Devin + AgentLine

Give Devin its own phone number

How do I give Devin a phone number?

You give Devin a phone number by installing the AgentLine skill, setting an API key, and buying a US or Canada number ($3.00 a month beyond your plan). Devin can start calls and retrieve transcripts; AgentLine hosts inbound and outbound voice at $0.12 a minute. This is a telephone number for the Devin coding agent, separate from Devin's on-call alerts.

Devin can use AgentLine to provision a number, start phone calls and read transcripts or incoming SMS. AgentLine hosts the conversation; a deployed application can provide live facts through a webhook.

Get an API key

One skill file

Install the AgentLine skill in Devin, set AGENTLINE_API_KEY, and ask it to provision a number. Deploy a persistent webhook handler separately if calls need application data.

text

Get yourself a phone number and call me. Follow https://agentline.cloud/skill.md

Why give Devin a phone number

A line for the autonomous engineer

Devin can follow up with a customer by voice the same way it opens a PR — without you sitting on the call.

Isolated identity per VM

Each Devin cloud machine gets its own number and transcripts. It never sends from your personal phone.

Text in, text out

AgentLine handles speech and normal conversation. The application Devin builds can return facts or explicit task results when the phone agent needs them.

Set up Devin

How the skill and the service land on this runtime.

1. Set your API key

Export AGENTLINE_API_KEY on Devin's cloud machine so the relay and the API can authenticate.

bash

export AGENTLINE_API_KEY="al_live_..."

2. Point a webhook at Devin

Deploy a persistent HTTPS application handler, verify webhook signatures, then register its URL. Test it with the coding session idle. Registering a URL alone does not create an always-available integration.

bash

curl -s -X POST https://api.agentline.cloud/v1/webhooks \
  -H "Authorization: Bearer $AGENTLINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"agent_id":"agt_xxx","url":"https://your-app.example.com/agentline"}'

Give a Devin-built application telephone calling

Guide updated 2026-10-18

Before you start

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.
A persistent application endpoint if calls need live application data. A temporary coding session is not an always-available webhook server.

1. Set up the phone agent

Have Devin read the AgentLine skill, use your API key securely and create a hosted phone agent. This adds telephone calling; it is separate from software incident-response and on-call workflows.

2. Test a self-contained call

Ask Devin to place a call to your own number with a callback-time question, then retrieve the final status and transcript. Complete this test before adding live tools.

3. Deploy the application integration

For live lookups, have Devin implement and deploy a persistent HTTPS webhook handler. Verify signatures and handle events using the current skill. Registering a URL alone does not implement the handler.

4. Test with the coding session idle

Verify that the deployed handler still responds when the development session is idle. AgentLine handles the conversation; the application supplies the requested facts or task result.

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.
Confirm that the webhook request reached the deployed application and that its result belongs to the correct call and turn.

Troubleshooting

Webhook returns an error or stops responding: Check deployment logs, signature verification and availability. Use a persistent application service, not a temporary development URL.
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

Does AgentLine work with Devin?

Yes. Install the skill, export AGENTLINE_API_KEY, and ask Devin to create an agent and buy a number.

Can Devin handle inbound calls while it is running a task?

The hosted phone agent can answer without the coding session. For live application lookups, deploy and test a persistent webhook handler that returns context for the correct call and turn.

Can I call a Devin agent on the phone?

Yes. Provision a number for the hosted phone agent Devin configures. AgentLine handles its conversation. To use live application tools, connect a persistent handler that returns facts; its output is not a script for every spoken turn.

Is there a number I can test against?

Call +1 (734) 471-3677 to hear a hosted AgentLine agent, then provision your own on a plan from $20/month.