> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tilt.io/llms.txt
> Use this file to discover all available pages before exploring further.

# List the construction catalog

> Browse every field and trailing-window capability available to construction rules.



## OpenAPI

````yaml api-reference/index-construction-preview-openapi.yaml GET /api/v1/catalog
openapi: 3.1.0
info:
  title: 'Tilt Index Construction API: Design Preview'
  version: 0.5.0-design-preview
  summary: >-
    A restrained public projection of Tilt's existing index construction
    workflow.
  description: |
    A Tilt is a persistent project for one index methodology. Its construction
    rules are the source, evaluated constituent snapshots are the build
    artifacts, and methodology history is version history. This bounded
    repository analogy does not imply branches, forks, merges, or cloning.

    This contract covers rules-based equity construction only. Applying
    construction saves the rules, evaluates them, and commits the complete
    weighted constituent snapshot atomically.
servers:
  - url: https://x.invalid
    description: Non-routable design preview
security:
  - ApiKey: []
tags:
  - name: Tilts
    description: Organization-owned Tilt projects and versions.
  - name: Construction
    description: Apply methodology and read its saved weighted evaluation.
  - name: Catalog
    description: >-
      Discover fields, functions, universes, and classifications used in
      expressions.
  - name: Tickers
    description: Resolve security identifiers to exact Tilt asset IDs.
  - name: Backtests
    description: Backtest a saved Tilt using its configured rebalance behavior.
paths:
  /api/v1/catalog:
    get:
      tags:
        - Catalog
      summary: List the construction catalog
      description: |
        Returns the complete set of base fields and constructed signals
        available to construction expressions, together with supported
        trailing-window functions and construction defaults when available.
        Array order is unspecified; sort by `name` for display.
      operationId: listConstructionCatalog
      responses:
        '200':
          description: The complete construction catalog.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ConstructionCatalog'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    ConstructionCatalog:
      type: object
      additionalProperties: false
      required:
        - success
        - base_columns
        - constructed_signals
      properties:
        success:
          type: boolean
          const: true
        base_columns:
          type: array
          items:
            $ref: '#/components/schemas/CatalogField'
        constructed_signals:
          type: array
          items:
            $ref: '#/components/schemas/ConstructedSignal'
        aggregation_functions:
          $ref: '#/components/schemas/AggregationFunctions'
        defaults:
          $ref: '#/components/schemas/CatalogDefaults'
    CatalogField:
      type: object
      additionalProperties: false
      required:
        - name
        - description
        - example
      properties:
        name:
          type: string
        description:
          type: string
        example:
          type: string
        type:
          type: string
        unit:
          type: string
        is_displayable:
          type: boolean
        enum_values:
          type: array
          items:
            $ref: '#/components/schemas/CatalogEnumValue'
    ConstructedSignal:
      type: object
      additionalProperties: false
      required:
        - name
        - description
        - example
        - equation
      properties:
        name:
          type: string
        description:
          type: string
        example:
          type: string
        equation:
          type: string
        type:
          type: string
        unit:
          type: string
        is_displayable:
          type: boolean
        enum_values:
          type: array
          items:
            $ref: '#/components/schemas/CatalogEnumValue'
    AggregationFunctions:
      type: object
      additionalProperties: false
      required:
        - functions
        - time_windows
        - supported_metrics
        - syntax
        - examples
        - description
      properties:
        functions:
          type: array
          items:
            type: string
        time_windows:
          type: object
          additionalProperties:
            type: number
        supported_metrics:
          type: array
          items:
            $ref: '#/components/schemas/SupportedMetric'
        syntax:
          type: string
        examples:
          type: array
          items:
            type: string
        description:
          type: string
    CatalogDefaults:
      type: object
      additionalProperties: false
      properties:
        default_min_score:
          type: number
        default_max_nb_companies:
          type: integer
    Error:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          additionalProperties: false
          required:
            - code
            - message
          properties:
            code:
              type: string
            message:
              type: string
    CatalogEnumValue:
      type: object
      additionalProperties: false
      required:
        - value
        - label
      properties:
        value:
          oneOf:
            - type: string
            - type: number
        label:
          type: string
    SupportedMetric:
      type: object
      additionalProperties: false
      required:
        - name
        - min_window
      properties:
        name:
          type: string
        min_window:
          type: string
        max_window:
          type: string
        functions:
          type: array
          items:
            type: string
  responses:
    Unauthorized:
      description: The API key is missing or invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    ApiKey:
      type: apiKey
      in: header
      name: X-Api-Key

````