The Companion

Web UI for Claude Code and Codex sessions.

Run multiple agents, inspect every tool call, and gate risky actions with explicit approvals.

Quick start

Requirements:

• Bun
• Claude Code and/or Codex CLI available on your machine

Run:

bunx the-companion

Open http://localhost:3456.

Alternative foreground command:

the-companion serve

Why this is useful

• Parallel sessions: work on multiple tasks without juggling terminals.
• Full visibility: see streaming output, tool calls, and tool results in one timeline.
• Permission control: approve/deny sensitive operations from the UI.
• Session recovery: restore work after process/server restarts.
• Dual-engine support: designed for both Claude Code and Codex-backed flows.

Screenshots

Chat + tool timeline	Permission flow

Architecture (simple)

Browser (React)
  <-> ws://localhost:3456/ws/browser/:session
Companion server (Bun + Hono)
  <-> ws://localhost:3456/ws/cli/:session
Claude Code / Codex CLI

The bridge uses the CLI --sdk-url websocket path and NDJSON events.

Development

make dev

Manual:

cd web
bun install
bun run dev

Checks:

cd web
bun run typecheck
bun run test

Docs

• Protocol reverse engineering: WEBSOCKET_PROTOCOL_REVERSED.md
• Contributor and architecture guide: CLAUDE.md

License

MIT