learn（学习）

/learn - Deep Dive Learning Pattern

Explore a codebase with 3 parallel Haiku agents → create organized documentation.

Usage

/learn [url]             # Auto: clone via ghq, symlink origin/, then explore
/learn [slug]            # Use slug from ψ/memory/slugs.yaml
/learn [repo-path]       # Path to repo
/learn [repo-name]       # Finds in ψ/learn/owner/repo
/learn --init            # Restore all origins after git clone (like submodule init)

Depth Modes

/learn --fast [target]   # Quick overview (1 agent, ~2 min)
/learn [target]          # Standard (3 agents, ~5 min)
/learn --deep [target]   # Deep dive (5 agents, ~10 min)

Directory Structure

ψ/learn/
├── .origins             # Manifest of learned repos (committed)
└── owner/
    └── repo/
        ├── origin       # Symlink to ghq source (gitignored)
        ├── repo.md      # Hub file - links to all sessions (committed)
        └── YYYY-MM-DD/  # Date folder
            ├── 1349_ARCHITECTURE.md      # Time-prefixed files
            ├── 1349_CODE-SNIPPETS.md
            ├── 1349_QUICK-REFERENCE.md
            ├── 1520_ARCHITECTURE.md      # Second run same day
            └── ...

Multiple learnings: Each run gets time-prefixed files (HHMM_), nested in date folder.

Offload source, keep docs:

unlink ψ/learn/owner/repo/origin   # Remove symlink
ghq rm owner/repo                  # Remove source
# Docs remain in ψ/learn/owner/repo/

/learn --init

Restore all origins after cloning (like git submodule init):

ROOT="$(pwd)"
# Read .origins manifest and restore symlinks
while read repo; do
  ghq get -u "https://github.com/$repo"
  OWNER=$(dirname "$repo")
  REPO=$(basename "$repo")
  mkdir -p "$ROOT/ψ/learn/$OWNER/$REPO"
  ln -sf "$(ghq root)/github.com/$repo" "$ROOT/ψ/learn/$OWNER/$REPO/origin"
  echo "✓ Restored: $repo"
done < "$ROOT/ψ/learn/.origins"

Step 0: Detect Input Type + Resolve Path

date "+🕐 %H:%M %Z (%A %d %B %Y)"

CRITICAL: Capture ABSOLUTE paths first (before spawning any agents):

ROOT="$(pwd)"
echo "Learning from: $ROOT"

IMPORTANT FOR SUBAGENTS: When spawning Haiku agents, you MUST give them TWO literal paths:

1. SOURCE_DIR (where to READ code) - the origin/ symlink
2. DOCS_DIR (where to WRITE docs) - the parent directory, NOT inside origin/

⚠️ THE BUG: If you only give agents origin/ path, they cd into it and write there → files end up in WRONG repo!

FIX: Always give BOTH paths as LITERAL absolute values (no variables!):

Example: ROOT=/home/user/ghq/.../my-oracle, learning acme-corp/cool-library, TODAY=2026-02-04, TIME=1349:

READ from:  .../ψ/learn/acme-corp/cool-library/origin/
WRITE to:   .../ψ/learn/acme-corp/cool-library/2026-02-04/1349_[FILENAME].md

Tell each agent: "Read from [SOURCE_DIR]. Write to [DOCS_DIR]/[TIME]_[FILENAME].md"

If URL (http* or owner/repo format)

Clone, create docs dir, symlink origin, update manifest:

# Replace [URL] with actual URL
URL="[URL]"
ROOT="$(pwd)"  # CRITICAL: Save current directory!
ghq get -u "$URL" && \
  GHQ_ROOT=$(ghq root) && \
  OWNER=$(echo "$URL" | sed -E 's|.*github.com/([^/]+)/.*|\1|') && \
  REPO=$(echo "$URL" | sed -E 's|.*/([^/]+)(\.git)?$|\1|') && \
  mkdir -p "$ROOT/ψ/learn/$OWNER/$REPO" && \
  ln -sf "$GHQ_ROOT/github.com/$OWNER/$REPO" "$ROOT/ψ/learn/$OWNER/$REPO/origin" && \
  echo "$OWNER/$REPO" >> "$ROOT/ψ/learn/.origins" && \
  sort -u -o "$ROOT/ψ/learn/.origins" "$ROOT/ψ/learn/.origins" && \
  echo "✓ Ready: $ROOT/ψ/learn/$OWNER/$REPO/origin → source"

Verify:

ls -la "$ROOT/ψ/learn/$OWNER/$REPO/"

Note: Grep tool doesn't follow symlinks. Use: rg -L "pattern" ψ/learn/owner/repo/origin/

Then resolve path:

# Find by name (searches origin symlinks)
find ψ/learn -name "origin" -type l | xargs -I{} dirname {} | grep -i "$INPUT" | head -1

Scope

For external repos: Clone with script first, then explore via origin/ For local projects (in specs/, ψ/lib/): Read directly

Step 1: Detect Mode & Calculate Paths

Check arguments for --fast or --deep:

• --fast → Single overview agent
• --deep → 5 parallel agents
• (neither) → 3 parallel agents (default)

Calculate ACTUAL paths (replace variables with real values):

TODAY = YYYY-MM-DD (e.g., 2026-02-04)
TIME = HHMM (e.g., 1349)
REPO_DIR = [ROOT]/ψ/learn/[OWNER]/[REPO]/
DOCS_DIR = [ROOT]/ψ/learn/[OWNER]/[REPO]/[TODAY]/   ← date folder
SOURCE_DIR = [ROOT]/ψ/learn/[OWNER]/[REPO]/origin/  ← symlink
FILE_PREFIX = [TIME]_                               ← time prefix for files

Example:
- ROOT = /home/user/ghq/github.com/my-org/my-oracle
- OWNER = acme-corp
- REPO = cool-library
- TODAY = 2026-02-04, TIME = 1349
- DOCS_DIR = .../ψ/learn/acme-corp/cool-library/2026-02-04/
- Files: 1349_ARCHITECTURE.md, 1349_CODE-SNIPPETS.md, etc.

⚠️ CRITICAL: Create symlink AND date folder FIRST, then spawn agents!

1. Run the clone + symlink script in Step 0 FIRST
2. Capture TIME: date +%H%M (e.g., 1349)
3. Create the date folder: mkdir -p "$DOCS_DIR"
4. Capture DOCS_DIR, SOURCE_DIR, and TIME as literal values
5. THEN spawn agents with paths including TIME prefix

Multiple runs same day? Each run gets unique TIME prefix → no overwrites.

Mode: --fast (1 agent)

Single Agent: Quick Overview

Prompt the agent with (use LITERAL paths, not variables!):

You are exploring a codebase.

READ source code from: [SOURCE_DIR]
WRITE your output to:   [DOCS_DIR]/[TIME]_OVERVIEW.md

⚠️ IMPORTANT: Write to DOCS_DIR (the date folder), NOT inside origin/!

Analyze:
- What is this project? (1 sentence)
- Key files to look at
- How to use it (install + basic example)
- Notable patterns or tech

Skip to Step 2 after agent completes.

Mode: Default (3 agents)

Launch 3 agents in parallel. Each prompt must include (use LITERAL paths!):

READ source code from: [SOURCE_DIR]
WRITE your output to:   [DOCS_DIR]/[TIME]_[filename].md

⚠️ IMPORTANT: Write to DOCS_DIR (the date folder), NOT inside origin/!

Agent 1: Architecture Explorer → [TIME]_ARCHITECTURE.md

• Directory structure
• Entry points
• Core abstractions
• Dependencies

Agent 2: Code Snippets Collector → [TIME]_CODE-SNIPPETS.md

• Main entry point code
• Core implementations
• Interesting patterns

Agent 3: Quick Reference Builder → [TIME]_QUICK-REFERENCE.md

• What it does
• Installation
• Key features
• Usage patterns

Skip to Step 2 after all agents complete.

Mode: --deep (5 agents)

Launch 5 agents in parallel. Each prompt must include (use LITERAL paths!):

READ source code from: [SOURCE_DIR]
WRITE your output to:   [DOCS_DIR]/[TIME]_[filename].md

⚠️ IMPORTANT: Write to DOCS_DIR (the date folder), NOT inside origin/!

Agent 1: Architecture Explorer → [TIME]_ARCHITECTURE.md

• Directory structure & organization philosophy
• Entry points (all of them)
• Core abstractions & their relationships
• Dependencies (direct + transitive patterns)

Agent 2: Code Snippets Collector → [TIME]_CODE-SNIPPETS.md

• Main entry point code
• Core implementations with context
• Interesting patterns & idioms
• Error handling examples

Agent 3: Quick Reference Builder → [TIME]_QUICK-REFERENCE.md

• What it does (comprehensive)
• Installation (all methods)
• Key features with examples
• Configuration options

Agent 4: Testing & Quality Patterns → [TIME]_TESTING.md

• Test structure and conventions
• Test utilities and helpers
• Mocking patterns
• Coverage approach

Agent 5: API & Integration Surface → [TIME]_API-SURFACE.md

• Public API documentation
• Extension points / hooks
• Integration patterns
• Plugin/middleware architecture

Skip to Step 2 after all agents complete.

Step 2: Create/Update Hub File ([REPO].md)

# [REPO] Learning Index

## Source
- **Origin**: ./origin/
- **GitHub**: https://github.com/$OWNER/$REPO

## Explorations

### [TODAY] [TIME] ([mode])
- [[YYYY-MM-DD/HHMM_ARCHITECTURE|Architecture]]
- [[YYYY-MM-DD/HHMM_CODE-SNIPPETS|Code Snippets]]
- [[YYYY-MM-DD/HHMM_QUICK-REFERENCE|Quick Reference]]
- [[YYYY-MM-DD/HHMM_TESTING|Testing]]        <!-- --deep only -->
- [[YYYY-MM-DD/HHMM_API-SURFACE|API Surface]] <!-- --deep only -->

**Key insights**: [2-3 things learned]

### [TODAY] [EARLIER-TIME] ([mode])
...

Output Summary

--fast mode

## 📚 Quick Learn: [REPO]

**Mode**: fast (1 agent)
**Location**: ψ/learn/$OWNER/$REPO/[TODAY]/[TIME]_*.md

| File | Description |
|------|-------------|
| [REPO].md | Hub (links all sessions) |
| [TODAY]/[TIME]_OVERVIEW.md | Quick overview |

Default mode

## 📚 Learning Complete: [REPO]

**Mode**: default (3 agents)
**Location**: ψ/learn/$OWNER/$REPO/[TODAY]/[TIME]_*.md

| File | Description |
|------|-------------|
| [REPO].md | Hub (links all sessions) |
| [TODAY]/[TIME]_ARCHITECTURE.md | Structure |
| [TODAY]/[TIME]_CODE-SNIPPETS.md | Code examples |
| [TODAY]/[TIME]_QUICK-REFERENCE.md | Usage guide |

**Key Insights**: [2-3 things learned]

--deep mode

## 📚 Deep Learning Complete: [REPO]

**Mode**: deep (5 agents)
**Location**: ψ/learn/$OWNER/$REPO/[TODAY]/[TIME]_*.md

| File | Description |
|------|-------------|
| [REPO].md | Hub (links all sessions) |
| [TODAY]/[TIME]_ARCHITECTURE.md | Structure & design |
| [TODAY]/[TIME]_CODE-SNIPPETS.md | Code examples |
| [TODAY]/[TIME]_QUICK-REFERENCE.md | Usage guide |
| [TODAY]/[TIME]_TESTING.md | Test patterns |
| [TODAY]/[TIME]_API-SURFACE.md | Public API |

**Key Insights**: [3-5 things learned]

.gitignore Pattern

For Oracles that want to commit docs but ignore symlinks:

# Ignore origin symlinks only (source lives in ghq)
# Note: no trailing slash - origin is a symlink, not a directory
ψ/learn/**/origin

After running /learn, check your repo's .gitignore has these patterns so docs are committed but symlinks are ignored.

Trace Connection

After writing docs, log the learning to Oracle so it's discoverable via /trace:

arra_learn({
  pattern: "Learned [REPO]: [2-3 key insights]",
  concepts: ["learn", "codebase", relevant-tags],
  source: "learn: OWNER/REPO"
})

This connects /learn to the shared knowledge layer — future /trace queries find what was learned.

Notes

• --fast: 1 agent, quick scan for "what is this?"
• Default: 3 agents in parallel, good balance
• --deep: 5 agents, comprehensive for complex repos
• Haiku for exploration = cost effective
• Main reviews = quality gate
• origin/ structure allows easy offload
• .origins manifest enables --init restore