not one of its inputs. Every component below stays published and read-only.

Bands on the 0 to 100 measured score: strong at 93 and above, solid from 75, mixed from 55, weak below 55. Price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, so the score places a service in its own field.

It is a score inside Verification, and only there: price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, which here means 177 listings, this one among them: the same 177 the position above is counted against. When the two differ, the field is the wider one, because a listing we have measured too little of to rank still sits in the field the price and the speed are normalized over. The same service in a different field would read differently. The same engine answers GET /api/v1/best, and asked for a different pool (the whole directory, or another filter) it returns a different number for this service under this same ranking generation. Neither is more correct: they answer different questions, and the methodology states which is which.

All measured facts

What it does

Use when an agent needs email validation, screening only, for an address from a form, a scrape or a CRM and must decide whether it is worth sending to. Screens the address: syntax, DNS mail exchanger, disposable domain, role account, free provider and common typos. It does not verify that the mailbox exists. A DNS failure answers 503 and is not charged.

PaywallWatch is a listed x402 Verification API. Captured payment terms name Base, Solana. Monitoring and settlement figures below describe the observations available to this directory; an unpaid HTTP 402 check does not prove that a paid call will deliver.

Assessment computed at . Latest service check observed at . Service data JSON · Measurement methodology.

Page rendered at . This response time is separate from the observation and computation times attached to each measurement.

Latest endpoint observation: . Latest price capture: . Prices are recorded quotes, not a promise of availability. Token assets and payment terms are listed separately. Endpoint data JSON · Price history JSON · Measurement methodology.

Assessment computed at . Uptime uses the stated daily-rollup window; response times are in milliseconds, compliance is passed/evaluated checks, and traction is a measured settlement floor. The comparison score is out of 100 within this category. Assessment JSON · Measurement methodology.

Observed daily coverage: 2026-09-30 to 2026-10-29 UTC. Daily monitoring and settlement rollups do not expose their computation time; a bucket date is not an update timestamp. Uptime and response JSON · Volume JSON · Buyers JSON · Measurement methodology.

Ranked from the measured category pool, refreshed at most once a minute. The comparison has no persisted computation timestamp; the assessment time above belongs to this service only. Ranking API documentation · Ranking methodology.

x402 List home · Services · Verification

uptime · latest daily rollup
-
uptime 7d
-
uptime 30d
-
uptime 90d
-
response p95
968ms
avg response
968ms
total checks
1

Measured on the unpaid 402 handshake, not the paid call. A service can 402 correctly and still fail after payment.

price (min)
$0.003
price (max)
$0.01
category percentile (min)
p21 in Verification
category percentile (max)
p25 in Verification
endpoints / prices
2 / 2
model
tiered
stability
100%

No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.

domain age
-
registrar
-
hosting
custom
domain created
---

Identity facts, not a risk score.

On-chain traction has not been assessed for this service yet.

member since
2026-10-29
Recent checks
Latest 8 unpaid HTTP checks, newest first; response times in milliseconds, observation times in UTC
Checked at (UTC)StatusHTTPResponseEndpoints
Online402662ms2
Online402641ms2
Online402406ms2
Online402276ms2
Online402638ms2
Online4022376ms2
Online402491ms2
Online402968ms2

Changes0 in 30d

No changes recorded in the last 30 days.

all changes

Over time

On-chain volume

On-chain traction has not been assessed for this service yet.

Uptime no completed-day data
Uptime
no completed-day data

On-chain traction has not been assessed for this service yet.

More charts
Response time daily average, ms min 828ms, avg 828ms, max 828ms

09-30 to 10-29* UTC

Each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/paywallwatch/price, /scores, /volume and /buyers.

Values

* today so far, partial (UTC).

The uptime summary counts completed UTC days only. The strip, readouts and table retain today's partial reading.

Assessment history last recorded at . Each UTC day uses its last recorded run; missing readings stay unmeasured. Assessment history JSON · Measurement methodology.

Daily values, 2026-10-29 to 2026-10-29: uptime percent, average response milliseconds, compliance passed/total, price percentile 0-100, site signals out of 6; UTC dates
DayUptimeResponseCompliancePrice percentileSite signals
2026-10-29*100%828.00ms14/14p212/6

Alternatives in Verification

agentshield.live facts strong 99/100 --- up 30d --- 30d
Grokbot Safe Read & x402 Preflight strong 98/100 --- up 30d --- 30d
BotsRated strong 97/100 --- up 30d --- 30d
how.is strong 96/100 --- up 30d --- 30d
Apex Pay · verified agent tools strong 95/100 --- up 30d --- 30d

5 of 176 other ranked services in Verification, ordered by the same measured score.

Own this service?

Keep this listing accurate. Ownership is proven with a domain check and every change is reviewed by hand.

Update this listing

Earn the verified tier: x402list pays a real call to this endpoint and, if it delivers, the service is delivery-verified. The fee covers the cost of the probe, not the badge; there is no refund if the call does not deliver. Agent and API only, no in-browser signing. See /api.

Verify this service ($0.25)
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<a href="https://x402-list.com/services/paywallwatch?utm_source=badge&utm_medium=referral&utm_campaign=embed">
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</a>

Markdown

[![PaywallWatch on x402-list](https://x402-list.com/badge/paywallwatch.svg)](https://x402-list.com/services/paywallwatch?utm_source=badge&utm_medium=referral&utm_campaign=embed)

HTML, live uptime variant

<a href="https://x402-list.com/services/paywallwatch?utm_source=badge&utm_medium=referral&utm_campaign=embed">
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</a>
Delisting

To request delisting, email info@x402-list.com with the service name, slug, or URL. Removal is free and does not require proof of ownership. See all free email requests.