| name | napkin |
| description | Maintain a per-repo napkin as a continuously curated runbook (not a session
log). Activates EVERY session. Read and curate it before work, keep only
recurring high-value guidance, organize by priority-sorted categories, and
cap each category at top 10 items. The napkin lives at `.claude/napkin.md`.
|
| author | Codex |
| version | 6.0.0 |
| date | "2026-02-21T00:00:00.000Z" |
Napkin
You maintain a per-repo markdown runbook, not a chronological log. The napkin
must be continuously curated for fast reuse in future sessions.
This skill is always active. Every session. No trigger required.
Session Start: Read And Curate
First thing, every session — read .claude/napkin.md before doing anything
else. Internalize what's there and apply it silently. Don't announce that you
read it. Just apply what you know.
Every time you read it, curate it immediately:
- Re-prioritize items by importance (highest first).
- Merge duplicates and remove stale/low-signal notes.
- Keep only recurring, high-frequency guidance.
- Ensure each item contains an explicit "Do instead" action.
- Enforce category caps (top 10 per category).
If no napkin exists yet, create one at .claude/napkin.md:
# Napkin Runbook
## Curation Rules
- Re-prioritize on every read.
- Keep recurring, high-value notes only.
- Max 10 items per category.
- Each item includes date + "Do instead".
## Execution & Validation (Highest Priority)
1. **[YYYY-MM-DD] Short rule**
Do instead: concrete repeatable action.
## Shell & Command Reliability
1. **[YYYY-MM-DD] Short rule**
Do instead: concrete repeatable action.
## Domain Behavior Guardrails
1. **[YYYY-MM-DD] Short rule**
Do instead: concrete repeatable action.
## User Directives
1. **[YYYY-MM-DD] Directive**
Do instead: exactly follow this preference.
Adapt categories to the repo, but keep category structure and priority ordering.
Do not use raw journal-style entries.
Continuous Runbook Updates
Update during work whenever you learn something reusable.
What qualifies for inclusion:
- Frequent gotchas or surprising behavior in this repo/toolchain.
- User directives that affect repeated behavior.
- Non-obvious tactics that repeatedly work.
What does not qualify:
- One-off timeline notes.
- Verbose postmortems without reusable action.
- Pure mistake logs without "Do instead" guidance.
Entry format requirements:
- Include date added (
[YYYY-MM-DD]).
- Include short rule title.
- Include explicit
Do instead: line.
- Keep wording concise and action-oriented.
Category And Priority Policy
- Organize notes by category.
- Keep each category sorted by importance descending.
- Re-evaluate category choice and priority whenever editing.
- Maximum 10 items per category; if over 10, remove lowest-priority entries.
- Prefer fewer high-signal items over broad coverage.
Practical Rule
Think of napkin as a live knowledge base for future execution speed and
reliability, not a history file.
Example Entry
1. **[2026-02-21] `rg` fails on giant expanded path lists**
Do instead: run `rg` on directory roots or iterate files via `while IFS= read -r`.
