nexus-dev-toolkit

Developer workflow toolkit for Claude Code, OpenCode and Codex. Gives any team a structured Day 0 scaffold and repeatable Day 1 feature cycle via the EPAV methodology.

Documentation

Why

Ad-hoc AI prompting doesn't scale. Every dev prompts differently, context drifts, and nobody knows what the AI was told last sprint.

nexus-dev-toolkit gives your team a single workflow:

• Day 0 — scaffold the project once, production-grade, zero credentials needed
• Day 1 — every feature follows the same four steps: evaluate → plan → apply → validate

Every skill, every rule, every pattern lives in the project repo — versioned, shared, and enforced.

Setup

1. Install prerequisites

uv (recommended package manager):

curl -LsSf https://astral.sh/uv/install.sh | sh

Claude Code:

npm install -g @anthropic-ai/claude-code
claude login

graphify (strongly recommended) — builds a queryable knowledge graph of your codebase. EPAV skills query this graph to understand blast radius and cross-file dependencies before touching any code.

uv tool install graphifyy   # PyPI package name has double y; command is "graphify"
graphify install             # registers /graphify skill into Claude Code

codegraph (alternative to graphify) — a different knowledge-graph tool EPAV skills can use instead. Pick one, not both; nexus doctor warns if it finds graphs from both built in the same project.

npm i -g @colbymchenry/codegraph
codegraph install   # wires codegraph into Claude Code / OpenCode / etc.

2. Install nexus-dev-toolkit

uv tool install nexus-dev-toolkit

3. Initialize your project

cd my-project
nexus init .                                        # Claude Code (default), prompts for graphify/codegraph/none
nexus init . --tool opencode                        # OpenCode
nexus init . --tool codex                           # Codex
nexus init . --graph-backend codegraph              # skip the prompt, use codegraph

4. Place your reference docs

Before running /scaffold, put everything Claude needs in docs/:

docs/
├── arch-docs/   ← architecture doc, ADRs
├── figma/       ← Figma export ZIP
├── brd/         ← Business Requirements Document
└── prd/         ← Product Requirements Document

5. Start Day 0

Open the project in Claude Code and run:

/scaffold

/scaffold runs EVALUATE first then stops. You drive each phase by typing the next command:

/scaffold → (review) → /plan → (review) → /apply → (review) → /validate

6. Build the knowledge graph

After /scaffold completes, build whichever backend you chose at init:

/graphify .                              # if you chose graphify
codegraph install && codegraph init      # if you chose codegraph, run in your terminal

This generates graphify-out/graph.json or .codegraph/codegraph.db — EPAV skills use whichever is present, or fall back to full file reads if neither is built yet. Run nexus doctor any time to check which backend is active.

The Workflow

Day 0 — /scaffold (once per project)

Produces a production-grade project from your architecture document and Figma design: correct stack, mock auth, mock data, design system, AGENTS.md — zero external dependencies. Runs npm install && npm run dev (or equivalent) from commit one.

Day 1 — EPAV (every feature, every sprint)

/evaluate <task>  →  /plan  →  /apply  →  /validate

Each step is a built-in skill in .claude/commands/. Every task starts from the dev tasks CSV. Every task ends with acceptance criteria verified.

What nexus init Creates

settings.json/graphify.js below are only created if you pick graphify (the default) at the --graph-backend prompt. Pick codegraph instead and neither is scaffolded — codegraph wires and syncs itself via codegraph install && codegraph init.

Claude Code (nexus init .):

.claude/
├── commands/          ← EPAV skills + 5 reviewer skills (/code-review, etc.)
├── agents/            ← 5 reviewer subagents (code-reviewer, database-reviewer, etc.)
└── settings.json      ← PostToolUse: graphify auto-updates after every file edit (graphify backend only)
knowledge/
├── rules/             ← coding standards, arch decisions
├── patterns/          ← reusable implementation patterns
├── prompts/dev/       ← task prompt templates
└── retros/            ← retrospective notes
.mcp.json              ← MCP server config

OpenCode (nexus init . --tool opencode):

.opencode/
├── commands/          ← same EPAV skills + reviewer skills
├── agents/            ← same reviewer subagents (adapted for OpenCode)
└── plugins/
    └── graphify.js    ← tool.execute.after: graphify auto-update (graphify backend only)
knowledge/             ← same structure
opencode.json          ← MCP server config

Codex (nexus init . --tool codex):

.agents/skills/<name>/
├── SKILL.md           ← same EPAV + reviewer skills — invoke with $evaluate, $plan, …
└── agents/openai.yaml ← EPAV steps only: blocks implicit invocation, so Codex never starts $apply on its own
.codex/
├── agents/*.toml      ← same reviewer subagents (converted to Codex TOML)
├── config.toml        ← [mcp_servers.nexus] (appended — your existing config is never rewritten)
└── hooks.json         ← PostToolUse: graphify auto-update (graphify backend only)
knowledge/             ← same structure

Codex only loads project .codex/ config and hooks for trusted projects — trust the project when Codex asks.

Commands

nexus init .                      # Claude Code — set up .claude/ + knowledge/ + .mcp.json
nexus init . --tool opencode      # OpenCode — set up .opencode/ + knowledge/ + opencode.json
nexus init . --tool codex         # Codex — set up .agents/skills/ + .codex/ + knowledge/
nexus --version                   # show installed version
nexus update                      # update the CLI itself; asks whether to also sync in a real terminal
nexus update --sync               # skip the prompt, always sync the current project's skills/agents too
nexus sync                        # sync built-in skills & agents to latest (custom files untouched)
nexus doctor                      # validate project setup

nexus skill list                  # list all skills in .claude/commands/
nexus skill add my-review         # create a custom skill

nexus agent list                  # list all subagents in .claude/agents/
nexus agent add my-agent          # create a custom subagent

nexus rule list                   # list all rules in knowledge/rules/
nexus rule add api-standards      # create a project rule

MCP Server

nexus init writes .mcp.json automatically. For Claude Desktop, add manually:

{
  "mcpServers": {
    "nexus": {
      "command": "uvx",
      "args": ["--refresh", "--from", "nexus-dev-toolkit", "nexus-mcp"]
    }
  }
}

MCP Tools

Custom Skills

nexus skill add my-code-review
# Edit .claude/commands/my-code-review.md
# Type /my-code-review in Claude Code

Custom skills live alongside built-in skills in .claude/commands/ — versioned in your repo, shared across the team.

License

MIT