Agent Skill

Use the open-source Xcode Build Optimization Agent Skill alongside RocketSim Build Insights to analyze slow builds, generate optimization plans, and verify improvements over time.

RocketSim helps you understand how your builds behave over time. The Xcode Build Optimization Agent Skill helps you improve them.

Together, they make a strong workflow:

Use RocketSim Build Insights to monitor clean and incremental build times across days, Xcode versions, and machines
Use the agent skill to investigate why builds are slow and generate a concrete optimization plan
Use RocketSim again afterwards to verify whether your changes actually improved the build loop over time

What the agent skill offers

The open-source skill package gives AI coding tools a structured workflow for Xcode build optimization. Its orchestrator benchmarks your project, runs specialist analyzers, and produces a plan before applying any changes.

It covers:

Clean and incremental build benchmarking
Compile hotspot analysis
Project settings and script phase review
Swift Package Manager dependency analysis
Recommend-first optimization plans
Re-benchmarking after approved fixes

That makes it especially useful when RocketSim shows a regression and you want help narrowing down the likely cause.

How it works with RocketSim

RocketSim and the skill solve different parts of the same problem.

RocketSim Build Insights

RocketSim tells you:

Whether build times are getting slower or faster
How clean builds compare to incremental builds
Which schemes are affected
How performance changes across Xcode versions, macOS versions, and machines

See Build Insights and Team Build Insights.

Xcode Build Optimization Agent Skill

The agent skill helps you answer:

What changed in the project that might be slowing down builds
Whether script phases, compiler settings, or package structure are contributing
Which optimizations are worth trying first
Whether the approved changes actually improved benchmark results

In short: RocketSim is your monitor, the agent skill is your optimization assistant.

Recommended workflow

Use RocketSim Build Insights to spot a slowdown or a consistently slow edit-build-run loop.
Run the xcode-build-orchestrator skill in your AI coding tool.
Review the generated optimization plan and approve the changes you want.
Apply the approved fixes and re-benchmark.
Keep RocketSim running over the next days or weeks to confirm the improvement holds up in real usage.

This workflow works especially well for teams: RocketSim gives ongoing visibility, while the agent skill gives a repeatable way to investigate and improve build performance when issues show up.

Quick start

Install the skill package:

npx skills add https://github.com/avdlee/xcode-build-optimization-agent-skill

Then ask your AI coding tool:

Use the /xcode-build-orchestrator skill to analyze build performance and come up with a plan for improvements.

The skill benchmarks your project, runs multiple analyzers, and produces an optimization plan before making any project changes.

When to use which tool

Use RocketSim when you want:

Passive monitoring over time
Visibility into trends and regressions
Team-wide comparisons across machines and Xcode versions

Use the agent skill when you want:

A focused optimization session
A plan for build performance improvements
Concrete next steps for fixing build bottlenecks

Use both when you want a complete workflow from detecting a build problem to fixing it and proving the result.