fastapi

name	fastapi
description	FastAPI - Modern Python web framework for building APIs with automatic validation, documentation, and async support. Use for API routes, dependency injection, Pydantic models, middleware, and authentication.

Fastapi Skill

Comprehensive assistance with fastapi development, generated from official documentation.

When to Use This Skill

This skill should be triggered when:

• Working with fastapi
• Asking about fastapi features or APIs
• Implementing fastapi solutions
• Debugging fastapi code
• Learning fastapi best practices

Quick Reference

Common Patterns

Pattern 1: This includes, for example:

BackgroundTasks

Pattern 2: Info To use forms, first install python-multipart. Make sure you create a virtual environment, activate it, and then install it, for example: $ pip install python-multipart

python-multipart

Pattern 3: Make sure you create a virtual environment, activate it, and then install it, for example:

$ pip install python-multipart

Pattern 4: fastapi.FastAPI ¶ FastAPI( *, debug=False, routes=None, title="FastAPI", summary=None, description="", version="0.1.0", openapi_url="/openapi.json", openapi_tags=None, servers=None, dependencies=None, default_response_class=Default(JSONResponse), redirect_slashes=True, docs_url="/docs", redoc_url="/redoc", swagger_ui_oauth2_redirect_url="/docs/oauth2-redirect", swagger_ui_init_oauth=None, middleware=None, exception_handlers=None, on_startup=None, on_shutdown=None, lifespan=None, terms_of_service=None, contact=None, license_info=None, openapi_prefix="", root_path="", root_path_in_servers=True, responses=None, callbacks=None, webhooks=None, deprecated=None, include_in_schema=True, swagger_ui_parameters=None, generate_unique_id_function=Default(generate_unique_id), separate_input_output_schemas=True, openapi_external_docs=None, **extra ) Bases: Starlette FastAPI app class, the main entrypoint to use FastAPI. Read more in the FastAPI docs for First Steps. Example¶ from fastapi import FastAPI app = FastAPI() PARAMETER DESCRIPTION debug Boolean indicating if debug tracebacks should be returned on server errors. Read more in the Starlette docs for Applications. TYPE: bool DEFAULT: False routes Note: you probably shouldn't use this parameter, it is inherited from Starlette and supported for compatibility. A list of routes to serve incoming HTTP and WebSocket requests. TYPE: Optional[List[BaseRoute]] DEFAULT: None title The title of the API. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI(title="ChimichangApp") TYPE: str DEFAULT: 'FastAPI' summary A short summary of the API. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI(summary="Deadpond's favorite app. Nuff said.") TYPE: Optional[str] DEFAULT: None description A description of the API. Supports Markdown (using CommonMark syntax). It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI( description=""" ChimichangApp API helps you do awesome stuff. 🚀 ## Items You can read items. ## Users You will be able to: * Create users (not implemented). * Read users (not implemented). """ ) TYPE: str DEFAULT: '' version The version of the API. Note This is the version of your application, not the version of the OpenAPI specification nor the version of FastAPI being used. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI(version="0.0.1") TYPE: str DEFAULT: '0.1.0' openapi_url The URL where the OpenAPI schema will be served from. If you set it to None, no OpenAPI schema will be served publicly, and the default automatic endpoints /docs and /redoc will also be disabled. Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI(openapi_url="/api/v1/openapi.json") TYPE: Optional[str] DEFAULT: '/openapi.json' openapi_tags A list of tags used by OpenAPI, these are the same tags you can set in the path operations, like: @app.get("/users/", tags=["users"]) @app.get("/items/", tags=["items"]) The order of the tags can be used to specify the order shown in tools like Swagger UI, used in the automatic path /docs. It's not required to specify all the tags used. The tags that are not declared MAY be organized randomly or based on the tools' logic. Each tag name in the list MUST be unique. The value of each item is a dict containing: name: The name of the tag. description: A short description of the tag. CommonMark syntax MAY be used for rich text representation. externalDocs: Additional external documentation for this tag. If provided, it would contain a dict with: description: A short description of the target documentation. CommonMark syntax MAY be used for rich text representation. url: The URL for the target documentation. Value MUST be in the form of a URL. Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI tags_metadata = [ { "name": "users", "description": "Operations with users. The login logic is also here.", }, { "name": "items", "description": "Manage items. So fancy they have their own docs.", "externalDocs": { "description": "Items external docs", "url": "https://fastapi.tiangolo.com/", }, }, ] app = FastAPI(openapi_tags=tags_metadata) TYPE: Optional[List[Dict[str, Any]]] DEFAULT: None servers A list of dicts with connectivity information to a target server. You would use it, for example, if your application is served from different domains and you want to use the same Swagger UI in the browser to interact with each of them (instead of having multiple browser tabs open). Or if you want to leave fixed the possible URLs. If the servers list is not provided, or is an empty list, the servers property in the generated OpenAPI will be: a dict with a url value of the application's mounting point (root_path) if it's different from /. otherwise, the servers property will be omitted from the OpenAPI schema. Each item in the list is a dict containing: url: A URL to the target host. This URL supports Server Variables and MAY be relative, to indicate that the host location is relative to the location where the OpenAPI document is being served. Variable substitutions will be made when a variable is named in {brackets}. description: An optional string describing the host designated by the URL. CommonMark syntax MAY be used for rich text representation. variables: A dict between a variable name and its value. The value is used for substitution in the server's URL template. Read more in the FastAPI docs for Behind a Proxy. Example from fastapi import FastAPI app = FastAPI( servers=[ {"url": "https://stag.example.com", "description": "Staging environment"}, {"url": "https://prod.example.com", "description": "Production environment"}, ] ) TYPE: Optional[List[Dict[str, Union[str, Any]]]] DEFAULT: None dependencies A list of global dependencies, they will be applied to each path operation, including in sub-routers. Read more about it in the FastAPI docs for Global Dependencies. Example from fastapi import Depends, FastAPI from .dependencies import func_dep_1, func_dep_2 app = FastAPI(dependencies=[Depends(func_dep_1), Depends(func_dep_2)]) TYPE: Optional[Sequence[Depends]] DEFAULT: None default_response_class The default response class to be used. Read more in the FastAPI docs for Custom Response - HTML, Stream, File, others. Example from fastapi import FastAPI from fastapi.responses import ORJSONResponse app = FastAPI(default_response_class=ORJSONResponse) TYPE: Type[Response] DEFAULT: Default(JSONResponse) redirect_slashes Whether to detect and redirect slashes in URLs when the client doesn't use the same format. Example from fastapi import FastAPI app = FastAPI(redirect_slashes=True) # the default @app.get("/items/") async def read_items(): return [{"item_id": "Foo"}] With this app, if a client goes to /items (without a trailing slash), they will be automatically redirected with an HTTP status code of 307 to /items/. TYPE: bool DEFAULT: True docs_url The path to the automatic interactive API documentation. It is handled in the browser by Swagger UI. The default URL is /docs. You can disable it by setting it to None. If openapi_url is set to None, this will be automatically disabled. Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI(docs_url="/documentation", redoc_url=None) TYPE: Optional[str] DEFAULT: '/docs' redoc_url The path to the alternative automatic interactive API documentation provided by ReDoc. The default URL is /redoc. You can disable it by setting it to None. If openapi_url is set to None, this will be automatically disabled. Read more in the FastAPI docs for Metadata and Docs URLs. Example from fastapi import FastAPI app = FastAPI(docs_url="/documentation", redoc_url="redocumentation") TYPE: Optional[str] DEFAULT: '/redoc' swagger_ui_oauth2_redirect_url The OAuth2 redirect endpoint for the Swagger UI. By default it is /docs/oauth2-redirect. This is only used if you use OAuth2 (with the "Authorize" button) with Swagger UI. TYPE: Optional[str] DEFAULT: '/docs/oauth2-redirect' swagger_ui_init_oauth OAuth2 configuration for the Swagger UI, by default shown at /docs. Read more about the available configuration options in the Swagger UI docs. TYPE: Optional[Dict[str, Any]] DEFAULT: None middleware List of middleware to be added when creating the application. In FastAPI you would normally do this with app.add_middleware() instead. Read more in the FastAPI docs for Middleware. TYPE: Optional[Sequence[Middleware]] DEFAULT: None exception_handlers A dictionary with handlers for exceptions. In FastAPI, you would normally use the decorator @app.exception_handler(). Read more in the FastAPI docs for Handling Errors. TYPE: Optional[Dict[Union[int, Type[Exception]], Callable[[Request, Any], Coroutine[Any, Any, Response]]]] DEFAULT: None on_startup A list of startup event handler functions. You should instead use the lifespan handlers. Read more in the FastAPI docs for lifespan. TYPE: Optional[Sequence[Callable[[], Any]]] DEFAULT: None on_shutdown A list of shutdown event handler functions. You should instead use the lifespan handlers. Read more in the FastAPI docs for lifespan. TYPE: Optional[Sequence[Callable[[], Any]]] DEFAULT: None lifespan A Lifespan context manager handler. This replaces startup and shutdown functions with a single context manager. Read more in the FastAPI docs for lifespan. TYPE: Optional[Lifespan[AppType]] DEFAULT: None terms_of_service A URL to the Terms of Service for your API. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more at the FastAPI docs for Metadata and Docs URLs. Example app = FastAPI(terms_of_service="http://example.com/terms/") TYPE: Optional[str] DEFAULT: None contact A dictionary with the contact information for the exposed API. It can contain several fields. name: (str) The name of the contact person/organization. url: (str) A URL pointing to the contact information. MUST be in the format of a URL. email: (str) The email address of the contact person/organization. MUST be in the format of an email address. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more at the FastAPI docs for Metadata and Docs URLs. Example app = FastAPI( contact={ "name": "Deadpoolio the Amazing", "url": "http://x-force.example.com/contact/", "email": "[e-mail]", } ) TYPE: Optional[Dict[str, Union[str, Any]]] DEFAULT: None license_info A dictionary with the license information for the exposed API. It can contain several fields. name: (str) REQUIRED (if a license_info is set). The license name used for the API. identifier: (str) An SPDX license expression for the API. The identifier field is mutually exclusive of the url field. Available since OpenAPI 3.1.0, FastAPI 0.99.0. url: (str) A URL to the license used for the API. This MUST be the format of a URL. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more at the FastAPI docs for Metadata and Docs URLs. Example app = FastAPI( license_info={ "name": "Apache 2.0", "url": "https://www.apache.org/licenses/LICENSE-2.0.html", } ) TYPE: Optional[Dict[str, Union[str, Any]]] DEFAULT: None openapi_prefix A URL prefix for the OpenAPI URL. TYPE: str DEFAULT: '' root_path A path prefix handled by a proxy that is not seen by the application but is seen by external clients, which affects things like Swagger UI. Read more about it at the FastAPI docs for Behind a Proxy. Example from fastapi import FastAPI app = FastAPI(root_path="/api/v1") TYPE: str DEFAULT: '' root_path_in_servers To disable automatically generating the URLs in the servers field in the autogenerated OpenAPI using the root_path. Read more about it in the FastAPI docs for Behind a Proxy. Example from fastapi import FastAPI app = FastAPI(root_path_in_servers=False) TYPE: bool DEFAULT: True responses Additional responses to be shown in OpenAPI. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Additional Responses in OpenAPI. And in the FastAPI docs for Bigger Applications. TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None callbacks OpenAPI callbacks that should apply to all path operations. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for OpenAPI Callbacks. TYPE: Optional[List[BaseRoute]] DEFAULT: None webhooks Add OpenAPI webhooks. This is similar to callbacks but it doesn't depend on specific path operations. It will be added to the generated OpenAPI (e.g. visible at /docs). Note: This is available since OpenAPI 3.1.0, FastAPI 0.99.0. Read more about it in the FastAPI docs for OpenAPI Webhooks. TYPE: Optional[APIRouter] DEFAULT: None deprecated Mark all path operations as deprecated. You probably don't need it, but it's available. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. TYPE: Optional[bool] DEFAULT: None include_in_schema To include (or not) all the path operations in the generated OpenAPI. You probably don't need it, but it's available. This affects the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Query Parameters and String Validations. TYPE: bool DEFAULT: True swagger_ui_parameters Parameters to configure Swagger UI, the autogenerated interactive API documentation (by default at /docs). Read more about it in the FastAPI docs about how to Configure Swagger UI. TYPE: Optional[Dict[str, Any]] DEFAULT: None generate_unique_id_function Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI. This is particularly useful when automatically generating clients or SDKs for your API. Read more about it in the FastAPI docs about how to Generate Clients. TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id) separate_input_output_schemas Whether to generate separate OpenAPI schemas for request body and response body when the results would be more precise. This is particularly useful when automatically generating clients. For example, if you have a model like: from pydantic import BaseModel class Item(BaseModel): name: str tags: list[str] = [] When Item is used for input, a request body, tags is not required, the client doesn't have to provide it. But when using Item for output, for a response body, tags is always available because it has a default value, even if it's just an empty list. So, the client should be able to always expect it. In this case, there would be two different schemas, one for input and another one for output. TYPE: bool DEFAULT: True openapi_external_docs This field allows you to provide additional external documentation links. If provided, it must be a dictionary containing: description: A brief description of the external documentation. url: The URL pointing to the external documentation. The value MUST be a valid URL format. Example: from fastapi import FastAPI external_docs = { "description": "Detailed API Reference", "url": "https://example.com/api-docs", } app = FastAPI(openapi_external_docs=external_docs) TYPE: Optional[Dict[str, Any]] DEFAULT: None **extra Extra keyword arguments to be stored in the app, not used by FastAPI anywhere. TYPE: Any DEFAULT: {} Source code in fastapi/applications.py 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000def init( self: AppType, *, debug: Annotated[ bool, Doc( """ Boolean indicating if debug tracebacks should be returned on server errors. Read more in the Starlette docs for Applications. """ ), ] = False, routes: Annotated[ Optional[List[BaseRoute]], Doc( """ Note: you probably shouldn't use this parameter, it is inherited from Starlette and supported for compatibility. --- A list of routes to serve incoming HTTP and WebSocket requests. """ ), deprecated( """ You normally wouldn't use this parameter with FastAPI, it is inherited from Starlette and supported for compatibility. In FastAPI, you normally would use the path operation methods, like app.get(), app.post(), etc. """ ), ] = None, title: Annotated[ str, Doc( """ The title of the API. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI(title="ChimichangApp") """ ), ] = "FastAPI", summary: Annotated[ Optional[str], Doc( """ A short summary of the API. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI(summary="Deadpond's favorite app. Nuff said.") """ ), ] = None, description: Annotated[ str, Doc( ''' A description of the API. Supports Markdown (using CommonMark syntax). It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI( description=""" ChimichangApp API helps you do awesome stuff. 🚀 ## Items You can **read items**. ## Users You will be able to: * **Create users** (_not implemented_). * **Read users** (_not implemented_). """ ) ''' ), ] = "", version: Annotated[ str, Doc( """ The version of the API. Note This is the version of your application, not the version of the OpenAPI specification nor the version of FastAPI being used. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI(version="0.0.1") """ ), ] = "0.1.0", openapi_url: Annotated[ Optional[str], Doc( """ The URL where the OpenAPI schema will be served from. If you set it to None, no OpenAPI schema will be served publicly, and the default automatic endpoints /docs and /redoc will also be disabled. Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI(openapi_url="/api/v1/openapi.json") """ ), ] = "/openapi.json", openapi_tags: Annotated[ Optional[List[Dict[str, Any]]], Doc( """ A list of tags used by OpenAPI, these are the same tags you can set in the path operations, like: * @app.get("/users/", tags=["users"]) * @app.get("/items/", tags=["items"]) The order of the tags can be used to specify the order shown in tools like Swagger UI, used in the automatic path /docs. It's not required to specify all the tags used. The tags that are not declared MAY be organized randomly or based on the tools' logic. Each tag name in the list MUST be unique. The value of each item is a dict containing: * name: The name of the tag. * description: A short description of the tag. CommonMark syntax MAY be used for rich text representation. * externalDocs: Additional external documentation for this tag. If provided, it would contain a dict with: * description: A short description of the target documentation. CommonMark syntax MAY be used for rich text representation. * url: The URL for the target documentation. Value MUST be in the form of a URL. Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI tags_metadata = [ { "name": "users", "description": "Operations with users. The **login** logic is also here.", }, { "name": "items", "description": "Manage items. So _fancy_ they have their own docs.", "externalDocs": { "description": "Items external docs", "url": "https://fastapi.tiangolo.com/", }, }, ] app = FastAPI(openapi_tags=tags_metadata) """ ), ] = None, servers: Annotated[ Optional[List[Dict[str, Union[str, Any]]]], Doc( """ A list of dicts with connectivity information to a target server. You would use it, for example, if your application is served from different domains and you want to use the same Swagger UI in the browser to interact with each of them (instead of having multiple browser tabs open). Or if you want to leave fixed the possible URLs. If the servers list is not provided, or is an empty list, the servers property in the generated OpenAPI will be: * a dict with a url value of the application's mounting point (root_path) if it's different from /. * otherwise, the servers property will be omitted from the OpenAPI schema. Each item in the list is a dict containing: * url: A URL to the target host. This URL supports Server Variables and MAY be relative, to indicate that the host location is relative to the location where the OpenAPI document is being served. Variable substitutions will be made when a variable is named in {brackets}. * description: An optional string describing the host designated by the URL. CommonMark syntax MAY be used for rich text representation. * variables: A dict between a variable name and its value. The value is used for substitution in the server's URL template. Read more in the FastAPI docs for Behind a Proxy. Example python from fastapi import FastAPI app = FastAPI( servers=[ {"url": "https://stag.example.com", "description": "Staging environment"}, {"url": "https://prod.example.com", "description": "Production environment"}, ] ) """ ), ] = None, dependencies: Annotated[ Optional[Sequence[Depends]], Doc( """ A list of global dependencies, they will be applied to each path operation, including in sub-routers. Read more about it in the FastAPI docs for Global Dependencies. Example python from fastapi import Depends, FastAPI from .dependencies import func_dep_1, func_dep_2 app = FastAPI(dependencies=[Depends(func_dep_1), Depends(func_dep_2)]) """ ), ] = None, default_response_class: Annotated[ Type[Response], Doc( """ The default response class to be used. Read more in the FastAPI docs for Custom Response - HTML, Stream, File, others. Example python from fastapi import FastAPI from fastapi.responses import ORJSONResponse app = FastAPI(default_response_class=ORJSONResponse) """ ), ] = Default(JSONResponse), redirect_slashes: Annotated[ bool, Doc( """ Whether to detect and redirect slashes in URLs when the client doesn't use the same format. Example python from fastapi import FastAPI app = FastAPI(redirect_slashes=True) # the default @app.get("/items/") async def read_items(): return [{"item_id": "Foo"}] With this app, if a client goes to /items (without a trailing slash), they will be automatically redirected with an HTTP status code of 307 to /items/. """ ), ] = True, docs_url: Annotated[ Optional[str], Doc( """ The path to the automatic interactive API documentation. It is handled in the browser by Swagger UI. The default URL is /docs. You can disable it by setting it to None. If openapi_url is set to None, this will be automatically disabled. Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI(docs_url="/documentation", redoc_url=None) """ ), ] = "/docs", redoc_url: Annotated[ Optional[str], Doc( """ The path to the alternative automatic interactive API documentation provided by ReDoc. The default URL is /redoc. You can disable it by setting it to None. If openapi_url is set to None, this will be automatically disabled. Read more in the FastAPI docs for Metadata and Docs URLs. Example python from fastapi import FastAPI app = FastAPI(docs_url="/documentation", redoc_url="redocumentation") """ ), ] = "/redoc", swagger_ui_oauth2_redirect_url: Annotated[ Optional[str], Doc( """ The OAuth2 redirect endpoint for the Swagger UI. By default it is /docs/oauth2-redirect. This is only used if you use OAuth2 (with the "Authorize" button) with Swagger UI. """ ), ] = "/docs/oauth2-redirect", swagger_ui_init_oauth: Annotated[ Optional[Dict[str, Any]], Doc( """ OAuth2 configuration for the Swagger UI, by default shown at /docs. Read more about the available configuration options in the Swagger UI docs. """ ), ] = None, middleware: Annotated[ Optional[Sequence[Middleware]], Doc( """ List of middleware to be added when creating the application. In FastAPI you would normally do this with app.add_middleware() instead. Read more in the FastAPI docs for Middleware. """ ), ] = None, exception_handlers: Annotated[ Optional[ Dict[ Union[int, Type[Exception]], Callable[[Request, Any], Coroutine[Any, Any, Response]], ] ], Doc( """ A dictionary with handlers for exceptions. In FastAPI, you would normally use the decorator @app.exception_handler(). Read more in the FastAPI docs for Handling Errors. """ ), ] = None, on_startup: Annotated[ Optional[Sequence[Callable[[], Any]]], Doc( """ A list of startup event handler functions. You should instead use the lifespan handlers. Read more in the FastAPI docs for lifespan. """ ), ] = None, on_shutdown: Annotated[ Optional[Sequence[Callable[[], Any]]], Doc( """ A list of shutdown event handler functions. You should instead use the lifespan handlers. Read more in the FastAPI docs for lifespan. """ ), ] = None, lifespan: Annotated[ Optional[Lifespan[AppType]], Doc( """ A Lifespan context manager handler. This replaces startup and shutdown functions with a single context manager. Read more in the FastAPI docs for lifespan. """ ), ] = None, terms_of_service: Annotated[ Optional[str], Doc( """ A URL to the Terms of Service for your API. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more at the FastAPI docs for Metadata and Docs URLs. Example python app = FastAPI(terms_of_service="http://example.com/terms/") """ ), ] = None, contact: Annotated[ Optional[Dict[str, Union[str, Any]]], Doc( """ A dictionary with the contact information for the exposed API. It can contain several fields. * name: (str) The name of the contact person/organization. * url: (str) A URL pointing to the contact information. MUST be in the format of a URL. * email: (str) The email address of the contact person/organization. MUST be in the format of an email address. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more at the FastAPI docs for Metadata and Docs URLs. Example python app = FastAPI( contact={ "name": "Deadpoolio the Amazing", "url": "http://x-force.example.com/contact/", "email": "[e-mail]", } ) """ ), ] = None, license_info: Annotated[ Optional[Dict[str, Union[str, Any]]], Doc( """ A dictionary with the license information for the exposed API. It can contain several fields. * name: (str) REQUIRED (if a license_info is set). The license name used for the API. * identifier: (str) An SPDX license expression for the API. The identifier field is mutually exclusive of the url field. Available since OpenAPI 3.1.0, FastAPI 0.99.0. * url: (str) A URL to the license used for the API. This MUST be the format of a URL. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more at the FastAPI docs for Metadata and Docs URLs. Example python app = FastAPI( license_info={ "name": "Apache 2.0", "url": "https://www.apache.org/licenses/LICENSE-2.0.html", } ) """ ), ] = None, openapi_prefix: Annotated[ str, Doc( """ A URL prefix for the OpenAPI URL. """ ), deprecated( """ "openapi_prefix" has been deprecated in favor of "root_path", which follows more closely the ASGI standard, is simpler, and more automatic. """ ), ] = "", root_path: Annotated[ str, Doc( """ A path prefix handled by a proxy that is not seen by the application but is seen by external clients, which affects things like Swagger UI. Read more about it at the FastAPI docs for Behind a Proxy. Example python from fastapi import FastAPI app = FastAPI(root_path="/api/v1") """ ), ] = "", root_path_in_servers: Annotated[ bool, Doc( """ To disable automatically generating the URLs in the servers field in the autogenerated OpenAPI using the root_path. Read more about it in the FastAPI docs for Behind a Proxy. Example python from fastapi import FastAPI app = FastAPI(root_path_in_servers=False) """ ), ] = True, responses: Annotated[ Optional[Dict[Union[int, str], Dict[str, Any]]], Doc( """ Additional responses to be shown in OpenAPI. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Additional Responses in OpenAPI. And in the FastAPI docs for Bigger Applications. """ ), ] = None, callbacks: Annotated[ Optional[List[BaseRoute]], Doc( """ OpenAPI callbacks that should apply to all path operations. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for OpenAPI Callbacks. """ ), ] = None, webhooks: Annotated[ Optional[routing.APIRouter], Doc( """ Add OpenAPI webhooks. This is similar to callbacks but it doesn't depend on specific path operations. It will be added to the generated OpenAPI (e.g. visible at /docs). Note: This is available since OpenAPI 3.1.0, FastAPI 0.99.0. Read more about it in the FastAPI docs for OpenAPI Webhooks. """ ), ] = None, deprecated: Annotated[ Optional[bool], Doc( """ Mark all path operations as deprecated. You probably don't need it, but it's available. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. """ ), ] = None, include_in_schema: Annotated[ bool, Doc( """ To include (or not) all the path operations in the generated OpenAPI. You probably don't need it, but it's available. This affects the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Query Parameters and String Validations. """ ), ] = True, swagger_ui_parameters: Annotated[ Optional[Dict[str, Any]], Doc( """ Parameters to configure Swagger UI, the autogenerated interactive API documentation (by default at /docs). Read more about it in the FastAPI docs about how to Configure Swagger UI. """ ), ] = None, generate_unique_id_function: Annotated[ Callable[[routing.APIRoute], str], Doc( """ Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI. This is particularly useful when automatically generating clients or SDKs for your API. Read more about it in the FastAPI docs about how to Generate Clients. """ ), ] = Default(generate_unique_id), separate_input_output_schemas: Annotated[ bool, Doc( """ Whether to generate separate OpenAPI schemas for request body and response body when the results would be more precise. This is particularly useful when automatically generating clients. For example, if you have a model like: python from pydantic import BaseModel class Item(BaseModel): name: str tags: list[str] = [] When Item is used for input, a request body, tags is not required, the client doesn't have to provide it. But when using Item for output, for a response body, tags is always available because it has a default value, even if it's just an empty list. So, the client should be able to always expect it. In this case, there would be two different schemas, one for input and another one for output. """ ), ] = True, openapi_external_docs: Annotated[ Optional[Dict[str, Any]], Doc( """ This field allows you to provide additional external documentation links. If provided, it must be a dictionary containing: * description: A brief description of the external documentation. * url: The URL pointing to the external documentation. The value MUST be a valid URL format. Example: python from fastapi import FastAPI external_docs = { "description": "Detailed API Reference", "url": "https://example.com/api-docs", } app = FastAPI(openapi_external_docs=external_docs) """ ), ] = None, **extra: Annotated[ Any, Doc( """ Extra keyword arguments to be stored in the app, not used by FastAPI anywhere. """ ), ], ) -> None: self.debug = debug self.title = title self.summary = summary self.description = description self.version = version self.terms_of_service = terms_of_service self.contact = contact self.license_info = license_info self.openapi_url = openapi_url self.openapi_tags = openapi_tags self.root_path_in_servers = root_path_in_servers self.docs_url = docs_url self.redoc_url = redoc_url self.swagger_ui_oauth2_redirect_url = swagger_ui_oauth2_redirect_url self.swagger_ui_init_oauth = swagger_ui_init_oauth self.swagger_ui_parameters = swagger_ui_parameters self.servers = servers or [] self.separate_input_output_schemas = separate_input_output_schemas self.openapi_external_docs = openapi_external_docs self.extra = extra self.openapi_version: Annotated[ str, Doc( """ The version string of OpenAPI. FastAPI will generate OpenAPI version 3.1.0, and will output that as the OpenAPI version. But some tools, even though they might be compatible with OpenAPI 3.1.0, might not recognize it as a valid. So you could override this value to trick those tools into using the generated OpenAPI. Have in mind that this is a hack. But if you avoid using features added in OpenAPI 3.1.0, it might work for your use case. This is not passed as a parameter to the FastAPI class to avoid giving the false idea that FastAPI would generate a different OpenAPI schema. It is only available as an attribute. Example python from fastapi import FastAPI app = FastAPI() app.openapi_version = "3.0.2" """ ), ] = "3.1.0" self.openapi_schema: Optional[Dict[str, Any]] = None if self.openapi_url: assert self.title, "A title must be provided for OpenAPI, e.g.: 'My API'" assert self.version, "A version must be provided for OpenAPI, e.g.: '2.1.0'" # TODO: remove when discarding the openapi_prefix parameter if openapi_prefix: logger.warning( '"openapi_prefix" has been deprecated in favor of "root_path", which ' "follows more closely the ASGI standard, is simpler, and more " "automatic. Check the docs at " "https://fastapi.tiangolo.com/advanced/sub-applications/" ) self.webhooks: Annotated[ routing.APIRouter, Doc( """ The app.webhooks attribute is an APIRouter with the path operations that will be used just for documentation of webhooks. Read more about it in the FastAPI docs for OpenAPI Webhooks. """ ), ] = webhooks or routing.APIRouter() self.root_path = root_path or openapi_prefix self.state: Annotated[ State, Doc( """ A state object for the application. This is the same object for the entire application, it doesn't change from request to request. You normally wouldn't use this in FastAPI, for most of the cases you would instead use FastAPI dependencies. This is simply inherited from Starlette. Read more about it in the Starlette docs for Applications. """ ), ] = State() self.dependency_overrides: Annotated[ Dict[Callable[..., Any], Callable[..., Any]], Doc( """ A dictionary with overrides for the dependencies. Each key is the original dependency callable, and the value is the actual dependency that should be called. This is for testing, to replace expensive dependencies with testing versions. Read more about it in the FastAPI docs for Testing Dependencies with Overrides. """ ), ] = {} self.router: routing.APIRouter = routing.APIRouter( routes=routes, redirect_slashes=redirect_slashes, dependency_overrides_provider=self, on_startup=on_startup, on_shutdown=on_shutdown, lifespan=lifespan, default_response_class=default_response_class, dependencies=dependencies, callbacks=callbacks, deprecated=deprecated, include_in_schema=include_in_schema, responses=responses, generate_unique_id_function=generate_unique_id_function, ) self.exception_handlers: Dict[ Any, Callable[[Request, Any], Union[Response, Awaitable[Response]]] ] = {} if exception_handlers is None else dict(exception_handlers) self.exception_handlers.setdefault(HTTPException, http_exception_handler) self.exception_handlers.setdefault( RequestValidationError, request_validation_exception_handler ) self.exception_handlers.setdefault( WebSocketRequestValidationError, # Starlette still has incorrect type specification for the handlers websocket_request_validation_exception_handler, # type: ignore ) self.user_middleware: List[Middleware] = ( [] if middleware is None else list(middleware) ) self.middleware_stack: Union[ASGIApp, None] = None self.setup() openapi_version instance-attribute ¶ openapi_version = '3.1.0' The version string of OpenAPI. FastAPI will generate OpenAPI version 3.1.0, and will output that as the OpenAPI version. But some tools, even though they might be compatible with OpenAPI 3.1.0, might not recognize it as a valid. So you could override this value to trick those tools into using the generated OpenAPI. Have in mind that this is a hack. But if you avoid using features added in OpenAPI 3.1.0, it might work for your use case. This is not passed as a parameter to the FastAPI class to avoid giving the false idea that FastAPI would generate a different OpenAPI schema. It is only available as an attribute. Example from fastapi import FastAPI app = FastAPI() app.openapi_version = "3.0.2" webhooks instance-attribute ¶ webhooks = webhooks or APIRouter() The app.webhooks attribute is an APIRouter with the path operations that will be used just for documentation of webhooks. Read more about it in the FastAPI docs for OpenAPI Webhooks. state instance-attribute ¶ state = State() A state object for the application. This is the same object for the entire application, it doesn't change from request to request. You normally wouldn't use this in FastAPI, for most of the cases you would instead use FastAPI dependencies. This is simply inherited from Starlette. Read more about it in the Starlette docs for Applications. dependency_overrides instance-attribute ¶ dependency_overrides = {} A dictionary with overrides for the dependencies. Each key is the original dependency callable, and the value is the actual dependency that should be called. This is for testing, to replace expensive dependencies with testing versions. Read more about it in the FastAPI docs for Testing Dependencies with Overrides. openapi ¶ openapi() Generate the OpenAPI schema of the application. This is called by FastAPI internally. The first time it is called it stores the result in the attribute app.openapi_schema, and next times it is called, it just returns that same result. To avoid the cost of generating the schema every time. If you need to modify the generated OpenAPI schema, you could modify it. Read more in the FastAPI docs for OpenAPI. Source code in fastapi/applications.py 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081def openapi(self) -> Dict[str, Any]: """ Generate the OpenAPI schema of the application. This is called by FastAPI internally. The first time it is called it stores the result in the attribute app.openapi_schema, and next times it is called, it just returns that same result. To avoid the cost of generating the schema every time. If you need to modify the generated OpenAPI schema, you could modify it. Read more in the FastAPI docs for OpenAPI. """ if not self.openapi_schema: self.openapi_schema = get_openapi( title=self.title, version=self.version, openapi_version=self.openapi_version, summary=self.summary, description=self.description, terms_of_service=self.terms_of_service, contact=self.contact, license_info=self.license_info, routes=self.routes, webhooks=self.webhooks.routes, tags=self.openapi_tags, servers=self.servers, separate_input_output_schemas=self.separate_input_output_schemas, external_docs=self.openapi_external_docs, ) return self.openapi_schema websocket ¶ websocket(path, name=None, *, dependencies=None) Decorate a WebSocket function. Read more about it in the FastAPI docs for WebSockets. Example from fastapi import FastAPI, WebSocket app = FastAPI() @app.websocket("/ws") async def websocket_endpoint(websocket: WebSocket): await websocket.accept() while True: data = await websocket.receive_text() await websocket.send_text(f"Message text was: {data}") PARAMETER DESCRIPTION path WebSocket path. TYPE: str name A name for the WebSocket. Only used internally. TYPE: Optional[str] DEFAULT: None dependencies A list of dependencies (using Depends()) to be used for this WebSocket. Read more about it in the FastAPI docs for WebSockets. TYPE: Optional[Sequence[Depends]] DEFAULT: None Source code in fastapi/applications.py 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338def websocket( self, path: Annotated[ str, Doc( """ WebSocket path. """ ), ], name: Annotated[ Optional[str], Doc( """ A name for the WebSocket. Only used internally. """ ), ] = None, *, dependencies: Annotated[ Optional[Sequence[Depends]], Doc( """ A list of dependencies (using Depends()) to be used for this WebSocket. Read more about it in the FastAPI docs for WebSockets. """ ), ] = None, ) -> Callable[[DecoratedCallable], DecoratedCallable]: """ Decorate a WebSocket function. Read more about it in the FastAPI docs for WebSockets. Example python from fastapi import FastAPI, WebSocket app = FastAPI() @app.websocket("/ws") async def websocket_endpoint(websocket: WebSocket): await websocket.accept() while True: data = await websocket.receive_text() await websocket.send_text(f"Message text was: {data}") """ def decorator(func: DecoratedCallable) -> DecoratedCallable: self.add_api_websocket_route( path, func, name=name, dependencies=dependencies, ) return func return decorator include_router ¶ include_router( router, *, prefix="", tags=None, dependencies=None, responses=None, deprecated=None, include_in_schema=True, default_response_class=Default(JSONResponse), callbacks=None, generate_unique_id_function=Default(generate_unique_id) ) Include an APIRouter in the same app. Read more about it in the FastAPI docs for Bigger Applications. Example¶ from fastapi import FastAPI from .users import users_router app = FastAPI() app.include_router(users_router) PARAMETER DESCRIPTION router The APIRouter to include. TYPE: APIRouter prefix An optional path prefix for the router. TYPE: str DEFAULT: '' tags A list of tags to be applied to all the path operations in this router. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None dependencies A list of dependencies (using Depends()) to be applied to all the path operations in this router. Read more about it in the FastAPI docs for Bigger Applications - Multiple Files. Example from fastapi import Depends, FastAPI from .dependencies import get_token_header from .internal import admin app = FastAPI() app.include_router( admin.router, dependencies=[Depends(get_token_header)], ) TYPE: Optional[Sequence[Depends]] DEFAULT: None responses Additional responses to be shown in OpenAPI. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Additional Responses in OpenAPI. And in the FastAPI docs for Bigger Applications. TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None deprecated Mark all the path operations in this router as deprecated. It will be added to the generated OpenAPI (e.g. visible at /docs). Example from fastapi import FastAPI from .internal import old_api app = FastAPI() app.include_router( old_api.router, deprecated=True, ) TYPE: Optional[bool] DEFAULT: None include_in_schema Include (or not) all the path operations in this router in the generated OpenAPI schema. This affects the generated OpenAPI (e.g. visible at /docs). Example from fastapi import FastAPI from .internal import old_api app = FastAPI() app.include_router( old_api.router, include_in_schema=False, ) TYPE: bool DEFAULT: True default_response_class Default response class to be used for the path operations in this router. Read more in the FastAPI docs for Custom Response - HTML, Stream, File, others. Example from fastapi import FastAPI from fastapi.responses import ORJSONResponse from .internal import old_api app = FastAPI() app.include_router( old_api.router, default_response_class=ORJSONResponse, ) TYPE: Type[Response] DEFAULT: Default(JSONResponse) callbacks List of path operations that will be used as OpenAPI callbacks. This is only for OpenAPI documentation, the callbacks won't be used directly. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for OpenAPI Callbacks. TYPE: Optional[List[BaseRoute]] DEFAULT: None generate_unique_id_function Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI. This is particularly useful when automatically generating clients or SDKs for your API. Read more about it in the FastAPI docs about how to Generate Clients. TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id) Source code in fastapi/applications.py 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543def include_router( self, router: Annotated[routing.APIRouter, Doc("The APIRouter to include.")], *, prefix: Annotated[str, Doc("An optional path prefix for the router.")] = "", tags: Annotated[ Optional[List[Union[str, Enum]]], Doc( """ A list of tags to be applied to all the path operations in this router. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. """ ), ] = None, dependencies: Annotated[ Optional[Sequence[Depends]], Doc( """ A list of dependencies (using Depends()) to be applied to all the path operations in this router. Read more about it in the FastAPI docs for Bigger Applications - Multiple Files. Example python from fastapi import Depends, FastAPI from .dependencies import get_token_header from .internal import admin app = FastAPI() app.include_router( admin.router, dependencies=[Depends(get_token_header)], ) """ ), ] = None, responses: Annotated[ Optional[Dict[Union[int, str], Dict[str, Any]]], Doc( """ Additional responses to be shown in OpenAPI. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Additional Responses in OpenAPI. And in the FastAPI docs for Bigger Applications. """ ), ] = None, deprecated: Annotated[ Optional[bool], Doc( """ Mark all the path operations in this router as deprecated. It will be added to the generated OpenAPI (e.g. visible at /docs). Example python from fastapi import FastAPI from .internal import old_api app = FastAPI() app.include_router( old_api.router, deprecated=True, ) """ ), ] = None, include_in_schema: Annotated[ bool, Doc( """ Include (or not) all the path operations in this router in the generated OpenAPI schema. This affects the generated OpenAPI (e.g. visible at /docs). Example python from fastapi import FastAPI from .internal import old_api app = FastAPI() app.include_router( old_api.router, include_in_schema=False, ) """ ), ] = True, default_response_class: Annotated[ Type[Response], Doc( """ Default response class to be used for the path operations in this router. Read more in the FastAPI docs for Custom Response - HTML, Stream, File, others. Example python from fastapi import FastAPI from fastapi.responses import ORJSONResponse from .internal import old_api app = FastAPI() app.include_router( old_api.router, default_response_class=ORJSONResponse, ) """ ), ] = Default(JSONResponse), callbacks: Annotated[ Optional[List[BaseRoute]], Doc( """ List of path operations that will be used as OpenAPI callbacks. This is only for OpenAPI documentation, the callbacks won't be used directly. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for OpenAPI Callbacks. """ ), ] = None, generate_unique_id_function: Annotated[ Callable[[routing.APIRoute], str], Doc( """ Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI. This is particularly useful when automatically generating clients or SDKs for your API. Read more about it in the FastAPI docs about how to Generate Clients. """ ), ] = Default(generate_unique_id), ) -> None: """ Include an APIRouter in the same app. Read more about it in the FastAPI docs for Bigger Applications. ## Example python from fastapi import FastAPI from .users import users_router app = FastAPI() app.include_router(users_router) """ self.router.include_router( router, prefix=prefix, tags=tags, dependencies=dependencies, responses=responses, deprecated=deprecated, include_in_schema=include_in_schema, default_response_class=default_response_class, callbacks=callbacks, generate_unique_id_function=generate_unique_id_function, ) get ¶ get( path, *, response_model=Default(None), status_code=None, tags=None, dependencies=None, summary=None, description=None, response_description="Successful Response", responses=None, deprecated=None, operation_id=None, response_model_include=None, response_model_exclude=None, response_model_by_alias=True, response_model_exclude_unset=False, response_model_exclude_defaults=False, response_model_exclude_none=False, include_in_schema=True, response_class=Default(JSONResponse), name=None, callbacks=None, openapi_extra=None, generate_unique_id_function=Default(generate_unique_id) ) Add a path operation using an HTTP GET operation. Example¶ from fastapi import FastAPI app = FastAPI() @app.get("/items/") def read_items(): return [{"name": "Empanada"}, {"name": "Arepa"}] PARAMETER DESCRIPTION path The URL path to be used for this path operation. For example, in http://example.com/items, the path is /items. TYPE: str response_model The type to use for the response. It could be any valid Pydantic field type. So, it doesn't have to be a Pydantic model, it could be other things, like a list, dict, etc. It will be used for: Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema). Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON. Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password. Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it's an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error). Read more about it in the FastAPI docs for Response Model. TYPE: Any DEFAULT: Default(None) status_code The default status code to be used for the response. You could override the status code by returning a response directly. Read more about it in the FastAPI docs for Response Status Code. TYPE: Optional[int] DEFAULT: None tags A list of tags to be applied to the path operation. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None dependencies A list of dependencies (using Depends()) to be applied to the path operation. Read more about it in the FastAPI docs for Dependencies in path operation decorators. TYPE: Optional[Sequence[Depends]] DEFAULT: None summary A summary for the path operation. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. TYPE: Optional[str] DEFAULT: None description A description for the path operation. If not provided, it will be extracted automatically from the docstring of the path operation function. It can contain Markdown. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. TYPE: Optional[str] DEFAULT: None response_description The description for the default response. It will be added to the generated OpenAPI (e.g. visible at /docs). TYPE: str DEFAULT: 'Successful Response' responses Additional responses that could be returned by this path operation. It will be added to the generated OpenAPI (e.g. visible at /docs). TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None deprecated Mark this path operation as deprecated. It will be added to the generated OpenAPI (e.g. visible at /docs). TYPE: Optional[bool] DEFAULT: None operation_id Custom operation ID to be used by this path operation. By default, it is generated automatically. If you provide a custom operation ID, you need to make sure it is unique for the whole API. You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class. Read more about it in the FastAPI docs about how to Generate Clients. TYPE: Optional[str] DEFAULT: None response_model_include Configuration passed to Pydantic to include only certain fields in the response data. Read more about it in the FastAPI docs for Response Model - Return Type. TYPE: Optional[IncEx] DEFAULT: None response_model_exclude Configuration passed to Pydantic to exclude certain fields in the response data. Read more about it in the FastAPI docs for Response Model - Return Type. TYPE: Optional[IncEx] DEFAULT: None response_model_by_alias Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used. Read more about it in the FastAPI docs for Response Model - Return Type. TYPE: bool DEFAULT: True response_model_exclude_unset Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default. When True, default values are omitted from the response. Read more about it in the FastAPI docs for Response Model - Return Type. TYPE: bool DEFAULT: False response_model_exclude_defaults Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response. When True, default values are omitted from the response. Read more about it in the FastAPI docs for Response Model - Return Type. TYPE: bool DEFAULT: False response_model_exclude_none Configuration passed to Pydantic to define if the response data should exclude fields set to None. This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense. Read more about it in the FastAPI docs for Response Model - Return Type. TYPE: bool DEFAULT: False include_in_schema Include this path operation in the generated OpenAPI schema. This affects the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Query Parameters and String Validations. TYPE: bool DEFAULT: True response_class Response class to be used for this path operation. This will not be used if you return a response directly. Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others. TYPE: Type[Response] DEFAULT: Default(JSONResponse) name Name for this path operation. Only used internally. TYPE: Optional[str] DEFAULT: None callbacks List of path operations that will be used as OpenAPI callbacks. This is only for OpenAPI documentation, the callbacks won't be used directly. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for OpenAPI Callbacks. TYPE: Optional[List[BaseRoute]] DEFAULT: None openapi_extra Extra metadata to be included in the OpenAPI schema for this path operation. Read more about it in the FastAPI docs for Path Operation Advanced Configuration. TYPE: Optional[Dict[str, Any]] DEFAULT: None generate_unique_id_function Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI. This is particularly useful when automatically generating clients or SDKs for your API. Read more about it in the FastAPI docs about how to Generate Clients. TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id) Source code in fastapi/applications.py 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916def get( self, path: Annotated[ str, Doc( """ The URL path to be used for this path operation. For example, in http://example.com/items, the path is /items. """ ), ], *, response_model: Annotated[ Any, Doc( """ The type to use for the response. It could be any valid Pydantic field type. So, it doesn't have to be a Pydantic model, it could be other things, like a list, dict, etc. It will be used for: * Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema). * Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON. * Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password. * Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it's an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error). Read more about it in the FastAPI docs for Response Model. """ ), ] = Default(None), status_code: Annotated[ Optional[int], Doc( """ The default status code to be used for the response. You could override the status code by returning a response directly. Read more about it in the FastAPI docs for Response Status Code. """ ), ] = None, tags: Annotated[ Optional[List[Union[str, Enum]]], Doc( """ A list of tags to be applied to the path operation. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. """ ), ] = None, dependencies: Annotated[ Optional[Sequence[Depends]], Doc( """ A list of dependencies (using Depends()) to be applied to the path operation. Read more about it in the FastAPI docs for Dependencies in path operation decorators. """ ), ] = None, summary: Annotated[ Optional[str], Doc( """ A summary for the path operation. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. """ ), ] = None, description: Annotated[ Optional[str], Doc( """ A description for the path operation. If not provided, it will be extracted automatically from the docstring of the path operation function. It can contain Markdown. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Path Operation Configuration. """ ), ] = None, response_description: Annotated[ str, Doc( """ The description for the default response. It will be added to the generated OpenAPI (e.g. visible at /docs). """ ), ] = "Successful Response", responses: Annotated[ Optional[Dict[Union[int, str], Dict[str, Any]]], Doc( """ Additional responses that could be returned by this path operation. It will be added to the generated OpenAPI (e.g. visible at /docs). """ ), ] = None, deprecated: Annotated[ Optional[bool], Doc( """ Mark this path operation as deprecated. It will be added to the generated OpenAPI (e.g. visible at /docs). """ ), ] = None, operation_id: Annotated[ Optional[str], Doc( """ Custom operation ID to be used by this path operation. By default, it is generated automatically. If you provide a custom operation ID, you need to make sure it is unique for the whole API. You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class. Read more about it in the FastAPI docs about how to Generate Clients. """ ), ] = None, response_model_include: Annotated[ Optional[IncEx], Doc( """ Configuration passed to Pydantic to include only certain fields in the response data. Read more about it in the FastAPI docs for Response Model - Return Type. """ ), ] = None, response_model_exclude: Annotated[ Optional[IncEx], Doc( """ Configuration passed to Pydantic to exclude certain fields in the response data. Read more about it in the FastAPI docs for Response Model - Return Type. """ ), ] = None, response_model_by_alias: Annotated[ bool, Doc( """ Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used. Read more about it in the FastAPI docs for Response Model - Return Type. """ ), ] = True, response_model_exclude_unset: Annotated[ bool, Doc( """ Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default. When True, default values are omitted from the response. Read more about it in the FastAPI docs for Response Model - Return Type. """ ), ] = False, response_model_exclude_defaults: Annotated[ bool, Doc( """ Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response. When True, default values are omitted from the response. Read more about it in the FastAPI docs for Response Model - Return Type. """ ), ] = False, response_model_exclude_none: Annotated[ bool, Doc( """ Configuration passed to Pydantic to define if the response data should exclude fields set to None. This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense. Read more about it in the FastAPI docs for Response Model - Return Type. """ ), ] = False, include_in_schema: Annotated[ bool, Doc( """ Include this path operation in the generated OpenAPI schema. This affects the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for Query Parameters and String Validations. """ ), ] = True, response_class: Annotated[ Type[Response], Doc( """ Response class to be used for this path operation. This will not be used if you return a response directly. Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others. """ ), ] = Default(JSONResponse), name: Annotated[ Optional[str], Doc( """ Name for this path operation. Only used internally. """ ), ] = None, callbacks: Annotated[ Optional[List[BaseRoute]], Doc( """ List of path operations that will be used as OpenAPI callbacks. This is only for OpenAPI documentation, the callbacks won't be used directly. It will be added to the generated OpenAPI (e.g. visible at /docs). Read more about it in the FastAPI docs for OpenAPI Callbacks. """ ), ] = None, openapi_extra: Annotated[ Optional[Dict[str, Any]], Doc( """ Extra metadata to be included in the OpenAPI schema for this path operation. Read more about it in the FastAPI docs for Path Operation Advanced Configuration. """ ), ] = None, generate_unique_id_function: Annotated[ Callable[[routing.APIRoute], str], Doc( """ Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI. This is particularly useful when automatically generating clients or SDKs for your API. Read more about it in the FastAPI docs about how to Generate Clients. """ ), ] = Default(generate_unique_id), ) -> Callable[[DecoratedCallable], DecoratedCallable]: """ Add a path operation using an HTTP GET operation. ## Example python from fastapi import FastAPI app = FastAPI() @app.get("/items/") def read_items(): return [{"name": "Empanada"}, {"name": "Arepa"}] """ return self.router.get( path, response_model=response_model, status_code=status_code, tags=tags, dependencies=dependencies, summary=summary, description=description, response_description=response_description, responses=responses, deprecated=deprecated, operation_id=operation_id, response_model_include=response_model_include, response_model_exclude=response_model_exclude, response_model_by_alias=response_model_by_alias, response_model_exclude_unset=response_model_exclude_unset, response_model_exclude_defaults=response_model_exclude_defaults, response_model_exclude_none=response_model_exclude_none, include_in_schema=include_in_schema, response_class=response_class, name=name, callbacks=callbacks, openapi_extra=openapi_extra, generate_unique_id_function=generate_unique_id_function, ) put ¶ put( path, *, response_model=Default(None), status_code=None, tags=None, dependencies=None, summary=None, description=None, response_description="Successful Response", responses=None, deprecated=None, operation_id=None, response_model_include=None, response_model_exclude=None, response_model_by_alias=True, response_model_exclude_unset=False, response_model_exclude_defaults=False, response_model_exclude_none=False, include_in_schema=True, response_class=Default(JSONResponse), name=None, callbacks=None, openapi_extra=None, generate_unique_id_function=Default(generate_unique_id) ) Add a path operation using an HTTP PUT operation. Example¶ from fastapi import FastAPI from pydantic import BaseModel class Item(BaseModel): name: str description: str | None = None app = FastAPI() @app.put("/items/{item_id}") def replace_item(item_id: str, item: Item): return {"message": "Item replaced", "id": item_id} PARAMETER DESCRIPTION path The URL path to be used for this path operation. For example, in http://example.com/items, the path is /items. TYPE: str response_model The type to use for the response. It could be any valid Pydantic field type. So, it doesn't have to be a Pydantic model, it could be other things, like a list, dict, etc. It will be used for: Documentation: the generated OpenAPI (and the UI at /d