Agent Bridge

Modular bridge that connects chat platforms to AI agents. Each layer is independent — swap platforms or agents without touching the others.

Currently supports: Slack + Claude Code

┌──────────────┐     ┌──────────┐     ┌──────────────┐
│   Platform   │────▶│  Bridge  │────▶│    Agent     │
│   (Slack)    │◀────│ (Router) │◀────│ (Claude Code)│
└──────────────┘     └──────────┘     └──────────────┘
  Session owner       Pure routing      Purely invoked
  Locking & render    Key → ID map      Yields events
  UI logic            Concurrency       No UI knowledge

Quick Start

Prerequisites

• Python 3.12+
• uv
• Claude Code CLI installed and authenticated

Install

git clone https://github.com/htkuan/ai-agent-bridge.git
cd agent-bridge
uv sync

Configure

cp .env.example .env

Edit .env with your tokens:

# Required for Slack
AGENT_BRIDGE_SLACK_BOT_TOKEN=xoxb-your-bot-token
AGENT_BRIDGE_SLACK_APP_TOKEN=xapp-your-app-level-token

# Claude Code working directory
AGENT_BRIDGE_CLAUDE_WORK_DIR=/path/to/your/project

See Environment Variables for the full list.

Slack App Setup

1. Create a Slack App at api.slack.com/apps
2. Enable Socket Mode → generate an App-Level Token (xapp-...)
3. Add Bot Token Scopes (OAuth & Permissions):
   • app_mentions:read, chat:write, files:write, im:history, im:read
4. Subscribe to Events:
   • app_mention, message.im
5. Install to workspace → copy Bot User OAuth Token (xoxb-...)

Run

uv run agent-bridge

Usage

Action	How
Channel	@AgentBridge help me refactor this function
DM	Send a direct message to the bot
Continue conversation	Reply in the same Slack thread
Attach files	Upload files in the message — the agent receives download URLs

Each Slack thread is one agent session. The agent remembers context within a thread.

Architecture

The system has three independent layers:

Layer	Role	Docs
Platform Adapter	Owns session semantics, per-session locking, UI rendering	Slack Adapter
Bridge	Routes messages, maps session keys → IDs, enforces concurrency	Core — see below
Agent Controller	Executes prompts, yields generic events	Claude Agent

Event Model

All agent output flows through generic events — the shared language between agents and platforms:

Event	Description
Processing	Slot acquired, agent is starting
TextDelta	Incremental text from agent
StatusUpdate	Agent performing an action (tool use, etc.)
UserQuestion	Agent asking user for input
Completion	Agent finished (with cost, duration, error status)

Session Lifecycle

1. User sends message → Platform constructs session key (e.g. slack:{channel}:{thread_ts})
2. Bridge resolves key → UUID session ID (creates new if first message)
3. Agent runs with session ID (new session or resume existing)
4. Sessions expire after configurable TTL (default 72h)

Environment Variables

Variable	Required	Default	Description
ANTHROPIC_API_KEY	No	—	API key for the Claude Code CLI (skip if already authenticated via claude login)
AGENT_BRIDGE_SLACK_BOT_TOKEN	Yes (if using Slack)	—	Slack Bot User OAuth Token (xoxb-...)
AGENT_BRIDGE_SLACK_APP_TOKEN	Yes (if using Slack)	—	Slack App-Level Token for Socket Mode (xapp-...)
AGENT_BRIDGE_CLAUDE_WORK_DIR	No	.	Working directory for Claude Code
AGENT_BRIDGE_CLAUDE_PERMISSION_MODE	No	acceptEdits	Claude permission mode
AGENT_BRIDGE_CLAUDE_TIMEOUT_SECONDS	No	600	Per-invocation timeout (seconds)
AGENT_BRIDGE_CLAUDE_WORKTREE_ENABLED	No	false	Run each session in an isolated git worktree (requires origin/HEAD)
AGENT_BRIDGE_SESSION_STORE_PATH	No	./sessions.json	Session mapping file path
AGENT_BRIDGE_SESSION_TTL_HOURS	No	72	Session TTL (hours)
AGENT_BRIDGE_MAX_CONCURRENT_SESSIONS	No	5	Max concurrent agent processes
AGENT_BRIDGE_HEARTBEAT_ENABLED	No	false	Enable the heartbeat platform — fires a fixed prompt on a fixed interval
AGENT_BRIDGE_HEARTBEAT_INTERVAL_MINUTES	Yes (if heartbeat enabled)	—	Interval between heartbeat ticks (minutes)
AGENT_BRIDGE_HEARTBEAT_PROMPT	Yes (if heartbeat enabled)	—	Prompt sent on every heartbeat tick
AGENT_BRIDGE_HEARTBEAT_STATE_PATH	No	./heartbeat.json	Last-run timestamp path (used for restart catch-up)
AGENT_BRIDGE_LOG_LEVEL	No	INFO	DEBUG / INFO / WARNING / ERROR

Extending

Add a new platform

Create platforms/{name}/ with config.py and adapter.py. Implement the PlatformAdapter protocol. Define your session key format. See Slack Adapter docs for reference.

Add a new agent

Create agents/{name}/ with config.py, controller.py, and events.py. Implement the AgentController protocol — your run() yields BridgeEvents. See Claude Agent docs for reference.

Neither change requires modifying the bridge, the other agent, or the other platform.

Development

# Run tests
uv run pytest tests/ -v

# Run with debug logging
AGENT_BRIDGE_LOG_LEVEL=DEBUG uv run agent-bridge

Commits follow Conventional Commits (lowercase types: feat:, fix:, ...) and are enforced on PRs. Merging to main cuts a release automatically — see docs/releasing.md.

License

MIT