Connect the call
to everything else.

Keep your business logic in your own systems. Connect it to a conversation with API triggers, HTTP and MCP tools, and call-outcome webhooks.

Make your first browser call.

Create a workspace, connect your providers, and test an agent in your browser. You do not need a carrier account or phone number for this step. Your providers bill for model and voice usage.

1. Create a workspaceCreate a Winter account, then open your workspace.

2. Connect providersIn Voice & models, choose speech recognition, a language model, and a voice, or a realtime voice model. Enter your provider credentials and save the settings.

3. Create an agentChoose a template, name the agent, and write its instructions. Refine the conversation in the visual editor and save it.

4. Test in your browserIn the agent editor, select Test, then Test Audio and Run Test. Allow microphone access and try the questions your callers ask.

Invited workspaces can select the hosted Winter trial in Voice & models instead. It uses a fixed setup for browser voice tests only; the application shows your remaining allowance. Phone calls, text tests and other AI features require your own providers.

Create a workspace ↗Open voice settings ↗

Make the goal explicit.

Create a workflow in the visual builder. Give it an opening prompt, define what information it needs, and add conditions for the different paths a caller can take.

Give each stage a specific purpose.
Define the variables to capture from the caller.
Add tools and a phone-transfer destination where needed.
Test the draft, then publish a version.

See an example conversation ↗

Let your agent take action.

HTTP tools call your endpoints during a conversation. MCP tools connect to your configured MCP servers. Use either to retrieve information or perform the actions your workflow needs.

Your tools define the integration. A calendar, CRM, or booking system needs its own configured endpoint or MCP connection.

Example business data to collect — define the schema for your own tool.

{
  "customer_id": "customer_123",
  "intent": "service_enquiry",
  "preferred_day": "tomorrow",
  "handoff_requested": true
}

Keep the useful part of the call.

Choose which fields to extract, then review the transcript and recording. Configure post-call QA criteria and send outcomes to your systems through webhooks.

Webhook delivery includes retries and delivery tracking. Build your receiver to handle repeated delivery without repeating a business action.

Connect and test phone calls.

Once the browser conversation works, connect your carrier in Phone numbers, import a number, and publish the agent. Assign the published agent to your number for inbound calls. Browser tests do not verify telephone routing or transfers.

Verify inbound routing and outbound caller identity.
Check credentials and public callback URLs.
Test tools against the intended environment.
Confirm carrier transfers with a real phone call.
Review saved recordings, extracted fields, and webhook delivery.

Open phone number settings ↗

Build the conversation your business needs.

Connect your own voice and model providers, build an agent, and test it in your browser. Add a phone number when you’re ready for calls.

View walkthrough Start building