Elixir Phoenix Plugin for Claude Code

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 skills-only edition for the same 51 Elixir, Phoenix, LiveView, Ecto, Oban, testing, and security skills. See Use with Amp for the important differences from the full Claude Code plugin.

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; 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; 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 and the OpenCode 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

The install name stays elixir-phoenix, while its public workflow commands remain /phx:*. Claude Code now derives plugin command names from the plugin namespace and each skill's final command name. On a fresh install, it also pulls in two small compatibility namespaces for /ecto:* and /lv:* automatically; you do not need to install them separately. Existing v2 installations should follow the staged upgrade below. After an update, run /reload-plugins before trying the commands in an already-open session.

Updating from v2.x

Update the marketplace, install the two compatibility namespaces introduced in v3, then update the main plugin:

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

Installing the compatibility plugins first prevents the updated main plugin from entering a missing-dependency state. 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.

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 can install the plugin's 51 skills from the generated Agent Skills target. Project-local installation is recommended because it keeps the Elixir/Phoenix guidance scoped to the repository where it applies:

# Install into one Elixir/Phoenix project
cd /path/to/your-phoenix-project
amp skill add \
  https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/amp/skills \
  --target "$PWD/.agents/skills"

# Or install for every Amp workspace
amp skill add \
  https://github.com/oliver-kriska/claude-elixir-phoenix/tree/main/targets/amp/skills \
  --global

Amp copies skills at installation time; it does not update them automatically. Rerun the same command with --overwrite to install the latest version from main. Cloning this repository is only necessary for local development.

Namespaced Claude commands use hyphenated Amp names: /phx:plan becomes phx-plan, /ecto:n1-check becomes ecto-n1-check, and so on. Start a fresh Amp session after installation. To invoke the equivalent of /phx:investigate reliably, open Amp's command palette with Ctrl+O (or type / in the CLI), run skill: invoke, and select phx-investigate. Amp forces the selected skill to load with your next message