> ## Documentation Index > Fetch the complete documentation index at: https://docs.callers.ai/llms.txt > Use this file to discover all available pages before exploring further. # One agent, every channel > How Callers agents work across phone, web calls, SMS, WhatsApp, and email, and which features each channel supports. Callers agents are not limited to the phone. The same building blocks (scripts, variables, actions, success criteria, webhooks, and contact memory) work across voice, web calls, SMS, WhatsApp, and email. You learn one editor and one results model, and your contacts can move between channels without starting over. ![Three devices showing the same appointment confirmation in Gmail, in a voice call, and in WhatsApp](https://mintcdn.com/voxiaai/UGuY0UNIphM-6pUX/images/brand/omnichannel-devices.webp?fit=max\&auto=format\&n=UGuY0UNIphM-6pUX\&q=85\&s=3db4c6c97db628c16d7b84e087cb232f) The same appointment confirmation delivered by email, as a voice call, and over WhatsApp from one agent. ## Channels at a glance | Channel | Agent type | How contacts reach it | Typical uses | | - | - | - | - | | **Phone, outbound** | Voice | The agent dials your contact list | Lead qualification, reminders, collections, surveys | | **Phone, inbound** | Voice | Contacts call your number | Support, intake, booking, after-hours lines | | **Web call and widget** | Voice, with web calls accepted | A button or widget on your site or app | Speak-to-sales, onboarding, in-app help | | **SMS** | Text (Twilio or Telnyx) | Agent texts first, or contact texts your number | Follow-ups, confirmations, re-engagement | | **WhatsApp** | Text | Agent starts with an approved template, or contact messages you | Follow-ups, support, international outreach | | **Email** | Email | Agent sends from your connected mailboxes and reads replies | Outreach sequences, nurturing, replies at scale | You choose the channel when you [create an agent](https://docs.callers.ai/documentation/build-your-agent/starting-a-new-agent.md). Web calls are a setting on a Voice agent, so one agent can take phone calls and web calls with the same script. ## What each channel supports | Capability | Phone (outbound) | Phone (inbound) | Web call / widget | SMS | WhatsApp | Email | | - | :-: | :-: | :-: | :-: | :-: | :-: | | Script (blocks and steps) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ ¹ | | Variables | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | Pre-conversation actions | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | In-conversation actions | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | Post-conversation actions | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | Knowledge base | ✓ | ✓ | ✓ | — ² | — ² | ✓ | | Success criteria | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | Post-conversation analysis (summary, key questions) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | Webhooks | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | | Automatic follow-ups | Dial retries | — | — | Follow-up messages | Follow-up messages | Follow-up sequence | | Contact memory | ✓ | ✓ | ³ | ✓ | ✓ | ✓ | | Pre-call chat (text before calling) | ✓ | — | — | Used as the pre-call channel | Used as the pre-call channel | — | ¹ Email agents can also send a human-written template instead of AI-written content. ² Knowledge base retrieval isn't available for text agents at this time. Put the facts a text agent needs in its script, scenarios, or instructions. ³ Not verified for web calls. Contact [support@callers.ai](mailto:support@callers.ai) if you need memory on web calls. Voice-only features include voices and emotions, patience and interruption settings, keypad input, call transfers, voicemail handling, and recording. Email adds mailbox rotation, send limits, and an optional human approval queue. ## Bridge text and voice with pre-call chat Pre-call chat connects a text channel to an outbound voice agent. Before dialing, the agent sends an SMS or WhatsApp message asking whether the contact is open to a call, then acts on the reply.
    Pre-call chat on an outbound voice agent Contacts who agree expect the call and answer more often. Contacts who decline aren't called. See [Pre-call chat](https://docs.callers.ai/documentation/build-your-agent/pre-call-chat.md). ## Contact memory across channels With contact memory on, the agent saves useful facts from each conversation, such as preferences, commitments, or reasons for declining. The next conversation starts with that context, so the agent doesn't ask the same questions twice. Memories belong to the contact. Across agents in your organization, they are matched by phone number, so a contact who texted your SMS agent last week can be greeted with that context when your voice agent calls. You can turn off memory per agent, or stop an agent from using memories created by other agents. See [Contact memory](https://docs.callers.ai/documentation/contacts/contact-memory.md). ## One results model Every channel produces the same kinds of results: * **Outcomes** from your [success criteria](https://docs.callers.ai/documentation/results/success-criteria.md), such as goal reached, not interested, or a custom outcome like "Follow-Up Scheduled." * **Summaries and key questions** from [post-conversation analysis](https://docs.callers.ai/documentation/using-callers/key-questions.md). * **Webhooks** for each channel's events, so one endpoint can receive call, chat, and email results. See [Webhook events](https://docs.callers.ai/documentation/webhook/webhook-events.md). * **Post-conversation actions** that update your CRM or trigger the next step, based on the outcome. This means you can route a contact from one channel to another with an outcome and an action. For example, send an SMS follow-up when a call ends with "Call me later," or have an email agent pick up contacts a voice agent couldn't reach. ## Build without code, or with the API Everything on this page can be set up in the dashboard, with help from [Studio Chat](https://docs.callers.ai/documentation/build-your-agent/studio-chat.md) if you prefer to describe what you want. Developers can create agents, add contacts, start and stop agents, and receive results through the [API](https://docs.callers.ai/api-reference/introduction.md) and [webhooks](https://docs.callers.ai/documentation/webhook/webhook-overview.md). Web calls can be embedded with the widget or the [Web SDK](https://docs.callers.ai/sdk/overview.md). ## Related > **[Create an agent](https://docs.callers.ai/documentation/build-your-agent/starting-a-new-agent.md)** > > Pick a channel and generate a script. > **[Text agents](https://docs.callers.ai/documentation/text-agents/overview.md)** > > SMS and WhatsApp setup. > **[Email agents](https://docs.callers.ai/documentation/email-agents/overview.md)** > > Mailboxes, sequences, and approvals. > **[Web call widget](https://docs.callers.ai/documentation/widget-agents/installing-the-widget.md)** > > Add voice to your website. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.