Borrowing it
Nothing to install: this file belongs to riwsky/iosef. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/riwsky/iosef/main/CLAUDE.mdgit clone --depth 1 https://github.com/riwsky/iosefWrote 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/instructions/riwsky/iosef/claude-md)<a href="https://agentmods.dev/instructions/riwsky/iosef/claude-md"><img src="https://agentmods.dev/badge/instructions/riwsky/iosef/claude-md/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/instructions/riwsky/iosef/claude-md"><img src="https://agentmods.dev/badge/instructions/riwsky/iosef/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00376 | $0.00376 |
| Opus 5.5 | $0.00150 | $0.00150 |
| Sonnet 5.5 | $0.00075 | $0.00075 |
| Haiku 4.5 | $0.00038 | $0.00038 |
Grade A, and why
iosef CLAUDE.md 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.
What it actually says
iosef
A Swift CLI for the iOS simulator (with MCP server support) that's optimized for agent usage.
Work guidelines
Use local checkout for researching other repositories: You will, reasonably, often want to compare approaches against joshuayoes/ios-simulator-mcp or facebook/idb. Do NOT compare by browsing raw.githubcontent or the github web interface - instead, clone the repos locally. Another useful source of comparison is ldomaradzki/xctree.
Test against the playground apps: the repo also includes two playground apps (one iOS, one watchOS); changes should generally be validated against one or both of those.
Keep references updated: the following locations are pretty cross-cutting, and should be reviewed (especially after changes to the interface) in case they need updating:
[ ] The guidance in skills/ios-simulator-interaction
[ ] The benchmarking in scripts/benchmark.py
[ ] The documentation in the README.md
[ ] Playground Xcode projects: the .xcodeprojs are generated by XcodeGen from MCPTestApp/project.yml and WatchTestApp/project.yml (and are gitignored — treat them as build artifacts). Sources are globbed from the app folder, so adding/renaming/removing a .swift file needs no project edits: just run xcodegen generate in the app dir (or scripts/build-test-app.sh, which regenerates automatically). Install the generator once with brew install xcodegen. Edit project.yml only to change build settings, deployment target, or schemes.
Scripts for frequent commands: ls the scripts directory to see commands for building and benchmarking. Consider adding more if you find yourself running any commands pretty often.
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 · 18 lines · 376 tokens per session scan A 297bf5492349
iosef CLAUDE.md is an instructions file published in the GitHub repository riwsky/iosef (19 stars, last pushed yesterday), licensed MIT. It adds 376 tokens to every session, about $0.0015 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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