ledger

List the published Category Ledger editions: period, status, data-as-of date and the count released in each.

List the published Category Ledger editions: period, status, data-as-of date and the count released in each.

When to use. Call this first to find which edition covers a period, then fetch that edition by id.

What it cannot provide. It returns no figures from inside an edition and no product data. A closed edition's identity never changes, so this list is safe to cache.

Requires the ledger:read scope. Each distinct signal named in a successful answer spends one unit of the key's daily signal budget. Asking twice about the same one costs once.

get/api/v1/ledger

Request

  • Base URL: https://formulasignal.com
  • URL: https://formulasignal.com/api/v1/ledger
  • Auth: HTTP bearer

Headers

X-FormulaSignal-Origin'api' | 'mcp'

Optional attribution: mcp when the call comes from the FormulaSignal MCP server, api otherwise. Self-reported and recorded on the usage row so a customer can see which surface their traffic came from. Nothing reads it to decide what a caller may do, so a wrong value costs only the accuracy of that customer's own reporting.

Response

A FormulaSignal answer. status says what kind of answer it is, and every value except supported is still a real answer about the Record rather than a fact about the product.

request_idstring required
capabilitystring required
status'supported' | 'partial' | 'stale' | 'under_review' | 'ambiguous' | 'unsupported' | 'refused' required

What kind of answer this is. Every value except supported is still a real answer about the Record rather than a fact about the product.

summarystring required

One sentence saying what kind of answer this is.

signalsobject[]
comparisonobject
coverageobject
ledgerobject
watchobject
next_cursorstring nullable
limitationsstring[] required

Always present, including when empty. Read it.

record_versionstring required

The Record data-state id. Two answers sharing it came from one committed state.

record_as_ofstring date required
record_timestampstring date-time required

The newest dated observation the Record holds. Deliberately not "now".

methodology_versionstring required
disclaimerstring required

Example response

{
  "methodology_version": "record-v1",
  "disclaimer": "FormulaSignal provides evidence-backed supplement information and does not provide individualized medical advice."
}

Changes

No recorded changes to this operation across all 1 revision of this API.