prep

prep is a skill for Claude Code from AcKeskin/contexture. It costs 73 tokens per session (4,258 once invoked), scanned A, original, MIT.

A session setup step that loads the architectural rules and project guidance relevant to the task before coding begins.

In plain words
What is it for?
Use it when starting substantial coding, debugging, design, or review work, after clearing a session, or when switching to a new project area.
Why use it?
It gives the coding agent the project’s conventions and constraints early, reducing work that later needs to be changed for breaking them.

Skill for Claude Code

Written for Claude Code: $CLAUDE_PROJECT_DIR variable. Also seen: reads .claude/ paths.

Good fit Use it when starting substantial coding, debugging, design, or review work, after clearing a session, or when switching to a new project area.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ackeskin/contexture/prep
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.

Any agent
npx skills add AcKeskin/contexture --skill prep
Clone the repo
git clone --depth 1 https://github.com/AcKeskin/contexture

Made for: Claude Code.

Wrote 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.

agentmods badge for prep

README.md
[![agentmods](https://agentmods.dev/badge/skills/ackeskin/contexture/prep.svg)](https://agentmods.dev/skills/ackeskin/contexture/prep)
Your own site
<a href="https://agentmods.dev/skills/ackeskin/contexture/prep"><img src="https://agentmods.dev/badge/skills/ackeskin/contexture/prep.svg" alt="Measured on agentmods" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,258 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00073 $0.04258
Opus 5 $0.00036 $0.02129
Sonnet 5 $0.00015 $0.00852
Haiku 4.5 $0.00007 $0.00426

Measured 4d ago against content hash c8bdf3a8f94f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

prep 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 4d 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.

skills/prep/SKILL.md · 232 lines

How it starts

The opening of the file, as written. The whole thing — 232 lines — stays where its author put it; the contents beside it link to each section on GitHub.

prep

The prep organ. Consumes discover, deliver, the architectural-rules tree, and project .claude/architecture.md (when present, per project-architecture.md).

Prep prevents drift by priming Claude with the rules before code is written. Review detects drift after the fact. Different jobs, complementary.

When to run

Auto-fire (the description field above drives this — Claude reads it and fires the skill at the right moment):

  1. First substantive task of a session. A substantive task is a code-writing, design, debugging, or review request. Trivial questions, lookups, and "what is X" style prompts do not trigger prep.
  2. First substantive task after /clear. Context was wiped; re-prime.
  3. User signals a topic shift. Phrases like "now let's work on X", "switching to Y", "different question about Z" where Z is a new domain / language / project.

Manual fire:

  1. User types /prep (explicit trigger, e.g. when Claude failed to auto-fire, or the user knows they are about to shift).
  2. User asks "prep for this" / "load architectural rules" / "prime for X".

Do not auto-fire on:

  • Session start itself (nothing to prep against yet).
  • Trivial questions / pure information requests ("what does git reflog do?").
  • Every message — prep is per-task, not per-turn.

Inputs

  • Task text. The substantive request that triggered prep. If invoked manually via /prep [scope-hint], use the hint to bias scope detection.
  • Working directory. $CLAUDE_PROJECT_DIR if set, otherwise cwd. Determines project context and whether a .claude/architecture.md is available.
  • Recent session state. Earlier turns in the same session (for topic-shift detection).

Procedure

0. Read the floor watermark (rule-prime hook handoff)

The rule-prime hook primes the floor — always-tier + project-tier rules, plus the one language tier in a single-language repo — mechanically at SessionStart, and incremental tiers per prompt at UserPromptSubmit. It records what it primed in a per-session watermark (~/.claude/session-state.json, key rulePrime, keyed by session id): { scopes: [...], floorPrimed: true|false, droppedRules: [...], language, polyglot }. When the floor exceeds its token budget the hook drops rules, sets floorPrimed: false, and lists the dropped rule keys in droppedRules — the watermark records what actually reached context, and the dropped rules are prep's to backfill.

Read the full file on GitHub · 232 lines

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. 4d ago First seen · 232 lines · 73 tokens per session scan A c8bdf3a8f94f

Subscribe to this mod's changes

prep is a skill published in the GitHub repository AcKeskin/contexture (2 stars, last pushed 1mo ago), licensed MIT. It adds 73 tokens to every session and 4,258 once invoked, about $0.0004 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 2026-09-03.

Related

Other skills, from other repositories