UltraBuild is a standalone TypeScript/Node agentic harness for developers who want provider freedom, workflow discipline, portable tools, releaseable bundles, and a terminal UX that feels alive.

Build with every model. Ship with every agent. Control every tool.

UltraBuild borrows the best lessons from Pi CLI, Claude Code + Superpowers, Oh-My-Codex, Kimi Code, Codex CLI, Gemini CLI, OpenCode, Crush, Aider, Goose, and friends — then keeps the core small enough to understand.

Meet Flux, the UltraBuild forge-dragon: fast, friendly, slightly dangerous around unreviewed shell commands.

UltraBuild v0.1 is an actual MVP, not a landing page:

• interactive CLI and --print one-shot mode
• explicit modes: chat, build, plan, review, debug, workers, yolo
• OpenAI-compatible provider
• Anthropic provider
• deterministic mock provider for offline demos and tests
• JSONL sessions
• tools: read, write, edit, bash, list, grep
• approvals for write/edit/bash with visible yolo auto-approval mode
• markdown skills
• simple worker spawning
• Vibe Island event compatibility
• cross-platform doctor
• E2E and release bundle smoke tests
• official bundle matrix for Linux/macOS/Windows x64/arm64

git clone https://github.com/VoidChecksum/UltraBuild.git
cd UltraBuild
npm install
npm run build
node dist/cli.js doctor
node dist/cli.js --provider mock --print "hello UltraBuild"

Interactive mode:

node dist/cli.js

One-shot plan mode:

node dist/cli.js --mode plan --provider mock --print "plan a safe refactor"

Workers:

node dist/cli.js workers --count 2 --provider mock "summarize this repository"

UltraBuild produces portable Node bundles with dist/, docs/assets, and launchers:

Build all bundles locally:

npm run package:all
npm run smoke:release

Use a bundle:

# Linux/macOS
tar -xzf ultrabuild-linux-x64.tar.gz
./ultrabuild-linux-x64/bin/ultrabuild doctor

# Windows PowerShell
Expand-Archive ultrabuild-windows-x64.zip
.\ultrabuild-windows-x64\bin\ultrabuild.cmd doctor

See docs/RELEASES.md.

Modes change the system prompt, tool availability, approvals, and status metadata.

ultrabuild --mode review --print "review this branch"
ultrabuild --mode yolo --print "run the trusted release checklist"

Interactive slash commands:

/help
/theme
/doctor
/skills
/workers 3 compare provider adapters
/mode plan
/exit

UltraBuild can report session and tool events to VoidChecksum/vibe-island.

ultrabuild vibe status
ultrabuild vibe test
ultrabuild --no-vibe --print "run without island events"

Transport is best-effort and non-blocking:

• Unix: ~/.vibe-island/run/vibe-island.sock, fallback /tmp/vibe-island.sock
• Windows: \\.\\pipe\\vibe-island
• event source: _source: "ultrabuild"

UltraBuild emits session start, prompt, tool, approval, stop, and session-end style events in Vibe Island's hook-event JSON shape.

UltraBuild creates ~/.ultrabuild/config.json on first run.

OpenAI-compatible:

export OPENAI_API_KEY="sk-..."
ultrabuild --provider openai --print "review this repo"

Anthropic:

export ANTHROPIC_API_KEY="sk-ant-..."
ultrabuild --provider anthropic --print "plan a refactor"

ULTRABUILD_HOME overrides the config/session directory.

UltraBuild is an agentic harness. It can write files and run commands when you let it.

Defaults:

• read/list/grep are allowed
• write/edit/bash require approval
• plan and review are read-only
• --yes auto-approves for automation
• yolo auto-approves and is intentionally obvious
• dangerous shell patterns are flagged
• sessions log prompts, assistant output, tool calls, and approval decisions

UltraBuild CLI
├─ command router: interactive, print, doctor, init, workers, vibe
├─ UI: dependency-light ANSI neon renderer
├─ modes: chat/build/plan/review/debug/workers/yolo
├─ core runtime: config, sessions, providers, tools, skills, approvals
├─ providers: mock, OpenAI-compatible, Anthropic, future OAuth adapters
├─ tools: read, write, edit, bash, list, grep
├─ integrations: Vibe Island socket/named-pipe events
├─ release: OS/arch bundles + smoke tests
└─ workers: child/log based orchestration primitive

See docs/ARCHITECTURE.md.

npm install
npm test
npm run e2e
npm run package:all
npm run smoke:release

• v0.2: native tool calling, MCP, richer worker orchestration
• v0.3: full-screen TUI, model switching, session resume/tree
• v0.4: LSP context, git worktree worker isolation, review gates
• v0.5: ACP/IDE adapters, OAuth adapter plugins, package marketplace
• later: native single-file binaries, signing/notarization, richer sandboxing

MIT