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 agentmods add skills/gvkhosla/compound-engineering-pi/test-xcodenpx skills add gvkhosla/compound-engineering-pi --skill test-xcodegit clone --depth 1 https://github.com/gvkhosla/compound-engineering-piWhat 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 | $0.00018 | $0.01434 |
| Opus 5 | $0.00009 | $0.00717 |
| Sonnet 5 | $0.00004 | $0.00287 |
| Haiku 4.5 | $0.00002 | $0.00143 |
Grade A, and why
test-xcode 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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 211 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Xcode Test Skill
Build, install, and test iOS apps on the simulator using XcodeBuildMCP. Captures screenshots, logs, and verifies app behavior.
Prerequisites
- Xcode installed with command-line tools
- XcodeBuildMCP MCP server connected
- Valid Xcode project or workspace
- At least one iOS Simulator available
Workflow
0. Verify XcodeBuildMCP is Available
Check that the XcodeBuildMCP MCP server is connected by calling its list_simulators tool.
MCP tool names vary by platform:
- Claude Code:
mcp__xcodebuildmcp__list_simulators - Other platforms: use the equivalent MCP tool call for the
XcodeBuildMCPserver'slist_simulatorsmethod
If the tool is not found or errors, inform the user they need to add the XcodeBuildMCP MCP server:
XcodeBuildMCP not installed
Install via Homebrew:
brew tap getsentry/xcodebuildmcp && brew install xcodebuildmcp
Or via npx (no global install needed):
npx -y xcodebuildmcp@latest mcp
Then add "XcodeBuildMCP" as an MCP server in your agent configuration
and restart your agent.
Do NOT proceed until XcodeBuildMCP is confirmed working.
1. Discover Project and Scheme
Call XcodeBuildMCP's discover_projs tool to find available projects, then list_schemes with the project path to get available schemes.
If an argument was provided, use that scheme name. If "current", use the default/last-used scheme.
2. Boot Simulator
Call list_simulators to find available simulators. Boot the preferred simulator (iPhone 15 Pro recommended) using boot_simulator with the simulator's UUID.
Wait for the simulator to be ready before proceeding.
3. Build the App
Call build_ios_sim_app with the project path and scheme name.
On failure:
- Capture build errors
- Create a P1 todo for each build error
- Report to user with specific error details
On success:
- Note the built app path for installation
- Proceed to step 4
4. Install and Launch
- Call
install_app_on_simulatorwith the built app path and simulator UUID - Call
launch_app_on_simulatorwith the bundle ID and simulator UUID - Call
capture_sim_logswith the simulator UUID and bundle ID to start log capture
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.
- 2d ago First seen · 211 lines · 18 tokens per session scan A 1f56bc3f803d
test-xcode is a skill published in the GitHub repository gvkhosla/compound-engineering-pi (51 stars, last pushed 4mo ago), licensed MIT. It adds 18 tokens to every session and 1,434 once invoked, about $0.0001 per session on Opus 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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