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

# Get variable

> Returns a single function variable by ID, with the fields that define it. A function variable is an input or output a function declares.



## OpenAPI

````yaml /specs-prettified/realtime/openapi.stable.json get /v1/stable/function-variable/{variableID}
openapi: 3.0.0
info:
  title: Realtime
  description: Realtime gateway API service
  version: 1.0.0
  contact: {}
servers:
  - url: https://realtime-api.voiceflow.com
security: []
tags: []
paths:
  /v1/stable/function-variable/{variableID}:
    get:
      tags:
        - Function Variable
      summary: Get variable
      description: >-
        Returns a single function variable by ID, with the fields that define
        it. A function variable is an input or output a function declares.
      operationId: StableFunctionVariableController_get
      parameters:
        - name: variableID
          required: true
          in: path
          schema:
            type: string
          x-vf-doc:
            description: The ID of the variable to operate on.
          description: The ID of the variable to operate on.
        - name: projectID
          required: true
          in: query
          schema:
            type: string
            description: The ID of the project to operate on.
        - name: environmentAlias
          required: true
          in: query
          schema:
            type: string
            description: The alias of the environment to operate on (e.g. `main`).
      responses:
        '200':
          description: >-
            Returns a single function variable, with the name the function code
            uses to reference it, whether it is an input or an output, and the
            ID of the function that declares it.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StableFunctionVariableResponse'
          x-vf-doc:
            description: >-
              Returns a single function variable, with the name the function
              code uses to reference it, whether it is an input or an output,
              and the ID of the function that declares it.
      security:
        - token: []
components:
  schemas:
    StableFunctionVariableResponse:
      type: object
      properties:
        variable:
          $ref: '#/components/schemas/StableFunctionVariable'
      required:
        - variable
    StableFunctionVariable:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
          description: The name used to reference the variable in the function code.
        type:
          $ref: '#/components/schemas/FunctionVariableKind'
        createdAt:
          type: string
          format: date-time
          pattern: >-
            ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z))$
        updatedAt:
          type: string
          format: date-time
          pattern: >-
            ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z))$
        functionID:
          type: string
          description: The ID of the function this variable belongs to.
        description:
          nullable: true
          description: A human-readable description of what the variable holds.
          type: string
      required:
        - id
        - name
        - type
        - createdAt
        - updatedAt
        - functionID
        - description
    FunctionVariableKind:
      type: string
      enum:
        - input
        - output
      x-enumNames:
        - INPUT
        - OUTPUT
  securitySchemes:
    token:
      scheme: bearer
      bearerFormat: JWT
      type: http
      description: Voiceflow bearer token

````