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/auth-signers/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/auth-signers)<a href="https://agentmods.dev/skills/vitorpamplona/amethyst/auth-signers"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/auth-signers/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/auth-signers"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/auth-signers.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
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 →
- medium Excessive Agency · line 87 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00000 | $0.01607 |
| Opus 5.5 | $0.00000 | $0.00643 |
| Sonnet 5.5 | $0.00000 | $0.00321 |
| Haiku 4.5 | $0.00000 | $0.00161 |
Grade A, and why
auth-signers 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 yesterday.
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 — 107 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Signers
Every signed event and every NIP-04/NIP-44 operation goes through a NostrSigner. Feature
code never knows which of the three kinds the user has.
The contract (all suspend)
quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/signers/NostrSigner.kt:
abstract class NostrSigner(pubKey: HexKey) {
open val pubKey: HexKey // open: NIP-46 resolves it from the bunker
abstract fun isWriteable(): Boolean
suspend fun <T : Event> sign(ev: EventTemplate<T>): T
abstract suspend fun <T : Event> sign(createdAt: Long, kind: Int, tags: Array<Array<String>>, content: String): T
abstract suspend fun nip04Encrypt(plaintext: String, toPublicKey: HexKey): String
abstract suspend fun nip04Decrypt(ciphertext: String, fromPublicKey: HexKey): String
abstract suspend fun nip44Encrypt(plaintext: String, toPublicKey: HexKey): String
abstract suspend fun nip44Decrypt(ciphertext: String, fromPublicKey: HexKey): String
abstract suspend fun decryptZapEvent(event: ZapRequestEvent): PrivateZapEvent
abstract suspend fun deriveKey(nonce: HexKey): HexKey
abstract suspend fun signPsbt(psbtHex: String): String // NIP-BC; may throw UnsupportedMethodException
abstract fun hasForegroundSupport(): Boolean
suspend fun decrypt(encryptedContent: String, fromPublicKey: HexKey): String // picks NIP-04 vs NIP-44
}
Failures are thrown as SignerExceptions (nip01Core/signers/SignerExceptions.kt):
ReadOnlyException, UnauthorizedDecryptionException, NothingToDecrypt,
AutomaticallyUnauthorizedException, ManuallyUnauthorizedException, TimedOutException,
CouldNotPerformException, RunningOnBackgroundWithoutAutomaticPermissionException,
SignerNotFoundException, UnsupportedMethodException. Same folder: NostrSignerSync
(blocking, for tests/scripts), EventTemplate.kt, caches/ (DecryptCache).
The three signers
| Signer | File | Notes |
|---|---|---|
NostrSignerInternal |
quartz/.../nip01Core/signers/NostrSignerInternal.kt |
key in process memory; created/imported accounts |
NostrSignerRemote |
quartz/.../nip46RemoteSigner/signer/NostrSignerRemote.kt |
NIP-46 bunker over kind 24133; references/nip46-remote-signer.md |
NostrSignerExternal |
quartz/src/androidMain/.../nip55AndroidSigner/client/NostrSignerExternal.kt |
NIP-55 app (Amber…) via intents + content provider; Android only; references/nip55-android-signer.md |
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.
- yesterday Changed · +2 lines f54b0f46d020
- 15d ago Changed 71b9e0deeebb
- 25d ago Changed · -102 tokens per session f473193653c9
- 28d ago Changed 56fe91d70e51
- 1mo ago Changed 3f42b5fdd9a7
- 2mo ago First seen · 105 lines · 102 tokens per session scan A 1aff8f2d16f3
auth-signers is a skill published in the GitHub repository vitorpamplona/amethyst (1,620 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,607 tokens. 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.
auth-signers compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| auth-signersvitorpamplona/amethyst | Skill | 1.6k | yesterday | MIT | A | 0 | Claude Code |
| burner-walletsepivip/SeekerClaw | Skill | 319 | 9d ago | MIT | A | 91 | Claude Code, Codex |
| crypto-pricessepivip/SeekerClaw | Skill | 319 | 9d ago | MIT | A | 70 | Claude Code, Codex |
| sceneviewsceneview/sceneview | Skill | 1.4k | yesterday | Apache-2.0 | A | 156 | Codex |
| compose-focus-navigationchrisbanes/skills | Skill | 1.1k | yesterday | Apache-2.0 | A | 41 | Claude Code |
| kotlin-androidericrisco/rsc-harness | Skill | 503 | 2d ago | MIT | A | 78 | Claude Code, Codex |
| compose-multiplatformericrisco/rsc-harness | Skill | 503 | 2d ago | MIT | A | 80 | Claude Code, Codex |