diff --git a/README.md b/README.md index fbf66a48b..a9843c41d 100644 --- a/README.md +++ b/README.md @@ -1,139 +1,160 @@

- FastAPI + + main +

+

- FastAPI framework, high performance, easy to learn, fast to code, ready for production + Test + Coverage + Package version

+

- - Test - - - Coverage - - - Package version - - - Supported Python versions - + Supported Python versions + License

---- - -**Documentation**: [https://fastapi.tiangolo.com](https://fastapi.tiangolo.com) - -**Source Code**: [https://github.com/fastapi/fastapi](https://github.com/fastapi/fastapi) +

+FastAPI framework, high performance, easy to learn, fast to code, ready for production. +

--- -FastAPI is a modern, fast (high-performance), web framework for building APIs with Python based on standard Python type hints. - -The key features are: - -* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance). -* **Fast to code**: Increase the speed to develop features by about 200% to 300%. * -* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. * -* **Intuitive**: Great editor support. Completion everywhere. Less time debugging. -* **Easy**: Designed to be easy to use and learn. Less time reading docs. -* **Short**: Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs. -* **Robust**: Get production-ready code. With automatic interactive documentation. -* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: [OpenAPI](https://github.com/OAI/OpenAPI-Specification) (previously known as Swagger) and [JSON Schema](https://json-schema.org/). - -* estimation based on tests conducted by an internal development team, building production applications. +FOR **DOCUMENTATION** CLICK [HERE](https://fastapi.tiangolo.com) -## Sponsors - - -### Keystone Sponsor +--- - +FOR **SOURCE CODE** CLICK [HERE](https://github.com/fastapi/fastapi) -### Gold Sponsors +--- - - - - - - - - +### What is FastAPI?: -### Silver Sponsors +FastAPI is a modern, fast (high-performance), web framework for building APIs with Python based on standard Python type hints. - - - - - - - +--- - +### Why use FastAPI?: -[Other sponsors](https://fastapi.tiangolo.com/fastapi-people/#sponsors) +✅ **Fast:** One of the [**FASTEST PYTHON FRAMEWORK**](https://github.com/fastapi/fastapi#performance) on par with **NodeJS** and **Go** (thanks to Starlette & Pydantic).
+✅ **Quick feature development :** Increases feature development speed approximately by **200%** to **300%**.
+✅ **Less Bugs:** Reduces human-induced bugs by approximately **40%**.
+✅ **Intuitive:** Comprehensive editor support. Completion everywhere. Minimized debugging time.
+✅ **Easy usability:** Gentle learning curve. Easy to use.
+✅ **Simple Syntax:** Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs.
+✅ **Production-Ready & Robust:** Get production-ready code. With automatic interactive documentation.
+✅ **Standards-Based Compliance:** Based on (and fully compatible with) the open standards for APIs: [OpenAPI](https://github.com/OAI/OpenAPI-Specification) (previously known as Swagger) and [JSON Schema](https://json-schema.org/). +
-## Opinions +**NOTE:** Estimations are based on benchmarks conducted by an internal development team building production-scale applications. +--- +### Our Sponsors: -
+**KEYSTONE SPONSOR:** -"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._" +
+ +
+
+ +**GOLD SPONSORS:** + +
+ + + + + + + + +
+
+ +**SILVER SPONSORS:** + +
+ + + + + + + +
+
-
Kabir Khan - Microsoft (ref)
+**OTHER** [**SPONSORS**](https://fastapi.tiangolo.com/fastapi-people/#sponsors) --- -"_We adopted the **FastAPI** library to spawn a **REST** server that can be queried to obtain **predictions**. [for Ludwig]_" - -
Piero Molino, Yaroslav Dudin, and Sai Sumanth Miryala - Uber (ref)
+### Testimonials ❤️: + + --- -"_**Netflix** is pleased to announce the open-source release of our **crisis management** orchestration framework: **Dispatch**! [built with **FastAPI**]_" +### FastAPI Conf: -
Kevin Glisson, Marc Vilanova, Forest Monsen - Netflix (ref)
+[**FastAPI Conf '26**](https://fastapiconf.com) is happening on **October 28, 2026** in **Amsterdam, NL**. All about FastAPI, right from the source. ---- - -"_If anyone is looking to build a production Python API, I would highly recommend **FastAPI**. It is **beautifully designed**, **simple to use** and **highly scalable**, it has become a **key component** in our API first development strategy and is driving many automations and services such as our Virtual TAC Engineer._" - -
Deon Pillsbury - Cisco (ref)
+

+ + FastAPI Conf '26 - October 28, 2026 - Amsterdam, NL + +

--- -
- -## FastAPI Conf +### The RISE and RISE of FastAPI: -[**FastAPI Conf '26**](https://fastapiconf.com) is happening on **October 28, 2026** in **Amsterdam, NL**. All about FastAPI, right from the source. 🎤 +[![Watch the video](https://img.youtube.com/vi/mpR8ngthqiE/maxresdefault.jpg)](https://youtu.be/mpR8ngthqiE?si=p2pQTo83OizqiaGd) -FastAPI Conf '26 - October 28, 2026 - Amsterdam, NL +WATCH OUR **MINI-DOCUMENTARY** [HERE](https://youtu.be/mpR8ngthqiE?si=p2pQTo83OizqiaGd) -## FastAPI mini documentary - -There's a [FastAPI mini documentary](https://www.youtube.com/watch?v=mpR8ngthqiE) released at the end of 2025, you can watch it online: - -FastAPI Mini Documentary +--- -## **Typer**, the FastAPI of CLIs +### Typer: - +
+ +
-If you are building a CLI app to be used in the terminal instead of a web API, check out [**Typer**](https://typer.tiangolo.com/). +* **Typer** is FastAPI's little sibling. And it's intended to be the **FastAPI of CLIs**. +* If you are building a CLI app to be used in the terminal instead of a web API, check out [**Typer**](https://typer.tiangolo.com/). -**Typer** is FastAPI's little sibling. And it's intended to be the **FastAPI of CLIs**. ⌨️ 🚀 +--- -## Requirements +### Requirements: FastAPI stands on the shoulders of giants: -* [Starlette](https://www.starlette.dev/) for the web parts. -* [Pydantic](https://docs.pydantic.dev/) for the data parts. +* [**Starlette**](https://www.starlette.dev/) for the web parts. +* [**Pydantic**](https://docs.pydantic.dev/) for the data parts. + +--- -## Installation +### Installation: Create and activate a [virtual environment](https://fastapi.tiangolo.com/virtual-environments/) and then install FastAPI: @@ -147,11 +168,13 @@ $ pip install "fastapi[standard]" -**Note**: Make sure you put `"fastapi[standard]"` in quotes to ensure it works in all terminals. +**NOTE:** Make sure you put `"fastapi[standard]"` in quotes to ensure it works in all terminals. -## Example +--- + +### Example: -### Create it +**CREATE:** Create a file `main.py` with: @@ -172,7 +195,7 @@ def read_item(item_id: int, q: str | None = None): ```
-Or use async def... +Or use async def If your code uses `async` / `await`, use `async def`: @@ -192,13 +215,11 @@ async def read_item(item_id: int, q: str | None = None): return {"item_id": item_id, "q": q} ``` -**Note**: - -If you don't know, check the _"In a hurry?"_ section about [`async` and `await` in the docs](https://fastapi.tiangolo.com/async/#in-a-hurry). +**NOTE:** If you don't know, check the _"In a hurry?"_ section about [`async` and `await` in the docs](https://fastapi.tiangolo.com/async/#in-a-hurry).
-### Run it +**RUN IT:** Run the server with: @@ -230,7 +251,7 @@ INFO: Application startup complete.
-About the command fastapi dev... +About the command fastapi dev The command `fastapi dev` reads your `main.py` file automatically, detects the **FastAPI** app in it, and starts a server using [Uvicorn](https://www.uvicorn.dev). @@ -240,7 +261,7 @@ You can read more about it in the [FastAPI CLI docs](https://fastapi.tiangolo.co
-### Check it +**CHECK IT:** Open your browser at [http://127.0.0.1:8000/items/5?q=somequery](http://127.0.0.1:8000/items/5?q=somequery). @@ -257,7 +278,7 @@ You already created an API that: * The _path_ `/items/{item_id}` has a _path parameter_ `item_id` that should be an `int`. * The _path_ `/items/{item_id}` has an optional `str` _query parameter_ `q`. -### Interactive API docs +**INTERACTIVE API DOCS:** Now go to [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs). @@ -265,7 +286,7 @@ You will see the automatic interactive API documentation (provided by [Swagger U ![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png) -### Alternative API docs +**ALTERNATIVE API DOCS:** And now, go to [http://127.0.0.1:8000/redoc](http://127.0.0.1:8000/redoc). @@ -273,7 +294,9 @@ You will see the alternative automatic documentation (provided by [ReDoc](https: ![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png) -## Example upgrade +--- + +### Example upgrade: Now modify the file `main.py` to receive a body from a `PUT` request. @@ -309,7 +332,7 @@ def update_item(item_id: int, item: Item): The `fastapi dev` server should reload automatically. -### Interactive API docs upgrade +**INTERACTIVE API DOCS UPGRADE:** Now go to [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs). @@ -325,7 +348,7 @@ Now go to [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs). ![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png) -### Alternative API docs upgrade +**ALTERNATIVE API DOCS UPGRADE:** And now, go to [http://127.0.0.1:8000/redoc](http://127.0.0.1:8000/redoc). @@ -333,15 +356,9 @@ And now, go to [http://127.0.0.1:8000/redoc](http://127.0.0.1:8000/redoc). ![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png) -### Recap - -In summary, you declare **once** the types of parameters, body, etc. as function parameters. - -You do that with standard modern Python types. +**RECAP:** -You don't have to learn a new syntax, the methods or classes of a specific library, etc. - -Just standard **Python**. +In summary, you declare **once** the types of parameters, body, etc. as function parameters. You do that with standard modern Python types. You don't have to learn a new syntax, the methods or classes of a specific library, etc.Just standard **Python**. For example, for an `int`: @@ -355,82 +372,63 @@ or for a more complex `Item` model: item: Item ``` -...and with that single declaration you get: - -* Editor support, including: - * Completion. - * Type checks. -* Validation of data: - * Automatic and clear errors when the data is invalid. - * Validation even for deeply nested JSON objects. -* Conversion of input data: coming from the network to Python data and types. Reading from: - * JSON. - * Path parameters. - * Query parameters. - * Cookies. - * Headers. - * Forms. - * Files. -* Conversion of output data: converting from Python data and types to network data (as JSON): - * Convert Python types (`str`, `int`, `float`, `bool`, `list`, etc). - * `datetime` objects. - * `UUID` objects. - * Database models. - * ...and many more. -* Automatic interactive API documentation, including 2 alternative user interfaces: - * Swagger UI. - * ReDoc. +**WITH THAT SINGLE DECLARATION YOU GET:** ---- +* **Editor support**, including: Completion, and Type checks. +* **Validation of data**: + * Automatic and clear errors when the data is invalid. + * Validation even for deeply nested JSON objects. +* **Conversion of input data** (coming from the network to Python data and types): + * *Reading from:* JSON, Path parameters, Query parameters, Cookies, Headers, Forms, and Files. +* **Conversion of output data** (converting from Python data and types to network data as JSON): + * Convert Python types (`str`, `int`, `float`, `bool`, `list`, etc). + * `datetime` objects, `UUID` objects, and Database models, etc. +* **Automatic interactive API documentation**, including 2 alternative user interfaces: Swagger UI and ReDoc. + +**BEHIND THE SCENES:** Coming back to the previous code example, **FastAPI** will: -* Validate that there is an `item_id` in the path for `GET` and `PUT` requests. -* Validate that the `item_id` is of type `int` for `GET` and `PUT` requests. - * If it is not, the client will see a useful, clear error. -* Check if there is an optional query parameter named `q` (as in `http://127.0.0.1:8000/items/foo?q=somequery`) for `GET` requests. - * As the `q` parameter is declared with `= None`, it is optional. - * Without the `None` it would be required (as is the body in the case with `PUT`). -* For `PUT` requests to `/items/{item_id}`, read the body as JSON: - * Check that it has a required attribute `name` that should be a `str`. - * Check that it has a required attribute `price` that has to be a `float`. - * Check that it has an optional attribute `is_offer`, that should be a `bool`, if present. - * All this would also work for deeply nested JSON objects. -* Convert from and to JSON automatically. -* Document everything with OpenAPI, that can be used by: - * Interactive documentation systems. - * Automatic client code generation systems, for many languages. -* Provide 2 interactive documentation web interfaces directly. - ---- +* **Validate Path Requirements:** Validate that there is an `item_id` in the path for `GET` and `PUT` requests. +* **Enforce Parameter Types:** Validate that the `item_id` is of type `int` for `GET` and `PUT` requests. If it is not, the client will see a useful, clear error. +* **Handle Optional Queries:** Check if there is an optional query parameter named `q` (as in `http://127.0.0.1:8000/items/foo?q=somequery`) for `GET` requests. + > As the `q` parameter is declared with `= None`, it is optional. Without the `None` it would be required (as is the body in the case with `PUT`). +* **Parse and Verify Request Bodies:** For `PUT` requests to `/items/{item_id}`, read the body as JSON and check that it has: + * A required attribute `name` that should be a `str`. + * A required attribute `price` that has to be a `float`. + * An optional attribute `is_offer`, that should be a `bool`, if present. + * *Note: All this would also work for deeply nested JSON objects.* +* **Automate JSON Serialization:** Convert from and to JSON automatically. +* **Standardize with OpenAPI:** Document everything with OpenAPI, that can be used by interactive documentation systems and automatic client code generation systems, for many languages. +* **Expose UI Interfaces:** Provide 2 interactive documentation web interfaces directly. We just scratched the surface, but you already get the idea of how it all works. -Try changing the line with: +Try changing the line WITH: ```Python return {"item_name": item.name, "item_id": item_id} ``` -...from: +FROM: ```Python ... "item_name": item.name ... ``` -...to: +TO: ```Python ... "item_price": item.price ... ``` -...and see how your editor will auto-complete the attributes and know their types: +And see how your editor will auto-complete the attributes and know their types: ![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png) -For a more complete example including more features, see the Tutorial - User Guide. +FOR MORE COMPLETE EXAMPLE VISIT TUTORIAL. -**Spoiler alert**: the tutorial - user guide includes: +**SPOILER ALERT FOR TUTORIAL**: * Declaration of **parameters** from other different places such as: **headers**, **cookies**, **form fields** and **files**. * How to set **validation constraints** such as `maximum_length` or `regex`. @@ -438,16 +436,11 @@ For a more complete example including more features, see the @@ -465,37 +458,36 @@ Deploying to FastAPI Cloud... The CLI will automatically detect your FastAPI application and deploy it to the cloud. If you are not logged in, your browser will open to complete the authentication process. -That's it! Now you can access your app at that URL. ✨ - -#### About FastAPI Cloud - -**[FastAPI Cloud](https://fastapicloud.com)** is built by the same author and team behind **FastAPI**. +That's it! Now you can access your app at that URL.
-It streamlines the process of **building**, **deploying**, and **accessing** an API with minimal effort. +**ABOUT FAST API CLOUD:** -It brings the same **developer experience** of building apps with FastAPI to **deploying** them to the cloud. 🎉 +* **[FastAPI Cloud](https://fastapicloud.com)** is built by the same author and team behind **FastAPI**. +* It streamlines the process of **building**, **deploying**, and **accessing** an API with minimal effort. +* It brings the same **developer experience** of building apps with FastAPI to **deploying** them to the cloud. +* FastAPI Cloud is the primary sponsor and funding provider for the *FastAPI and friends* open source projects.
-FastAPI Cloud is the primary sponsor and funding provider for the *FastAPI and friends* open source projects. ✨ +**DEPLOY TO OTHER CLOUD PROVIDERS:** -#### Deploy to other cloud providers +* FastAPI is open source and based on standards. You can deploy FastAPI apps to any cloud provider you choose. +* Follow your cloud provider's guides to deploy FastAPI apps with them. -FastAPI is open source and based on standards. You can deploy FastAPI apps to any cloud provider you choose. - -Follow your cloud provider's guides to deploy FastAPI apps with them. 🤓 +--- -## Performance +### Performance: -Independent TechEmpower benchmarks show **FastAPI** applications running under Uvicorn as [one of the fastest Python frameworks available](https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7), only below Starlette and Uvicorn themselves (used internally by FastAPI). (*) +* Independent TechEmpower benchmarks show **FastAPI** applications running under Uvicorn as one of the [**FASTEST Python frameworks**](https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7) available, only below Starlette and Uvicorn themselves (used internally by FastAPI). (*) +* To understand more about it, see the section [Benchmarks](https://fastapi.tiangolo.com/benchmarks/). -To understand more about it, see the section [Benchmarks](https://fastapi.tiangolo.com/benchmarks/). +--- -## Dependencies +### Dependencies: FastAPI depends on Pydantic and Starlette. -### `standard` Dependencies +**[A] `standard` DEPENDENCIES:** -When you install FastAPI with `pip install "fastapi[standard]"` it comes with the `standard` group of optional dependencies: +* When you install FastAPI with `pip install "fastapi[standard]"` it comes with the `standard` group of optional dependencies: Used by Pydantic: @@ -503,38 +495,98 @@ Used by Pydantic: Used by Starlette: -* [`httpx`](https://www.python-httpx.org) - Required if you want to use the `TestClient`. -* [`jinja2`](https://jinja.palletsprojects.com) - Required if you want to use the default template configuration. -* [`python-multipart`](https://github.com/Kludex/python-multipart) - Required if you want to support form "parsing", with `request.form()`. +
+ + + + + + + + + + + + + + + + + + + + + +
DependencyPurpose
httpxRequired if you want to use the TestClient.
jinja2Required if you want to use the default template configuration.
python-multipartRequired if you want to support form "parsing", with request.form().
+
Used by FastAPI: * [`uvicorn`](https://www.uvicorn.dev) - for the server that loads and serves your application. This includes `uvicorn[standard]`, which includes some dependencies (e.g. `uvloop`) needed for high performance serving. * `fastapi-cli[standard]` - to provide the `fastapi` command. - * This includes `fastapi-cloud-cli`, which allows you to deploy your FastAPI application to [FastAPI Cloud](https://fastapicloud.com). + * This includes `fastapi-cloud-cli`, which allows you to deploy your FastAPI application to [FastAPI Cloud](https://fastapicloud.com).
-### Without `standard` Dependencies +**[B] WITHOUT `standard` DEPENDENCIES:** -If you don't want to include the `standard` optional dependencies, you can install with `pip install fastapi` instead of `pip install "fastapi[standard]"`. +* If you don't want to include the `standard` optional dependencies, you can install with `pip install fastapi` instead of `pip install "fastapi[standard]"`.
-### Without `fastapi-cloud-cli` +**[C] WITHOUT `fastapi-cloud-cli`:** -If you want to install FastAPI with the standard dependencies but without the `fastapi-cloud-cli`, you can install with `pip install "fastapi[standard-no-fastapi-cloud-cli]"`. +* If you want to install FastAPI with the standard dependencies but without the `fastapi-cloud-cli`, you can install with `pip install "fastapi[standard-no-fastapi-cloud-cli]"`.
-### Additional Optional Dependencies +**[D] ADDITIONAL OPTIONAL DEPENDENCIES:** There are some additional dependencies you might want to install. -Additional optional Pydantic dependencies: +* Pydantic Extensions: + +
+ + + + + + + + + + + + + + + + + +
DependencyPurpose
pydantic-settingsFor settings management.
pydantic-extra-typesFor extra types to be used with Pydantic.
+
-* [`pydantic-settings`](https://docs.pydantic.dev/latest/usage/pydantic_settings/) - for settings management. -* [`pydantic-extra-types`](https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/) - for extra types to be used with Pydantic. +* FastAPI Custom Responses: + +
+ + + + + + + + + + + + + + + + + +
DependencyPurpose
orjsonRequired if you want to use ORJSONResponse.
ujsonRequired if you want to use UJSONResponse.
+
-Additional optional FastAPI dependencies: +--- -* [`orjson`](https://github.com/ijl/orjson) - Required if you want to use `ORJSONResponse`. -* [`ujson`](https://github.com/esnme/ultrajson) - Required if you want to use `UJSONResponse`. +### License: -## License +Licensed under the [MIT License](https://github.com/fastapi/fastapi/blob/master/LICENSE). -This project is licensed under the terms of the MIT license.