phx-compound

Name: phx-compound
Author: oliver-kriska/claude-elixir-phoenix

$npx mdskill add oliver-kriska/claude-elixir-phoenix/phx-compound

Capture and search solution documents after fixing problems

Identifies recent engineering work for documentation creation
Depends on session context, git history, and previous completions
Decides whether to create new or update existing solutions based on root cause
Generates searchable solution documents in the `.claude/solutions/` directory

SKILL.md

.github/skills/phx-compoundView on GitHub ↗

---
name: phx-compound
description: Capture solved problems as searchable solution docs. Use after fixing
  bugs, when "that worked", or after successful phx-review or phx-investigate.
---

# Compound — Capture Solutions as Knowledge

After fixing a problem, capture the solution as searchable
institutional documentation.

## Usage

```
phx-compound Fixed N+1 query in user listing
phx-compound Resolved LiveView timeout in dashboard
phx-compound   # Auto-detects from recent session context
```

## Philosophy

> Each unit of engineering work should make subsequent units
> easier — not harder.

## Workflow

### Step 1: Detect Context

1. If `$ARGUMENTS` provided, use as description
2. If no args, check scratchpad DEAD-END/DECISION entries,
   `git diff`, `.claude/plans/{slug}/progress.md` for recent completions
3. If unclear, ask: "What problem did you just solve?"

**Only document non-trivial problems** that required investigation.

### Step 2: Search Existing Solutions

Create `.claude/solutions/` directory if it doesn't exist (run `mkdir -p .claude/solutions`).
Then search `.claude/solutions/` for relevant keywords using Grep.

If found: **Create new** (different root cause), **Update
existing** (same root cause, new symptom), or **Skip**.

### Step 3: Gather Details and Create Solution

Extract from session context: module, symptoms, investigation
steps, root cause, solution code, and prevention advice.

Validate frontmatter against `../compound-docs/references/schema.md`,
then create file using `../compound-docs/references/resolution-template.md`.

**Write-blocked fallback**: if writing to `.claude/solutions/` is denied
by permissions, do NOT silently drop the solution. Output the full
solution doc inline (fenced markdown the user can paste), then suggest
`phx-permissions` to allow `.claude/solutions/` writes for next time.

### Step 4: Decision Menu

1. **Continue** (default)
2. **Promote to Iron Law check** — Add to iron-law-judge
3. **Update skill reference** — Add to relevant skill
4. **Update CLAUDE.md** — Add prevention rule

## Auto-Trigger Phrases

When user says "that worked", "it's fixed", "problem solved",
"the fix was" — suggest `phx-compound`.

### Supply-chain finding auto-feed (Phase 3)

When `phx-deps-audit` produces a BLOCK-severity finding that the
user investigates and confirms is a real malicious pattern (not a
false positive), suggest:

> Caught a high-severity finding in `<pkg>@<version>`. Run
> `phx-compound` to capture this for future audits?

If accepted, the resulting solution doc goes to
`.claude/solutions/supply-chain/<pkg>-<cve_or_pattern>.md` and
includes the exact rule-id + snippet + diff window that triggered
the finding. This compounds the audit corpus: future runs of
`phx-deps-audit` grep `solutions/supply-chain/` for snippet
matches and pre-elevate severity on known-bad patterns.

**Always prompt; never auto-write.** Solution docs are durable and
shape future trust calls — the user reviews before committing.

## Iron Laws

1. **YAML frontmatter validates or STOP**
2. **Symptoms must be specific** — not "it broke"
3. **Root cause is WHY, not WHAT**
4. **One problem per file**
5. **NEVER document a fix before verifying it works** — run `mix compile && mix test` first; unverified solutions poison the knowledge base

## Integration with Workflow

```text
phx-review → Complete → phx-compound  ← YOU ARE HERE
                              │
                 .claude/solutions/{category}/{fix}.md
                              │
              phx-investigate and phx-plan search here
```

## References

- `references/compound-workflow.md` — Detailed step-by-step
- See also: `compound-docs` skill for schema and templates

More from oliver-kriska/claude-elixir-phoenix

Skill	Description
ash-framework	Ash Framework — resources, actions, policies, aggregates, calculations, AshPhoenix.Form, LiveView, migrations. Use when generating resources via mix ash.codegen, editing changes, checks, types, validations, or domain code interfaces.
catchup	Summarize and review what changed while you were away. Use after a weekend, vacation, or flight to check missed PRs, git commits, Linear tickets, and meetings — one prioritized brief, not a firehose.
cc-changelog	\|
codex-ab	Run an A/B codex review experiment — holistic codex review vs 3 focused dimension passes (security, ecto, liveview) on the branch diff, classify findings, report a panel-value verdict. Use when the branch is fresh, before any codex review runs.
compound-docs	Searchable Elixir/Phoenix/Ecto solution documentation system with YAML frontmatter. Builds institutional knowledge from solved problems. Use when consulting past solutions before investigating new issues.
docs-check	\|
ecto-n1-check	Detect N+1 query anti-patterns specifically — Repo calls inside Enum/for
ecto-patterns	Ecto patterns — schemas, changesets, queries, migrations, Multi, associations, preloads, upserts. Use when editing Repo calls, Ecto.Query, or schema fields. Skip for Ash.
ecto:constraint-debug	Debug Ecto constraint violations - trace triggers, check migrations, find duplicate data. Use when seeing unique_constraint, foreign_key_constraint, or check_constraint errors.
ecto:n1-check	Detect N+1 query anti-patterns specifically — Repo calls inside Enum/for loops, missing preloads on associations. Use when N+1 is explicitly suspected, NOT for unrelated Ecto questions or wider database performance.