Amethyst is an Android client for Nostr, a social network protocol that lets people control their own social activity and connections. People use it to read and publish Nostr content, follow accounts, and exchange encrypted direct messages from Android and other supported platforms. The catalogue add-ons support workflows for developing or operating the client.
Borrowing it
Nothing to install: this file belongs to vitorpamplona/amethyst. 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/vitorpamplona/amethyst/main/.claude/skills/amy-expert/SKILL.mdgit clone --depth 1 https://github.com/vitorpamplona/amethystWrote 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/vitorpamplona/amethyst/amy-expert)<a href="https://agentmods.dev/skills/vitorpamplona/amethyst/amy-expert"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/amy-expert/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/vitorpamplona/amethyst/amy-expert"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/amy-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Privilege Escalation · line 175 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- medium Rogue Agent · line 94 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
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 | $0.00217 | $0.03294 |
| Opus 5 | $0.00109 | $0.01647 |
| Sonnet 5 | $0.00043 | $0.00659 |
| Haiku 4.5 | $0.00022 | $0.00329 |
Grade A, and why
amy-expert 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 10d 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 — 259 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Amy CLI Expert
Practical patterns for touching the cli/ module without breaking
its public contract.
When to use this skill
- Adding a new
amy <verb>subcommand. - Editing anything under
cli/src/main/kotlin/…/cli/. - Writing a shell script or test harness that drives Amy.
- Extracting code out of
amethyst/so the CLI can call it (this is the single most common reason an Amy feature request stalls). - Deciding whether a piece of logic belongs in
cli/vscommons/vsquartz/(answer: almost nevercli/).
Not for: general Nostr protocol work (nostr-expert), general
Kotlin (kotlin-expert), Compose UI (compose-expert), Android-only
flows (android-expert), gradle/build (gradle-expert).
The rules that matter
Amy has a small number of hard rules. Any change that breaks them is a breaking change to the CLI's public API, and breaks the interop- test harnesses that depend on it.
Rule 1 — cli/ is a thin assembly layer
No new Nostr protocol, filter assembly, state machines, or encryption
lives in cli/. Ever. If you need logic that doesn't exist yet:
- Protocol piece (event kind, tags, signing)? Add it to
quartz/. - Business logic (state, defaults, ordering, filter assembly)?
Add it to
commons/— extract fromamethyst/first if needed (see Rule 5).
A commands/*.kt file longer than ~200 lines is a code smell.
Either the command is doing too many things, or the logic has
leaked in from where it should have lived.
Rule 2 — text by default, --json is the machine contract
amy ships a dual-output contract:
- Default stdout is human-readable text. A YAML-ish render of the result map. No shape promise — the renderer can change between releases.
--jsonswitches stdout to one JSON object, one line. Stable snake_case keys; this shape is the public API.- stderr is for humans. Progress logs, warnings, per-relay ACK
traces. Errors go here too —
error: <code>: <detail>by default, JSON{"error":"…","detail":"…"}under--json. - Exit codes:
0success ·1runtime ·2bad args ·124await timeout. - Adding a
--jsonkey is safe; renaming or removing one is a breaking change and needs the commit message to say so.
What ships with it
3 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.
- 10d ago First seen · 259 lines · 217 tokens per session scan A 3cb364436e40
amy-expert is a skill published in the GitHub repository vitorpamplona/amethyst (1,597 stars, last pushed today), licensed MIT. It adds 217 tokens to every session and 3,294 once invoked, about $0.0011 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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