# API Reference | Modal Docs - **URL:** https://modal.com/docs/sdk/py/latest - **Summary:** Complete API reference for the Modal Python package. Documentation for App, Function, Image, Volume, and all Modal primitives. Copy page API Reference ============= This is the API reference for the [`modal`](https://pypi.org/project/modal/) Python package, which allows you to run distributed applications on Modal. The reference provides low-level descriptions of various programmatic functionality. If you’re just getting started with Modal, we would instead recommend looking at the [guide](https://modal.com/docs/guide) first or getting started with one of our [examples](https://modal.com/docs/examples) . Application construction  | | | | --- | --- | | [`App`](https://modal.com/docs/sdk/py/latest/modal.App) | The main unit of deployment for code on Modal | | [`App.function`](https://modal.com/docs/sdk/py/latest/modal.App#function) | Decorator for registering a function with an App | | [`App.cls`](https://modal.com/docs/sdk/py/latest/modal.App#cls) | Decorator for registering a class with an App | | [`App.server`](https://modal.com/docs/sdk/py/latest/modal.App#server) | Decorator for registering a server with an App | Serverless execution  | | | | --- | --- | | [`Function`](https://modal.com/docs/sdk/py/latest/modal.Function) | A serverless function backed by an autoscaling container pool | | [`Cls`](https://modal.com/docs/sdk/py/latest/modal.Cls) | A serverless class supporting parametrization and lifecycle hooks | | [`Server`](https://modal.com/docs/sdk/py/latest/modal.Server) | A serverless HTTP application with low-latency request routing | Extended Function configuration  ### Class parametrization  | | | | --- | --- | | [`parameter`](https://modal.com/docs/sdk/py/latest/modal.parameter) | Used to define class parameters, akin to a Dataclass field | ### Lifecycle hooks  | | | | --- | --- | | [`enter`](https://modal.com/docs/sdk/py/latest/modal.enter) | Decorator for a method that will be executed during container startup | | [`exit`](https://modal.com/docs/sdk/py/latest/modal.exit) | Decorator for a method that will be executed during container shutdown | | [`method`](https://modal.com/docs/sdk/py/latest/modal.method) | Decorator for exposing a method as an invokable function | ### Web integrations  | | | | --- | --- | | [`fastapi_endpoint`](https://modal.com/docs/sdk/py/latest/modal.fastapi_endpoint) | Decorator for exposing a simple FastAPI-based endpoint | | [`asgi_app`](https://modal.com/docs/sdk/py/latest/modal.asgi_app) | Decorator for functions that construct an ASGI web application | | [`wsgi_app`](https://modal.com/docs/sdk/py/latest/modal.wsgi_app) | Decorator for functions that construct a WSGI web application | | [`web_server`](https://modal.com/docs/sdk/py/latest/modal.web_server) | Decorator for functions that construct an HTTP web server | ### Function semantics  | | | | --- | --- | | [`batched`](https://modal.com/docs/sdk/py/latest/modal.batched) | Decorator that enables [dynamic input batching](https://modal.com/docs/guide/dynamic-batching) | | [`concurrent`](https://modal.com/docs/sdk/py/latest/modal.concurrent) | Decorator that enables [input concurrency](https://modal.com/docs/guide/concurrent-inputs) | ### Scheduling  | | | | --- | --- | | [`Cron`](https://modal.com/docs/sdk/py/latest/modal.Cron) | A schedule that runs based on cron syntax | | [`Period`](https://modal.com/docs/sdk/py/latest/modal.Period) | A schedule that runs at a fixed interval | ### Exception handling  | | | | --- | --- | | [`Retries`](https://modal.com/docs/sdk/py/latest/modal.Retries) | Function retry policy for input failures | Sandboxed execution  | | | | --- | --- | | [`Sandbox`](https://modal.com/docs/sdk/py/latest/modal.Sandbox) | An interface for restricted code execution | | [`ContainerProcess`](https://modal.com/docs/sdk/py/latest/modal.container_process#modalcontainer_processcontainerprocess) | An object representing a sandboxed process | | [`FileIO`](https://modal.com/docs/sdk/py/latest/modal.file_io#modalfile_iofileio) | A handle for a file in the Sandbox filesystem | Container configuration  | | | | --- | --- | | [`Image`](https://modal.com/docs/sdk/py/latest/modal.Image) | An API for specifying container images | | [`Secret`](https://modal.com/docs/sdk/py/latest/modal.Secret) | A pointer to secrets that will be exposed as environment variables | Data primitives  ### Persistent storage  | | | | --- | --- | | [`Volume`](https://modal.com/docs/sdk/py/latest/modal.Volume) | Distributed storage supporting highly performant parallel reads | | [`CloudBucketMount`](https://modal.com/docs/sdk/py/latest/modal.CloudBucketMount) | Storage backed by a third-party cloud bucket (S3, etc.) | ### In-memory storage  | | | | --- | --- | | [`Dict`](https://modal.com/docs/sdk/py/latest/modal.Dict) | A distributed key-value store | | [`Queue`](https://modal.com/docs/sdk/py/latest/modal.Queue) | A distributed FIFO queue | Account configuration  | | | | --- | --- | | [`Workspace`](https://modal.com/docs/sdk/py/latest/modal.Workspace) | Workspace-level configuration and observability | | [`Environment`](https://modal.com/docs/sdk/py/latest/modal.Environment) | Manage workspace subdivisions | Networking  | | | | --- | --- | | [`Proxy`](https://modal.com/docs/sdk/py/latest/modal.Proxy) | An object that provides a static outbound IP address for containers | | [`forward`](https://modal.com/docs/sdk/py/latest/modal.forward) | A context manager for publicly exposing a port from a container | [API Reference](https://modal.com/docs/sdk/py/latest#api-reference) [Application construction](https://modal.com/docs/sdk/py/latest#application-construction) [Serverless execution](https://modal.com/docs/sdk/py/latest#serverless-execution) [Extended Function configuration](https://modal.com/docs/sdk/py/latest#extended-function-configuration) [Class parametrization](https://modal.com/docs/sdk/py/latest#class-parametrization) [Lifecycle hooks](https://modal.com/docs/sdk/py/latest#lifecycle-hooks) [Web integrations](https://modal.com/docs/sdk/py/latest#web-integrations) [Function semantics](https://modal.com/docs/sdk/py/latest#function-semantics) [Scheduling](https://modal.com/docs/sdk/py/latest#scheduling) [Exception handling](https://modal.com/docs/sdk/py/latest#exception-handling) [Sandboxed execution](https://modal.com/docs/sdk/py/latest#sandboxed-execution) [Container configuration](https://modal.com/docs/sdk/py/latest#container-configuration) [Data primitives](https://modal.com/docs/sdk/py/latest#data-primitives) [Persistent storage](https://modal.com/docs/sdk/py/latest#persistent-storage) [In-memory storage](https://modal.com/docs/sdk/py/latest#in-memory-storage) [Account configuration](https://modal.com/docs/sdk/py/latest#account-configuration) [Networking](https://modal.com/docs/sdk/py/latest#networking)