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September 15, 2025 02:36
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Automatic browser reloading in FastAPI
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| import os | |
| import arel | |
| from fastapi import FastAPI, Request | |
| from fastapi.templating import Jinja2Templates | |
| app = FastAPI() | |
| templates = Jinja2Templates("templates") | |
| if _debug := os.getenv("DEBUG"): | |
| hot_reload = arel.HotReload(paths=[arel.Path(".")]) | |
| app.add_websocket_route("/hot-reload", route=hot_reload, name="hot-reload") | |
| app.add_event_handler("startup", hot_reload.startup) | |
| app.add_event_handler("shutdown", hot_reload.shutdown) | |
| templates.env.globals["DEBUG"] = _debug | |
| templates.env.globals["hot_reload"] = hot_reload | |
| @app.get("/") | |
| def index(request: Request): | |
| return templates.TemplateResponse("index.html", context={"request": request}) | |
| # run: | |
| # DEBUG=true uvicorn main:app --reload |
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| fastapi | |
| uvicorn[standard] | |
| arel | |
| jinja2 |
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| <body> | |
| {% block content %}{% endblock %} | |
| <!-- Hot reload script --> | |
| {% if DEBUG %} {{ hot_reload.script(url_for('hot-reload')) | safe }} {% endif | |
| %} | |
| </body> |
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| {% extends "base.html" %} {% block content %} Hello, world! {% endblock %} |
Author
@dicolasi Please share your code 😊
Author
@thisisthemurph I don't understand exactly your setup. Can you share a minimal reproducible example of what you're saying?
It works in Safari (Version 17.2 (19617.1.17.11.9)) just fine.
Author
It works in Safari (Version 17.2 (19617.1.17.11.9)) just fine.
@yanky2000 Just tested it in Safari 17.1—it also works. Removed the comment, thanks.
thx 👍
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This works for me, but only on the routes defined within the main file where
appis defined. Any ideas on how to get this to work on other routes? I have separate routes defined within aroutersdirectory and then apply them in the main file withapp.include_router(my_router).