Add @endpoint decorator for ModelAdmin custom FastAPI routes

[borhanst]

Overview

Create a new @endpoint decorator for ModelAdmin classes that adds custom FastAPI routes with full configuration support, similar to the existing @action decorator but for arbitrary API endpoints.

Problem

Currently, there's no standardized way to add custom FastAPI endpoints to the admin panel beyond the @action decorator (which only supports list/row/detail actions) or manually adding routes. Users need a decorator that can register arbitrary @app.router.add_api_route() endpoints on registered models.

Use Cases

1. Custom health check endpoints
2. Custom export/import APIs
3. Custom status/monitoring endpoints
4. Any arbitrary JSON API endpoint within the admin prefix

Proposed Solution

Implement an @endpoint decorator in fastapi_admin_kit/admin/decorators.py that:

• Stores endpoint configuration on the decorated method as _admin_endpoint attribute
• Automatically discovers and registers routes in build_model_router() via router.add_api_route()
• Supports all FastAPI add_api_route parameters: path, methods, tags, dependencies, status_code, response_model, etc.
• Integrates with existing RBAC via FastAPI dependencies
• Is fully backward compatible

Decorator API

from fastapi_admin_kit.admin.decorators import endpoint

class ProductAdmin(ModelAdmin):
    @endpoint(
        path="/health-check",
        methods=["GET"],
        tags=["monitoring"],
        description="Health check endpoint",
        permission="can_view",
    )
    async def health_check(self, request):
        return {"status": "healthy"}

Supported Parameters

Param	Type	Required	Default
path	str	Yes	-
methods	list[str]	No	["GET"]
tags	list[str]	No	[]
description	str	No	""
name	str	No	auto-generated
dependencies	list[Any]	No	[]
status_code	int	No	200
response_model	Type[BaseModel]	No	None
summary	str	No	""
response_description	str	No	""

Router Changes

Modify fastapi_admin_kit/router.py::build_model_router() to iterate admin methods, check for _admin_endpoint, and register routes.

Backward Compatibility

• Fully additive - doesn't break existing @action, @column, etc.
• New endpoints opt-in via decoration
• Existing models/routes continue to work unchanged

Example Usage

# Simple endpoint
@endpoint(path="/health", methods=["GET"])
async def health_check(self, request):
    return {"status": "ok"}

# With permissions
@endpoint(
    path="/stats",
    dependencies=[Depends(require_permission("products", "view"))],
)
async def stats(self, request):
    pass

Labels

enhancement, feature-request, admin