Saylor Innovations Data Desk

Bayes calculator for a diagnostic test - positive and negative predictive value, likelihood ratios and a confusion matrix from prevalence, sensitivity and specificity

DataUnknowneip155:8453Exactvia facilitator:payAI
What is the chance i have itPositive predictive valueBayes theorem medical testFalse positive rate base rateLikelihood ratio
Calls · 30d
1
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 9 snapshots so far.
$15.76
Verified settled volume
1,657 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.
—
Calls · 30d
Upstream's own call count for this endpoint, not ours.
—
Unique payers · 30d
Never called
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa

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 0xA2A8…fc8aa. The signed payment is good for 2 minutes.

USD Coin contract
0x8335…02913
Payment window
2 minutes
As published
10000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "memo": "saylor:datadesk:bayes-diagnostic",
      "name": "USD Coin",
      "version": "2",
      "facilitatorOnly": true,
      "assetTransferMethod": "eip3009"
    },
    "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
    "amount": "10000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 120
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "prevalence_percent": "1",
          "sensitivity_percent": "95",
          "specificity_percent": "90"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "note": "Bayes theorem with a single test and independent errors; real tests vary by population and are not medical advice.",
          "inputs": {
            "population": 100000,
            "prevalence_percent": 1,
            "sensitivity_percent": 95,
            "specificity_percent": 90
          },
          "source": "Bayes theorem applied to prevalence, sensitivity and specificity",
          "plain_language": "Of every 100 people who test positive, about 9 actually have the condition when prevalence is 1%.",
          "confusion_matrix": {
            "true_negatives": 89100,
            "true_positives": 950,
            "false_negatives": 50,
            "false_positives": 9900
          },
          "false_discovery_percent": 91.244,
          "negative_likelihood_ratio": 0.055556,
          "positive_likelihood_ratio": 9.5,
          "negative_predictive_value_percent": 99.944,
          "positive_predictive_value_percent": 8.756,
          "probability_of_positive_test_percent": 10.85,
          "probability_disease_given_negative_percent": 0.0561
        }
      }
    },
    "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": [
                "prevalence_percent",
                "sensitivity_percent",
                "specificity_percent"
              ],
              "properties": {
                "prevalence_percent": {
                  "type": "string",
                  "description": "How common the condition is, percent"
                },
                "sensitivity_percent": {
                  "type": "string",
                  "description": "True positive rate, percent"
                },
                "specificity_percent": {
                  "type": "string",
                  "description": "True negative rate, percent"
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "json"
            },
            "example": {
              "type": "object",
              "required": [
                "inputs",
                "positive_predictive_value_percent"
              ],
              "properties": {
                "note": {
                  "type": "string",
                  "description": "Caveat or context for reading the result"
                },
                "inputs": {
                  "type": "object",
                  "properties": {
                    "population": {
                      "type": [
                        "number",
                        "null"
                      ],
                      "description": "Population size used for the confusion matrix"
                    },
                    "prevalence_percent": {
                      "type": [
                        "number",
                        "null"
                      ],
                      "description": "Prevalence, as a percentage"
                    },
                    "sensitivity_percent": {
                      "type": [
                        "number",
                        "null"
                      ],
                      "description": "Sensitivity, as a percentage"
                    },
                    "specificity_percent": {
                      "type": [
                        "number",
                        "null"
                      ],
                      "description": "Specificity, as a percentage"
                    }
                  },
                  "description": "Inputs after validation, as percentages and the population size"
                },
                "source": {
                  "type": "string",
                  "description": "Data source the values come from"
                },
                "plain_language": {
                  "type": [
                    "string",
                    "null"
                  ],
                  "description": "Plain language"
                },
                "confusion_matrix": {
                  "type": "object",
                  "description": "Confusion matrix"
                },
                "false_discovery_percent": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "False discovery, as a percentage"
                },
                "negative_likelihood_ratio": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "Negative likelihood ratio"
                },
                "positive_likelihood_ratio": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "Positive likelihood ratio"
                },
                "negative_predictive_value_percent": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "Negative predictive value, as a percentage"
                },
                "positive_predictive_value_percent": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "Positive predictive value, as a percentage"
                },
                "probability_of_positive_test_percent": {
                  "type": "number",
                  "description": "Probability of positive test, as a percentage"
                },
                "probability_disease_given_negative_percent": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "Probability disease given negative, as a percentage"
                }
              }
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-10-26 02:49Z
Last indexed by Roundhouse
2026-10-26 20:15Z
Last enriched (probe, favicon, geo)
—
x402 version
2
Max timeout
120s
Liveness probe
Not probed
Report

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GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 9 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 Saylor Innovations Data Desk 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=Saylor%20Innovations%20Data%20Desk'
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://saylorinnovations.com/api/stats/bayes, 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.