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/event-store-semantics/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/event-store-semantics)<a href="https://agentmods.dev/skills/vitorpamplona/amethyst/event-store-semantics"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/event-store-semantics/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/event-store-semantics"><img src="https://agentmods.dev/badge/skills/vitorpamplona/amethyst/event-store-semantics.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 | $0.00167 | $0.05243 |
| Opus 5 | $0.00084 | $0.02622 |
| Sonnet 5 | $0.00033 | $0.01049 |
| Haiku 4.5 | $0.00017 | $0.00524 |
Grade A, and why
event-store-semantics 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 9d 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 — 326 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Event Store Semantics — the IEventStore / SQLite-store contract
The SQLite EventStore (quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/)
is the de-facto reference implementation of what a Quartz event store must do. Other
implementations — the in-repo filesystem store (nip01Core/store/fs/, held to parity by
quartz/src/jvmTest/.../store/fs/FsParityTest.kt) and external engines (e.g. a Vespa-backed
store) — reimplement its observable behavior and assert parity in CI. This skill states that
behavior as named, numbered decisions so a parity divergence becomes a lookup, not an
archaeology session through QueryBuilder/MergeQueryExecutor.
Every rule below was verified against the code as of this skill's last update. When you change store behavior, update the rule here in the same PR and add a line to the Semantics changelog — downstream implementations pin Quartz by commit and review pin bumps against this file.
Key files
| Concern | File |
|---|---|
| Public contract (KDoc is normative) | nip01Core/store/IEventStore.kt |
| High-level store (owns pool + planner) | sqlite/EventStore.kt, sqlite/SQLiteEventStore.kt |
| Filter → SQL, ordering, limits, counts | sqlite/QueryBuilder.kt |
| k-way merge fast path (feed shapes) | sqlite/MergeQueryExecutor.kt |
| Schema, tag hashing, immutability | sqlite/EventIndexesModule.kt, sqlite/TagNameValueHasher.kt, sqlite/SeedModule.kt |
| Replaceable / addressable supersession | sqlite/ReplaceableModule.kt, sqlite/AddressableModule.kt |
| NIP-09 / NIP-40 / NIP-62 / ephemeral | sqlite/DeletionRequestModule.kt, sqlite/ExpirationModule.kt, sqlite/RightToVanishModule.kt, sqlite/EphemeralModule.kt |
| NIP-50 FTS | sqlite/FullTextSearchModule.kt (see also the searchable-events skill) |
| Index/feature toggles | sqlite/IndexingStrategy.kt (client default) and geode's RelayIndexingStrategy.kt (relay preset) |
| Operational README | sqlite/README.md (concurrency, pragmas, maintenance) |
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.
- 9d ago First seen · 326 lines · 167 tokens per session scan A d2fda7f68775
event-store-semantics is a skill published in the GitHub repository vitorpamplona/amethyst (1,596 stars, last pushed today), licensed MIT. It adds 167 tokens to every session and 5,243 once invoked, about $0.0008 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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