> ## Documentation Index
> Fetch the complete documentation index at: https://docs.callem.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Channels
> Connect your agents to voice (phone) and chat (web) channels; configure telephony and widget routing.
# Channels
Channels are the bridge between your AI agents and users. Callem Studio is **multichannel**: the same agents can handle **voice** (phone) and **chat** (web widget) conversations. Additional channels (e.g. WhatsApp, social networks) are on the roadmap.
| Channel | Description |
| --------- | ------------------------------------------------------------------------------------------------------------- |
| **Voice** | Phone calls via SIP/telephony; configured with phone numbers and routing (see below). |
| **Chat** | Text conversations from the web widget or the test chat in the agent configuration; no phone number required. |
## Overview
For **Voice**, each channel typically represents a phone number or SIP endpoint linked to an agent. When a call arrives on that number, the assigned agent answers and begins the conversation. For **Chat**, the agent is exposed through the Callem Studio web interface (test chat) or an embeddable widget; the same agent configuration (workflow, tools, call analysis) powers both voice and chat.
***
## Voice Channel (Phone Numbers)
### Assigning an Agent
Go to **Deploy > Channels** to see all available phone numbers.
Click on the phone number you want to configure.
Choose the agent (single-prompt or workflow) that should handle calls on this number.
Save the configuration. Incoming calls to this number will now be handled by the assigned agent.
### Supported Features
| Feature | Description |
| ------------------ | -------------------------------------------------------------------------------------------- |
| **Inbound calls** | Receive calls — the assigned agent answers automatically with the configured welcome message |
| **Outbound calls** | Place calls using this number as the caller ID (used by campaigns) |
SIP trunking and number porting are on the roadmap. Contact **[contact@callem.ai](mailto:contact@callem.ai)** if you need custom telephony integration.
### Multi-Number Setup
You can assign the same agent to multiple numbers, or different agents to different numbers:
| Pattern | Example |
| ---------------------- | ------------------------------------------------------------ |
| **Language routing** | French number → French agent, English number → English agent |
| **Department routing** | Sales number → Sales agent, Support number → Support agent |
| **Geographic routing** | Regional numbers → location-specific agents |
| **Overflow** | Primary + backup number → same agent for high availability |
### A/B Testing (Weighted Agent Routing)
You can assign **multiple agents** to a single phone number with traffic split percentages. This enables A/B testing of different agent configurations on real calls.
#### Setting Up A/B Testing
Go to **Deploy > Channels** and find the phone number you want to configure.
Click **Add variant** to add a second agent to the number.
Choose a different agent for each variant (e.g. your current agent as control, a new prompt version as variant).
Use the slider or type a percentage for each variant. For example, 80% for the control and 20% for the new variant.
For each variant, use the **version dropdown** to pin a specific [published version](/build/agent-versioning) or leave it on "Draft". This lets you test a frozen configuration against a new draft.
Click the **Save** button that appears at the bottom of the phone number card. The button is only enabled when all variants have an agent selected and the total weight equals exactly **100%**. An **A/B Test** badge appears on the card.
#### How Routing Works
When a call arrives on a number with multiple agents configured:
1. The Voice Gateway reads the weight of each agent variant
2. A **weighted random selection** picks one agent for this call
3. The selected agent handles the entire call as if it were the only agent assigned
Each call is independently routed — there is no session stickiness or caller-based assignment.
#### Traffic Split Examples
| Configuration | Effect |
| ---------------------------------------- | ----------------------------------------------------------- |
| Agent A: 50%, Agent B: 50% | Even split — each agent handles roughly half the calls |
| Agent A: 90%, Agent B: 10% | Conservative test — only 10% of calls go to the new variant |
| Agent A: 33%, Agent B: 33%, Agent C: 34% | Three-way test |
#### Visual Feedback
The configuration UI provides:
* A **colored weight bar** showing the proportional split visually
* A **legend** with agent names and percentages
* A **warning** if the total weight does not equal 100%
The Save button is disabled until weights total exactly 100% and every variant has an agent selected. This prevents accidentally deploying an incomplete configuration.
#### Removing A/B Testing
To go back to single-agent mode, remove the extra variants by clicking the trash icon. The remaining agent is automatically set to 100%.
#### Backward Compatibility
Numbers without A/B testing configured continue to work exactly as before — the single assigned agent handles all calls. No migration is needed.
***
## Chat Channel
The **Chat** channel lets users talk to your agent via text in a browser. No phone number is required.
### Where Chat Is Available
| Context | Description |
| ----------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Test chat (Callem Studio)** | In **Build > Agents**, open an agent and use the **Test Chat** sidebar to run a conversation. Useful for development and QA. |
| **Web widget** | Embed the chat widget on your website or app; it connects to the same Voice Gateway chatbot service and uses the same agent (workflow, tools, knowledge base, call analysis). |
### Same Agent, Same Features
The same agent configuration powers both voice and chat: system prompt, workflow, tools, knowledge base, end-call and transfer tools, and **call analysis**. At the end of a chat session, call analysis runs on the message history (if configured) and the result is stored on the chat record, so you can filter and analyze chat sessions in **Monitor > Analytics** and **Monitor > Calls** (Chats tab) the same way as voice calls.
### Configuration
Chat uses the **Voice Gateway** chatbot service. Ensure the agent’s workflow and model are correctly set; the dashboard frontend connects to the chatbot via the configured socket URL. No per-channel assignment is needed for chat — each agent is available for chat from the moment it is configured.
***
## Best Practices
Always call your configured number from a personal phone to verify the agent responds correctly before publishing the number publicly.
After deployment, check **Monitor > Calls** regularly for dropped calls, poor transcription, or unexpected agent behavior.
Separating sales from support at the phone number level makes analytics cleaner and allows you to assign specialized agents to each function.