> ## 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. # Create a durable sandbox session > Starts a persistent code sandbox billed for the session lifetime. Default threadId is http:{uuid}. ## OpenAPI ````yaml /api-reference/openapi.json post /api/v1/sandbox/sessions 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. 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 - name: usage description: Credit balance and usage ledger for the project API key paths: /api/v1/sandbox/sessions: post: tags: - Sandbox summary: Create a durable sandbox session description: >- Starts a persistent code sandbox billed for the session lifetime. Default threadId is http:{uuid}. operationId: SandboxController_createSession parameters: - 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/CreateSandboxSessionDto' responses: '201': description: Sandbox session created content: application/json: schema: $ref: '#/components/schemas/SandboxSessionResponseDtoSuccessResponse' security: - x-api-key: [] - x-api-key: [] x-username: [] components: schemas: CreateSandboxSessionDto: type: object properties: threadId: type: string description: >- Isolation thread id. Defaults to http:{uuid} so HTTP sessions do not collide with chat threads. example: b737d8af-a9e0-4251-9714-3fdc1126e5fb workflowId: type: string description: Optional workflow id for billing attribution example: 3fa85f64-5717-4562-b3fc-2c963f66afa6 format: uuid templateId: type: string description: Sandbox template name or id override example: code-interpreter-v1 maxDurationSec: type: number minimum: 60 maximum: 86400 description: Max session duration in seconds (capped by server config) example: 3600 SandboxSessionResponseDtoSuccessResponse: type: object properties: success: type: boolean description: Success status example: true message: type: string description: Success message example: Operation completed successfully data: type: object properties: id: type: string description: Public session id (ledger UUID) sandboxId: type: string description: Provider sandbox id status: type: string enum: - active - settling - settled - failed description: Session status threadId: type: string nullable: true description: Isolation thread id cpuCount: type: number description: vCPU count memoryMB: type: number description: Memory in MB maxDurationSec: type: number description: Max session duration in seconds startedAt: type: string description: Session start time (ISO) required: - id - sandboxId - status - cpuCount - memoryMB - maxDurationSec - startedAt example: id: '' sandboxId: '' status: active threadId: '' cpuCount: 0 memoryMB: 0 maxDurationSec: 0 startedAt: '' required: - success - message - data 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: 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: ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.