spm-build-analysis

Xcode Build Optimization Agent Skills

Open-source Agent Skills for benchmarking and optimizing Xcode build performance across clean builds, incremental builds, compile hotspots, project settings, and Swift Package Manager overhead.

Quick Start

Install all six skills (the orchestrator needs the specialist skills to work):

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

Then open your Xcode project in your AI coding tool and say:

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

The agent will benchmark your clean and incremental builds, audit build settings, find compile hotspots, and produce an optimization plan at .build-benchmark/optimization-plan.md. No project files are modified until you explicitly approve changes.

For long-term monitoring across days, machines, Xcode versions, and teams, use RocketSim Build Insights and Team Build Insights.

Every Second Counts

A 1-second improvement on a 30-second incremental build sounds small. At 50 builds a day, that adds up to 3.5 hours per developer per year -- or 35 hours across a team of ten.

Most projects have several seconds of easy wins hiding in build settings, script phases, and compiler flags. This skill finds them.

How It Works

The orchestrator coordinates five specialist skills in a recommend-first workflow. Nothing is modified until you approve.

flowchart LR
    Orchestrator --> Benchmark["Benchmark\n(clean + incremental)"]
    Benchmark --> Compilation["Compilation\nAnalyzer"]
    Benchmark --> Project["Project\nAnalyzer"]
    Benchmark --> SPM["SPM\nAnalyzer"]
    Compilation --> Plan["Optimization\nPlan"]
    Project --> Plan
    SPM --> Plan
    Plan --> You{{"You review\n& approve"}}
    You --> Fixer["Build\nFixer"]
    Fixer --> ReBenchmark["Re-benchmark\n& verify"]

Phase 1 -- Analyze. The orchestrator benchmarks your project, runs the three specialist analyzers, and produces a prioritized optimization plan at .build-benchmark/optimization-plan.md. No project files are modified.

Use the Xcode build orchestrator to analyze build performance and come up with a plan for improvements.

Phase 2 -- Fix. Review the plan, check the approval boxes for the items you want, and ask the agent to apply them. The fixer implements only approved changes and re-benchmarks to verify.

Implement the approved items from the optimization plan at .build-benchmark/optimization-plan.md, then re-benchmark to verify the improvements.

The plan file is your evidence trail -- shareable with teammates, reviewable in PRs, and diffable over time.

What It Checks

The agent runs over 40 individual checks across build settings, project configuration, source code, and package dependencies.

Community Results

Real-world improvements reported by developers who used these skills. Add your own by opening a pull request.

The xcode-build-orchestrator generates your table row at the end of every optimization run, so contributing is a single copy-paste.

[!NOTE] A small clean-build increase is normal when enabling compilation caching -- the first cold build populates the cache. Cached clean builds (branch switching, pulling changes) and incremental builds are where the real gains show up.

Who This Is For

• iOS and macOS teams with slow local build loops
• developers investigating a recent build-time regression
• teams that want evidence-backed Xcode build optimization instead of guesswork
• developers who want a reusable Agent Skills package, not a one-off script

Included Skills

The orchestrator is the recommended starting point -- it coordinates the other five skills automatically. Install all six skills so the orchestrator can access each specialist.

Installation Options

Option A: Using skills.sh

Install all six skills (required -- the orchestrator depends on the specialist skills):

npx skills add https://github.com/avdl