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Penny x402 Endpoint Audit

payment-readyonline

payment-ready until 2026-11-03

Pay-per-call audit of any public x402 endpoint: fetches a URL and reports whether its HTTP 402 challenge is a schema-valid x402 v2 PaymentRequired, payable in Base USDC, and catalog-ready (bazaar discovery declaration plus facilitator support).

Call it x402 v2

x402 v2

Base URL
https://penny-x402-endpoint-audit.penny-mcamp.workers.dev
Payment
x402 v2, header channel
$ curl -i 'https://penny-x402-endpoint-audit.penny-mcamp.workers.dev/v1/audit'

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

Endpoints 3 paid routes on penny-x402-endpoint-audit.penny-mcamp.workers.dev

GET/v1/auditBase$0.010318since 10-27
GET/v1/passBase$1.00since 10-27
GET/v1/reportBase$5.00since 10-27

Prices as captured in the 402 response: median $1.00 across the 3 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/auditFetch any public URL and report whether its HTTP 402 challenge is a schema-valid x402 v2 PaymentRequired, payable in Base USDC, and catalog-ready (bazaar discovery declaration + facilitator support).$0.010318BaseUSDCheadersince 10-27
GET/v1/passBuyer-side pass: GET ?urls=<comma separated list> with up to 20 public URLs and receive one verdict row per URL - is the endpoint's 402 a schema-valid x402 v2 PaymentRequired, payable in Base USDC, catalog-ready, and is its declared EIP-712 domain the token's on-chain domain. Rows are CC0.$1.00BaseUSDCheadersince 10-27
GET/v1/reportVerified paid-path report: GET ?urls=<comma separated list> with up to 10 public URLs. We attempt one real paid call against each URL from our own wallet, capped at 50000 atomic USDC per attempt, and publish one row per URL - settled yes or no, the transaction id, whether the declared payTo and amount matched what actually settled, and whether the paid response carried a body - at the order URL within 24 hours. If we cannot attempt a paid call on at least one URL we return the amount to the sender. Rows are CC0.$5.00BaseUSDCheadersince 10-27

Payment evidence

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

First of 3 payloads captured by the monitor.

153 lines, scroll inside

{
  "error": "PAYMENT-SIGNATURE header is required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x8b8543A9566b7C75e5484Ce4385D76879EDA2068",
      "amount": "10318",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://penny-x402-endpoint-audit.penny-mcamp.workers.dev/v1/audit",
    "tags": [
      "x402",
      "payments",
      "audit",
      "base-usdc",
      "discovery"
    ],
    "mimeType": "application/json",
    "description": "Fetch any public URL and report whether its HTTP 402 challenge is a schema-valid x402 v2 PaymentRequired, payable in Base USDC, and catalog-ready (bazaar discovery declaration + facilitator support).",
    "serviceName": "Penny x402 Endpoint Audit"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://us-rates.use.x402atlas.com/latest"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "bazaar": {
              "valid": true,
              "present": true
            },
            "schema": {
              "valid": true,
              "errors": []
            },
            "target": {
              "method": "GET",
              "status": 402,
              "reachable": true
            },
            "accepts": [
              {
                "usd": 0.01,
                "scheme": "exact",
                "network": "eip155:8453",
                "amountAtomic": "10000"
              }
            ],
            "readiness": {
              "reasons": [],
              "verdict": "listed_ready"
            },
            "checkedUrl": "https://us-rates.use.x402atlas.com/latest",
            "facilitator": {
              "checked": true,
              "acceptsDeclaredNetwork": true,
              "bazaarExtensionAdvertised": 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": {
                  "url": {
                    "type": "string"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2,
  "amountOffset": {
    "sku": "sku:audit:v1/audit",
    "note": "advertised amount = list price + a deterministic 1..999 micro offset keyed by the SKU id, so the settled on-chain amount identifies which SKU was bought (an EIP-3009 authorization carries no resource id)",
    "route": "/v1/audit",
    "listAtomic": "10000",
    "offsetMicros": "318",
    "advertisedAtomic": "10318"
  },
  "challengeRecord": {
    "path": "/v1/audit",
    "payTo": "0x8b8543A9566b7C75e5484Ce4385D76879EDA2068",
    "storage": {
      "key": "chal:chal_80c539f5f5075e9e8c648d5a",
      "reason": null
    },
    "issuedAt": "2026-10-27T11:32:02.560Z",
    "priceUsd": 0.01,
    "resource": "https://penny-x402-endpoint-audit.penny-mcamp.workers.dev/v1/audit",
    "persisted": true,
    "challengeId": "chal_80c539f5f5075e9e8c648d5a",
    "amountAtomic": "10318"
  }
}
Other captured 402 responses (2)

Captured payload 2 of 3

{
  "error": "PAYMENT-SIGNATURE header is required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x8b8543A9566b7C75e5484Ce4385D76879EDA2068",
      "amount": "1000000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://penny-x402-endpoint-audit.penny-mcamp.workers.dev/v1/pass",
    "tags": [
      "x402",
      "payments",
      "audit",
      "base-usdc",
      "discovery"
    ],
    "mimeType": "application/json",
    "description": "Buyer-side pass: GET ?urls=<comma separated list> with up to 20 public URLs and receive one verdict row per URL - is the endpoint's 402 a schema-valid x402 v2 PaymentRequired, payable in Base USDC, catalog-ready, and is its declared EIP-712 domain the token's on-chain domain. Rows are CC0.",
    "serviceName": "Penny x402 Endpoint Audit"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "urls": "comma or newline separated list of up to 20 absolute http(s) URLs"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "rows": [
              {
                "status": 402,
                "verdict": "listed_ready",
                "checkedUrl": "https://us-rates.use.x402atlas.com/latest",
                "acceptsCount": 1,
                "domainMismatchCount": 0,
                "paymentRequiredHeaderPresent": true
              }
            ],
            "orderId": "po_1a2b3c4d",
            "service": "penny-x402-endpoint-pass",
            "rowCount": 20
          }
        }
      },
      "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": {
                  "urls": {
                    "type": "string"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Captured payload 3 of 3

{
  "error": "PAYMENT-SIGNATURE header is required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x8b8543A9566b7C75e5484Ce4385D76879EDA2068",
      "amount": "5000000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://penny-x402-endpoint-audit.penny-mcamp.workers.dev/v1/report",
    "tags": [
      "x402",
      "payments",
      "audit",
      "base-usdc",
      "discovery"
    ],
    "mimeType": "application/json",
    "description": "Verified paid-path report: GET ?urls=<comma separated list> with up to 10 public URLs. We attempt one real paid call against each URL from our own wallet, capped at 50000 atomic USDC per attempt, and publish one row per URL - settled yes or no, the transaction id, whether the declared payTo and amount matched what actually settled, and whether the paid response carried a body - at the order URL within 24 hours. If we cannot attempt a paid call on at least one URL we return the amount to the sender. Rows are CC0.",
    "serviceName": "Penny x402 Endpoint Audit"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "urls": "comma or newline separated list of up to 10 absolute http(s) URLs"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "plan": [
              {
                "attempt": "queued",
                "checkedUrl": "https://api.example.com/x402/resource",
                "declaredAtomic": "2000"
              }
            ],
            "tier": "paid_path",
            "status": "paid_pending_delivery",
            "orderId": "po_1a2b3c4d",
            "service": "penny-x402-paid-path-report",
            "deliveryHours": 24,
            "maxPaidCallAtomic": "50000"
          }
        }
      },
      "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": {
                  "urls": {
                    "type": "string"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Can I trust it score from our own monitoring

score from our own monitoring

85/100 Solid

#61 of 169 in Verification. Bands: strong 93+, solid 75+, mixed 55+, weak below 55.

Reliability
100% uptime since 10-27
Compliance
A 14/14 checks pass
Price
$0.010318 to $5.00 p62 in Verification
Risk
clean no risk flag
Traction
$0.00 30d 0 buyers
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 2026-10-27. Last up 2026-10-27.

── 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), 109ms response p95, x402 compliance 14 of 14, $0.010318 price against the category, on-chain traction measured. 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 169 listings, this one among them: the same 169 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.

Traction is a conservative undercount.

All measured facts

What it does

Pay-per-call audit of any public x402 endpoint: fetches a URL and reports whether its HTTP 402 challenge is a schema-valid x402 v2 PaymentRequired, payable in Base USDC, and catalog-ready (bazaar discovery declaration plus facilitator support). 0.010318 USDC per call on Base.

Penny x402 Endpoint Audit is a listed x402 Verification API. Captured payment terms name Base. 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: 2026-09-28 to 2026-10-27 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
109ms
avg response
109ms
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)
$0.010318
price (max)
$5.00
category percentile (min)
p62 in Verification
category percentile (max)
p95 in Verification
endpoints / prices
3 / 3
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
free host
domain created
---

Identity facts, not a risk score.

assessment volume 30d
$0.00
exact assessment volume 30d (USD)
0
assessment recorded at (UTC)
2026-10-27T11:34:14.177Z
buyers 30d
0
settlements 30d
0
measured since
--- (start of our harvest window)
last settlement
---
top buyer share
-
top 3 buyers share
-
concentrated volume
no
trend 7d vs 30d
-
networks
eip155:8453
volume all-time
$0
settlements all-time
0
median settlement 30d
-
max settlement 30d
-

Assessment volume uses the latest 30d assessment. Over time sums daily address snapshots, rounded to cents and refreshed separately. The two sources can differ in timing, precision and shared-address attribution. Amounts use cents for comparison; known sub-cent values keep up to 12 significant digits. The exact stored assessment value is shown above.

Conservative undercount: only USDC settlements via facilitators we measure are counted. A measured floor, not an estimate.

Top buyer share lowers the on-chain traction part of the ranking score behind this page's verdict and /best, by up to half when one address holds all 30d volume. The Recommended and Highest volume sorts of the services list do not use it; they use the Concentrated volume rule instead.

member since
2026-10-27
Recent checks
Latest 9 unpaid HTTP checks, newest first; response times in milliseconds, observation times in UTC
Checked at (UTC)StatusHTTPResponseEndpoints
Online402151ms3
Online402620ms3
Online402330ms3
Online402592ms3
Online402309ms3
Online402544ms3
Online402364ms3
Online402103ms3
Online402109ms3

Changes0 in 30d

No changes recorded in the last 30 days.

all changes

Over time

On-chain volume daily snapshots, USD 30d: $0.00, peak $0.02 on 10-11
volume no data in the payload
Distinct buyers per dayDistinct buyers per day
Uptime no completed-day data
Volume 30d
$0.00
Uptime
no completed-day data
Daily on-chain settlement volume in US dollars, 2026-09-28 to 2026-10-27; highest day $0.02 on 10-11; 13 days have no data in the payload; distinct buyers per day
More charts
Response time daily average, ms min 337ms, avg 337ms, max 337ms

09-28 to 10-27* UTC

Each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/penny-x402-endpoint-audit/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.

Daily snapshot total, 30d: $0.07, peak $0.02 on 10-11. The visible 30d total in Traction comes from the latest assessment. These sources can differ in their window, refresh time, cent rounding and shared-address attribution.

Daily address snapshots: 2026-09-28 to 2026-10-27 UTC; * today so far, partial (UTC). Daily snapshots store cents. A recorded $0.00 with settlements cannot distinguish exact zero from volume rounded away. Lost precision is unavailable here.

Settlement volume uses the stored USD valuation of tracked payments; it is distinct from token quantities. USD-pegged assets are valued at 1 USD per token in these rollups. The measured settlement floor does not cover all payments to this service.

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

Daily values, 2026-10-10 to 2026-10-27: address settlement volume in USD, distinct buyer and settlement counts, uptime percent, average response milliseconds, compliance passed/total, price percentile 0-100, site signals out of 6; UTC dates
DayVolumeBuyersSettlementsUptimeResponseCompliancePrice percentileSite signals
2026-10-10$0.0111no datano datano datano datano data
2026-10-11$0.0212no datano datano datano datano data
2026-10-12no datano datano datano datano datano datano datano data
2026-10-13no datano datano datano datano datano datano datano data
2026-10-14no datano datano datano datano datano datano datano data
2026-10-15no datano datano datano datano datano datano datano data
2026-10-16no datano datano datano datano datano datano datano data
2026-10-17no datano datano datano datano datano datano datano data
2026-10-18no datano datano datano datano datano datano datano data
2026-10-19$0.0222no datano datano datano datano data
2026-10-20no datano datano datano datano datano datano datano data
2026-10-21no datano datano datano datano datano datano datano data
2026-10-22no datano datano datano datano datano datano datano data
2026-10-23no datano datano datano datano datano datano datano data
2026-10-24$0.0111no datano datano datano datano data
2026-10-25no datano datano datano datano datano datano datano data
2026-10-26no datano datano datano datano datano datano datano data
2026-10-27*$0.0111100%336.83ms14/14p623/6

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5 of 168 other ranked services in Verification, ordered by the same measured score.

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