Elixir Phoenix Plugin for Claude Code

Docs: phxagents.dev -- install guides per runtime, the runtime compatibility matrix, all 26 Iron Laws, and a browsable skill and agent catalog.

Claude Code is great. But it doesn't know that assign_new silently skips on reconnect, that :float will corrupt your money fields, or that your Oban job isn't idempotent.

This plugin does. It coordinates 26 specialist agents that plan, implement, review, and verify your Elixir/Phoenix code in parallel -- each with domain expertise, fresh context, and enforced Iron Laws that catch the bugs your tests won't.

Using Amp? Install the generated edition for the same 51 Elixir, Phoenix, LiveView, Ecto, Oban, testing, and security skills, plus 40 deterministic workflow wrappers, five read-only specialist agents, parallel review/investigation, and native edit/verification guards, and the native PR watch lifecycle plugin. See Use with Amp for the important differences from the full Claude Code plugin, or the Amp install guide on phxagents.dev.

Using Codex? Install the native generated skills plugin for all 51 skills, including $elixir-phoenix:phx-investigate and $elixir-phoenix:phx-review workflows. See Use with Codex or the Codex install guide; a trust-gated destructive-command safeguard is included, while custom agents are intentionally not included and Tidewave MCP registration remains external.

Using Pi? Install the native generated skills package for all 51 skills, including Pi-compatible /skill:phx-investigate and /skill:phx-review workflows. See Use with Pi or the Pi install guide; extensions, prompt templates, MCP, and custom agents are intentionally not included yet. Tidewave can be used when the Pi host exposes it independently.

Using OpenCode? Install the generated skills-only target for all 51 skills, including phx-investigate and phx-review. In the tested OpenCode 1.17.2 setup, they are also available as /phx-investigate and /phx-review; the skill tool is the portable explicit interface. See Use with OpenCode, the OpenCode guide, or the OpenCode install guide.

Compare native invocation, installation, and deliberately deferred capabilities in the canonical runtime support matrix. Generated skills support does not imply full Claude Code feature parity.

# You describe the feature. The plugin figures out the rest.
/phx:plan Add real-time comment notifications

# 4 research agents analyze your codebase in parallel.
# A structured plan lands in .claude/plans/comment-notifications/plan.md
# Then:

/phx:work .claude/plans/comment-notifications/plan.md
# Implements task by task. Compiles after each change.
# Stops cold if code violates an Iron Law.

/phx:review
# 4 specialist agents audit in parallel:
# idioms, security, tests, compilation.
# Deduplicates findings. Flags pre-existing issues separately.

No prompt engineering. No "please check for N+1 queries." The plugin auto-loads the right domain knowledge based on what files you're editing and enforces rules that prevent the mistakes Elixir developers actually make in production.

┌─────────────────────────────────────────────────────────────────────┐
│  ⚗  Elixir/Phoenix Plugin for Claude Code                           │
│                                                                     │
│  ┌──────────┬──────────┬──────────┬──────────┬──────────┐           │
│  │    26    │    51    │   140    │    30    │    26    │           │
│  │  Agents  │  Skills  │   Refs   │Hook Regs │Iron Laws │           │
│  └──────────┴──────────┴──────────┴──────────┴──────────┘           │
│                                                                     │
│  AGENTS                          COMMANDS                           │
│  ─────────────────────           ──────────────────────────         │
│  Orchestrators (opus)            Workflow                           │
│    workflow-orchestrator           /phx:plan    /phx:work           │
│    planning-orchestrator           /phx:review  /phx:full           │
│    parallel-reviewer               /phx:compound /phx:quick         │
│    context-supervisor              /phx:brief   /phx:triage         │
│                                                                     │
│  Reviewers (sonnet)              Investigation & Debug              │
│    elixir-reviewer                 /phx:investigate /phx:trace      │
│    testing-reviewer                /ecto:n1-check   /phx:perf       │
│    security-analyzer (opus)        /ecto:constraint-debug           │
│    iron-law-judge                  /lv:assigns                      │
│                                                                     │
│  Architecture (sonnet)           Analysis & Review                  │
│    liveview-architect              /phx:audit    /phx:verify        │
│    ecto-schema-designer            /phx:techdebt /phx:boundaries    │
│    phoenix-patterns-analyst        /phx:pr-review /phx:challenge    │
│    otp-advisor                     /phx:research  /phx:document     │
│                                                                     │
│  Investigation (sonnet/haiku)    Knowledge (auto-loaded)            │
│    deep-bug-investigator           liveview-patterns  ecto-patterns │
│    call-tracer                     elixir-idioms      security      │
│    xref-analyzer                   phoenix-contexts   oban          │
│    verification-runner             testing   deploy   tidewave      │
│                                                                     │
│  Domain (sonnet)                 Hooks                              │
│    oban-specialist                 auto-format · auto-compile       │
│    deployment-validator            iron-law-verify · security-scan  │
│    hex-library-researcher          debug-stmt-detect · error-critic │
│    web-researcher (haiku)          progress-tracking · block-danger │
│                                                                     │
│  ───────────────────────────────────────────────────────────        │
│  26 Iron Laws · Tidewave-aware · plan→work→verify→review→compound   │
│  github.com/oliver-kriska/claude-elixir-phoenix                     │
└─────────────────────────────────────────────────────────────────────┘

v3.0.0 -- all 51 canonical skill trees have generated distributions for Amp, Codex, Pi, and OpenCode. Nine core workflows are fully adapted: the six flagship lifecycle workflows plus phx-trace, phx-audit, and phx-research. The remaining projections preserve domain knowledge but may require the runtime to translate Claude-specific orchestration. Claude Code remains the full canonical plugin; hooks, agents, MCP, instructions, and workflow portability intentionally vary by runtime. See the support matrix before assuming feature parity. Issues welcome.

Installation

Claude Code

From GitHub (recommended)

# In Claude Code, add the marketplace
/plugin marketplace add oliver-kriska/claude-elixir-phoenix

# Install the plugin
/plugin install elixir-phoenix

Requires Claude Code 2.1.110 or newer. The install name stays elixir-phoenix, while its public workflow commands remain /phx:* — Claude Code namespaces commands by the plugin's manifest name, not its install name. A fresh install also pulls in two small compatibility namespaces for /ecto:* and /lv:* automatically; you do not need to install them separately. After an update, run /reload-plugins before trying the commands in an already-open session.

Updating from v2.x

[!WARNING] Do not run claude plugin update on its own. v3 introduced two compatibility plugins (ecto, lv) that v2 never declared, and claude plugin update does not install dependencies a new version newly declares. The updated plugin then fails to load entirely — you lose all 36 /phx:* commands, not just /ecto:* and /lv:*. Install the two compatibility plugins first, using the exact order below.

claude plugin marketplace update oliver-kriska
claude plugin install ecto@oliver-kriska
claude plugin install lv@oliver-kriska
claude plugin update elixir-phoenix@oliver-kriska

Restart Claude Code afterward. In an already-open session, /reload-plugins reloads the updated skills, agents, and hooks. Confirm that /phx:help, /ecto:n1-check, and /lv:assigns appear before continuing work.

Already updated in the wrong order?

If claude plugin list reports ✘ failed to load with Dependency "ecto@oliver-kriska" is not installed, install the two compatibility plugins to recover — nothing is lost, and no reinstall is needed:

claude plugin install ecto@oliver-kriska
claude plugin install lv@oliver-kriska

Note that claude plugin install elixir-phoenix@oliver-kriska also repairs the state, but resolves only one missing dependency per run, so it needs two invocations here.

Commands are /phx:*, not /elixir-phoenix:*

Plugin versions before v3.0.0 shipped a manifest named elixir-phoenix, so their commands resolved as /elixir-phoenix:work even though /phx:init wrote /phx:* into CLAUDE.md. v3.0.0 renamed the manifest to phx, which is what makes /phx:* correct. If Claude Code reports /phx: commands as unknown, you are on a pre-v3 version — follow the upgrade steps above, then re-run /phx:init --update.

Claude Code subagent compatibility

No configuration is required. Claude Code 2.1.219+ defaults to a maximum subagent spawn depth of 3, so /phx:full, deep /phx:plan, parallel /phx:investigate, and /phx:trace can use their nested orchestrators. Claude Code 2.1.217–2.1.218 defaulted to depth 1; on those versions, or when you explicitly configure depth 1–2, the workflows keep orchestration in the main conversation and spawn leaf specialists directly. They preserve the same decisions, artifacts, verification, and review gates; only the agent topology changes.

To explicitly enable the full nested topology, start Claude Code with depth 3:

CLAUDE_CODE_MAX_SUBAGENT_SPAWN_DEPTH=3 claude

Depth 2 is sufficient for /phx:trace's call-tracer alone. This must be set in the environment that starts Claude Code; a plugin hook cannot change its parent process environment.

Multi-stack tip — project-scope enable. This plugin is opinionated for Elixir/Phoenix. If you work across multiple language stacks, prefer enabling it per-project rather than globally — drop this into <project>/.claude/settings.json:

{ "enabledPlugins": { "elixir-phoenix@oliver-kriska": true } }

Hooks self-gate on mix.exs presence (v2.10.1+), so global enable is safe — project-scoping is just a tidiness preference.

Companion plugin: catchup

The same marketplace also ships catchup — a framework-agnostic /catchup return-from-absence briefing (PRs, reviews, git, Linear, calendar → one prioritized Context Brief, including which upstream changes touch your in-flight files). Independent plugin, separate manifest, install only if you want it:

/plugin install catchup@oliver-kriska

See plugins/catchup/README.md. Not coupled to Elixir/Phoenix.

From Local Path (for development)

git clone https://github.com/oliver-kriska/claude-elixir-phoenix.git

# Option A: Add as local marketplace
/plugin marketplace add ./claude-elixir-phoenix
/plugin install elixir-phoenix

# Option B: Test the plugin and its command namespaces directly
claude \
  --plugin-dir ./claude-elixir-phoenix/plugins/elixir-phoenix \
  --plugin-dir ./claude-elixir-phoenix/plugins/ecto \
  --plugin-dir ./claude-elixir-phoenix/plugins/lv

Keep all three --plugin-dir arguments when testing public command compatibility. The main directory provides /phx:*; the ecto and lv directories provide the legacy /ecto:* and /lv:* aliases.

Use with Amp

Amp supports two profiles from the same generated snapshot:

• Hosted-native: publish the skills and plugin independently to Amp personal or workspace repositories. Use Amp's native skill: invoke command. The plugin still provides specialists, parallel analysis, and edit lock, but its filesystem wrappers cannot load hosted-only skills and native phx-full does not arm the plugin verification gate.
• Paired-full: install matching skills and plugin locally. This preserves all 40 phx:*/ecto:*/lv:* wrappers and the wrapper-activated phx-full gate.

Project-local paired installation is recommended for reproducible full behavior:

cd /path/to/your-phoenix-project

# Install the 51 skills into this project
amp skill add \
  https://github.com/oliver-kriska/amp-elixir-phoenix/tree/stable/skills \
  --target "$PWD/.agents/skills"

# Add deterministic workflows, read-only agents, and native guards
mkdir -p .amp/plugins
plugin=".amp/plugins/elixir-phoenix.ts"
temporary="$(mktemp "${plugin}.XXXXXX")"
curl --fail --silent --show-error --location \
  https://raw.githubusercontent.com/oliver-kriska/amp-elixir-phoenix/stable/plugins/elixir-phoenix.ts \
  --output "$temporary" && mv "$temporary" "$plugin"

Open Amp's command palette with Ctrl+O, run skill: invoke, choose phx-investigate, and send the bug details. This native path resolves the effective skill whether it is local, built-in, personal hosted, or workspace hosted. With paired-full, the familiar phx: investigate, phx: review, ecto: n1-check, and lv: assigns wrappers are also available; they inject the matching local skill for one turn. phx: full activates the plugin verification gate only through that wrapper, not through native skill: invoke.

amp skill add --global means machine-local, under ~/.config/agents/skills/; it is not personal hosted/account-wide. Personal hosted artifacts are managed through Amp's Personal Settings or personal Git repositories and work across machines and orbs. See the complete Amp guide for hosted publication, source precedence, wrapper limits, updates, fallback installation, specialists, safety boundaries, and verification.

phx-watch-pr additionally needs the separate phx-watch-pr.ts plugin. Install it into the project where the worker Orb opens and watches PRs:

mkdir -p .amp/plugins
plugin=".amp/plugins/phx-watch-pr.ts"
temporary="$(mktemp "${plugin}.XXXXXX")"
curl --fail --silent --show-error --location \
  https://raw.githubusercontent.com/oliver-kriska/amp-elixir-phoenix/stable/plugins/phx-watch-pr.ts \
  --output "$temporary" && mv "$temporary" "$plugin"

It holds a bounded Orb keep-alive lease, filters deployment-like checks out of readiness, persists reload-safe state, and wakes the same worker thread only for failed/cancelled required CI, unresolved feedback, and terminal outcomes. With --fix, actionable feedback and branch-owned CI failures are repaired in one serialized same-thread workflow. It never blindly reruns shared CI, merges, or deploys.

Use with Codex

Codex installs the generated target as a native skills plugin. Registration and installation are separate steps:

codex plugin marketplace add oliver-kriska/claude-elixir-phoenix --ref main
codex plugin add elixir-phoenix@oliver-kriska
codex plugin list

Start a fresh Codex session, then invoke workflows explicitly with $elixir-phoenix:phx-investigate or $elixir-phoenix:phx-review, browse them with /skills, or let Codex select a relevant skill from its description. Codex namespaces plugin skills; unqualified $phx-investigate is not an explicit alias. This edition also ships one synchronous native hook that blocks destructive Ecto resets/drops, unguarded force pushes, and accidental MIX_ENV=prod mix commands. Codex requires users to review and trust plugin hooks before they run; the skills work without it. Custom agents, plugin-root instructions, the remaining Claude hooks remain deferred; Tidewave MCP registration is external. See the complete Codex guide for updates, uninstall, isolation, troubleshooting, tested version, and capability details.

Use with Pi

Install the repository as a Pi package globally, or add -l to scope it to the current project:

pi install git:github.com/oliver-kriska/claude-elixir-phoenix
pi list

Start a fresh Pi session, then invoke workflows explicitly with /skill:phx-investigate or /skill:phx-review. Pi can also select a skill from its description automatically. This edition ships skills and their complete bundled resources only—not extensions, prompt templates, custom agents, or package-root instructions. Tidewave MCP registration is external. See the complete Pi guide for project-local installation, updates, uninstall, isolation, troubleshooting, tested version, and capability details.

Use with OpenCode

OpenCode 1.17.2 discovers the generated skills recursively. Install a sparse checkout into one project (recommended) or the global OpenCode config root:

git clone --filter=blob:none --sparse https://github.com/oliver-kriska/claude-elixir-phoenix.git .opencode/skills/elixir-phoenix
git -C .opencode/skills/elixir-phoenix sparse-checkout set targets/opencode

Start a fresh session and explicitly say “Use the skill tool to load the phx-investigate skill, then …”. In the tested OpenCode 1.17.2 setup, /phx-investigate and /phx-review also work when they do not collide with existing commands, but the skill tool is the documented portable interface. OpenCode selects the model implicitly. This target contains skills and complete bundled resources only—not hooks or custom agents. Tidewave MCP registration is external. Investigation, review, plan, work, PR-review, and full-lifecycle workflows are explicitly adapted; some other skills may still describe optional Claude-specific orchestration APIs. See the OpenCode installation and support guide for global setup, updates, uninstall, feature-branch review, discovery debugging, and limitations.

Getting Started

The remainder of this README describes the full Claude Code plugin and uses Claude Code /phx:*, /ecto:*, and /lv:* syntax. For generated runtimes, translate invocations using the runtime guide: Amp natively uses skill: invoke and paired-full also provides generated entries such as phx: investigate; Codex uses $elixir-phoenix:<skill>, Pi uses /skill:<name>, and OpenCode uses its skill tool. Generated editions do not install Claude Code's complete custom agent, lifecycle-hook, permission, or MCP configuration.

New to the plugin? Run the interactive tutorial:

/phx:intro

It walks through the workflow, commands, and features in 6 short sections (~5 min). Skip to any section with /phx:intro --section N.

Quick Examples

# Just describe what you need — the plugin detects complexity and suggests the right approach
> Fix the N+1 query in the user dashboard

# Plan a feature with parallel research agents, then execute
/phx:plan Add email notifications for new comments
/phx:work .claude/plans/email-notifications/plan.md

# Full autonomous mode — plan, implement, review, capture learnings
/phx:full Add user profile avatars with S3 upload

# 4-agent parallel code review (idioms, security, tests, compilation)
/phx:review

# Quick implementation — skip ceremony, just code
/phx:quick Add pagination to the users list

# Structured bug investigation with 4 parallel tracks
/phx:investigate Timeout errors in the checkout LiveView

# Project health audit across 5 categories
/phx:audit

The plugin auto-loads domain knowledge based on what files you're editing (LiveView patterns for *_live.ex, Ecto patterns for schemas, security rules for auth code) and enforces Iron Laws that prevent common Elixir/Phoenix mistakes.

How It Works

The Lifecycle

The plugin implements a Brainstorm, Plan, Work, Verify, Review, Compound lifecycle. Each phase produces artifacts in a namespaced directory:

/phx:brainstorm → /phx:plan → /phx:work → /phx:verify → /phx:review → /phx:compound
       │               │           │            │              │              │
       ↓               ↓           ↓            ↓              ↓              ↓
  interview.md    plans/{slug}/  (in namespace) (in namespace) (in namespace) solutions/

• Plan -- Research agents analyze your codebase in parallel, then synthesize a structured implementation plan
• Work -- Execute the plan task-by-task with quick compile checks after each change
• Verify -- Full verification loop (compile, format, credo, test) before review
• Review -- Four specialist agents audit your code in parallel (idioms, security, tests, static analysis)
• Compound -- Capture what you learned as reusable knowledge for future sessions

Key Concepts

• Filesystem is the state machine. Each phase reads from the previous phase's output. No hidden state.
• Plan namespaces. Each plan owns all its artifacts in .claude/plans/{slug}/ -- plan, research, reviews, progress, scratchpad.
• Plan checkboxes track progress. [x] = done, [ ] = pending. /phx:work finds the first unchecked task and continues.
• One plan = one work unit. Large features get split into multiple plans. Each is self-contained.
• Agents are automatic. The plugin spawns specialist agents behind the scenes. You don't manage them directly.

Plan Namespaces

Every plan gets its own directory with all related artifacts:

.claude/
├── plans/{slug}/          # Everything for ONE plan
│   ├── plan.md            # The plan itself (checkboxes = state)
│   ├── research/          # Research agent output
│   ├── reviews/           # Review findings (individual tracks)
│   ├── summaries/         # Compressed multi-agent output
│   ├── progress.md        # Session progress log
│   └── scratchpad.md      # Auto-written decisions, dead-ends, handoffs
├── reviews/               # Ad-hoc reviews (no plan context)
└── solutions/             # Compound knowledge (reusable across plans)

No more scattered files across .claude/planning/, .claude/progress/, .claude/reviews/. One plan, one directory, everything together.

Architecture

Agent Hierarchy

The plugin uses 26 agents organized into 3 tiers:

                    ┌──────────────────────────────┐
                    │  Orchestrators (opus model)  │
                    │  Coordinate phases, spawn    │
                    │  specialists, manage flow    │
                    └──────────┬───────────────────┘
                               │
        ┌──────────────────────┼──────────────────────┐
        │                      │                      │
        ▼                      ▼                      ▼
┌───────────────┐  ┌───────────────────┐  ┌────────────────────┐
│ workflow-     │  │ planning-         │  │ parallel-          │
│ orchestrator  │  │ orchestrator      │  │ reviewer           │
│ (full cycle)  │  │ (research phase)  │  │ (review phase)     │
└───────────────┘  └───────────────────┘  └────────────────────┘
                               │                      │
                    ┌──────────┼──────────┐    ┌──────┼──────┐
                    ▼          ▼          ▼    ▼      ▼      ▼
             ┌──────────┐ ┌────────┐ ┌──────┐ ... 4 specialist
             │ liveview │ │ ecto   │ │ web  │     review agents
             │ architect│ │ schema │ │ rsch │
             └──────────┘ └────────┘ └──────┘
                               │
                    ┌──────────┴──────────┐
                    ▼                     ▼
             ┌────────────┐      ┌──────────────┐
             │  context-  │      │ Orchestrator  │
             │ supervisor │ ───► │ reads ONLY    │
             │  (haiku)   │      │ the summary   │
             └────────────┘      └──────────────┘

Orchestrators (opus) -- Primary workflow coordinators, security-critical analysis. Specialists (sonnet) -- Domain experts, secondary orchestrators, judgment-heavy tasks. sonnet resolves to Sonnet 5 (CC's default, 1M context) -- near-opus quality at sonnet pricing. Lightweight (haiku) -- Mechanical tasks: verification, compression, dependency analysis.

The Context Supervisor Pattern

When an orchestrator spawns 4-8 research agents, their combined output can exceed 50k tokens -- flooding the parent's context window. The context-supervisor solves this using an OTP-inspired pattern:

┌────────────────────────────────────────────────────┐
│  Orchestrator (thin coordinator, ~10k context)     │
│  Only reads: summaries/consolidated.md             │
└──────────────────┬─────────────────────────────────┘
                   │ spawns AFTER workers finish
┌──────────────────▼─────────────────────────────────┐
│  context-supervisor (haiku, fresh 200k context)    │
│  Reads: all worker output files                    │
│  Applies: compression strategy based on size       │
│  Validates: every input file represented           │
│  Writes: summaries/consolidated.md                 │
└──────────────────┬─────────────────────────────────┘
                   │ reads from
     ┌─────────────┼─────────────┐
     ▼             ▼             ▼
  worker 1      worker 2      worker N
  research/     research/     research/
  patterns.md   security.md   liveview.md

How compression works:

The supervisor also deduplicates -- if two agents flag the same issue (e.g., both the security analyzer and code reviewer find a missing authorization check), it merges them into one finding with both sources cited.

Used by: planning-orchestrator (research synthesis), parallel-reviewer (review deduplication), audit skill (cross-category analysis).

How Planning Works

When you run /phx:plan Add real-time notifications:

1. planning-orchestrator analyzes your request
   │
2. Spawns specialists IN PARALLEL based on feature needs:
   ├── phoenix-patterns-analyst  (always -- scans your codebase)
   ├── liveview-architect        (if UI/real-time feature)
   ├── ecto-schema-designer      (if database changes needed)
   ├── security-analyzer         (if auth/user data involved)
   ├── oban-specialist           (if background jobs needed)
   ├── web-researcher            (if unfamiliar technology)
   └── ... up to 8 agents
   │
3. Each agent writes to plans/{slug}/research/{topic}.md
   │
4. context-supervisor compresses all research into one summary
   │
5. Orchestrator reads the summary + synthesizes the plan
   │
6. Output: plans/{slug}/plan.md with [P1-T1] checkboxes

How Review Works

When you run /phx:review:

1. parallel-reviewer collects your git diff
   │
2. Delegates to 4 EXISTING specialist agents:
   ├── elixir-reviewer      → Idioms, patterns, error handling
   ├── security-analyzer    → SQL injection, XSS, auth gaps
   ├── testing-reviewer     → Test coverage, factory patterns
   └── verification-runner  → mix compile, format, credo, test
   │
3. Each writes to plans/{slug}/reviews/{track}.md
   │
4. context-supervisor deduplicates + consolidates
   │
5. Output: plans/{slug}/summaries/review-consolidated.md

Hooks — the deterministic layer

Skills and agents are instructions a model may or may not follow. Hooks are shell scripts that always run. The plugin ships 23 of them across 10 lifecycle events:

• Block destructive commands — mix ecto.reset/drop, MIX_ENV=prod, force pushes are denied before they execute, with a safer alternative attached
• Verify Iron Laws on every edit — the lines you just wrote are scanned for :float money fields, String.to_atom on user input, raw/1 with a variable, implicit cross joins, unsupervised start_link
• Inject context where models can't reach it — all 26 Iron Laws into every spawned subagent; /phx: routing suggestions on PR URLs and stack traces
• Keep the plan workflow coherent — hard-stop after planning, re-inject phase rules and scratchpad dead ends across compaction
• Break debugging loops — repeated mix failures escalate from hints to a structured critic that consolidates the error history

Everything Elixir-specific self-gates on mix.exs, so the plugin is inert in your non-Elixir repos. Hooks fail open — a broken hook means the guard is off, never that the session is unusable.

→ HOOKS.md for the full list, the lifecycle diagram, and per-hook deep dives.

Usage Guide

Quick tasks (bug fixes, small changes)

Just describe what you need. The plugin auto-detects complexity and suggests the right approach:

> Fix the N+1 query in the dashboard

Claude: This is a simple fix (score: 2). I'll handle it directly.

Or use /phx:quick to skip ceremony:

/phx:quick Add pagination to the users list

Medium tasks (new features, refactors)

Use /phx:plan to create an implementation plan, then /phx:work to execute it:

/phx:plan Add email notifications for new comments

The plugin will:

1. Spawn research agents to analyze your codebase patterns
2. Show a completeness check (every requirement mapped to a task)
3. Ask you how to proceed (start implementation, review plan, adjust)

When starting implementation, the plugin recommends a fresh session for plans with 5+ tasks. The plan file is self-contained, so no context from the planning session is needed:

# In a new Claude Code session:
/phx:work .claude/plans/email-notifications/plan.md

Large tasks (new domains, security features)

Use deep research planning:

/phx:plan Add OAuth login with Google and GitHub --depth deep

This spawns 4+ parallel research agents, then produces a detailed plan. For security-sensitive features, the plugin will ask clarifying questions before proceeding. Or use /phx:full for fully autonomous development.

Fixing review issues

After implementing, run a review:

/phx:review

Four parallel agents check your code (idioms, tests, security, compilation). If blockers are found, the plugin asks whether to replan or fix directly:

Review found 2 blockers:
1. Missing authorization in handle_event -- security risk
2. N+1 query in list_comments -- performance issue

Options:
- Replan fixes (/phx:plan --existing)
- Fix directly (/phx:work)
- Handle myself

Project health checks

Run a comprehensive audit with 5 parallel specialist agents:

/phx:audit                    # Full audit
/phx:audit --quick            # 2-3 minute pulse check
/phx:audit --focus=security   # Deep dive single area
/phx:audit --since HEAD~10    # Audit recent changes only

The audit scores your project across 5 categories (architecture, performance, security, tests, dependencies) and produces an actionable report.

Full autonomous mode

For hands-off development:

/phx:full Add user profile avatars with S3 upload

Runs the complete cycle: plan (with research), work, verify, review. After review fixes, re-verifies before cycling back. Captures learnings on completion.

Workflow Tips

Context management

• /phx:plan creates a self-contained plan file with all implementation details
• For 5+ task plans, start /phx:work in a fresh session to maximize context space
• For small plans (2-4 tasks), continuing in the same session is fine

Resuming work

Plan checkboxes are the state. If a session ends mid-work:

# Just run /phx:work on the same plan -- it finds the first [ ] and continues
/phx:work .claude/plans/my-feature/plan.md

Splitting large features

When a feature has 10+ tasks across different domains, the plugin offers to split into multiple plan files:

Created 3 plans (14 total tasks):
1. .claude/plans/auth/plan.md (5 tasks -- login, register, reset)
2. .claude/plans/profiles/plan.md (4 tasks -- avatar, bio, settings)
3. .claude/plans/admin/plan.md (5 tasks -- dashboard, roles)

Recommended order: 1 -> 2 -> 3

Execute each plan separately with /phx:work.

Learning from mistakes

After fixing a bug or receiving a correction:

/phx:learn-from-fix Fixed N+1 query -- always preload associations in context functions
/phx:learn-from-fix --library ical --scope personal ICal.to_ics output needs CRLF line endings

This stores verified general lessons in personal ~/.claude/CLAUDE.md, project instructions, or project-keyed memory. The library route creates or safely updates native background knowledge at ~/.claude/skills/hex-<package>/SKILL.md (personal) or .claude/skills/hex-<package>/SKILL.md (project). Claude selects it from its description; dependency presence alone does not guarantee activation. Cached plugin files are never modified.

Iron Laws (Non-Negotiable Rules)

The plugin enforces critical rules and stops with an explanation if code would violate them:

LiveView: No database queries in disconnected mount. Use streams for lists >100 items. Check connected?/1 before PubSub subscribe.

Ecto: Never use :float for money. Always pin values with ^ in queries. Separate queries for has_many, JOIN for belongs_to.

Oban: Jobs must be idempotent. Args use string keys. Never store structs in args.

Security: No String.to_atom with user input. Authorize in every LiveView handle_event. Treat forms, hooks, and phx-value-* as user-controlled. IDs rendered in HTML or event payloads are public identifiers, not proof of access. Never use raw/1 with untrusted content.

Deployment: Keep core release secrets required, but gate credentials for optional services behind the feature that enables them. runtime.exs also runs when an eval-based migration boots the release, so unconditional S3 or Redis requirements can break unrelated migrations.

OTP: No process without a runtime reason. Supervise all long-lived processes.

Elixir: Declare @external_resource for compile-time files. Wrap third-party library APIs behind project-owned modules. Never use assign_new for values refreshed every mount.

Code style: Comments aren't commit messages — a change's reasoning goes in the commit/PR, not the code. No issue-reference tags inline (# ENA-1234).

Commands Reference

Workflow

Utility

Analysis

Security & dependencies

Agents (26)

Agents with project memory build up knowledge across sessions in .claude/agent-memory/<agent-name>/. Orchestrators remember architectural decisions; pattern analysts skip redundant discovery.

Reference Skills (Auto-Loaded)

These load automatically based on file context -- no commands needed:

Tidewave MCP Integration

When your Phoenix app runs with Tidewave, the plugin detects the local server and prefers its runtime tools. Add Tidewave to the application:

# Add to mix.exs
{:tidewave, "~> 0.6", only: :dev}

# Add to endpoint.ex (in dev block)
plug Tidewave

Then register the running endpoint with Claude Code, replacing $PORT with the Phoenix port:

claude mcp add --transport http tidewave \
  http://localhost:$PORT/tidewave/mcp

Use /mcp to verify the connection. The plugin does not silently register a fixed-port MCP endpoint. Once connected, Tidewave can execute Elixir code, run SQL queries, get documentation for exact dependency versions, introspect Ecto schemas, and read application logs.

Requirements

• Claude Code CLI
• Elixir/Phoenix project

Optional

• Tidewave for runtime debugging
• ccrider for session analysis (see Contributing)
• Ralph Wiggum Loop for autonomous iteration across context resets
• OpenAI Codex as an external reviewer: /phx:review --codex, /phx:full --codex, and /phx:codex-loop use the local codex CLI; /phx:watch-pr --codex uses the Codex GitHub connector. Install the shared Elixir review rubric into AGENTS.md via /phx:init. Users without codex are unaffected — all codex behavior is flag-gated

Security

This plugin runs skills, agents, and hooks inside Claude Code with your tool permissions, so it ships a verifiable security posture:

• Independently scanned with NVIDIA SkillSpector (static analysis, zero covert-egress findings): 66 / 77 components SAFE, 7 CAUTION, 4 DO_NOT_INSTALL raw. The four DO_NOT_INSTALL components are documented false positives with reviewed baselines, so after baselines 0 remain and the scan gate passes (the 7 CAUTION-tier components stay documented). A static scanner flags the safety-enforcing and security-auditing skills precisely because they name dangerous patterns in order to forbid or detect them (e.g. the line literally reads NEVER bypass security checks for speed).
• No telemetry or covert egress; workflows can make visible, user-authorized GitHub, Hex, web-search, or configured MCP calls through the host runtime. Review agents are read-only by default (source edits disallowed), and the Bash hooks are auditable in plugins/elixir-phoenix/hooks/ — every one of them is documented in HOOKS.md.

Full report, line-by-line triage, and a reproduce-it-yourself command live in SECURITY.md. Re-run the scan anytime with make security.

Contributing

PRs welcome! See CLAUDE.md for full conventions.

Quality Gate

Every PR must pass the CI quality gate (lint + test + eval). Run locally before pushing:

make help             # Show all available commands
make eval             # Quick: lint + score changed skills/agents only
make eval-all         # Full structural: all 51 skills + all 26 agents
make eval-fix         # Auto-fix lint + show failures + suggest autoresearch
make test             # Pytest suites for the eval framework and port tooling
make generated-skills-sync # Regenerate and verify all four runtime targets
make ci               # Full CI: lint + test + validate + eval + security (same as GitHub Actions)

The eval framework scores skills across 8 dimensions and agents across 5 dimensions. Skills must score >= 0.95 to pass. Run make eval-all for details.

Development Rules

• Skills: ~100 lines SKILL.md + references/ for details. Must include Iron Laws, "Use when..." in description.
• Agents: under 300 lines, disallowedTools: Write, Edit, NotebookEdit for reviewers, permissionMode: bypassPermissions always.
• All markdown passes npm run lint
• New skills/agents must pass npm run eval before merging
• Autoresearch: Run npm run eval:fix to auto-detect and fix quality issues

Autoresearch (Self-Improvement Loop)

The plugin includes an internal eval framework (lab/eval/) that scores all skills and agents. When quality drops, the autoresearch loop can fix it:

# Score everything, show failures, get auto-fix command
npm run eval:fix

# Or run the autoresearch loop directly (targets weakest skill, fixes one issue per iteration)
claude -p 'Run autoresearch...' --allowedTools 'Edit,Read,Write,Bash,Glob,Grep'

The eval framework uses 24 deterministic Python matchers plus a separate, fresh Haiku behavioral gate. make eval-full requires every skill to reach 75% trigger accuracy; ignored local result caches never affect structural CI. See lab/eval/ for details.

Analyze your sessions to improve the plugin

The plugin includes session analysis tools that help identify improvement opportunities. If you use this plugin (or work on Elixir/Phoenix projects with Claude Code), you can analyze your own sessions to find patterns that the plugin should handle better.

Setup:

1. Clone this repo: git clone https://github.com/oliver-kriska/claude-elixir-phoenix.git
2. Install ccrider MCP: claude mcp add ccrider -- npx @neilberkman/ccrider

Available tools (dev-only, not shipped with the plugin):

# Tier 1: Discover sessions and compute deterministic metrics
/session-scan
/session-scan --project myapp

# Tier 2: Qualitative analysis of high-signal sessions
/session-deep-dive
/session-deep-dive --date 2026-03-01

# Trends: Windowed aggregates (7d/30d/all) from metrics ledger
/session-trends
/session-trends --compare baseline
/session-trends --html out.html       # HTML report with ASCII bar charts

# Pure context-window stats (max tokens, ctx %, compaction rate) across raw JSONL
python3 .claude/skills/session-scan/references/compute-metrics.py \
  --scan-jsonl ~/.claude/projects/<project-id>/ \
  --since 2026-04-01 --html ctx-stats.html

# Skill effectiveness monitoring (requires session-scan data)
/skill-monitor                  # Dashboard: all skills
/skill-monitor --improve        # Generate improvement recommendations

What session analysis finds

• Friction points -- where you got stuck, repeated commands, abandoned approaches
• Workflow patterns -- how you work (planning vs diving in, tool usage)
• Plugin improvement opportunities -- missing automation, skills, or Iron Laws

Each analysis report includes a Plugin Improvement Opportunities section that identifies:

• Manual workflows that could be automated by a new skill or hook
• Code patterns that caused bugs but the plugin doesn't catch (Iron Law candidates)
• Missing skills or agents for common tasks
• Auto-loading gaps where skills should trigger but don't

Share these findings in issues or PRs to help make the plugin better for everyone.

Roadmap

• elixir-inspector (in progress) -- Separate plugin for 6-layer codebase analysis. Generates Credo checks, skills, CI steps, and review prompts from your project patterns. See the open PR.
• Tier 2/3 behavioral eval -- Instruction-following tests and full A/B skill comparison (with-skill vs without-skill outcome quality).
• Runtime eval integration -- Connect session metrics to the eval framework for measuring real-world skill effectiveness.

Sources and Inspiration

This plugin was built with insights from these articles, repositories, and tools:

Repositories and Tools

• https://github.com/tidewave-ai/tidewave_phoenix
• https://github.com/neilberkman/ccrider
• https://github.com/nicobailon/visual-explainer
• https://github.com/VoltAgent/awesome-claude-code-subagents
• https://github.com/shanraisshan/claude-code-best-practice
• https://github.com/anthropics/claude-code
• https://github.com/anthropics/claude-plugins-official
• https://github.com/anthropics/skills
• https://github.com/rjs/shaping-skills
• https://github.com/earendil-works/pi/blob/main/scripts/session-context-stats.mjs (badlogic — token usage / context % metrics, per-model + per-day breakdown, and ASCII-bar HTML report layout borrowed for compute-metrics.py --scan-jsonl and /session-trends --html)
• https://github.com/affaan-m/everything-claude-code
• https://github.com/blader/theorist
• https://github.com/tmchow/tmc-marketplace (iterative-engineering plugin)
• https://github.com/SamJHudson01/Carmack-Council (persona-grounded expert council review)
• https://github.com/obra/superpowers (verification discipline, CSO patterns)
• https://github.com/boshu2/agentops

Articles

• https://www.codecon.sk/search-is-not-magic-with-postgresql
• https://peterullrich.com/complete-guide-to-full-text-search-with-postgres-and-ecto
• https://peterullrich.com/efficient-name-search-with-postgres-and-ecto
• https://elixirmerge.com/p/exploring-postgresql-search-techniques-with-elixir-and-ecto
• https://tidewave.ai/blog/the-future-of-coding-agents-is-vertical-integration
• https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents
• https://openai.com/index/harness-engineering/
• https://www.ignorance.ai/p/the-emerging-harness-engineering
• https://martinfowler.com/articles/exploring-gen-ai/harness-engineering.html
• https://stripe.dev/blog/minions-stripes-one-shot-end-to-end-coding-agents
• https://boristane.com/blog/how-i-use-claude-code/
• https://mitchellh.com/writing/my-ai-adoption-journey
• https://www.thepragmaticcto.com/p/no-vibes-allowed-context-engineering
• https://basecamp.com/shapeup
• https://pragprog.com/titles/jwpaieng/a-common-sense-guide-to-ai-engineering/
• https://allanmacgregor.com/posts/setting-up-tidewave-beam-introspection
• https://theengineeringmanager.substack.com/p/councils-of-agents
• https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling
• https://arxiv.org/abs/2603.03329 (AutoHarness: improving LLM agents by automatically synthesizing a code harness)
• https://x.com/heynavtoor

License

MIT