kernel-slice

A code-reading tool for extracting only the definitions and imports that can affect a selected Python or Go function, class, or type.

In plain words
What is it for?
Use it before analyzing or changing a specific Python or Go symbol, especially when the surrounding file is large.
Why use it?
It reduces the amount of unrelated code you need to read when investigating one symbol in a large file. A symbol is a named code element such as a function or class.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/pinperepette/context-kernel/kernel-slice
Any agent
npx skills add Pinperepette/context-kernel --skill kernel-slice
Clone the repo
git clone --depth 1 https://github.com/Pinperepette/context-kernel

Made for: Claude Code, Codex.

Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 665 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00068 $0.00665
Opus 5 $0.00034 $0.00332
Sonnet 5 $0.00014 $0.00133
Haiku 4.5 $0.00007 $0.00067

Measured 2d ago against content hash 81b80d59cf9e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

kernel-slice 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 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/slice.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

claude-context-kernel/skills/kernel-slice/SKILL.md · 51 lines

What it actually says

kernel-slice — proiezione formale del codice

Quando serve ragionare su un simbolo specifico (una funzione, una classe, un tipo) dentro un file Python o Go grande, non leggere l'intero file: estrai solo la sua chiusura di raggiungibilita' sul grafo def-use. Tutto il resto (funzioni morte, import inutilizzati, classi scollegate) non puo' cambiare il comportamento del target, quindi e' rumore per il contesto.

Come usarlo

  • Pi: chiama il tool nativo kernel_slice con file e symbols.
  • Claude Code: esegui via Bash lo script incluso:
python3 "${CLAUDE_PLUGIN_ROOT}/skills/kernel-slice/scripts/slice.py" <file.(py|go)> <simbolo> [<simbolo2> ...]

Negli altri harness risolvi scripts/slice.py relativamente alla directory di questa skill. Lo script stampa solo le definizioni top-level raggiungibili dai target, piu' gli import effettivamente usati. Ragiona su quell'output invece del file intero.

Garanzia

Rispetto ai simboli chiesti, il comportamento di un simbolo dipende solo dalle sue dipendenze transitive:

  • Python (.py): answer-preserving per costruzione ed ESATTO — l'AST della stdlib da' l'insieme d'uso preciso di ogni unita' top-level.
  • Go (.go): answer-preserving conservativo — senza un parser Go nella stdlib, l'insieme d'uso e' la sovra-approssimazione "tutti gli identificatori del corpo" (stringhe e commenti mascherati): la fetta puo' tenere piu' del minimo, ma non lascia mai fuori una dipendenza del target. Confine delle unita' = convenzione gofmt (dichiarazioni a colonna 0); se lo split non e' fidato (graffe sbilanciate su codice non-gofmt) ritorna il file intero.

Se un simbolo non e' riconosciuto, o il file non e' .py/.go, lo script ritorna il file intero (fail-safe): non perde mai informazione rilevante.

Quando NON usarlo

  • Se ti serve una visione d'insieme del file (non un simbolo specifico).
  • Se il file e' piccolo (< ~100 righe): leggerlo intero costa poco.
Files

What ships with it

1 file 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.

Changes

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.

  1. 2d ago First seen · 51 lines · 68 tokens per session scan A 81b80d59cf9e

Subscribe to this mod's changes

kernel-slice is a skill published in the GitHub repository Pinperepette/context-kernel (24 stars, last pushed 1mo ago), licensed MIT. It adds 68 tokens to every session and 665 once invoked, about $0.0003 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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