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imsg · understudy-ai | DecimalAI

productivityby understudy-ai

imsg

understudy-ai/imsg

Source understudy-ai/understudy ↗License MIT

iMessage/SMS CLI for listing chats, history, and sending messages via Messages.app.

SkillScore73Maintained

Automatic

Personal Assistant pack

Last verified 8/19/2026

What it changes

Passed 15 of 20 test cases with the skill, and 4 of 20 without it.

Without skill18%

With skill73%

Checks it passed that the model alone missed

Passes --limit 50 flag
Includes the --json flag
Passes the --limit 5 flag

and 16 more in the full report

12 fixed4 passed either way6 still failing0 broke

Pass-rate lift: +55 pp
Tokens: -10%
Agent turns: 0%
Response time: -49%

Model gemini-3.6-flashMeasured 8/19/2026v116 of 22 cases passed with skill · 20 comparable

Tokens, turns and time describe resource use, not a dollar price.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/understudy-ai-imsg/SKILL.md https://app.decimal.ai/s/understudy-ai-imsg/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add understudy-ai-imsg, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/understudy-ai-imsg/ and pins it in .decimal/skills.lock

decimalai skills add understudy-ai-imsg

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/understudy-ai-imsg/SKILL.md https://app.decimal.ai/s/understudy-ai-imsg/SKILL.md

Raw file: /s/understudy-ai-imsg/SKILL.md ↗ · machine-readable summary at /s/understudy-ai-imsg.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

One of 12 test cases the skill fixed. Same model, same prompt, with and without the skill.

1 of 12

Prompt

Please send a chat message to the gaming discord channel with the text 'Game night starts in 10 minutes'.

What was checked, without and with the skill
Checked	Without skill	With skill
Does not use the imsg command	Passed	Passed
Recommends using message_send with channel discord	Missed	Passed

case-07 · gemini-3.6-flash · 8/19/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md97 linessingle file

imsg

Use imsg to read and send iMessage/SMS via macOS Messages.app.

When to Use

✅ USE this skill when:

User explicitly asks to send iMessage or SMS
Reading iMessage conversation history
Checking recent Messages.app chats
Sending to phone numbers or Apple IDs

When NOT to Use

❌ DON'T use this skill when:

Telegram messages → use message_send with channel: "telegram"
Signal messages → use Signal channel if configured
WhatsApp messages → use WhatsApp channel if configured
Discord messages → use message_send with channel: "discord"
Slack messages → use slack skill
Group chat management (adding/removing members) → not supported
Bulk/mass messaging → always confirm with user first
Replying in current conversation → just reply normally (Understudy routes automatically)

Requirements

macOS with Messages.app signed in
Full Disk Access for terminal
Automation permission for Messages.app (for sending)

Common Commands

List Chats

imsg chats --limit 10 --json

Track record

Benchmark

15 / 20

test cases passed, vs 4 / 20 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v4 — 8/3/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

understudy-ai / understudy

skills/imsg/SKILL.md

View on GitHub ↗

License MITImported 8/3/2026Version v1

Other skills for the same job

Published skills whose descriptions closely match this one, with their headline benchmark lift.

More skills from the same source and nearby in the registry, with their headline benchmark lift.

Ready to supercharge your AI agents?

See it in action

What's inside

imsg

When to Use

When NOT to Use

Requirements

Common Commands

List Chats

Track record

Benchmark

Adoption

SkillSafety

Source

Other skills for the same job

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