Agent Bridge

AgentBridge

[](https://github.com/raysonmeng/agent-bridge/actions/workflows/ci.yml) [](LICENSE)

[中文文档](README.zh-CN.md)

Local bridge for bidirectional communication between Claude Code and Codex inside the same working session.

AgentBridge uses a two-process architecture:

• bridge.ts is the foreground MCP client started by Claude Code via the AgentBridge plugin
• daemon.ts is a persistent local background process that owns the Codex app-server proxy and bridge state

When Claude Code closes, the foreground MCP process exits while the background daemon and Codex proxy keep running. When Claude Code starts again, it reconnects automatically with exponential backoff.

What this project is / is not

This project is:

• A local developer tool for connecting Claude Code and Codex in one workflow
• A bridge that forwards messages between an MCP channel and the Codex app-server protocol
• An experimental setup for human-in-the-loop collaboration between multiple agents

This project is not:

• A hosted service or multi-tenant system
• A generic orchestration framework for arbitrary agent backends
• A hardened security boundary between tools you do not trust

Features

• Bidirectional Claude ↔ Codex messaging in one working session — Codex output is intercepted and pushed to Claude as channel notifications; Claude replies via the reply MCP tool, injected into the Codex thread as a turn/start.
• Push delivery with fallback — messages arrive as channel notifications; a failed push falls back to an in-memory queue drained by get_messages. Loop prevention via the per-message source field.
• Turn coordination — a busy-guard rejects replies during an active Codex turn; a per-turn inactivity watchdog stops a lost turn/completed from locking injection forever; noisy intermediate events are collapsed so only meaningful agentMessage payloads reach Claude.
• Multiple pairs side by side — one Claude+Codex pair per project directory, ports allocated per pair in +10 strides from 4500. Pair-aware claude / codex / resume / kill / doctor / budget via --pair.
• Resilient lifecycle — a persistent background daemon survives Claude Code restarts (auto-reconnect with backoff); orphan-process cleanup; abg doctor read-only diagnostics; abg pairs prune reclaims stranded state.
• Thread auto-resume — bare abg codex resumes the pair's last Codex thread; abg resume prints/performs the resume commands for both sides.
• Budget coordination, slowdown-line & fully-automatic resume — keep a long task moving across subscription-quota windows instead of dying at a limit. See [Budget Coordination & Auto-Resume](#budget-coordination--auto-resume).

Architecture

┌──────────────┐     MCP stdio / plugin     ┌────────────────────┐
│ Claude Code  │ ──────────────────────────▶ │ bridge.ts          │
│ Session      │ ◀──────────────────────────  │ foreground client  │
└──────────────┘                             └─────────┬──────────┘
                                                       │
                                                       │ control WS (:4502)
                                                       ▼
                                             ┌────────────────────┐
                                             │ daemon.ts          │
                                             │ bridge daemon      │
                                             └─────────┬──────────┘
                                                       │
                                     ws://127.0.0.1:4501 proxy
                                                       │
                                                       ▼
                                             ┌────────────────────┐
                                             │ Codex app-server   │
                                             └────────────────────┘

Data flow

| Direction | Path | |-----------|------| | Codex -> Claude | daemon.ts captures agentMessage -> control WS -> bridge.ts -> notifications/claude/channel | | Claude -> Codex | Claude calls the reply tool -> bridge.ts -> control WS -> daemon.ts -> turn/start injects into the Codex thread |

Loop prevention

Each message carries a source field ("claude" or "codex"). The bridge never forwards a message back to its origin.

Prerequisites

| Dependency | Version | Install | |-----------|---------|---------| | Bun | v1.0+ | curl -fsSL https://bun.sh/install \| bash | | Claude Code | v2.1.80+ | npm install -g @anthropic-ai/claude-code | | Codex CLI | latest | npm install -g @openai/codex |

> Note: Bun is required as the runtime for the AgentBridge daemon and plugin server. Node.js alone is not sufficient.

Quick Start

Install via Plugin Marketplace (recommended)

Install AgentBridge directly from Claude Code using the plugin marketplace:

# 1. In Claude Code, add the AgentBridge marketplace
/plugin marketplace add raysonmeng/agent-bridge

# 2. Install the plugin
/plugin install agentbridge@agentbridge

# 3. Reload plugins to activate
/reload-plugins

Then install the CLI tool:

# 4. Install the CLI globally
npm install -g @raysonmeng/agentbridge

# 5. Generate project config (optional)
abg init

# 6. Start Claude Code with AgentBridge channel enabled
abg claude

# 7. Start Codex TUI connected to the bridge (in another terminal)
abg codex

> Tip: abg is a short alias for agentbridge. Both commands are identical — use whichever you prefer.

That's it. The daemon starts automatically when needed and reconnects if restarted.

Updating the plugin

When a new version is released, update from Claude Code:

/plugin marketplace update agentbridge
/reload-plugins

Or enable auto-update: run /plugin → Marketplaces tab → select agentbridge → Enable auto-update.

Install for local development

If you want to modify AgentBridge source code, use the local development setup instead:

# 1. Clone and install dependencies
git clone https://github.com/raysonmeng/agent-bridge.git
cd agent-bridge
bun install
bun link

# 2. Set up local plugin + project config
agentbridge dev     # Register local marketplace + install plugin
agentbridge init    # Check dependencies, generate .agentbridge/config.json

# 3. Start Claude Code with AgentBridge plugin loaded
agentbridge claude

# 4. Start Codex TUI connected to the bridge (in another terminal)
agentbridge codex

> Note: agentbridge claude injects --dangerously-load-development-channels plugin:agentbridge@agentbridge automatically. This loads a local development channel into Claude Code (currently a Research Preview workflow). Only enable channels and MCP servers you trust.

Updating after code changes

After modifying AgentBridge source code, re-run agentbridge dev to sync changes to the plugin cache, then restart Claude Code or run /reload-plugins in an active session.

CLI Reference

> All commands work with both agentbridge and the short alias abg.

| Command | Description | |---------|-------------| | abg init | Install plugin, check dependencies (bun/claude/codex), generate .agentbridge/config.json | | abg claude [args...] | Start Claude Code with push channel enabled. Runs with --dangerously-skip-permissions by default (opt out: --safe or AGENTBRIDGE_SAFE=1). Clears any killed sentinel from a previous kill. Pass-through args are forwarded to claude | | abg codex [args...] | Start Codex TUI connected to AgentBridge daemon. Bare abg codex auto-resumes the pair's last thread; use abg codex --new for a fresh thread. TUI launches run with --yolo by default (opt out: --safe or AGENTBRIDGE_SAFE=1; non-TUI subcommands like exec are never touched). Manages TUI process lifecycle (pid tracking, cleanup). Pass-through args forwarded to codex | | abg resume [claude\|codex] | No target: print the resume commands for this directory's last Claude Code session and this pair's current Codex thread. With a target: resume that side directly (delegates to abg claude --resume / abg codex resume-current) | | abg pairs | List registered pairs; abg pairs rm removes one; abg pairs prune previews reclaimable orphan dirs + stranded registry entries (cwd-gone, dead, >1 day), abg pairs prune --apply deletes them | | abg doctor [--json] | Read-only diagnosis: env, daemon health/readiness, build drift, artifact alignment, TUI attachment, logs | | abg budget [--json] | Both agents' subscription quota snapshot (5h/weekly windows, drift, pause state) | | abg logs [--codex] [-f] [-n N] | Tail this pair's daemon log (or the Codex wrapper log with --codex); -f follows, -n N sets the line count (default 100) | | abg kill | Gracefully stop this pair's daemon and managed Codex TUI, write killed sentinel; abg kill --all stops every pair | | abg dev | (Dev only) Register local marketplace + force-sync plugin to cache | | abg --help | Show help | | abg --version | Show version |

The pair-aware commands (claude, codex, resume, kill, doctor, budget, logs) accept --pair to target a specific pair — one pair per project directory by default, with ports allocated per pair in +10 strides from 4500.

Owned flags

Some flags are automatically injected and cannot be manually specified:

• agentbridge claude owns: --channels, --dangerously-load-development-channels
• agentbridge codex owns: --remote, --enable tui_app_server
• Both launchers consume the wrapper flag --safe (it is never forwarded): it disables the max-permission defaults for that launch. The defaults are also auto-suppressed when you pass any explicit permission flag yourself (-a/--ask-for-approval/-s/--sandbox for codex; --permission-mode/--allow-dangerously-skip-permissions for claude) — injecting --yolo next to an explicit approval policy is a hard codex CLI conflict.

Passing these flags manually will result in a hard error with guidance to use the native command directly.

> Note on flag positioning for agentbridge codex: For the bare TUI form > (agentbridge codex …), bridge flags are injected at the front. For TUI > subcommands that carry per-subcommand args (resume, fork), they are > injected after the subcommand name (so clap parses them as options of the > actually-invoked command, not the root). Non-TUI subcommands like exec, > mcp, plugin, remote-control, update etc. are passed through > unchanged — no bridge flags injected. See src/cli/codex.ts buildCodexArgs > for the full positioning logic.

Project Config

Running agentbridge init creates a .agentbridge/ directory in your project root:

| File | Purpose | |------|---------| | config.json | Machine-readable project config (Codex ports, turn coordination, idle shutdown) |

The config is loaded by the CLI and daemon at startup. Re-running init is idempotent and will not overwrite existing files.

File Structure

agent_bridge/
├── .github/
│   ├── ISSUE_TEMPLATE/           # Bug report and feature request templates
│   ├── pull_request_template.md
│   └── workflows/ci.yml          # GitHub Actions CI
├── assets/                        # Static assets (images, etc.)
├── docs/                          # Project growth timeline (stages 01-09; index: docs/README.md)
│   ├── 01-起步与v1协作核心.md       # Stage 1: bidirectional bridge + v1 collaboration core
│   ├── 02-Phase3产品化.md          # Stage 2: two-process architecture + CLI + plugin
│   ├── …(03-08)                    # release / reliability / multi-pair / protocol v2 / budget / v2 vision
│   └── 09-v3协作系统规格.md         # Stage 9: latest v3 cross-network collaboration spec
├── plugins/agentbridge/           # Claude Code plugin bundle
│   ├── .claude-plugin/plugin.json
│   ├── commands/init.md
│   ├── hooks/hooks.json
│   ├── scripts/health-check.sh
│   └── server/                    # Bundled bridge-server.js + daemon.js
├── src/
│   ├── bridge.ts                  # Claude foreground MCP client (plugin entry point)
│   ├── daemon.ts                  # Persistent background daemon
│   ├── daemon-client.ts           # WebSocket client for daemon control port
│   ├── daemon-lifecycle.ts        # Shared daemon lifecycle (ensureRunning, kill, startup lock)
│   ├── control-protocol.ts        # Foreground/background control protocol types
│   ├── claude-adapter.ts          # MCP server adapter for Claude Code channels
│   ├── codex-adapter.ts           # Codex app-server WebSocket proxy and message interception
│   ├── config-service.ts          # Project config (.agentbridge/) read/write
│   ├── state-dir.ts               # Platform-aware state directory resolver
│   ├── message-filter.ts          # Smart message filtering (markers, summary buffer)
│   ├── types.ts                   # Shared types
│   ├── cli.ts                     # CLI entry point and command router
│   └── cli/
│       ├── init.ts                # agentbridge init
│       ├── claude.ts              # agentbridge claude
│       ├── codex.ts               # agentbridge codex
│       ├── pairs.ts               # agentbridge pairs (list / rm / prune)
│       ├── doctor.ts              # agentbridge doctor (read-only diagnosis)
│       ├── budget.ts              # agentbridge budget (quota snapshot)
│       ├── kill.ts                # agentbridge kill
│       ├── pkg-root.ts            # package-root resolution helper
│       └── dev.ts                 # agentbridge dev
├── CLAUDE.md                      # Project rules for AI agents
├── CODE_OF_CONDUCT.md
├── CONTRIBUTING.md
├── LICENSE
├── README.md
├── README.zh-CN.md
├── SECURITY.md
├── package.json
└── tsconfig.json

Configuration

Environment Variables

| Variable | Default | Description | |----------|---------|-------------| | CODEX_WS_PORT | 4500 | Codex app-server WebSocket port | | CODEX_PROXY_PORT | 4501 | Bridge proxy port for the Codex TUI | | AGENTBRIDGE_CONTROL_PORT | 4502 | Control port between bridge.ts and daemon.ts | | AGENTBRIDGE_LIVENESS_PROBE_TIMEOUT_MS | 3000 | Maximum wait for incumbent Claude pong before evicting on contention (issue #68) | | AGENTBRIDGE_TURN_WATCHDOG_MS | 300000 | Per-turn inactivity watchdog: force-completes a turn after this many ms of app-server silence so a lost turn/completed can't lock injection forever (issue #69) | | AGENTBRIDGE_CODEX_TRANSPORT | auto | How the daemon reaches the Codex app-server: auto (probe codex app-server --help, use ws:// if supported else fall back to a unix:// socket via a transparent relay), ws (force ws), or unix (force unix socket + relay). For builds that drop ws:// listen support (issue #85) | | AGENTBRIDGE_STATE_DIR | Platform default | State directory for pid, status, logs (macOS: ~/Library/Application Support/agentbridge/, Linux: $XDG_STATE_HOME/agentbridge/) | | AGENTBRIDGE_DAEMON_ENTRY | ./daemon.ts | Override daemon entry point (used by plugin bundles) | | NO_UPDATE_NOTIFIER | unset | Set to any value to disable the "update available" notice (ecosystem-standard opt-out) | | AGENTBRIDGE_NO_UPDATE_NOTIFIER | unset | Namespaced opt-out for the update notice (same effect as NO_UPDATE_NOTIFIER) | | AGENTBRIDGE_UPDATE_PROMPT | unset | Set to 0 to disable the interactive update prompt and keep pure notice-only behavior | | AGENTBRIDGE_UPDATE_CHECK_INTERVAL_MS | 86400000 | How often abg claude/abg codex may check npm for a newer version (default once/day). The notice is otherwise printed from cache — zero network on most runs |

Update notifications

abg claude and abg codex print a one-line notice to stderr when a newer stable AgentBridge is published to npm, e.g.:

⚠ A

…

## Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [quilin-ai](https://github.com/quilin-ai)
- **Source:** [quilin-ai/agent-bridge](https://github.com/quilin-ai/agent-bridge)
- **License:** MIT

Install and usage instructions live in the source repository linked above.