> ## Documentation Index > Fetch the complete documentation index at: https://fal.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > fal has two developer products. Model APIs run hosted models through an API key. fal Serverless deploys your own Python apps and models on fal GPUs. > To call a hosted model, start with the [Quick Start](https://fal.ai/docs/documentation/quickstart.md) and the [Model APIs overview](https://fal.ai/docs/documentation/model-apis/overview.md). > To deploy your own model with fal Serverless, start with these pages: > - [Introduction to Serverless](https://fal.ai/docs/documentation/serverless/index.md): What fal Serverless is and the three ways to deploy on it. > - [Installation & Setup](https://fal.ai/docs/documentation/development/getting-started/installation.md): Install the fal CLI with `pip install fal` and authenticate. > - [Quick Start](https://fal.ai/docs/documentation/development/getting-started/quick-start.md): Build a Hello World app, test it with `fal run`, and ship it with `fal deploy`. > - [App Lifecycle](https://fal.ai/docs/documentation/development/app-lifecycle.md): How a `fal.App` goes from code to running runners. > - [Define Your Endpoints](https://fal.ai/docs/documentation/development/endpoints-overview.md): Structure the API endpoints that your app exposes. > - [Deploy to Production](https://fal.ai/docs/documentation/deployment/deploy-to-production.md): Persistent URLs, authentication modes, and automatic scaling. > - [Machine Types](https://fal.ai/docs/documentation/deployment/machine-types.md): Available GPU and CPU machine types and how to choose one. > - [Pricing](https://fal.ai/docs/documentation/serverless/pricing.md): Per-second billing and the runner states that are billed. > - [Scaling Parameter Reference](https://fal.ai/docs/documentation/deployment/scale-your-application.md): Parameters that control runners, concurrency, and scale to zero. > - [Optimizing Cold Starts](https://fal.ai/docs/documentation/serverless/optimizations/optimize-cold-starts.md): Causes of cold starts and ways to make them shorter. > - [Examples](https://fal.ai/docs/examples/index.md): Complete Serverless apps for image, video, audio, 3D, realtime, and multi-GPU workloads. > - [Migrating to fal](https://fal.ai/docs/documentation/development/migrating-to-fal.md): Guides to move an existing Docker server or an app from another platform to fal. > fal Serverless deploys need access that the fal team approves for each account. Request access at https://fal.ai/dashboard/serverless-get-started. # Queue Size > Retrieves the current queue size for a specific application. **Required permissions:** `serverless:queues:read`. Key presets that include them: `SERVERLESS`, `READONLY`, `FULL`. See [key permissions](https://fal.ai/docs/documentation/model-apis/authentication/key-based#permissions). ## OpenAPI ````yaml /api-reference/platform-apis/openapi/v1.json get /serverless/apps/{owner}/{name}/queue openapi: 3.1.0 info: title: Platform APIs version: v1 description: fal REST API for programmatic access to platform resources. servers: - url: https://api.fal.ai/v1 description: Production server security: [] paths: /serverless/apps/{owner}/{name}/queue: get: tags: - Serverless - Apps summary: Queue Size description: >- Retrieves the current queue size for a specific application. **Required permissions:** `serverless:queues:read`. Key presets that include them: `SERVERLESS`, `READONLY`, `FULL`. See [key permissions](https://fal.ai/docs/documentation/model-apis/authentication/key-based#permissions). operationId: serverlessGetAppQueueInfo parameters: - schema: type: string description: Username of the app owner example: user_123 required: true description: Username of the app owner name: owner in: path - schema: type: string description: Application name example: my-app required: true description: Application name name: name in: path responses: '200': description: Successfully retrieved queue information content: application/json: schema: type: object properties: queue_size: type: integer minimum: 0 description: Current number of requests in the queue example: 5 required: - queue_size additionalProperties: false description: Status of the app queue example: queue_size: 5 '401': description: Authentication required content: application/json: schema: type: object properties: error: type: object properties: type: type: string enum: - authorization_error - validation_error - not_found - rate_limited - server_error - not_implemented description: The category of error that occurred message: type: string description: Human-readable error message docs_url: type: string format: uri description: Link to relevant documentation request_id: type: string description: Unique request identifier for debugging required: - type - message description: Error details required: - error description: Standard error response format example: error: type: authorization_error message: Authentication required '403': description: Access denied content: application/json: schema: type: object properties: error: type: object properties: type: type: string enum: - authorization_error - validation_error - not_found - rate_limited - server_error - not_implemented description: The category of error that occurred message: type: string description: Human-readable error message docs_url: type: string format: uri description: Link to relevant documentation request_id: type: string description: Unique request identifier for debugging required: - type - message description: Error details required: - error description: Standard error response format example: error: type: authorization_error message: Access denied '404': description: Resource not found content: application/json: schema: type: object properties: error: type: object properties: type: type: string enum: - authorization_error - validation_error - not_found - rate_limited - server_error - not_implemented description: The category of error that occurred message: type: string description: Human-readable error message docs_url: type: string format: uri description: Link to relevant documentation request_id: type: string description: Unique request identifier for debugging required: - type - message description: Error details required: - error description: Standard error response format example: error: type: not_found message: Resource not found '429': description: Rate limit exceeded content: application/json: schema: type: object properties: error: type: object properties: type: type: string enum: - authorization_error - validation_error - not_found - rate_limited - server_error - not_implemented description: The category of error that occurred message: type: string description: Human-readable error message docs_url: type: string format: uri description: Link to relevant documentation request_id: type: string description: Unique request identifier for debugging required: - type - message description: Error details required: - error description: Standard error response format example: error: type: rate_limited message: Rate limit exceeded '500': description: Internal server error content: application/json: schema: type: object properties: error: type: object properties: type: type: string enum: - authorization_error - validation_error - not_found - rate_limited - server_error - not_implemented description: The category of error that occurred message: type: string description: Human-readable error message docs_url: type: string format: uri description: Link to relevant documentation request_id: type: string description: Unique request identifier for debugging required: - type - message description: Error details required: - error description: Standard error response format example: error: type: server_error message: An unexpected error occurred security: - readonlyApiKey: [] components: securitySchemes: readonlyApiKey: type: apiKey in: header name: Authorization description: >- Key on the `READONLY` preset, or any key whose permissions include the ones this API lists. Prefix it with "Key ", e.g. Authorization: Key YOUR_API_KEY ````