Compound Docs — Institutional Knowledge Base

Searchable, categorized solution documentation that makes each debugging session easier than the last.

Directory Structure

.claude/solutions/
├── ecto-issues/
├── liveview-issues/
├── oban-issues/
├── otp-issues/
├── security-issues/
├── testing-issues/
├── phoenix-issues/
├── deployment-issues/
├── performance-issues/
└── build-issues/

Iron Laws

1. ALWAYS search solutions before investigating — Check

   .claude/solutions/

   for existing fixes before debugging
2. YAML frontmatter is MANDATORY — Every solution needs validated metadata per

   ${CLAUDE_SKILL_DIR}/references/schema.md

3. One problem per file — Never combine multiple solutions
4. Include prevention — Every solution documents how to prevent recurrence

Solution File Format

---
module: "Accounts"
date: "2025-12-01"
problem_type: runtime_error
component: ecto_schema
symptoms:
  - "Ecto.Association.NotLoaded on user.posts"
root_cause: missing_preload
severity: medium
tags: [preload, association, n-plus-one]
---

# Association NotLoaded on User Posts

## Symptoms
Ecto.Association.NotLoaded raised when accessing user.posts
in UserListLive after filtering.

## Root Cause
Query in Accounts context missing preload for :posts.

## Solution
Added `Repo.preload(:posts)` to `list_users/1`.

## Prevention
Use n1-check skill before shipping list views.

Searching Solutions

Use Grep to search

.claude/solutions/

by symptom (e.g.,

NotLoaded

), by tag (e.g.,

tags:.*preload

), or by component (e.g.,

component: ecto

).

Integration

• /phx:compound

  creates solution docs here

• /phx:investigate

  searches here before debugging

• /phx:plan

  consults for known risks

• learn-from-fix

  feeds into this system

References

• ${CLAUDE_SKILL_DIR}/references/schema.md

  — YAML frontmatter validation schema

• ${CLAUDE_SKILL_DIR}/references/resolution-template.md

  — Full solution template