Using pyinstrument to profile Air apps

"Air is built on FastAPI, so we could use [pyinstrument's instructions](https://pyinstrument.readthedocs.io/en/latest/guide.html#profile-a-web-request-in-fastapi) modified. However, because profilers reveal a LOT of internal data, in our example we actively use an environment variable. You will need both `air` and `pyinstrument` to get this working: ```sh # preferred uv add "air[standard]" pyinstrument # old school pip install "air[standard]" pyinstrument ```"

"import asyncio from os import getenv import air from pyinstrument import Profiler app = air.Air() # Use an environment variable to control if we are profiling # This is a value that should never be set in production if getenv("PROFILING"): @app.middleware("http") async def profile_request(request: air.Request, call_next): profiling = request.query_params.get("profile", False) if profiling: profiler = Profiler() profiler.start() await call_next(request) profiler.stop() return air.responses.HTMLResponse(profiler.output_html()) else: return await call_next(request)"

"@app.page async def index(pause: float = 0): if pause: await asyncio.sleep(pause) title = f"Pausing for {pause} seconds" return air.layouts.mvpcss( air.Title(title), air.H1(title), # Provide three options for testing the profiler air.P('Using asyncio.sleep to simulate bottlenecks'), air.Ol( air.Li( air.A( f"Pause for 0.1 seconds", href="/?profile=1&pause=0.1", target="_blank", ) ), air.Li( air.A( f"Pause for 0.3 seconds", href="/?profile=1&pause=0.3", target="_blank", ) ), air.Li( air.A( f"Pause for 1.0 seconds", href="/?profile=1&pause=1.0", target="_blank", ) ), ),"

Air apps can use pyinstrument with a drop-in HTTP middleware to profile individual requests. Install air and pyinstrument, guard profiling behind an environment variable to avoid exposing internal data in production, and enable profiling per request with a query parameter. The middleware starts the Profiler when ?profile=1 is present, awaits the request, stops the profiler, and returns profiler.output_html() as an HTMLResponse. A sample page simulates bottlenecks with asyncio.sleep and provides links for 0.1, 0.3, and 1.0 second pauses to exercise the profiler in controlled scenarios.

Read at daniel.feldroy.com