●

Attester: Verification Oracle & Verified Research

AI PAYMENT-READY

payment-ready until 2026-08-20

Independent verification of agent work products: citation-support checks and data/schema validation returning wallet-signed attestations (EIP-191), plus cited coding research that ships pre-verified with a signed attestation over its citations. Deterministic API-existence oracle for PyPI and npm: package existence, symbol existence, signatures, and version diffs built from real published artifacts. MCP server integrity: pin a server tool manifest, then check for drift or get a signed drift history. USDC on Base mainnet via CDP facilitator. Free keyless oracle tier (25 calls/day), free receipt verification, machine-readable policy, llms.txt + OpenAPI.

Pay from $0.002 to $0.15 per request in USDC on Base, settled onchain via the x402 protocol, no signup, no API key needed.

first settlement 2026-07-21 · $1.33 all-time · settled via coinbase

BASE URL https://attester.dev │ WEBSITE https://attester.dev │ ENDPOINTS 11 │ NETWORK Base │ ASSET USDC │ MEMBER SINCE 2026-07-21 │ MONITORED SINCE 2026-07-21

ASSESSMENT

updated 4h ago

Evidence-backed signals, not a single score. Click any chip for the proof. Measured values stay read-only; unknown is honest.

reliability 100%

uptime 24h: 100%
uptime 7d: 99.8%
uptime 30d: 100%
uptime 90d: 100%
response p95: 1687ms
avg response: 700ms
total checks: 2,066

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

compliance A (14/14)

14 of 14 x402 conformance checks pass. Full checklist below.

jump to compliance checklist

price $0.002 to $0.15 (p17 in AI)

price (min): $0.002
price (max): $0.15
category percentile (min): p17 in AI
category percentile (max): p60 in AI
endpoints / prices: 11 / 7
model: tiered
stability: 0%

risk clean

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: 22d
registrar: CloudFlare, Inc.
hosting: custom
domain created: 2026-07-20

Identity facts, not a risk score.

traction $1.323 30d · 4 buyers · top buyer 95%

volume 30d: $1.323
buyers 30d: 4
settlements 30d: 30
first settlement: 2026-07-21
last settlement: 2026-08-10
top buyer share: 95% of 30d volume
trend 7d vs 30d: 0.18x the 30d daily rate
networks: eip155:8453
volume all-time: $1.33
settlements all-time: 30
median settlement 30d: $0.015
max settlement 30d: $0.15
settled via: coinbase ($1.32, 30 tx)

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

Top buyer share is a concentration signal, not part of the ranking score.

CHANGES

2 events, detecting since 2026-07-24

Payout, price, and schema changes detected on this service's x402 wire. A payout rotation at an unchanged price shows up here even when nothing else moves. Full feed at /changes.

changes schema changed 26h ago (2 since 2026-07-24)

schema changed · 26h ago

endpoint added GET /v2/mcp/check

endpoint added GET /v2/mcp/report

schema added GET /v2/mcp/check exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 USDC 2 300 {"name":"USD Coin","version":"2"}

schema added GET /v2/mcp/report exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 USDC 2 300 {"name":"USD Coin","version":"2"}

schema changed · 16d ago

endpoint added GET /v1/diff

endpoint added GET /v1/package/exists

endpoint added GET /v1/symbol/exists

endpoint added GET /v1/symbol/signature

schema added GET /v1/diff exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 2

schema added GET /v1/package/exists exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 2

schema added GET /v1/symbol/exists exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 2

schema added GET /v1/symbol/signature exact eip155:8453 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 2

see all changes for this service

WHAT IT DOES

ai-derived

No AI synthesis has been produced for this service yet.

ENDPOINTS

Service endpoints with HTTP method, path, description, pricing, and network
METHOD	PATH	PRICE	NETWORK	ASSET	402 CHANNEL
POST	/code-research	$0.10	Base	USDC	header
GET	/judge	$0.10	Base	USDC	header
GET	/spend-check	$0.005	Base	USDC	header
GET	/v1/diff	$0.02	Base	USDC	header
GET	/v1/package/exists	$0.002	Base	USDC	header
GET	/v1/symbol/exists	$0.005	Base	USDC	header
GET	/v1/symbol/signature	$0.01	Base	USDC	header
GET	/v2/mcp/check	$0.01	Base	USDC	header
GET	/v2/mcp/report	$0.05	Base	USDC	header
POST	/verify	$0.15	Base	USDC	header
GET	/watchtower/report	$0.05	Base	USDC	header

11 endpoints

REQUEST / RESPONSE EXAMPLE

An unpaid request to GET /judge returns HTTP 402 with the payment terms. Settle onchain via your facilitator, then retry with the X-Payment header.

// request

curl -i 'https://attester.dev/judge'

// 402 response (captured by monitor) · 11 payloads · click to expand

[
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "10000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/v2/mcp/check",
      "mimeType": "application/json",
      "description": "MCP manifest drift check (use POST; metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "50000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/v2/mcp/report",
      "mimeType": "application/json",
      "description": "MCP manifest drift report (use POST; metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "100000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/code-research",
      "tags": [
        "research",
        "coding",
        "citations",
        "docs",
        "agents"
      ],
      "mimeType": "application/json",
      "description": "Cited coding research for agents: library/API usage answers, error diagnosis and best-practice lookups with real citations. $0.10 USDC per call.",
      "serviceName": "Cited Coding Research"
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "query": "How do I stream responses with the OpenAI Python SDK?",
              "context": null
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "answer": "Use stream=True ...",
              "citations": [
                {
                  "url": "https://platform.openai.com/docs",
                  "title": "OpenAI docs",
                  "snippet": "..."
                }
              ]
            }
          }
        },
        "schema": {
          "$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": [
                    "query"
                  ],
                  "properties": {
                    "query": {
                      "type": "string",
                      "description": "Coding question to research"
                    },
                    "context": {
                      "type": [
                        "string",
                        "null"
                      ],
                      "description": "Optional extra context"
                    }
                  }
                },
                "type": {
                  "type": "string",
                  "const": "http"
                },
                "method": {
                  "enum": [
                    "POST"
                  ],
                  "type": "string"
                },
                "bodyType": {
                  "enum": [
                    "json"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            },
            "output": {
              "type": "object",
              "required": [
                "example"
              ],
              "properties": {
                "example": {
                  "type": "object"
                }
              }
            }
          }
        },
        "category": "ai",
        "discoverable": true
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "100000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/judge",
      "mimeType": "application/json",
      "description": "QA Judge (use POST; full Bazaar metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "20000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/v1/diff",
      "mimeType": "application/json",
      "description": "Package version diff (use POST; metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "2000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/v1/package/exists",
      "mimeType": "application/json",
      "description": "Package existence check (use POST; metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "5000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/v1/symbol/exists",
      "mimeType": "application/json",
      "description": "Symbol existence check (use POST; metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "50000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/watchtower/report",
      "mimeType": "application/json",
      "description": "SLA Watchtower report (use POST; full Bazaar metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "150000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/verify",
      "tags": [
        "verification",
        "attestation",
        "agents",
        "trust",
        "audit"
      ],
      "mimeType": "application/json",
      "description": "Verification Oracle: independent checks on another agent's work (citation support, data/schema validation) returning a wallet-signed attestation. $0.15 USDC per verification.",
      "serviceName": "Verification Oracle"
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "job": {
                "type": "citation",
                "claim": "Python was created by Guido van Rossum",
                "sources": [
                  "https://en.wikipedia.org/wiki/Python_(programming_language)"
                ]
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "verdict": "pass",
              "signature": "0x…",
              "confidence": 0.83,
              "attestation": {
                "service_version": "0.2.0",
                "verifier_address": "0x31520f9c14360470040807fAba64938ebcfF9C8f"
              }
            }
          }
        },
        "schema": {
          "$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": [
                    "job"
                  ],
                  "properties": {
                    "job": {
                      "type": "object",
                      "required": [
                        "type"
                      ],
                      "properties": {
                        "type": {
                          "enum": [
                            "citation",
                            "code",
                            "data"
                          ],
                          "type": "string"
                        },
                        "claim": {
                          "type": "string"
                        },
                        "sources": {
                          "type": "array",
                          "items": {
                            "type": "string"
                          }
                        }
                      },
                      "description": "Verification job: citation support check, data/schema validation"
                    }
                  }
                },
                "type": {
                  "type": "string",
                  "const": "http"
                },
                "method": {
                  "enum": [
                    "POST"
                  ],
                  "type": "string"
                },
                "bodyType": {
                  "enum": [
                    "json"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            },
            "output": {
              "type": "object",
              "required": [
                "example"
              ],
              "properties": {
                "example": {
                  "type": "object"
                }
              }
            }
          }
        },
        "category": "ai",
        "discoverable": true
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "5000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/spend-check",
      "mimeType": "application/json",
      "description": "Spend Check (use POST; full Bazaar metadata on POST)."
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD",
        "amount": "10000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://attester.dev/v1/symbol/signature",
      "mimeType": "application/json",
      "description": "Symbol signature lookup (use POST; metadata on POST)."
    },
    "x402Version": 2
  }
]

OVER TIME

All charts use the 90d selector; each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/attester-verification-oracle-verified-research/price, /scores, /volume and /buyers. On-chain volume and distinct buyers are measured over the service's settlement address and are a conservative undercount (only settlements that reach a measured facilitator are counted). The on-chain series roll up hourly, so the latest day can be up to about an hour behind; distinct buyers are counted per payout address, so a service that settles to more than one address is an upper bound.

UPTIME

90d UPTIME 100%

RESPONSE TIME

AVG RESP 704ms

PRICE (captured 402, USD)

Median across 11 endpoints. Use the selector to isolate one.

SUB-SCORES (uptime + x402 compliance)

checklist grew 11->14 on 2026-07-28; a step here is a metric change, not a regression

PILLARS OVER TIME (measured)

price percentile in AI

site signals present (of 6)

Measured site and economics pillars from the assessment history, so the latest value shown elsewhere on this page reads as a point on a trend rather than a permanent state.

VOLUME (on-chain settlement, USD)

DISTINCT BUYERS

COMPLIANCE

14/14 checks pass · grade A

last 402 captured 2026-08-12 · last up 2026-08-13

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

SITE PILLARS

homepage reachable
openapi doc
pricing page
llms.txt
robots.txt
terms page

recent checks (18) live · click to expand

TIME STATUS RESP CAUSE

16:10:37 UTC ● SLOW 1317ms

15:54:42 UTC ● SLOW 1366ms

15:38:34 UTC ● SLOW 1232ms

15:22:39 UTC ● SLOW 1322ms

15:06:42 UTC ● SLOW 1413ms

14:50:42 UTC ● SLOW 1344ms

14:34:34 UTC ● SLOW 1388ms

14:18:39 UTC ● SLOW 1129ms

14:02:42 UTC ● SLOW 1444ms

13:46:39 UTC ● SLOW 1241ms

13:30:38 UTC ● SLOW 1309ms

13:14:37 UTC ● SLOW 1155ms

12:58:41 UTC ● OK 983ms

12:42:36 UTC ● OK 1022ms

12:26:42 UTC ● SLOW 1529ms

12:10:34 UTC ● SLOW 1103ms

11:54:37 UTC ● SLOW 1085ms

11:38:39 UTC ● SLOW 1218ms

EMBED THIS BADGE

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status

Attester: Verification Oracle & Verified Research uptime on x402-list — live uptime

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Keep this listing accurate: propose changes to the name, description, website, category or add new endpoints to monitor. Ownership is verified with a domain proof and every change is reviewed manually; measured data stays read-only.

[ 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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