Alphanume Historical Market Cap API

openapi: 3.2.0
info:
  contact:
    url: https://alphanume.com
  description: 'Point-in-time, survivorship-aware datasets for US equities and options research. Every response is JSON: {"count": N, "data": [...]} (paginated endpoints add has_more and next_cursor). Dates are always YYYY-MM-DD. Access: every dataset requires an Alphanume Pro API key (the Free plan is retired as of September 6, 2026). A 403 error with code PRO_SUBSCRIPTION_REQUIRED or DATE_RANGE_RESTRICTED means the key''s plan does not cover the request -- it does not mean the data is missing. Authentication: send your API key in the X-API-Key header (or Authorization: Bearer). Rate limit: 600 requests/minute. Keys come with a Pro subscription at https://alphanume.com/pricing. The same datasets are available as MCP tools at https://mcp.alphanume.com/mcp.'
  title: Alphanume Historical Market Cap API
  version: 1.1.0
servers:
- url: https://api.alphanume.com
security:
- ApiKeyHeader: []
- BearerKey: []
tags:
- name: Historical Market Cap
paths:
  /v1/historical-market-cap:
    get:
      description: 'Point-in-time historical market capitalization: daily market_cap and

        shares_outstanding per US ticker, as they were known on each date (no restatement,

        no survivorship bias). The backbone reference for size filters, cap-weighted

        baskets, and normalizing anything by company size in a backtest.


        Requirements: provide `ticker` OR at least one date filter. A single `date` with no

        ticker returns the whole market for that day; a date RANGE without a ticker is

        capped at 7 calendar days. Pagination: results are capped at 50,000 rows

        per request; when the response has has_more=true, pass next_cursor''s date and

        ticker back as cursor_date and cursor_ticker to fetch the next page.


        Companion tool: list_market_cap_tickers shows which tickers exist and their first

        available date.


        Requires an Alphanume Pro API key. A 403 PRO_SUBSCRIPTION_REQUIRED or

        DATE_RANGE_RESTRICTED error means the key''s plan does not cover the request --

        it does not mean the data is missing.'
      operationId: get_historical_market_cap
      parameters:
      - description: Ticker symbol filter, e.g. 'AAPL'. Case-insensitive.
        in: query
        name: ticker
        required: false
        schema:
          type: string
      - description: Exact date, YYYY-MM-DD. Cannot be combined with the date range parameters.
        in: query
        name: date
        required: false
        schema:
          type: string
      - description: Start of date range, inclusive (YYYY-MM-DD).
        in: query
        name: date_gte
        required: false
        schema:
          type: string
      - description: End of date range, inclusive (YYYY-MM-DD).
        in: query
        name: date_lte
        required: false
        schema:
          type: string
      - description: Start of date range, exclusive (YYYY-MM-DD).
        in: query
        name: date_gt
        required: false
        schema:
          type: string
      - description: End of date range, exclusive (YYYY-MM-DD).
        in: query
        name: date_lt
        required: false
        schema:
          type: string
      - description: 'Pagination: the ''date'' value from the previous response''s next_cursor. Must be sent together with cursor_ticker.'
        in: query
        name: cursor_date
        required: false
        schema:
          type: string
      - description: 'Pagination: the ''ticker'' value from the previous response''s next_cursor. Must be sent together with cursor_date.'
        in: query
        name: cursor_ticker
        required: false
        schema:
          type: string
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PaginatedEnvelope'
          description: Matching rows.
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '429':
          $ref: '#/components/responses/RateLimited'
      summary: 'Point-in-time historical market capitalization: daily market_cap and'
      tags:
      - Historical Market Cap
  /v1/historical-market-cap/tickers:
    get:
      description: 'Coverage map for the historical market cap dataset: every available ticker with

        its first available date. Use it to check whether (and since when) a name is

        covered before querying get_historical_market_cap, or to enumerate the full

        point-in-time universe. No parameters besides the row cap.'
      operationId: list_market_cap_tickers
      parameters: []
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Envelope'
          description: Matching rows.
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '429':
          $ref: '#/components/responses/RateLimited'
      summary: 'Coverage map for the historical market cap dataset: every available ticker with'
      tags:
      - Historical Market Cap
components:
  responses:
    Forbidden:
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
      description: 'PRO_SUBSCRIPTION_REQUIRED: the key''s plan does not include API access; every endpoint requires an active Pro subscription. DATE_RANGE_RESTRICTED: a legacy free-tier key asked for dates outside its window. In both cases the data is not missing.'
    Unauthorized:
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
      description: Missing or unrecognized API key.
    BadRequest:
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
      description: Invalid or conflicting query parameters.
    RateLimited:
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
      description: Rate limit exceeded (600/min); the body carries retry_after_seconds.
  schemas:
    PaginatedEnvelope:
      properties:
        count:
          type: integer
        data:
          items:
            type: object
          type: array
        has_more:
          type: boolean
        next_cursor:
          description: 'Keyset cursor: pass its fields back as the cursor_* query parameters to fetch the next page.'
          type:
          - object
          - 'null'
      required:
      - count
      - data
      - has_more
      - next_cursor
      type: object
    Envelope:
      properties:
        count:
          type: integer
        data:
          items:
            type: object
          type: array
      required:
      - count
      - data
      type: object
    Error:
      additionalProperties: true
      properties:
        error: {}
      type: object
  securitySchemes:
    ApiKeyHeader:
      in: header
      name: X-API-Key
      type: apiKey
    BearerKey:
      scheme: bearer
      type: http
externalDocs:
  description: MCP server exposing these datasets as tools (OAuth or X-API-Key).
  url: https://mcp.alphanume.com/mcp