Claude Duet + AgentLine
Give Claude Duet its own phone number
Can Claude Duet make phone calls?
Yes, through AgentLine. Add AgentLine as a connector in your Claude account and Duet carries it over, so it can create a hosted phone agent and provision a US or Canada number ($3.00 a month beyond your plan) once you approve. That phone agent places and answers real calls at $0.12 a minute and sends and receives SMS, and Duet reads the transcripts afterward.
Claude Duet already watches your inbox and calendar, drafts replies, and handles admin while you work. AgentLine covers the jobs that still need a phone: a real US or Canada number with a hosted voice agent, call transcripts, and two-way SMS that Duet can set up through your Claude connector and check on for you.
What is Claude Duet?
Claude Duet is Anthropic's proactive agent for professionals and small business owners. It launched on October 21, 2026 as a research preview by waitlist for US Pro and Max subscribers, on the web, iOS, and Android. Duet runs on Claude Opus 5.5 in its own virtual machine with a browser, checks your connected apps every few hours, sends a morning brief, and asks before it sends a message, makes a payment, signs a document, or deletes anything. It carries over the connectors, memory, and skills from your Claude account. AgentLine adds what Duet does not have: a real US or Canada phone number for a hosted phone agent that Duet can set up and check on for you.
- 01
Claude Duet
Plans the task and uses AgentLine through your Claude connector or its browser.
- 02
AgentLine
Hosts the phone agent, number, and voice.
- 03
Calls and SMS inbox
Make and receive calls; send and read texts.
An AgentLine number reaches your hosted AgentLine phone agent, not your Duet thread. Duet's own alerts and messages are Anthropic features and separate from this number. Live call handling runs on AgentLine; connecting Duet itself to live turns would require a persistent service.
Official product and artwork references: Introducing Claude Duet — Anthropic · Claude Duet product page and waitlist · Anthropic launches Claude Duet — MacRumors
Independent guide by AgentLine. Anthropic product names and artwork belong to Anthropic. Updated 2026-10-25.
One connector
Create the AgentLine account yourself, then add AgentLine as a custom connector in Claude with the URL https://api.agentline.cloud/mcp and approve access on the AgentLine consent page. Duet carries your Claude connectors over and asks before it sends a message or makes a payment.
Get yourself a phone number and call me. Follow https://agentline.cloud/skill.mdWhy give Claude Duet a phone number
Follow-ups that need a call
Duet flags the client who wants a callback or the supplier who only answers the phone. A hosted phone agent lets it close the loop instead of leaving you a reminder.
A dedicated business line
Calls and texts go through a separate US or Canada number, never your personal phone.
Approval before spending
Duet asks before it sends messages or makes payments. Buying a number and placing calls stay under your control.
Set up Claude Duet
Connect the tools, provision a number, and test the phone agent.
1. Connect AgentLine to your Claude account
Duet uses the connectors on your Claude account. Add AgentLine as a custom connector with the URL below, sign in to AgentLine, and press Allow. If the connector does not show up in Duet during the research preview, Duet can do the same setup in the AgentLine dashboard through its browser.
https://api.agentline.cloud/mcp2. Create the phone agent and number
Duet drafts the voice prompt and you approve it. Plans from $20/month include a number and minutes; beyond that, numbers cost $3.00/month and calls $0.12/min, billed per second after a one-minute minimum; SMS costs $0.02/message.
Read https://agentline.cloud/skill.md. Using the AgentLine connector, create a phone agent with the prompt I approve. Explain the costs, then check in with me before you provision a US or Canada number.3. Test the number and review results
Call the new number from your own phone, then have Duet read the transcript and the SMS inbox. For live lookups during a call, connect a persistent webhook service that AgentLine can reach.
I just called my new AgentLine number. Pull the latest call transcript and summarize it, and tell me about any texts this number received. Add anything that needs a reply to tomorrow's morning brief.Verify Claude Duet's phone connection
Guide updated
Before you start
- Claude Duet access (US Pro or Max research preview) and permission to add a custom connector to your Claude account.
- An AgentLine account with an API key, an active US or Canada number and available plan allowance or wallet credit. Check current terms on the pricing page.
- A destination number you control for the first test, plus a short approved instruction for the hosted phone agent.
1. Connect AgentLine to Claude
Add a custom connector with the URL https://api.agentline.cloud/mcp, sign in to AgentLine and allow access. Then ask Duet which AgentLine tools it can see. If none appear during the preview, use the AgentLine dashboard through Duet's browser instead.
2. Create a focused phone agent
Give Duet a greeting and one business task, such as returning a client's callback request. Review the hosted agent's prompt and the number purchase before you approve them.
3. Prove the connection with your own phone
Ask Duet to call your test number and collect a preferred callback time. After the call, ask for the call ID, final status and the transcript showing the answer.
4. Fold results into the morning brief
Ask Duet to check the AgentLine call log and SMS inbox on its regular rounds and flag anything that needs a reply. Live lookups during a call still need a persistent relay or webhook.
Check the result
- Keep the agent ID, assigned number and call ID. A successful create-call response means the call was requested, not that someone answered.
- Check the final call status and transcript. Compare the transcript with the task you asked the phone agent to complete.
- For a booking, payment or other external action, check the destination system too. Spoken agreement is not proof that a calendar or database was updated.
Troubleshooting
- Duet cannot see the AgentLine tools
- Check that the connector is enabled on the same Claude account Duet uses and that you pressed Allow on the AgentLine consent page. Reconnect it if the grant was revoked.
- Tools are missing or authentication fails
- Check that the MCP connection is enabled in this client and that AGENTLINE_API_KEY is available to its process. Do not paste your key into a public prompt or example.
- The call works but live lookups do not
- Test the relay or webhook separately. The hosted phone agent can speak without your runtime; live tools require a reachable, authenticated integration. Follow the skill for call.utterance and turn-scoped context replies.
Related guides
FAQ
What is Claude Duet?
Claude Duet is Anthropic's proactive agent, launched on October 21, 2026 as a research preview for US Pro and Max subscribers. It runs on Claude Opus 5.5 in its own virtual machine, checks your connected apps, sends a morning brief, and asks for approval before consequential actions.
Does Claude Duet have a phone number of its own?
Anthropic's announcement does not list a phone number, calling, or SMS. AgentLine supplies a US or Canada number for a hosted phone agent that Duet can set up and manage through your Claude connector.
Can I call Claude Duet on this number?
The number reaches your hosted AgentLine phone agent, which answers from the prompt you approved. It does not route into your Duet thread. Connecting Duet itself to live call turns requires a persistent integration service.
Will Duet spend money without asking?
Anthropic says Duet asks for approval before sending a message, making a payment, signing a document, or deleting anything. Ask it to confirm with you before buying a number or placing calls too.
How much does an AgentLine number for Claude Duet cost?
Plans start at $20/month with a US or Canada number and 100 minutes included. Beyond the plan, numbers cost $3.00/month and calls $0.12/min with per-second billing after a one-minute minimum; a 0-second call is free. SMS is $0.02/message. Duet itself is included in Claude Pro and Max and uses your Claude usage limits.
Is this an official Anthropic integration?
No. This is an independent AgentLine guide. Claude, Claude Duet, and the Duet artwork belong to Anthropic.