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

# Execute code in a sandbox session

> Runs JavaScript or Python inside an existing live session. The session stays alive after the run.



## OpenAPI

````yaml /api-reference/openapi.json post /api/v1/sandbox/sessions/{id}/execute
openapi: 3.0.0
info:
  title: Flowra API (API Key Endpoints)
  description: >-
    **Flowra** is an AI-powered platform for building agents, workflows, and
    integrations.


    ### Capabilities

    - **Tools & Toolkits** – Define and group tools for agents and workflows.

    - **Workflows** – Orchestrate steps and automate processes.

    - **Triggers** – Schedule or event-based execution.

    - **Auth & Connections** – OAuth, API keys, and connected accounts.

    - **MCP** – Model Context Protocol server integration.

    - **Knowledge / RAG** – Add files and URLs for retrieval-augmented
    generation.


    ### Authentication

    Use the **x-api-key** header with a project API key to access endpoints that
    support API Key auth. Create and manage API keys in the dashboard under your
    project settings.


    Only endpoints that support API Key authentication via the @ApiKeyEnabled()
    decorator.


    Send x-api-key (required). On multi-tenant endpoints, optionally send
    x-username to act as an external user.


    Only endpoints that support API Key authentication via the @ApiKeyEnabled()
    decorator.


    Send x-api-key (required). On multi-tenant endpoints, optionally send
    x-username (defaults to the project’s default external user).
  version: '1.0'
  contact:
    name: Flowra
    url: https://flowra.dev
servers:
  - url: https://flowra.dev
    description: Flowra API
security: []
tags:
  - name: Users
    description: User profile
  - name: External Users
    description: End-user identities inside a project (x-username)
  - name: Auth Configs
    description: OAuth and API key configs for toolkits
  - name: Connected Accounts
    description: OAuth connected accounts and link creation
  - name: Toolkits
    description: List and search toolkits
  - name: Tools
    description: List, execute, and manage tools
  - name: Skills
    description: Browse, create, import, and install skills
  - name: Workflow & Agent
    description: Create, run, and inspect workflows and agents
  - name: Triggers
    description: Schedule and event-based trigger instances
  - name: Chat
    description: Threads and streaming agent runs
  - name: File
    description: Upload, list, and download files
  - name: Knowledge
    description: RAG knowledge collections
  - name: Table
    description: Collections and documents
  - name: Sandbox
    description: Ephemeral and durable code sandboxes
  - name: Browser
    description: Live browser sessions and view
  - name: LLM
    description: List AI models and generate completions
  - name: MCP
    description: MCP server management
paths:
  /api/v1/sandbox/sessions/{id}/execute:
    post:
      tags:
        - Sandbox
      summary: Execute code in a sandbox session
      description: >-
        Runs JavaScript or Python inside an existing live session. The session
        stays alive after the run.
      operationId: SandboxController_executeInSession
      parameters:
        - name: id
          required: true
          in: path
          schema:
            type: string
        - name: x-username
          in: header
          required: false
          description: >-
            External user (end user) to act as. Optional — if omitted, Flowra
            uses the project’s default external user. Send a stable username
            (e.g. customer_alice) only when you need another end-user context.
          schema:
            type: string
            default: (project default user)
          example: customer_alice
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SandboxSessionExecuteDto'
      responses:
        '200':
          description: Session execute result
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SuccessResponseDto'
        '201':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SandboxEphemeralResponseDto'
      security:
        - x-api-key: []
        - x-api-key: []
          x-username: []
components:
  schemas:
    SandboxSessionExecuteDto:
      $ref: '#/components/schemas/SandboxSessionExecuteDto'
      type: object
      properties:
        language:
          enum:
            - javascript
            - python
          type: string
          description: Script language
        source:
          type: string
          description: Script source (JavaScript or Python)
        state:
          type: object
          description: State object passed to the script (default preview state if omitted)
        timeoutMs:
          type: number
          minimum: 1000
          maximum: 20000
          description: Timeout in milliseconds (default 8000, max 20000)
          default: 8000
      required:
        - language
        - source
    SuccessResponseDto:
      $ref: '#/components/schemas/SuccessResponseDto'
      type: object
      properties:
        success:
          type: boolean
          description: Success status
          example: true
        message:
          type: string
          description: Success message
          example: Operation completed successfully
        data:
          type: object
          description: Response data
      required:
        - success
        - message
        - data
    SandboxEphemeralResponseDto:
      $ref: '#/components/schemas/SandboxEphemeralResponseDto'
      type: object
      properties:
        id:
          type: string
          description: Ephemeral run id
        status:
          type: string
          enum:
            - succeeded
            - failed
          description: Run outcome
        language:
          type: string
          description: Language used for the run
        result:
          type: object
          description: Result object when status is succeeded
        error:
          type: string
          description: Error message when status is failed
        durationMs:
          type: number
          description: Wall-clock duration in milliseconds
      required:
        - id
        - status
        - language
  securitySchemes:
    x-api-key:
      type: apiKey
      in: header
      name: x-api-key
      description: >-
        Project API key. Create and manage keys in the dashboard under Project →
        API Keys. Send as header: x-api-key: <your-key>
    x-username:
      type: apiKey
      in: header
      name: x-username
      description: >-
        Optional. External user username. If omitted, Flowra uses the project’s
        default external user. Send as header: x-username: <username>

````