Oct 8, 2026

Claude + JustCall: MCP Connector Setup and Limits

Yes, Claude works with JustCall through JustCall’s own MCP server. You add it as a custom connector and sign in with your JustCall API key and secret. Then Claude can read calls, texts, transcripts and AI summaries, send texts and build Sales Dialer campaigns. It can start a call only by sending out a JustCall AI Voice Agent, it can’t steer that call, and no JustCall event can start Claude. For AI calls you can watch and steer from Claude, add Carly Teams.

What JustCall offers Claude today

JustCall hosts an official remote MCP server (JustCall’s MCP server docs). As of October 8, 2026, it isn’t in Claude’s connector directory, so you add it by its address.

Sign-in runs through a JustCall page that asks for your API key and secret, and Claude works with that key’s access. API access starts on JustCall’s Team plan, and the Sales Dialer tools need Pro or above. JustCall’s older help guide routes Claude Desktop through Zapier MCP for a few actions, but the official server covers far more.

What Claude can do with the JustCall connector

Ask Claude to:

Catch up on calls by date, number, agent or direction, and add a disposition, notes or a rating.
Read what was said: transcripts, AI summaries and coaching insights for regular and Sales Dialer calls. Summaries are an add-on on Team and Pro, included from Pro Plus.
Text customers by SMS, MMS or WhatsApp from a JustCall number, read threads, and check whether someone replied.
Work your contacts: look one up, create or update it, or add it to your do-not-call list.
Build dialer campaigns: create a Sales Dialer campaign, assign reps, bulk-import contacts and pull campaign stats. Reps still run the dialer in JustCall.
Book meetings in an open slot on a JustCall calendar, and see which reps are available.

The full list of more than 60 tools is in JustCall’s MCP server repo.

How to connect Claude to JustCall

Copy your API key and secret. In JustCall, click your profile icon, then APIs and Webhooks, and copy both (JustCall’s API key guide).
Add the connector. In Claude, open Customize, then Connectors. Click + Add, then Add custom connector. Name it JustCall, paste https://mcp.justcall.host/mcp and click Continue.
Keep sign-in on. If Claude asks how it should identify itself to JustCall, choose Register automatically, which JustCall’s sign-in supports. Click Add.
Sign in with the key. Click Connect next to JustCall. A JustCall page asks for the API key and secret. Paste both, click Continue, and you land back in Claude.
Turn it on for the chat. Click + in the message box, then Connectors, and switch on JustCall.
Test with a read. Ask “Which calls did we miss on the sales line yesterday?” before you send anything.

On Team or Enterprise, an Owner adds JustCall first under Organization settings, then Connectors, Add, Custom and Web. Members then find it under Customize, then Connectors, and click Connect. Owners can also limit what a connector does for everyone, for example allow reads and block texts. On the Free plan, JustCall uses your one custom connector.

Where it works. The connector carries over to Claude Desktop, Cowork and the phone apps. In Claude Code, use the header JustCall documents: claude mcp add --transport http justcall https://mcp.justcall.host/mcp --header "Authorization: Bearer KEY:SECRET", with your own key and secret.

Can Claude make calls through JustCall?

Only through JustCall’s own AI. One tool sends a JustCall AI Voice Agent you’ve already built to call a number, with details like the person’s name passed in. JustCall’s agent does the talking. Claude isn’t on the line and can’t change the call’s course, since JustCall’s API can’t update a call in progress. It needs the AI Voice Agent add-on, runs at most 5 calls a minute, and asks Claude to confirm you have the person’s prior written consent.

No tool rings a rep’s phone or starts a dialing session. JustCall’s own AI also scores calls and coaches reps live on Pro Plus, inside JustCall.

The limits that matter

No JustCall trigger. Claude works when you ask, and its scheduled tasks run on a clock, hourly at most, on paid plans. JustCall can send a webhook the moment a call is missed or completed, but claude.ai has nowhere to receive it. Claude Code routines can start from a web request carrying the routine’s token, which JustCall’s webhooks can’t add. You’d build a relay in between.
Plan gates. API access and webhooks start on Team, Sales Dialer tools on Pro. Call summaries are an add-on below Pro Plus, and the AI Voice Agent is a paid add-on on every plan.
US texts need registration. JustCall warns that carriers can block or filter texts from numbers without A2P 10DLC registration.
Guard the key. The key and secret open your JustCall data. If they leak, reset the pair on the same APIs and Webhooks page.
Customer words are not orders. A text or transcript can hold instructions written by a stranger. Read every text Claude proposes.

JustCall work that runs on its own: Carly

Carly runs workflows in the cloud on a schedule, or when an email, form or calendar event comes in, with no chat open. You describe each one in plain English.

Connecting JustCall takes one step: at carlyassistant.com/integrations, open MCP servers, add JustCall’s server (the address above) and sign in with your key and secret. Or paste the API key and secret there directly. Then ask for things like:

“Every weekday at 8, find yesterday’s missed JustCall calls and send each caller we have an email for a short follow-up from my Outlook.”
“Every hour, find JustCall calls with the disposition ‘Demo’, create a HubSpot deal for each caller, and add the call summary as a note.”
“When someone fills out our demo form, add them to the Inbound campaign in JustCall’s Sales Dialer and email Josh their details.”

Carly also runs email sequences from each rep’s own Gmail or Outlook that stop when the person replies. Carly connects to thousands of apps, so the same workflow can update your CRM or book the callback. Pricing: Free Zapier-style workflows; AI agents from $35/month. To set these up from a Claude chat, add the Carly connector: Get the Carly connector

AI calls and texts from Claude: Carly Teams

Carly Teams gives Claude a business line it can call and text from. It runs on your team’s line in Carly, separate from your JustCall numbers. If your team already has a Twilio account, connect it on the Phone page in Carly. If not, the Carly team sets up a number with you on a short call. From the chat, Claude can:

Place calls with a live AI voice agent that does a task, like confirming a demo time, and reports back with a summary and transcript.
Watch a call live, send new instructions mid-call, or hang up.
Send and answer texts, and review missed calls and voicemail.
Build your agents: a voice agent that answers the line 24/7 or after hours, qualifies callers, books meetings on the team calendar, or transfers the call live to a person, in English or Spanish to match the caller. Or a text agent that texts back missed calls.
Reach new leads fast: the voice agent calls each new web lead within a minute of the form coming in.

Every call is logged with a summary and transcript, and the CRM updates based on how it went. Before any text or call, Claude confirms the team, the recipient and the message or task with you, within your team permissions.

Setup is one prompt. Paste it into a new Claude chat and it walks you through the same Add custom connector clicks as above, then checks that it can see your phone lines.

Carly business setup prompt

Paste this into ChatGPT, Claude, Grok or any AI agent. It connects your team's calls, texts, voicemail and voice agents, one step at a time.

Help me connect Carly Teams so I can work with my organization's business texts, phone calls, voicemail and voice/text agents from this chat.

I'll add Carly Teams to you myself. It isn't in any plugin or connector directory yet, so it gets added as a custom connection by URL: https://carlyassistant.com/team/mcp. Tell me exactly what to click for the app you are, one step at a time, and wait for me to confirm before moving on. If you can run the setup yourself (Claude Code, Codex, Muse, Grok Bot), go ahead.

1. Tell me how to add Carly Teams. Give me only the steps for the app you are:
- ChatGPT: I open https://chatgpt.com/plugins, click Add, and choose Create MCP App (not Create plugin or Upload plugin archive). If Create MCP App isn't on the menu, I turn on Developer mode first in Settings > Security and login. I name it "Carly Teams" with the description "Work with my team's business texts, calls, voicemail and voice/text agents," paste https://carlyassistant.com/team/mcp as the server URL, choose OAuth, create it, and sign in. Then in the message box I open the + menu, choose Developer mode, and pick Carly Teams. Don't have me build, package or upload a plugin.
- Claude (claude.ai, Claude Desktop, or Cowork): I go to Customize > Connectors > Add custom connector, name it Carly Teams, paste https://carlyassistant.com/team/mcp, and sign in.
- Claude Code: run claude mcp add --transport http --scope user carly-teams https://carlyassistant.com/team/mcp then I run /mcp, pick carly-teams, and authenticate.
- Codex: run codex mcp add carly-teams --url https://carlyassistant.com/team/mcp then codex mcp login carly-teams
- Cursor: I add {"mcpServers": {"carly-teams": {"url": "https://carlyassistant.com/team/mcp"}}} to ~/.cursor/mcp.json, then sign in to carly-teams from Customize.
- Muse: I create a Carly API key at carlyassistant.com/integrations (Advanced > API Keys > Create a new key, with organization read and write scopes for the actions I need). You build a custom connector to https://carlyassistant.com/team/mcp using the key as a bearer token and ask me for it in your secure credential prompt.
- Grok: I go to grok.com/connectors, choose New Connector, then Custom, paste https://carlyassistant.com/team/mcp, and sign in.
- Grok Bot: add a custom remote MCP server named carly-teams with https://carlyassistant.com/team/mcp, then I approve it and sign in.
- Perplexity: I go to Settings > Connectors > Custom connector > Remote, paste https://carlyassistant.com/team/mcp, and sign in.
- Anything else: I add a remote MCP server (streamable HTTP) named carly-teams with https://carlyassistant.com/team/mcp. It signs in with OAuth.
I sign in with the Carly account that belongs to my organization. If a step doesn't match what I see, ask me what's on my screen before giving the next one.

2. When I say it's added, check that you can see the Carly Teams tools, including list_phone_lines. If you can't yet, tell me how to turn Carly Teams on for this chat, or tell me to open a new chat and paste this prompt again.

3. Check it worked: call list_phone_lines to show the teams and phone lines I can access. Don't tell me it's connected until that call succeeds. If I have several teams, ask which to use. If the team needs a phone line, help me connect its existing Twilio account on the Phone page in Carly.

4. Ask what I want to do first, for example: "Review our missed calls and voicemail and help me reply to customers." I can also read and answer business texts, have the team's agent make a call, or edit the voice and text agents. Before sending texts or making calls, confirm the team, recipient and message or task with me. Respect my team permissions.

For my email, calendars, files, booking pages and workflows, add the regular Carly plugin as a separate connection. It's listed in ChatGPT's plugin directory (https://chatgpt.com/plugins/plugin_asdk_app_6a67a26316b88191860222f918d4ec54) and Claude's connector directory (https://claude.ai/directory/carly), and anywhere else it connects at https://carlyassistant.com/mcp/.

Then try:

“Have the agent call Michael to confirm tomorrow’s 2pm demo. Watch the call, and if he needs to move it, tell the agent to offer Thursday morning.”
“Set up our voice agent to answer the sales line after 6pm, book qualified callers on Claire’s calendar, and transfer anything urgent to Emily.”

See a call placed from the chat in the walkthrough video, or read can Claude make phone calls for the full setup.

Claude + JustCall vs Carly

	Claude + JustCall connector	Carly (JustCall server + Carly Teams)
Setup	Custom connector, sign in with your JustCall API key and secret	Add JustCall’s server or API key in Carly; one prompt for Carly Teams
Read calls, texts, transcripts	Yes, in a chat or a scheduled task	Yes, in a chat or on a schedule
Send a text	From a JustCall number	From a JustCall number in a workflow, or the team’s Carly line with a text agent that answers replies
React to a missed call	No JustCall trigger to fire on	Scheduled check, then email or text
AI calls	Sends out a JustCall AI Voice Agent, no steering	Live AI calls on the team’s Carly line, watched and steered from the chat
Lead follow-up	Drafted in the chat	Speed-to-lead calls, plus email sequences from your own inbox that stop on reply
Price	Your JustCall plan (API from Team) and Claude plan	Free Zapier-style workflows; AI agents from $35/month. The phone line is set up on a short call

FAQ

Is there an official JustCall MCP server for Claude?

Yes. JustCall hosts one and publishes setup steps for Claude. It isn’t in Claude’s connector directory, so add it as a custom connector with its address and sign in with your JustCall API key and secret.

Can Claude send texts through JustCall?

Yes, as SMS, MMS or WhatsApp from a JustCall number your key can reach. API access starts on the Team plan, and US numbers need A2P 10DLC registration before carriers deliver texts reliably.

Can Claude make calls on my JustCall number?

Only by sending out a JustCall AI Voice Agent you’ve built, which is a paid add-on, and Claude can’t steer that call. For calls Claude starts, watches and steers, Carly Teams places them with a live AI voice agent on your team’s Carly line.

Can Claude follow up on a missed JustCall call automatically?

Not on its own, since a missed call can’t start it. Carly can check JustCall on a schedule and send the follow-up from your own inbox.

Ready to automate your busywork?

Carly schedules, researches, and briefs you—so you can focus on what matters.

See what people say

"Before Carly, I relied on a Calendly link, but the whole process felt impersonal and not very professional. Carly changed that by handling all the back-and-forth, so I'm no longer stuck in endless email threads trying to line up schedules.

Now Carly reaches out to candidates, shares my real-time availability, lets them pick a slot, then sends a Zoom link and drops it straight into my calendar. She sends reminders to both of us before each call, which has significantly reduced no-shows and last-minute confusion.

On top of scheduling, Carly acts like a full executive assistant, sending me my schedule the night before so I can prepare for each call. It reminds me of the old x.ai assistant, but Carly is noticeably smarter, faster, and better suited to my healthcare recruitment business."

Gus Ibrahim, Founder & Director, IHR