Caplight Composite Index API

openapi: 3.2.0
info:
  version: 2.0.0
  title: Caplight REST Composite Index API
  description: 'This page provides documentation for the Caplight API, a paid add-on product of [Caplight Data](https://www.data.caplight.com). To request API access, please contact us at contact@caplight.com.


    # Production server

    https://us-central1-caplight-prod.cloudfunctions.net/api/public


    # Staging/sandbox server

    https://us-central1-caplight-staging.cloudfunctions.net/api/public


    # API versions

    Endpoints are versioned via path prefix: `/v1/` for company, market price, and order book; `/v2/` for company lookup, funding rounds, investors, company details, and comps.


    # Company IDs

    Companies have two ID formats: a **v1 company ID** (used in v1 endpoints) and a **v2 company ID** (used in v2 endpoints). Both v1 and v2 company responses include both in `caplightIds` for cross-referencing. Path params that accept company identifiers support either format, plus PitchBook ID and company domain where applicable.


    If you have a domain, a v1 company ID or a PitchBook ID and need the v2 company ID, call `GET /v2/companies` — it resolves up to 50 identifiers per request and covers companies added recently.


    # V2 Access & Permissions


    **Company access:** v2 company-scoped endpoints (funding rounds, investors, company details, and comps) enforce per-account access control. Your account may have (1) a whitelist of permitted companies, (2) an annual limit on distinct companies you can access, or both. Accessing the same company multiple times counts once toward the limit. The `/funding-rounds/updates` endpoint returns only rounds for companies you have access to.


    **Restricted fields:** Some accounts have field-level restrictions. When a field is restricted, it is omitted from the response and its name appears in `restricted.fields` on the funding round object. Restricted fields may include: `amounts`, `valuation`, `pps`, `participants`, `citations`. Check for a `restricted` object and handle omitted fields in your integration.


    # Widget Embed

    In addition to this API, Caplight also provides an embeddable widget for customers who would like an easy way of integrating Caplight Data into their platform. [See example](https://storage.googleapis.com/caplight-prod.appspot.com/images/embed-example-3.png). For inquiries, please contact us directly.


    # Authentication


    <SecurityDefinitions />

    '
  termsOfService: https://platform.caplight.com/terms
  contact:
    name: 'Contact: Caplight Engineering'
    email: engineering@caplight.com
  x-logo:
    url: https://storage.googleapis.com/caplight-prod.appspot.com/caplight-logos/api-logo.png
    altText: Caplight logo
servers:
- url: //us-central1-caplight-prod.cloudfunctions.net/api/public
  description: Production
- url: //us-central1-caplight-staging.cloudfunctions.net/api/public
  description: Staging/Sandbox
tags:
- name: Composite Index
paths:
  /v2/composite-index:
    get:
      tags:
      - Composite Index
      summary: Get composite index timeseries
      description: Returns a market-cap weighted composite index timeseries for private companies in a given sector or vertical, or the overall Caplight Top 20 (`scope=overall`). The index is rebased to 100 on the start date; each day includes the constituent list and weights. Companies that exit the private market (M&A, IPO, or wind-down) are excluded after their exit date. Only the parameters documented below are accepted — any other parameter is rejected with a 400 so index values are never silently computed under non-standard settings.
      parameters:
      - name: sector
        in: query
        description: Sector name to build the index from. Provide exactly one of `sector`, `vertical`, or `scope=overall`. Use `/composite-index/sectors` for valid names.
        required: false
        schema:
          type: string
        example: Cybersecurity
      - name: vertical
        in: query
        description: Vertical name to build the index from. Provide exactly one of `sector`, `vertical`, or `scope=overall`. Use `/composite-index/verticals` for valid names.
        required: false
        schema:
          type: string
        example: Endpoint Security
      - name: scope
        in: query
        description: Set to `overall` for the Caplight Top 20 — the flagship private-market index across all sectors (the 20 most liquid private companies, price-per-share weighted, monthly rebalance). Cannot be combined with `sector` or `vertical`.
        required: false
        schema:
          type: string
          enum:
          - overall
        example: overall
      - name: startDate
        in: query
        description: Start date for the timeseries. Defaults to 1 year ago.
        required: false
        schema:
          $ref: '#/components/schemas/Date'
        example: '2025-04-01'
      - name: endDate
        in: query
        description: End date for the timeseries. Defaults to yesterday.
        required: false
        schema:
          $ref: '#/components/schemas/Date'
        example: '2026-04-01'
      responses:
        '200':
          description: Successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CompositeIndexResponse'
        '400':
          description: Invalid or unsupported parameters. The endpoint accepts only the parameters documented above; unknown parameters are rejected rather than ignored.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '404':
          description: No companies found for the given filter
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
  /v2/composite-index/sectors:
    get:
      tags:
      - Composite Index
      summary: List available sectors
      description: Returns a list of all active sector names that can be used with the composite index endpoint.
      responses:
        '200':
          description: Successful operation
          content:
            application/json:
              schema:
                type: array
                items:
                  type: string
                example:
                - AI, Data & Cloud Infrastructure
                - Consumer & Commerce
                - Crypto & Web3
                - Cybersecurity
                - Energy & Sustainability
                - Enterprise Software
                - FinTech
                - Frontier & Industrial Tech
                - Healthcare & Life Sciences
                - Media, Entertainment & Gaming
                - Mobility, Transportation & Logistics
                - Real Estate & PropTech
                - Telecommunications & Networking
  /v2/composite-index/verticals:
    get:
      tags:
      - Composite Index
      summary: List available verticals
      description: Returns a list of all active verticals with their parent sector names. Optionally filter by sector.
      parameters:
      - name: sector
        in: query
        description: Filter verticals by sector name. Must be a valid sector (use /composite-index/sectors to list).
        required: false
        schema:
          type: string
        example: Cybersecurity
      responses:
        '200':
          description: Successful operation
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object
                  properties:
                    name:
                      type: string
                    sectorName:
                      type: string
                example:
                - name: Cloud Infrastructure
                  sectorName: AI, Data & Cloud Infrastructure
                - name: ML Platforms
                  sectorName: AI, Data & Cloud Infrastructure
                - name: Endpoint Security
                  sectorName: Cybersecurity
                - name: Cloud Security
                  sectorName: Cybersecurity
                - name: Payments
                  sectorName: FinTech
components:
  schemas:
    Date:
      type: string
      description: ISO formatted date without time
      example: '2022-09-10'
    CompositeIndexResponse:
      type: object
      required:
      - timeseries
      - warnings
      properties:
        timeseries:
          type: array
          items:
            $ref: '#/components/schemas/CompositeIndexTimeseriesPoint'
        metadata:
          type: object
          description: 'Run metadata (whitelisted subset): weighting, top_n, selection_method, rebalance settings, requested date range, and exclusion counts.'
        warnings:
          description: Structured warnings surfaced by the private index and any requested overlays. Callers can filter on `overlay` + `code` without regex-matching the free-form `message`.
          type: array
          items:
            $ref: '#/components/schemas/CompositeIndexWarning'
    CompositeIndexWarning:
      type: object
      required:
      - overlay
      - code
      - message
      properties:
        overlay:
          type: string
          enum:
          - bespoke-public-index
          - etf-price-timeseries
          - composite-index
        code:
          type: string
          description: Structured warning code. `python-warning` propagates a free-form warning from the python server's `warnings[]` field (e.g. 'thin universe', 'coverage warning') regardless of which overlay emitted it. `python-metadata-error` indicates the python server returned HTTP 200 with `metadata.error` set, typically a partial failure. `python-error` is a full overlay failure — the overlay soft-degraded but the primary index still succeeded. `vertical-not-found` means the ETF overlay caller passed a vertical that doesn't exist in the classification DB.
          enum:
          - no-public-tickers
          - empty-result
          - python-error
          - python-warning
          - python-metadata-error
          - missing-constituents
          - etf-mapping-missing
          - vertical-not-found
        message:
          type: string
    CompositeIndexConstituent:
      type: object
      properties:
        id:
          type:
          - string
          - 'null'
          description: Company identifier (UUID). Same as the companyId used in other v2 endpoints.
        name:
          type:
          - string
          - 'null'
          description: Company name
        weight:
          type: number
          description: Constituent weight in the index (0-1)
    ErrorResponse:
      type: object
      properties:
        status:
          type: string
          example: error
        error:
          type: string
          example: sector or vertical query param is required
    CompositeIndexTimeseriesPoint:
      type: object
      properties:
        date:
          $ref: '#/components/schemas/Date'
        index:
          type: number
          description: Index value (rebased to 100 on start date)
        constituents:
          type: array
          items:
            $ref: '#/components/schemas/CompositeIndexConstituent'
  securitySchemes:
    api_key:
      description: Caplight API authentication is managed through an api_key header value. Please contact us if you do not yet have an API key.
      type: apiKey
      name: api_key
      in: header
x-tagGroups:
- name: V1
  tags:
  - Company
  - Companies
  - MarketPrice
  - Live Orderbook
  - Trade History
  - Order History
  - Company Filings
  - Stock Splits
  - Fund Marks
  - News
  - company_model
  - order_model
  - market_price_model
  - trade_model
  - 409a_valuation_model
  - fund_mark_model
  - comp_model
  - stock_split_model
  - coi_model
- name: V2
  tags:
  - Funding Rounds
  - Investors
  - Company Lookup
  - Company Details
  - Comps