How do I install the Native App Performance skill?

Run npx skillmds@latest add modbender/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.

Is Native App Performance safe to use?

This skill has not completed SkillMD's automated safety review yet. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. Capability flags: executes scripts. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Native App Performance?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Native App Performance free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Native App Performance?

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

Native App Performance by modbender

Name: Native App Performance
Rating: 4.2 (5 reviews)
Author: modbender

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.

modbender Updated Sep 9, 2026 12 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