Xcode Build Optimization Agent Skills is a collection of agent skills that benchmarks and analyzes Xcode clean and incremental builds, compiler hotspots, project settings, and Swift Package Manager overhead. It is for iOS developers who want an AI coding agent to identify build-performance improvements and produce an optimization plan before changes are approved. The catalogue entries provide the skills, instructions, and plugin used for this workflow.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add AvdLee/Xcode-Build-Optimization-Agent-Skill --skill xcode-build-benchmarkgit clone --depth 1 https://github.com/AvdLee/Xcode-Build-Optimization-Agent-SkillWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/avdlee/xcode-build-optimization-agent-skill/xcode-build-benchmark)<a href="https://agentmods.dev/skills/avdlee/xcode-build-optimization-agent-skill/xcode-build-benchmark"><img src="https://agentmods.dev/badge/skills/avdlee/xcode-build-optimization-agent-skill/xcode-build-benchmark/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/avdlee/xcode-build-optimization-agent-skill/xcode-build-benchmark"><img src="https://agentmods.dev/badge/skills/avdlee/xcode-build-optimization-agent-skill/xcode-build-benchmark.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00077 | $0.00995 |
| Opus 5.5 | $0.00031 | $0.00398 |
| Sonnet 5.5 | $0.00015 | $0.00199 |
| Haiku 4.5 | $0.00008 | $0.00100 |
Grade A, and why
xcode-build-benchmark scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
4 near-identical copies found in the catalogue:
- xcode-build-benchmark — 100% identical, 0 lines differ
- xcode-build-benchmark — 100% identical, 0 lines differ
- xcode-build-benchmark — 98% identical, 2 lines differ
- xcode-build-benchmark — 94% identical, 7 lines differ
How it starts
The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Xcode Build Benchmark
Use this skill to produce a repeatable Xcode build baseline before anyone tries to optimize build times.
Core Rules
- Measure before recommending changes.
- Capture clean and incremental builds separately.
- Keep the command, destination, configuration, scheme, and warm-up rules consistent across runs.
- Write a timestamped JSON artifact to
.build-benchmark/. - Do not change project files as part of benchmarking.
Inputs To Collect
Confirm or infer:
- workspace or project path
- scheme
- configuration
- destination
- whether the user wants simulator or device numbers
- whether a custom
DerivedDatapath is needed
If the project has both clean-build and incremental-build pain, benchmark both. That is the default.
Worktree Considerations
When benchmarking inside a git worktree, SPM packages with exclude: paths that reference gitignored directories (e.g., __Snapshots__) will cause xcodebuild -resolvePackageDependencies to crash. Create those missing directories before running any builds.
Default Workflow
- Normalize the build command and note every flag that affects caching or module reuse.
- Run one warm-up build if needed to validate that the command succeeds.
- Run 3 clean builds.
- If
COMPILATION_CACHE_ENABLE_CACHING = YESis detected, run 3 cached clean builds. These measure clean build time with a warm compilation cache -- the realistic scenario for branch switching, pulling changes, or Clean Build Folder. The script handles this automatically by building once to warm the cache, then deleting DerivedData (but not the compilation cache) before each measured run. Pass--no-cached-cleanto skip. - Run 3 zero-change builds (build immediately after a successful build with no edits). This measures the fixed overhead floor: dependency computation, project description transfer, build description creation, script phases, codesigning, and validation. A zero-change build that takes more than a few seconds indicates avoidable per-build overhead. Use the default
benchmark_builds.pyinvocation (no--touch-fileflag). - Optionally run 3 incremental builds with a file touch to measure a real edit-rebuild loop. Use
--touch-file path/to/SomeFile.swiftto touch a representative source file before each build. - Save the raw results and summary into
.build-benchmark/. - Report medians and spread, not just the single fastest run.
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 89 lines · 77 tokens per session scan A 91b85f1b9b73
xcode-build-benchmark is a skill published in the GitHub repository AvdLee/Xcode-Build-Optimization-Agent-Skill (1,264 stars, last pushed 1mo ago), licensed MIT. It adds 77 tokens to every session and 995 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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