1 2{!../../../docs/missing-translation.md!} 3 4 5<p align="center"> 6 <a href="https://fastapi.tiangolo.com"><img src="https://fastapi.tiangolo.com/img/logo-margin/logo-teal.png" alt="FastAPI"></a> 7</p> 8<p align="center"> 9 <em>FastAPI framework, high performance, easy to learn, fast to code, ready for production</em> 10</p> 11<p align="center"> 12<a href="https://travis-ci.com/tiangolo/fastapi" target="_blank"> 13 <img src="https://travis-ci.com/tiangolo/fastapi.svg?branch=master" alt="Build Status"> 14</a> 15<a href="https://codecov.io/gh/tiangolo/fastapi" target="_blank"> 16 <img src="https://img.shields.io/codecov/c/github/tiangolo/fastapi" alt="Coverage"> 17</a> 18<a href="https://pypi.org/project/fastapi" target="_blank"> 19 <img src="https://badge.fury.io/py/fastapi.svg" alt="Package version"> 20</a> 21</p> 22 23--- 24 25**Documentation**: <a href="https://fastapi.tiangolo.com" target="_blank">https://fastapi.tiangolo.com</a> 26 27**Source Code**: <a href="https://github.com/tiangolo/fastapi" target="_blank">https://github.com/tiangolo/fastapi</a> 28 29--- 30 31FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints. 32 33The key features are: 34 35* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance). 36 37* **Fast to code**: Increase the speed to develop features by about 200% to 300%. * 38* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. * 39* **Intuitive**: Great editor support. <abbr title="also known as auto-complete, autocompletion, IntelliSense">Completion</abbr> everywhere. Less time debugging. 40* **Easy**: Designed to be easy to use and learn. Less time reading docs. 41* **Short**: Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs. 42* **Robust**: Get production-ready code. With automatic interactive documentation. 43* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: <a href="https://github.com/OAI/OpenAPI-Specification" class="external-link" target="_blank">OpenAPI</a> (previously known as Swagger) and <a href="https://json-schema.org/" class="external-link" target="_blank">JSON Schema</a>. 44 45<small>* estimation based on tests on an internal development team, building production applications.</small> 46 47## Sponsors 48 49<!-- sponsors --> 50 51{% if sponsors %} 52{% for sponsor in sponsors.gold -%} 53<a href="{{ sponsor.url }}" target="_blank" title="{{ sponsor.title }}"><img src="{{ sponsor.img }}" style="border-radius:15px"></a> 54{% endfor -%} 55{%- for sponsor in sponsors.silver -%} 56<a href="{{ sponsor.url }}" target="_blank" title="{{ sponsor.title }}"><img src="{{ sponsor.img }}" style="border-radius:15px"></a> 57{% endfor %} 58{% endif %} 59 60<!-- /sponsors --> 61 62<a href="https://fastapi.tiangolo.com/fastapi-people/#sponsors" class="external-link" target="_blank">Other sponsors</a> 63 64## Opinions 65 66"_[...] 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._" 67 68<div style="text-align: right; margin-right: 10%;">Kabir Khan - <strong>Microsoft</strong> <a href="https://github.com/tiangolo/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div> 69 70--- 71 72"_We adopted the **FastAPI** library to spawn a **REST** server that can be queried to obtain **predictions**. [for Ludwig]_" 73 74<div style="text-align: right; margin-right: 10%;">Piero Molino, Yaroslav Dudin, and Sai Sumanth Miryala - <strong>Uber</strong> <a href="https://eng.uber.com/ludwig-v0-2/" target="_blank"><small>(ref)</small></a></div> 75 76--- 77 78"_**Netflix** is pleased to announce the open-source release of our **crisis management** orchestration framework: **Dispatch**! [built with **FastAPI**]_" 79 80<div style="text-align: right; margin-right: 10%;">Kevin Glisson, Marc Vilanova, Forest Monsen - <strong>Netflix</strong> <a href="https://netflixtechblog.com/introducing-dispatch-da4b8a2a8072" target="_blank"><small>(ref)</small></a></div> 81 82--- 83 84"_I’m over the moon excited about **FastAPI**. It’s so fun!_" 85 86<div style="text-align: right; margin-right: 10%;">Brian Okken - <strong><a href="https://pythonbytes.fm/episodes/show/123/time-to-right-the-py-wrongs?time_in_sec=855" target="_blank">Python Bytes</a> podcast host</strong> <a href="https://twitter.com/brianokken/status/1112220079972728832" target="_blank"><small>(ref)</small></a></div> 87 88--- 89 90"_Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that._" 91 92<div style="text-align: right; margin-right: 10%;">Timothy Crosley - <strong><a href="https://www.hug.rest/" target="_blank">Hug</a> creator</strong> <a href="https://news.ycombinator.com/item?id=19455465" target="_blank"><small>(ref)</small></a></div> 93 94--- 95 96"_If you're looking to learn one **modern framework** for building REST APIs, check out **FastAPI** [...] It's fast, easy to use and easy to learn [...]_" 97 98"_We've switched over to **FastAPI** for our **APIs** [...] I think you'll like it [...]_" 99 100<div style="text-align: right; margin-right: 10%;">Ines Montani - Matthew Honnibal - <strong><a href="https://explosion.ai" target="_blank">Explosion AI</a> founders - <a href="https://spacy.io" target="_blank">spaCy</a> creators</strong> <a href="https://twitter.com/_inesmontani/status/1144173225322143744" target="_blank"><small>(ref)</small></a> - <a href="https://twitter.com/honnibal/status/1144031421859655680" target="_blank"><small>(ref)</small></a></div> 101 102--- 103 104## **Typer**, the FastAPI of CLIs 105 106<a href="https://typer.tiangolo.com" target="_blank"><img src="https://typer.tiangolo.com/img/logo-margin/logo-margin-vector.svg" style="width: 20%;"></a> 107 108If you are building a <abbr title="Command Line Interface">CLI</abbr> app to be used in the terminal instead of a web API, check out <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>. 109 110**Typer** is FastAPI's little sibling. And it's intended to be the **FastAPI of CLIs**. ⌨️ 111 112## Requirements 113 114Python 3.6+ 115 116FastAPI stands on the shoulders of giants: 117 118* <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> for the web parts. 119* <a href="https://pydantic-docs.helpmanual.io/" class="external-link" target="_blank">Pydantic</a> for the data parts. 120 121## Installation 122 123<div class="termy"> 124 125```console 126$ pip install fastapi 127 128---> 100% 129``` 130 131</div> 132 133You will also need an ASGI server, for production such as <a href="https://www.uvicorn.org" class="external-link" target="_blank">Uvicorn</a> or <a href="https://gitlab.com/pgjones/hypercorn" class="external-link" target="_blank">Hypercorn</a>. 134 135<div class="termy"> 136 137```console 138$ pip install uvicorn[standard] 139 140---> 100% 141``` 142 143</div> 144 145## Example 146 147### Create it 148 149* Create a file `main.py` with: 150 151```Python 152from fastapi import FastAPI 153from typing import Optional 154 155app = FastAPI() 156 157 158@app.get("/") 159def read_root(): 160 return {"Hello": "World"} 161 162 163@app.get("/items/{item_id}") 164def read_item(item_id: int, q: str = Optional[None]): 165 return {"item_id": item_id, "q": q} 166``` 167 168<details markdown="1"> 169<summary>Or use <code>async def</code>...</summary> 170 171If your code uses `async` / `await`, use `async def`: 172 173```Python hl_lines="7 12" 174from fastapi import FastAPI 175from typing import Optional 176 177app = FastAPI() 178 179 180@app.get("/") 181async def read_root(): 182 return {"Hello": "World"} 183 184 185@app.get("/items/{item_id}") 186async def read_item(item_id: int, q: Optional[str] = None): 187 return {"item_id": item_id, "q": q} 188``` 189 190**Note**: 191 192If you don't know, check the _"In a hurry?"_ section about <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` and `await` in the docs</a>. 193 194</details> 195 196### Run it 197 198Run the server with: 199 200<div class="termy"> 201 202```console 203$ uvicorn main:app --reload 204 205INFO: Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit) 206INFO: Started reloader process [28720] 207INFO: Started server process [28722] 208INFO: Waiting for application startup. 209INFO: Application startup complete. 210``` 211 212</div> 213 214<details markdown="1"> 215<summary>About the command <code>uvicorn main:app --reload</code>...</summary> 216 217The command `uvicorn main:app` refers to: 218 219* `main`: the file `main.py` (the Python "module"). 220* `app`: the object created inside of `main.py` with the line `app = FastAPI()`. 221* `--reload`: make the server restart after code changes. Only do this for development. 222 223</details> 224 225### Check it 226 227Open your browser at <a href="http://127.0.0.1:8000/items/5?q=somequery" class="external-link" target="_blank">http://127.0.0.1:8000/items/5?q=somequery</a>. 228 229You will see the JSON response as: 230 231```JSON 232{"item_id": 5, "q": "somequery"} 233``` 234 235You already created an API that: 236 237* Receives HTTP requests in the _paths_ `/` and `/items/{item_id}`. 238* Both _paths_ take `GET` <em>operations</em> (also known as HTTP _methods_). 239* The _path_ `/items/{item_id}` has a _path parameter_ `item_id` that should be an `int`. 240* The _path_ `/items/{item_id}` has an optional `str` _query parameter_ `q`. 241 242### Interactive API docs 243 244Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>. 245 246You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>): 247 248![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png) 249 250### Alternative API docs 251 252And now, go to <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>. 253 254You will see the alternative automatic documentation (provided by <a href="https://github.com/Rebilly/ReDoc" class="external-link" target="_blank">ReDoc</a>): 255 256![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png) 257 258## Example upgrade 259 260Now modify the file `main.py` to receive a body from a `PUT` request. 261 262Declare the body using standard Python types, thanks to Pydantic. 263 264```Python hl_lines="2 7-10 23-25" 265from fastapi import FastAPI 266from pydantic import BaseModel 267from typing import Optional 268 269app = FastAPI() 270 271 272class Item(BaseModel): 273 name: str 274 price: float 275 is_offer: bool = Optional[None] 276 277 278@app.get("/") 279def read_root(): 280 return {"Hello": "World"} 281 282 283@app.get("/items/{item_id}") 284def read_item(item_id: int, q: Optional[str] = None): 285 return {"item_id": item_id, "q": q} 286 287 288@app.put("/items/{item_id}") 289def update_item(item_id: int, item: Item): 290 return {"item_name": item.name, "item_id": item_id} 291``` 292 293The server should reload automatically (because you added `--reload` to the `uvicorn` command above). 294 295### Interactive API docs upgrade 296 297Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>. 298 299* The interactive API documentation will be automatically updated, including the new body: 300 301![Swagger UI](https://fastapi.tiangolo.com/img/index/index-03-swagger-02.png) 302 303* Click on the button "Try it out", it allows you to fill the parameters and directly interact with the API: 304 305![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png) 306 307* Then click on the "Execute" button, the user interface will communicate with your API, send the parameters, get the results and show them on the screen: 308 309![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png) 310 311### Alternative API docs upgrade 312 313And now, go to <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>. 314 315* The alternative documentation will also reflect the new query parameter and body: 316 317![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png) 318 319### Recap 320 321In summary, you declare **once** the types of parameters, body, etc. as function parameters. 322 323You do that with standard modern Python types. 324 325You don't have to learn a new syntax, the methods or classes of a specific library, etc. 326 327Just standard **Python 3.6+**. 328 329For example, for an `int`: 330 331```Python 332item_id: int 333``` 334 335or for a more complex `Item` model: 336 337```Python 338item: Item 339``` 340 341...and with that single declaration you get: 342 343* Editor support, including: 344 * Completion. 345 * Type checks. 346* Validation of data: 347 * Automatic and clear errors when the data is invalid. 348 * Validation even for deeply nested JSON objects. 349* <abbr title="also known as: serialization, parsing, marshalling">Conversion</abbr> of input data: coming from the network to Python data and types. Reading from: 350 * JSON. 351 * Path parameters. 352 * Query parameters. 353 * Cookies. 354 * Headers. 355 * Forms. 356 * Files. 357* <abbr title="also known as: serialization, parsing, marshalling">Conversion</abbr> of output data: converting from Python data and types to network data (as JSON): 358 * Convert Python types (`str`, `int`, `float`, `bool`, `list`, etc). 359 * `datetime` objects. 360 * `UUID` objects. 361 * Database models. 362 * ...and many more. 363* Automatic interactive API documentation, including 2 alternative user interfaces: 364 * Swagger UI. 365 * ReDoc. 366 367--- 368 369Coming back to the previous code example, **FastAPI** will: 370 371* Validate that there is an `item_id` in the path for `GET` and `PUT` requests. 372* Validate that the `item_id` is of type `int` for `GET` and `PUT` requests. 373 * If it is not, the client will see a useful, clear error. 374* 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. 375 * As the `q` parameter is declared with `= None`, it is optional. 376 * Without the `None` it would be required (as is the body in the case with `PUT`). 377* For `PUT` requests to `/items/{item_id}`, Read the body as JSON: 378 * Check that it has a required attribute `name` that should be a `str`. 379 * Check that it has a required attribute `price` that has to be a `float`. 380 * Check that it has an optional attribute `is_offer`, that should be a `bool`, if present. 381 * All this would also work for deeply nested JSON objects. 382* Convert from and to JSON automatically. 383* Document everything with OpenAPI, that can be used by: 384 * Interactive documentation systems. 385 * Automatic client code generation systems, for many languages. 386* Provide 2 interactive documentation web interfaces directly. 387 388--- 389 390We just scratched the surface, but you already get the idea of how it all works. 391 392Try changing the line with: 393 394```Python 395 return {"item_name": item.name, "item_id": item_id} 396``` 397 398...from: 399 400```Python 401 ... "item_name": item.name ... 402``` 403 404...to: 405 406```Python 407 ... "item_price": item.price ... 408``` 409 410...and see how your editor will auto-complete the attributes and know their types: 411 412![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png) 413 414For a more complete example including more features, see the <a href="https://fastapi.tiangolo.com/tutorial/">Tutorial - User Guide</a>. 415 416**Spoiler alert**: the tutorial - user guide includes: 417 418* Declaration of **parameters** from other different places as: **headers**, **cookies**, **form fields** and **files**. 419* How to set **validation constraints** as `maximum_length` or `regex`. 420* A very powerful and easy to use **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system. 421* Security and authentication, including support for **OAuth2** with **JWT tokens** and **HTTP Basic** auth. 422* More advanced (but equally easy) techniques for declaring **deeply nested JSON models** (thanks to Pydantic). 423* Many extra features (thanks to Starlette) as: 424 * **WebSockets** 425 * **GraphQL** 426 * extremely easy tests based on `requests` and `pytest` 427 * **CORS** 428 * **Cookie Sessions** 429 * ...and more. 430 431## Performance 432 433Independent TechEmpower benchmarks show **FastAPI** applications running under Uvicorn as <a href="https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7" class="external-link" target="_blank">one of the fastest Python frameworks available</a>, only below Starlette and Uvicorn themselves (used internally by FastAPI). (*) 434 435To understand more about it, see the section <a href="https://fastapi.tiangolo.com/benchmarks/" class="internal-link" target="_blank">Benchmarks</a>. 436 437## Optional Dependencies 438 439Used by Pydantic: 440 441* <a href="https://github.com/esnme/ultrajson" target="_blank"><code>ujson</code></a> - for faster JSON <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>. 442* <a href="https://github.com/JoshData/python-email-validator" target="_blank"><code>email_validator</code></a> - for email validation. 443 444Used by Starlette: 445 446* <a href="https://requests.readthedocs.io" target="_blank"><code>requests</code></a> - Required if you want to use the `TestClient`. 447* <a href="https://github.com/Tinche/aiofiles" target="_blank"><code>aiofiles</code></a> - Required if you want to use `FileResponse` or `StaticFiles`. 448* <a href="https://jinja.palletsprojects.com" target="_blank"><code>jinja2</code></a> - Required if you want to use the default template configuration. 449* <a href="https://andrew-d.github.io/python-multipart/" target="_blank"><code>python-multipart</code></a> - Required if you want to support form <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>, with `request.form()`. 450* <a href="https://pythonhosted.org/itsdangerous/" target="_blank"><code>itsdangerous</code></a> - Required for `SessionMiddleware` support. 451* <a href="https://pyyaml.org/wiki/PyYAMLDocumentation" target="_blank"><code>pyyaml</code></a> - Required for Starlette's `SchemaGenerator` support (you probably don't need it with FastAPI). 452* <a href="https://graphene-python.org/" target="_blank"><code>graphene</code></a> - Required for `GraphQLApp` support. 453* <a href="https://github.com/esnme/ultrajson" target="_blank"><code>ujson</code></a> - Required if you want to use `UJSONResponse`. 454 455Used by FastAPI / Starlette: 456 457* <a href="https://www.uvicorn.org" target="_blank"><code>uvicorn</code></a> - for the server that loads and serves your application. 458* <a href="https://github.com/ijl/orjson" target="_blank"><code>orjson</code></a> - Required if you want to use `ORJSONResponse`. 459 460You can install all of these with `pip install fastapi[all]`. 461 462## License 463 464This project is licensed under the terms of the MIT license. 465