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/nostr-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/nostr-expert)<a href="https://agentmods.dev/skills/vitorpamplona/amethyst/nostr-expert"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/nostr-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/nostr-expert"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/nostr-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.05467 |
| Opus 5 | $0.00000 | $0.02733 |
| Sonnet 5 | $0.00000 | $0.01093 |
| Haiku 4.5 | $0.00000 | $0.00547 |
Grade A, and why
nostr-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 11d 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 — 617 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Nostr Protocol Expert (Quartz Implementation)
Practical patterns for working with Nostr in Quartz, AmethystMultiplatform's KMP Nostr library.
When to Use This Skill
- Implementing Nostr event types (TextNote, Reaction, Zap, etc.)
- Creating/parsing events with TagArrayBuilder DSL
- Working with event kinds and tags
- Finding NIP implementations in quartz/ codebase
- Nostr cryptography (secp256k1 signing, NIP-44 encryption)
- Bech32 encoding/decoding (npub, nsec, note formats)
- Resolving user input (hex / npub / nprofile / NIP-05
name@domain) to a pubkey - Event validation and verification
For NIP specifications → Use nostr-protocol agent
For Quartz implementation → Use this skill
Quartz Architecture
Quartz organizes code by NIP number:
quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/
├── nip01Core/ # Core protocol (Event, Kind, Tags)
├── nip04Dm/ # Legacy DMs (deprecated)
├── nip10Notes/ # Text notes with threading
├── nip17Dm/ # Private DMs (gift wrap)
├── nip19Bech32/ # Bech32 encoding
├── nip44Encryption/ # Modern encryption (ChaCha20)
├── nip57Zaps/ # Lightning zaps
├── ... (57 NIPs total)
└── experimental/ # Draft NIPs
Pattern: nip##<Name>/ directories contain event classes, tags, and utilities for that NIP.
Find implementations: Use scripts/nip-lookup.sh <nip-number> or see references/nip-catalog.md.
Event Anatomy
Core Structure
@Immutable
open class Event(
val id: HexKey, // SHA-256 hash of serialized event
val pubKey: HexKey, // Author's public key (32 bytes hex)
val createdAt: Long, // Unix timestamp
val kind: Kind, // Event kind (Int typealias)
val tags: TagArray, // Array of tag arrays
val content: String, // Event content
val sig: HexKey, // Schnorr signature (64 bytes hex)
) : IEvent
Key insight: Event is the base class. Specific event types (TextNoteEvent, ReactionEvent) extend it and add parsing/helper methods.
What ships with it
9 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.
- references/crypto-and-encryption.md 4.3 KB
- references/event-factory.md 3.4 KB
- references/event-hierarchy.md 7.7 KB
- references/large-cache.md 3.2 KB
- references/nip-catalog.md 9.0 KB
- references/nip05-identifiers.md 5.4 KB
- references/nip19-bech32.md 4.1 KB
- references/tag-patterns.md 7.9 KB
- scripts/nip-lookup.sh 1.9 KB runs code
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.
- 11d ago First seen · 617 lines · 0 tokens per session scan A 2340fafdc4a2
nostr-expert is a skill published in the GitHub repository vitorpamplona/amethyst (1,598 stars, last pushed today), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 5,467 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.
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