A mobile-device control skill for driving iOS Simulators and Android emulators or connected devices. It can read the screen and interact by tapping, swiping, and typing.

Use it to automate mobile-app interactions, inspect what is shown, enter text, take screenshots, and verify changes on iOS or Android devices.

It removes the need for an agent to guess how to operate a mobile app or manually repeat device actions. It also supports checking that the device is connected and responding before use.

sim-use — Skill for Claude Code and Codex by cafe3310

Install

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.

Any agent

npx skills add cafe3310/public-agent-skills --skill sim-use

Clone the repo

git clone --depth 1 https://github.com/cafe3310/public-agent-skills

Made for: Claude Code, Codex.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/cafe3310/public-agent-skills/sim-use/github.svg)](https://agentmods.dev/skills/cafe3310/public-agent-skills/sim-use)

Your own site

<a href="https://agentmods.dev/skills/cafe3310/public-agent-skills/sim-use"><img src="https://agentmods.dev/badge/skills/cafe3310/public-agent-skills/sim-use/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/cafe3310/public-agent-skills/sim-use"><img src="https://agentmods.dev/badge/skills/cafe3310/public-agent-skills/sim-use.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,672 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.00048	$0.01672
Opus 5.5	$0.00019	$0.00669
Sonnet 5.5	$0.00010	$0.00334
Haiku 4.5	$0.00005	$0.00167

Measured 2d ago against content hash 7ac1aca84405, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

sim-use 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/preflight.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills_parked/sim-use/SKILL.md · 132 lines

How it starts

The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.

0. Preflight

Before first interaction with a device, run the preflight check:

python3 scripts/preflight.py --device <UDID>

This verifies sim-use is installed, the device is reachable, and the daemon is healthy. If you don't have the script, do the checks manually:

sim-use --version — confirm sim-use is on PATH.
sim-use devices — confirm the target device is listed and booted/connected.
sim-use ui --device <UDID> — confirm you can read the screen.

--device is optional when only one simulator is booted or one daemon is running. For Android, run sim-use android init --device <serial> once to install the bridge APK.

1. The observe-act loop

Every interaction follows the same cycle: observe → act → verify.

Observe

sim-use ui --device <UDID>

Read the outline. Each element has an @N alias and optionally a #<id> identifier. List cells carry #N (dominant list) or #N@M (scoped).

Frames in the JSON output (--json: entries[].frame, screen) are in platform-native units — iOS points, Android pixels. Key off the envelope's platform field before doing math on coordinates across platforms.

Act

Pick a selector, in order of preference:

Selector	When to use
`tap @N`	Right after `ui`. Fastest, cache-backed.
`tap #<id>`	Stable across minor layout changes. Paste from the outline.
`tap --label 'X'`	Scripted flows. Combine with `--wait-timeout` for transitions.
`tap --label-regex '...'`	Dynamic labels with counters/timestamps. Anchor with `^...$`.
`tap --label-contains 'X'`	Substring match when exact label is unknown.
`tap -x N -y N` / `tap --point x,y`	Last resort for elements with no AX data.

Disambiguate collisions with --element-type or --frame minY=0.7r (see references/cheatsheet.md).

Verify

Always verify after acting — commands are fire-and-forget:

sim-use ui --device <UDID>       # read the new screen state
sim-use screenshot --device <UDID> --output after.png

Read the full file on GitHub · 132 lines

Files

What ships with it

5 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.

Changes

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 · 132 lines · 48 tokens per session scan A 7ac1aca84405

Subscribe to this mod's changes

sim-use is a skill published in the GitHub repository cafe3310/public-agent-skills (256 stars, last pushed yesterday), licensed Apache-2.0. It adds 48 tokens to every session and 1,672 once invoked, about $0.0002 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 2026-11-05.

Mobile agent-skill-repository gemini-cli skills

sim-use next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
sim-usecafe3310/public-agent-skills	Skill	256	yesterday	Apache-2.0	A	48	Claude Code, Codex
android-ui-engineeringGuillemRoca/agent-skills-android	Skill	5	1mo ago	MIT	A	52	Claude Code
security-and-hardeningGuillemRoca/agent-skills-android	Skill	5	1mo ago	MIT	A	62	Claude Code
android-accessibilityGuillemRoca/agent-skills-android	Skill	5	1mo ago	MIT	A	35	Claude Code
android-data-persistenceGuillemRoca/agent-skills-android	Skill	5	1mo ago	MIT	A	41	Claude Code
android-device-testingGuillemRoca/agent-skills-android	Skill	5	1mo ago	MIT	A	39	Claude Code
git-workflow-and-versioningGuillemRoca/agent-skills-android	Skill	5	1mo ago	MIT	A	77	Claude Code