Capture Lessons

Turn the current session into a concise markdown note that future agents can reuse. Capture only the parts that would save time later: constraints, root causes, decisions, commands, and file-level evidence.

Workflow

1. Review the current conversation and the files that matter.

• Prefer concrete evidence from code, configs, and command results.
• Ignore routine back-and-forth unless it explains a non-obvious decision.

2. Decide what is worth keeping.

• Keep root causes, fixes, decision rationale, reusable commands, and repo-specific constraints.
• Skip raw transcript content, generic advice, and dead ends that add no future value.

3. Draft a short note before writing anything.

• Use a specific title tied to the problem or decision.
• Keep the note scannable and reuse-oriented.
• Prefer this structure:

# <title>

## Context

## Lessons
- <lesson>

## Evidence

## Affected Files
- [path](/absolute/path)

## Open Questions

4. Resolve the output directory and save the note.

• Run python3 scripts/save_lesson.py --workspace <repo> --title "<title>" --content-file <tmp-markdown-file>.
• The script searches upward from --workspace.
• In each directory, it checks AGENTS.md before CLAUDE.md.
• It accepts explicit declarations such as LESSONS_DIR: Lessons, lessons folder: docs/lessons, save lessons to: .agents/lessons/, or save lessons to: .claude/lessons/.
• If no declaration is found, it reuses .agents/lessons/ when present, otherwise .claude/lessons/ when present, otherwise creates .agents/lessons/ under the workspace root.

5. Re-open the written file and verify quality.

• Every lesson should be actionable or explanatory.
• The note should be shorter and cleaner than the original conversation.
• Keep filenames stable and descriptive; let the script append a numeric suffix if the slug already exists.

Destination Rules

• Support absolute or relative paths declared in AGENTS.md or CLAUDE.md.
• Resolve relative paths from the directory containing the declaration file.
• Prefer the nearest declaration to the current workspace.
• Fall back in this order when no declaration exists: .agents/lessons/, then .claude/lessons/ if it already exists.

Supported Declarations

The bundled script recognizes these common forms:

LESSONS_DIR: Lessons
LESSONS_PATH = docs/lessons
- lessons folder: .agents/lessons/
- lessons folder: .claude/lessons/
- lessons directory: docs/lessons
- save lessons to: docs/retros

Keep declarations simple: one path per line. The helper also tolerates legacy values joined with or, but new declarations should stay single-path.

Content Bar

Good lesson notes usually include:

• Why something failed or succeeded.
• Constraints that are easy to miss on a fresh read.
• Commands, paths, or patterns worth reusing.
• Evidence pointing to the changed files or configs.

Weak lesson notes usually include:

• Generic best practices.
• Raw transcript snippets.
• Status updates with no reusable insight.
• Exhaustive implementation detail with no future decision value.

Script Reference

Use the bundled helper from this skill directory:

python3 scripts/save_lesson.py --workspace "$PWD" --print-dir
python3 scripts/save_lesson.py --workspace "$PWD" --title "fix data loader race" --content-file /tmp/lesson.md

Arguments:

• --workspace: repository or working directory to resolve against.
• --title: optional note title; if omitted, the first markdown H1 is used.
• --content-file: read the lesson body from a markdown file. If omitted, read from stdin.
• --print-dir: print the resolved lessons directory without writing a note.
• --dry-run: print the resolved output path without writing the file.