---
summary: "Broadcast a WhatsApp message to multiple agents"
read_when:
  - Configuring broadcast groups
  - Debugging multi-agent replies in WhatsApp
status: experimental
title: "Broadcast Groups"
---

# Broadcast Groups

**Status:** Experimental  
**Version:** Added in 2026.1.9

## Overview

Broadcast Groups enable multiple agents to process and respond to the same message simultaneously. This allows you to create specialized agent teams that work together in a single WhatsApp group or DM — all using one phone number.

Current scope: **WhatsApp only** (web channel).

Broadcast groups are evaluated after channel allowlists and group activation rules. In WhatsApp groups, this means broadcasts happen when KaijiBot would normally reply (for example: on mention, depending on your group settings).

## Use Cases

### 1. Specialized Agent Teams

Deploy multiple agents with atomic, focused responsibilities:

```
Group: "Development Team"
Agents:
  - CodeReviewer (reviews code snippets)
  - DocumentationBot (generates docs)
  - SecurityAuditor (checks for vulnerabilities)
  - TestGenerator (suggests test cases)
```

Each agent processes the same message and provides its specialized perspective.

### 2. Multi-Language Support

```
Group: "International Support"
Agents:
  - Agent_EN (responds in English)
  - Agent_DE (responds in German)
  - Agent_ES (responds in Spanish)
```

### 3. Quality Assurance Workflows

```
Group: "Customer Support"
Agents:
  - SupportAgent (provides answer)
  - QAAgent (reviews quality, only responds if issues found)
```

### 4. Task Automation

```
Group: "Project Management"
Agents:
  - TaskTracker (updates task database)
  - TimeLogger (logs time spent)
  - ReportGenerator (creates summaries)
```

## Configuration

### Basic Setup

Add a top-level `broadcast` section (next to `bindings`). Keys are WhatsApp peer ids:

- group chats: group JID (e.g. `120363403215116621@g.us`)
- DMs: E.164 phone number (e.g. `+15551234567`)

```json
{
  "broadcast": {
    "120363403215116621@g.us": ["alfred", "baerbel", "assistant3"]
  }
}
```

**Result:** When KaijiBot would reply in this chat, it will run all three agents.

### Processing Strategy

Control how agents process messages:

#### Parallel (Default)

All agents process simultaneously:

```json
{
  "broadcast": {
    "strategy": "parallel",
    "120363403215116621@g.us": ["alfred", "baerbel"]
  }
}
```

#### Sequential

Agents process in order (one waits for previous to finish):

```json
{
  "broadcast": {
    "strategy": "sequential",
    "120363403215116621@g.us": ["alfred", "baerbel"]
  }
}
```

### Complete Example

```json
{
  "agents": {
    "list": [
      {
        "id": "code-reviewer",
        "name": "Code Reviewer",
        "workspace": "/path/to/code-reviewer",
        "sandbox": { "mode": "all" }
      },
      {
        "id": "security-auditor",
        "name": "Security Auditor",
        "workspace": "/path/to/security-auditor",
        "sandbox": { "mode": "all" }
      },
      {
        "id": "docs-generator",
        "name": "Documentation Generator",
        "workspace": "/path/to/docs-generator",
        "sandbox": { "mode": "all" }
      }
    ]
  },
  "broadcast": {
    "strategy": "parallel",
    "120363403215116621@g.us": ["code-reviewer", "security-auditor", "docs-generator"],
    "120363424282127706@g.us": ["support-en", "support-de"],
    "+15555550123": ["assistant", "logger"]
  }
}
```

## How It Works

### Message Flow

1. **Incoming message** arrives in a WhatsApp group
2. **Broadcast check**: System checks if peer ID is in `broadcast`
3. **If in broadcast list**:
   - All listed agents process the message
   - Each agent has its own session key and isolated context
   - Agents process in parallel (default) or sequentially
4. **If not in broadcast list**:
   - Normal routing applies (first matching binding)

Note: broadcast groups do not bypass channel allowlists or group activation rules (mentions/commands/etc). They only change _which agents run_ when a message is eligible for processing.

### Session Isolation

Each agent in a broadcast group maintains completely separate:

- **Session keys** (`agent:alfred:whatsapp:group:120363...` vs `agent:baerbel:whatsapp:group:120363...`)
- **Conversation history** (agent doesn't see other agents' messages)
- **Workspace** (separate sandboxes if configured)
- **Tool access** (different allow/deny lists)
- **Memory/context** (separate IDENTITY.md, SOUL.md, etc.)
- **Group context buffer** (recent group messages used for context) is shared per peer, so all broadcast agents see the same context when triggered

This allows each agent to have:

- Different personalities
- Different tool access (e.g., read-only vs. read-write)
- Different models (e.g., opus vs. sonnet)
- Different skills installed

### Example: Isolated Sessions

In group `120363403215116621@g.us` with agents `["alfred", "baerbel"]`:

**Alfred's context:**

```
Session: agent:alfred:whatsapp:group:120363403215116621@g.us
History: [user message, alfred's previous responses]
Workspace: /Users/user/kaijibot-alfred/
Tools: read, write, exec
```

**Bärbel's context:**

```
Session: agent:baerbel:whatsapp:group:120363403215116621@g.us
History: [user message, baerbel's previous responses]
Workspace: /Users/user/kaijibot-baerbel/
Tools: read only
```

## Best Practices

### 1. Keep Agents Focused

Design each agent with a single, clear responsibility:

```json
{
  "broadcast": {
    "DEV_GROUP": ["formatter", "linter", "tester"]
  }
}
```

✅ **Good:** Each agent has one job  
❌ **Bad:** One generic "dev-helper" agent

### 2. Use Descriptive Names

Make it clear what each agent does:

```json
{
  "agents": {
    "security-scanner": { "name": "Security Scanner" },
    "code-formatter": { "name": "Code Formatter" },
    "test-generator": { "name": "Test Generator" }
  }
}
```

### 3. Configure Different Tool Access

Give agents only the tools they need:

```json
{
  "agents": {
    "reviewer": {
      "tools": { "allow": ["read", "exec"] } // Read-only
    },
    "fixer": {
      "tools": { "allow": ["read", "write", "edit", "exec"] } // Read-write
    }
  }
}
```

### 4. Monitor Performance

With many agents, consider:

- Using `"strategy": "parallel"` (default) for speed
- Limiting broadcast groups to 5-10 agents
- Using faster models for simpler agents

### 5. Handle Failures Gracefully

Agents fail independently. One agent's error doesn't block others:

```
Message → [Agent A ✓, Agent B ✗ error, Agent C ✓]
Result: Agent A and C respond, Agent B logs error
```

## Compatibility

### Providers

Broadcast groups currently work with:

- ✅ WhatsApp (implemented)
- 🚧 Telegram (planned)
- 🚧 Discord (planned)
- 🚧 Slack (planned)

### Routing

Broadcast groups work alongside existing routing:

```json
{
  "bindings": [
    {
      "match": { "channel": "whatsapp", "peer": { "kind": "group", "id": "GROUP_A" } },
      "agentId": "alfred"
    }
  ],
  "broadcast": {
    "GROUP_B": ["agent1", "agent2"]
  }
}
```

- `GROUP_A`: Only alfred responds (normal routing)
- `GROUP_B`: agent1 AND agent2 respond (broadcast)

**Precedence:** `broadcast` takes priority over `bindings`.

## Troubleshooting

### Agents Not Responding

**Check:**

1. Agent IDs exist in `agents.list`
2. Peer ID format is correct (e.g., `120363403215116621@g.us`)
3. Agents are not in deny lists

**Debug:**

```bash
tail -f ~/.kaijibot/logs/gateway.log | grep broadcast
```

### Only One Agent Responding

**Cause:** Peer ID might be in `bindings` but not `broadcast`.

**Fix:** Add to broadcast config or remove from bindings.

### Performance Issues

**If slow with many agents:**

- Reduce number of agents per group
- Use lighter models (sonnet instead of opus)
- Check sandbox startup time

## Examples

### Example 1: Code Review Team

```json
{
  "broadcast": {
    "strategy": "parallel",
    "120363403215116621@g.us": [
      "code-formatter",
      "security-scanner",
      "test-coverage",
      "docs-checker"
    ]
  },
  "agents": {
    "list": [
      {
        "id": "code-formatter",
        "workspace": "~/agents/formatter",
        "tools": { "allow": ["read", "write"] }
      },
      {
        "id": "security-scanner",
        "workspace": "~/agents/security",
        "tools": { "allow": ["read", "exec"] }
      },
      {
        "id": "test-coverage",
        "workspace": "~/agents/testing",
        "tools": { "allow": ["read", "exec"] }
      },
      { "id": "docs-checker", "workspace": "~/agents/docs", "tools": { "allow": ["read"] } }
    ]
  }
}
```

**User sends:** Code snippet  
**Responses:**

- code-formatter: "Fixed indentation and added type hints"
- security-scanner: "⚠️ SQL injection vulnerability in line 12"
- test-coverage: "Coverage is 45%, missing tests for error cases"
- docs-checker: "Missing docstring for function `process_data`"

### Example 2: Multi-Language Support

```json
{
  "broadcast": {
    "strategy": "sequential",
    "+15555550123": ["detect-language", "translator-en", "translator-de"]
  },
  "agents": {
    "list": [
      { "id": "detect-language", "workspace": "~/agents/lang-detect" },
      { "id": "translator-en", "workspace": "~/agents/translate-en" },
      { "id": "translator-de", "workspace": "~/agents/translate-de" }
    ]
  }
}
```

## API Reference

### Config Schema

```typescript
interface KaijiBotConfig {
  broadcast?: {
    strategy?: "parallel" | "sequential";
    [peerId: string]: string[];
  };
}
```

### Fields

- `strategy` (optional): How to process agents
  - `"parallel"` (default): All agents process simultaneously
  - `"sequential"`: Agents process in array order
- `[peerId]`: WhatsApp group JID, E.164 number, or other peer ID
  - Value: Array of agent IDs that should process messages

## Limitations

1. **Max agents:** No hard limit, but 10+ agents may be slow
2. **Shared context:** Agents don't see each other's responses (by design)
3. **Message ordering:** Parallel responses may arrive in any order
4. **Rate limits:** All agents count toward WhatsApp rate limits

## Future Enhancements

Planned features:

- [ ] Shared context mode (agents see each other's responses)
- [ ] Agent coordination (agents can signal each other)
- [ ] Dynamic agent selection (choose agents based on message content)
- [ ] Agent priorities (some agents respond before others)

## See Also

- [Multi-Agent Configuration](/tools/multi-agent-sandbox-tools)
- [Routing Configuration](/channels/channel-routing)
- [Session Management](/concepts/session)
