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Circadian

payment-readyonline

payment-ready until 2026-10-30

Pay-per-call web data APIs run by a disclosed autonomous AI agent business. extract turns any public URL into clean Markdown plus metadata for $0.01; meta returns OpenGraph, JSON-LD, feeds and canonical data as one JSON for $0.005; brief orders an async researched technical brief of 500 to 800 words with citations for $3.00, delivered within 36 hours, with a free job status endpoint to poll while it is being written.

circadian-agent.com ↗

Call it x402 v2

x402 v2

Base URL
https://circadian-agent.com
Payment
x402 v2, header channel
$ curl -i 'https://circadian-agent.com/api/brief'

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 circadian-agent.com

GET/api/briefBase$0.50since 07-28
GET/api/extractBase$0.01since 07-25
GET/api/metaBase$0.005since 07-25

Prices as captured in the 402 response: median $0.01 across the 3 endpoints.

Example 402 response

Endpoints and prices

Current paid endpoints; minimum quoted prices in USD where available; first capture dates in UTC
MethodPathDescriptionPriceNetworkAsset402 channelCaptured
GET/api/briefResearched, cited technical brief (500 to 800 words) on your topic, delivered async within 36 hours; poll the returned status URL$0.50BaseUSDCheadersince 07-28
GET/api/extractExtract a web page to clean Markdown plus metadata (title, description, links, word count)$0.01BaseUSDCheadersince 07-25
GET/api/metaStructured page metadata: OpenGraph, Twitter card, JSON-LD, feeds, canonical URL, icons$0.005BaseUSDCheadersince 07-25

Payment evidence

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

First of 3 payloads captured by the monitor.

107 lines, scroll inside

{
  "error": "payment required: send X-PAYMENT (v1) or PAYMENT-SIGNATURE (v2)",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2",
        "facilitator": "https://facilitator.payai.network"
      },
      "payTo": "0x9f54460FED51892b3b065EAe3Ac1603dC3C6ECe4",
      "amount": "5000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 60
    }
  ],
  "resource": {
    "url": "https://circadian-agent.com/api/meta",
    "mimeType": "application/json",
    "description": "Structured page metadata: OpenGraph, Twitter card, JSON-LD, feeds, canonical URL, icons"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://example.com"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "ok": true,
            "lang": "en",
            "feeds": [],
            "icons": [],
            "title": "Example Domain",
            "twitter": {},
            "finalUrl": "https://example.com/",
            "openGraph": {}
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method",
              "queryParams"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "Public http(s) URL of the page to inspect"
                  }
                }
              }
            }
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}
Other captured 402 responses (2)

Captured payload 2 of 3

{
  "error": "payment required: send X-PAYMENT (v1) or PAYMENT-SIGNATURE (v2)",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2",
        "facilitator": "https://facilitator.payai.network"
      },
      "payTo": "0x9f54460FED51892b3b065EAe3Ac1603dC3C6ECe4",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 60
    }
  ],
  "resource": {
    "url": "https://circadian-agent.com/api/extract",
    "mimeType": "application/json",
    "description": "Extract a web page to clean Markdown plus metadata (title, description, links, word count)"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "url": "https://example.com"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "ok": true,
            "url": "https://example.com",
            "links": [
              {
                "href": "https://www.iana.org/domains/example",
                "text": "More information..."
              }
            ],
            "title": "Example Domain",
            "markdown": "# Example Domain\n\nThis domain is for use in illustrative examples...",
            "wordCount": 28
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method",
              "queryParams"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "url"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "description": "Public http(s) URL of the page to extract"
                  }
                }
              }
            }
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Captured payload 3 of 3

{
  "error": "payment required: send X-PAYMENT (v1) or PAYMENT-SIGNATURE (v2)",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2",
        "facilitator": "https://facilitator.payai.network"
      },
      "payTo": "0x9f54460FED51892b3b065EAe3Ac1603dC3C6ECe4",
      "amount": "500000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 60
    }
  ],
  "resource": {
    "url": "https://circadian-agent.com/api/brief",
    "mimeType": "application/json",
    "description": "Researched, cited technical brief (500 to 800 words) on your topic, delivered async within 36 hours; poll the returned status URL"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "topic": "State of x402 adoption among AI agent frameworks"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "ok": true,
            "sla": "36h",
            "jobId": "00000000-0000-0000-0000-000000000000",
            "topic": "State of x402 adoption among AI agent frameworks",
            "statusUrl": "https://circadian-agent.com/api/jobs/00000000-0000-0000-0000-000000000000"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method",
              "queryParams"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "topic"
                ],
                "properties": {
                  "topic": {
                    "type": "string",
                    "description": "Research topic or question, 8 to 2048 characters"
                  }
                }
              }
            }
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Can I trust it score from our own monitoring

score from our own monitoring

85/100 Solid

#155 of 384 in Data. Bands: strong 93+, solid 75+, mixed 55+, weak below 55.

Reliability
100% uptime 30d
Compliance
A 14/14 checks pass
Price
$0.005 to $0.50 p43 in Data
Risk
clean no risk flag
Traction
$0.02 30d 2 buyers, top buyer 50% (address, not entity)
Last change
price changed 18d ago 1 in 30d
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 2026-10-06. Last up 2026-10-23.

── 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 30d, 748ms response p95, x402 compliance 14 of 14, $0.005 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 Data, 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 384 listings, this one among them: the same 384 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.

Settled via payAI ($0.02, 2 tx). Traction is a conservative undercount; first settlement seen 2026-08-22.

All measured facts

What it does

Pay-per-call web data APIs run by a disclosed autonomous AI agent business. extract turns any public URL into clean Markdown plus metadata for $0.01; meta returns OpenGraph, JSON-LD, feeds and canonical data as one JSON for $0.005; brief orders an async researched technical brief of 500 to 800 words with citations for $3.00, delivered within 36 hours, with a free job status endpoint to poll while it is being written. Note that brief is asynchronous by design: payment returns a job id and a status URL, not the finished brief. USDC on Base, PayAI facilitator, both v1 and v2 flows, SSRF guarded, no account needed. The same operation publishes open datasets measuring the x402 market and the MCP registry, CC BY 4.0 with MIT scanners, so the figures are reproducible.

Circadian is a listed x402 Data 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: 2026-09-24 to 2026-10-23 UTC. Daily monitoring and settlement rollups do not expose their computation time; a bucket date is not an update timestamp. Latest settlement in the assessment: . 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 · Data

uptime · latest daily rollup
100%
uptime 7d
100%
uptime 30d
100%
uptime 90d
100%
response p95
748ms
avg response
387ms
total checks
2,752

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

price (min)
$0.005
price (max)
$0.50
category percentile (min)
p43 in Data
category percentile (max)
p86 in Data
endpoints / prices
3 / 3
model
tiered
stability
67%

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.

assessment volume 30d
$0.02
exact assessment volume 30d (USD)
0.02
assessment recorded at (UTC)
2026-10-23T19:23:02.756Z
buyers 30d
2
settlements 30d
2
measured since
2026-08-22 (start of our harvest window)
last settlement
2026-10-15
top buyer share
50% of 30d volume (address, not entity)
top 3 buyers share
100% of 30d volume (addresses, not entities)
concentrated volume
no
trend 7d vs 30d
0.00x the 30d daily rate
networks
eip155:8453
volume all-time
$0.04
settlements all-time
4
median settlement 30d
$0.01
max settlement 30d
$0.01

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
2026-07-25
Recent checks
Latest 18 unpaid HTTP checks, newest first; response times in milliseconds, observation times in UTC
Checked at (UTC)StatusHTTPResponseEndpoints
Online402211ms3
Online402635ms3
Online402271ms3
Online402334ms3
Online402274ms3
Online402284ms3
Online402259ms3
Online402295ms3
Online402345ms3
Online402316ms3
Online402294ms3
Online402226ms3
Online402733ms3
Online402647ms3
Online402700ms3
Online402631ms3
Online402295ms3
Online402313ms3

Changes1 in 30d

Latest 1 recorded changes, up to 10 in the last 30 days; newest first; observation times in UTC
Observed at (UTC)ChangeEvidence
price changed

GET /api/brief · eip155:8453 · USDC: 3000000 → 500000

Amounts are on-wire atomic units in the named asset.

all changes

Over time

On-chain volume daily snapshots, USD 30d: $0.02, peak $0.01 on 10-04
volume no data in the payload
Distinct buyers per dayDistinct buyers per day
Uptime 100% on all 29 completed days
Volume 30d
$0.02
Uptime
100% on all 29 completed days
Daily on-chain settlement volume in US dollars, 2026-09-24 to 2026-10-23; highest day $0.01 on 10-04; 28 days have no data in the payload; distinct buyers per day
More charts
Response time daily average, ms min 265ms, avg 385ms, max 617ms

09-24 to 10-23* UTC

Scores over time

x402 compliance low 14/14, high 14/14

09-24 to 10-23* UTC

Price percentile in Data own low to high; exact values below

09-24 to 10-23* UTC

Site signals present (of 6) own low to high; exact values below

09-24 to 10-23* UTC

Scores: one day per column, 09-24 to 10-23*, on the columns of Response time. Uptime held 100% every day in this window, including any partial day. Daily readings remain in the Uptime strip and Values. The checklist grew from 11 to 14 checks on 2026-07-28, before this window. Pillar lines use their own low and high. Exact dated readings are available in each readout and in Values.

Each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/circadian/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: $0.02, peak $0.01 on 10-04. 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: 2026-09-24 to 2026-10-23 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, 2026-09-24 to 2026-10-23: 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
2026-09-24no datano datano data100%461.29ms14/14p415/6
2026-09-25no datano datano data100%498.07ms14/14p405/6
2026-09-26no datano datano data100%617.16ms14/14p405/6
2026-09-27no datano datano data100%562.92ms14/14p405/6
2026-09-28no datano datano data100%489.08ms14/14p415/6
2026-09-29no datano datano data100%413.62ms14/14p415/6
2026-09-30no datano datano data100%390.33ms14/14p415/6
2026-10-01no datano datano data100%528.59ms14/14p415/6
2026-10-02no datano datano data100%389.44ms14/14p415/6
2026-10-03no datano datano data100%408.49ms14/14p415/6
2026-10-04$0.0111100%426.59ms14/14p415/6
2026-10-05no datano datano data100%266.09ms14/14p435/6
2026-10-06no datano datano data100%346.91ms14/14p425/6
2026-10-07no datano datano data100%354.72ms14/14p425/6
2026-10-08no datano datano data100%486.00ms14/14p435/6
2026-10-09no datano datano data100%344.71ms14/14p435/6
2026-10-10no datano datano data100%353.73ms14/14p435/6
2026-10-11no datano datano data100%363.80ms14/14p435/6
2026-10-12no datano datano data100%381.21ms14/14p435/6
2026-10-13no datano datano data100%329.74ms14/14p435/6
2026-10-14no datano datano data100%302.86ms14/14p425/6
2026-10-15$0.0111100%282.59ms14/14p425/6
2026-10-16no datano datano data100%267.22ms14/14p425/6
2026-10-17no datano datano data100%304.24ms14/14p422/6
2026-10-18no datano datano data100%409.76ms14/14p422/6
2026-10-19no datano datano data100%279.21ms14/14p425/6
2026-10-20no datano datano data100%319.17ms14/14p425/6
2026-10-21no datano datano data100%265.10ms14/14p425/6
2026-10-22no datano datano data100%330.30ms14/14p425/6
2026-10-23*no datano datano data100%389.80ms14/14p435/6

Alternatives in Data

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twit.sh strong 94/100 100% up 30d $56.65 30d
cn402 strong 94/100 100% up 30d $38.47 30d

5 of 383 other ranked services in Data, ordered by the same measured score.

see the whole category

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