Returning redirects¶

We support returning redirects from API endpoints with APIRedirectError exception:

views.py¶

from http import HTTPStatus
from typing import Final

from django.http import HttpResponse

from dmr import APIRedirectError, Controller, HeaderSpec, modify, validate
from dmr.metadata import ResponseSpec
from dmr.plugins.pydantic import PydanticSerializer

_RedirectSpec: Final = ResponseSpec(
    None,
    status_code=HTTPStatus.FOUND,
    headers={'Location': HeaderSpec()},
)


class UserController(Controller[PydanticSerializer]):
    @validate(_RedirectSpec)
    def get(self) -> HttpResponse:
        raise APIRedirectError('https://example.com/api/new/user/list')

    @modify(extra_responses=[_RedirectSpec])
    def post(self) -> dict[str, str]:
        raise APIRedirectError('https://example.com/api/new/user/create')

Run result

$ curl http://127.0.0.1:8000/api/user/ -D - -X GET
HTTP/1.1 302 Found
date: Sun, 05 Apr 2026 17:51:42 GMT
server: uvicorn
Location: https://example.com/api/new/user/list
Content-Type: application/json
X-Frame-Options: DENY
Vary: Accept-Language
Content-Language: en
Content-Length: 0
X-Content-Type-Options: nosniff
Referrer-Policy: same-origin
Cross-Origin-Opener-Policy: same-origin


$ curl http://127.0.0.1:8000/api/user/ -D - -X POST
HTTP/1.1 302 Found
date: Sun, 05 Apr 2026 17:51:42 GMT
server: uvicorn
Location: https://example.com/api/new/user/create
Content-Type: application/json
X-Frame-Options: DENY
Vary: Accept-Language
Content-Language: en
Content-Length: 0
X-Content-Type-Options: nosniff
Referrer-Policy: same-origin
Cross-Origin-Opener-Policy: same-origin

OpenAPI Schema

Preview openapi.json

{
  "components": {
    "schemas": {
      "ErrorDetail": {
        "description": "Base schema for error details description.",
        "properties": {
          "loc": {
            "items": {
              "anyOf": [
                {
                  "type": "integer"
                },
                {
                  "type": "string"
                }
              ]
            },
            "title": "Loc",
            "type": "array"
          },
          "msg": {
            "title": "Msg",
            "type": "string"
          },
          "type": {
            "title": "Type",
            "type": "string"
          }
        },
        "required": [
          "msg"
        ],
        "title": "ErrorDetail",
        "type": "object"
      },
      "ErrorModel": {
        "description": "Default error response schema.\n\nCan be customized.\nSee :ref:`customizing-error-messages` for more details.",
        "properties": {
          "detail": {
            "items": {
              "$ref": "#/components/schemas/ErrorDetail"
            },
            "title": "Detail",
            "type": "array"
          }
        },
        "required": [
          "detail"
        ],
        "title": "ErrorModel",
        "type": "object"
      }
    },
    "securitySchemes": {}
  },
  "info": {
    "title": "Django Modern Rest",
    "version": "0.1.0"
  },
  "openapi": "3.2.0",
  "paths": {
    "/api/usercontroller/": {
      "get": {
        "deprecated": false,
        "operationId": "getUsercontrollerApiUsercontroller",
        "responses": {
          "302": {
            "content": {
              "application/json": {
                "schema": {
                  "type": "null"
                }
              }
            },
            "description": "Found",
            "headers": {
              "Location": {
                "required": true,
                "schema": {
                  "type": "string"
                }
              }
            }
          },
          "406": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ErrorModel"
                }
              }
            },
            "description": "Raised when provided `Accept` header cannot be satisfied"
          },
          "422": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ErrorModel"
                }
              }
            },
            "description": "Raised when returned response does not match the response schema"
          }
        }
      },
      "post": {
        "deprecated": false,
        "operationId": "postUsercontrollerApiUsercontroller",
        "responses": {
          "201": {
            "content": {
              "application/json": {
                "schema": {
                  "additionalProperties": {
                    "type": "string"
                  },
                  "type": "object"
                }
              }
            },
            "description": "Created"
          },
          "302": {
            "content": {
              "application/json": {
                "schema": {
                  "type": "null"
                }
              }
            },
            "description": "Found",
            "headers": {
              "Location": {
                "required": true,
                "schema": {
                  "type": "string"
                }
              }
            }
          },
          "406": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ErrorModel"
                }
              }
            },
            "description": "Raised when provided `Accept` header cannot be satisfied"
          },
          "422": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ErrorModel"
                }
              }
            },
            "description": "Raised when returned response does not match the response schema"
          }
        }
      }
    }
  }
}

Note

APIError does not support 3xx status codes. Redirects are different from regular errors.

The second way is to use default Django’s django.http.HttpResponseRedirect:

views.py¶

[source]

from http import HTTPStatus

from django.http import HttpResponse, HttpResponseRedirect

from dmr import Controller, HeaderSpec, validate
from dmr.metadata import ResponseSpec
from dmr.plugins.pydantic import PydanticSerializer


class UserController(Controller[PydanticSerializer]):
    @validate(
        ResponseSpec(
            None,
            status_code=HTTPStatus.FOUND,
            headers={'Location': HeaderSpec()},
        ),
    )
    def get(self) -> HttpResponse:
        return HttpResponseRedirect(
            'https://example.com/api/new/user/list',
            content_type='application/json',
        )

Run result

$ curl http://127.0.0.1:8000/api/user/ -D - -X GET
HTTP/1.1 302 Found
date: Sun, 05 Apr 2026 17:51:42 GMT
server: uvicorn
Content-Type: application/json
Location: https://example.com/api/new/user/list
X-Frame-Options: DENY
Vary: Accept-Language
Content-Language: en
Content-Length: 0
X-Content-Type-Options: nosniff
Referrer-Policy: same-origin
Cross-Origin-Opener-Policy: same-origin

OpenAPI Schema

Preview openapi.json

{
  "components": {
    "schemas": {
      "ErrorDetail": {
        "description": "Base schema for error details description.",
        "properties": {
          "loc": {
            "items": {
              "anyOf": [
                {
                  "type": "integer"
                },
                {
                  "type": "string"
                }
              ]
            },
            "title": "Loc",
            "type": "array"
          },
          "msg": {
            "title": "Msg",
            "type": "string"
          },
          "type": {
            "title": "Type",
            "type": "string"
          }
        },
        "required": [
          "msg"
        ],
        "title": "ErrorDetail",
        "type": "object"
      },
      "ErrorModel": {
        "description": "Default error response schema.\n\nCan be customized.\nSee :ref:`customizing-error-messages` for more details.",
        "properties": {
          "detail": {
            "items": {
              "$ref": "#/components/schemas/ErrorDetail"
            },
            "title": "Detail",
            "type": "array"
          }
        },
        "required": [
          "detail"
        ],
        "title": "ErrorModel",
        "type": "object"
      }
    },
    "securitySchemes": {}
  },
  "info": {
    "title": "Django Modern Rest",
    "version": "0.1.0"
  },
  "openapi": "3.2.0",
  "paths": {
    "/api/usercontroller/": {
      "get": {
        "deprecated": false,
        "operationId": "getUsercontrollerApiUsercontroller",
        "responses": {
          "302": {
            "content": {
              "application/json": {
                "schema": {
                  "type": "null"
                }
              }
            },
            "description": "Found",
            "headers": {
              "Location": {
                "required": true,
                "schema": {
                  "type": "string"
                }
              }
            }
          },
          "406": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ErrorModel"
                }
              }
            },
            "description": "Raised when provided `Accept` header cannot be satisfied"
          },
          "422": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ErrorModel"
                }
              }
            },
            "description": "Raised when returned response does not match the response schema"
          }
        }
      }
    }
  }
}

Note that in both cases you would need to document Location header in a response spec.

API Reference¶

exception dmr.response.APIRedirectError(redirect_to: _StrOrPromise, *, status_code: HTTPStatus = HTTPStatus.FOUND, headers: dict[str, str] | None = None)[source]¶

Special class to fast return redirects from API.

We model this class closely to match django.http.HttpResponseRedirect.

Usage:

>>> from http import HTTPStatus
>>> from dmr import (
...     APIRedirectError,
...     Controller,
...     ResponseSpec,
...     modify,
...     HeaderSpec,
... )
>>> from dmr.errors import ErrorType
>>> from dmr.plugins.pydantic import PydanticSerializer

>>> class UserController(Controller[PydanticSerializer]):
...     @modify(
...         extra_responses=[
...             ResponseSpec(
...                 None,
...                 status_code=HTTPStatus.FOUND,
...                 headers={'Location': HeaderSpec()},
...             ),
...         ],
...     )
...     def get(self) -> str:
...         # This API endpoint is deprecated, use new one:
...         raise APIRedirectError(
...             '/api/new/users/',
...             status_code=HTTPStatus.FOUND,
...         )