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Run npx skillmds add majiayu000/native-app-performance in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

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Is Native App Performance free to use?

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Who published Native App Performance?

majiayu000 (@majiayu000) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Native App Performance by majiayu000

Name: Native App Performance
Rating: 4.5 (4 reviews)
Author: majiayu000

Native App Performance

Native macOS/iOS app performance profiling via xctrace/Time Profiler and CLI-only analysis of Instruments traces. Use when asked to profile, attach, record, or analyze Instruments .trace files, find hotspots, or optimize native app performance without opening Instruments UI.

majiayu000 db230fc 2 files · 2.7 KB Updated Sep 9, 2026 567 repo stars

File contents

Native App Performance (CLI-only)

Goal: record Time Profiler via xctrace, extract samples, symbolicate, and propose hotspots without opening Instruments.

Quick start (CLI)

Record Time Profiler (attach):

# Start app yourself, then attach
xcrun xctrace record --template 'Time Profiler' --time-limit 90s --output /tmp/App.trace --attach <pid>

Record Time Profiler (launch):

xcrun xctrace record --template 'Time Profiler' --time-limit 90s --output /tmp/App.trace --launch -- /path/App.app/Contents/MacOS/App

Extract time samples:

scripts/extract_time_samples.py --trace /tmp/App.trace --output /tmp/time-sample.xml

Get load address for symbolication:

# While app is running
vmmap <pid> | rg -m1 "__TEXT" -n

Symbolicate + rank hotspots:

scripts/top_hotspots.py --samples /tmp/time-sample.xml \
  --binary /path/App.app/Contents/MacOS/App \
  --load-address 0x100000000 --top 30

Workflow notes

Always confirm you’re profiling the correct binary (local build vs /Applications). Prefer direct binary path for --launch.
Ensure you trigger the slow path during capture (menu open/close, refresh, etc.).
If stacks are empty, capture longer or avoid idle sections.
xcrun xctrace help record and xcrun xctrace help export show correct flags.

Included scripts

scripts/record_time_profiler.sh: record via attach or launch.
scripts/extract_time_samples.py: export time-sample XML from a trace.
scripts/top_hotspots.py: symbolicate and rank top app frames.

Gotchas

ASLR means you must use the runtime __TEXT load address from vmmap.
If using a new build, update the --binary path; symbols must match the trace.
CLI-only flow: no need to open Instruments if stacks are symbolicated via atos.

---name: native-app-performancedescription: Native macOS/iOS app performance profiling via xctrace/Time Profiler and CLI-only analysis of Instruments traces. Use when asked to profile, attach, record, or analyze Instruments .trace files, find hotspots, or optimize native app performance without opening Instruments UI.--- # Native App Performance (CLI-only) Goal: record Time Profiler via `xctrace`, extract samples, symbolicate, and propose hotspots without opening Instruments. ## Quick start (CLI) 1. Record Time Profiler (attach): ```bash # Start app yourself, then attach xcrun xctrace record --template 'Time Profiler' --time-limit 90s --output /tmp/App.trace --attach <pid> ``` 2. Record Time Profiler (launch): ```bash xcrun xctrace record --template 'Time Profiler' --time-limit 90s --output /tmp/App.trace --launch -- /path/App.app/Contents/MacOS/App ``` 3. Extract time samples: ```bash scripts/extract_time_samples.py --trace /tmp/App.trace --output /tmp/time-sample.xml ``` 4. Get load address for symbolication: ```bash # While app is running vmmap <pid> | rg -m1 "__TEXT" -n ``` 5. Symbolicate + rank hotspots: ```bash scripts/top_hotspots.py --samples /tmp/time-sample.xml \ --binary /path/App.app/Contents/MacOS/App \ --load-address 0x100000000 --top 30 ``` ## Workflow notes - Always confirm you’re profiling the correct binary (local build vs /Applications). Prefer direct binary path for `--launch`. - Ensure you trigger the slow path during capture (menu open/close, refresh, etc.). - If stacks are empty, capture longer or avoid idle sections. - `xcrun xctrace help record` and `xcrun xctrace help export` show correct flags. ## Included scripts - `scripts/record_time_profiler.sh`: record via attach or launch. - `scripts/extract_time_samples.py`: export time-sample XML from a trace. - `scripts/top_hotspots.py`: symbolicate and rank top app frames. ## Gotchas - ASLR means you must use the runtime `__TEXT` load address from `vmmap`. - If using a new build, update the `--binary` path; symbols must match the trace. - CLI-only flow: no need to open Instruments if stacks are symbolicated via `atos`.

Frequently asked questions