Use Assindo in ChatGPT (Make Real Phone Calls from ChatGPT)

ChatGPT can plan a phone call in seconds: who to ring, what to ask, what to say if they push back. What it cannot do on its own is pick up the phone. Assindo can. Assindo is an AI phone assistant: it calls businesses for you, works through phone menus, waits on hold, talks to whoever answers, and writes up what they said. Add Assindo to ChatGPT as a custom MCP server and ChatGPT can hand the call to Assindo, then read you the result.

What You Need

ChatGPT on the web, on a plan or workspace that lets you add custom MCP servers (see "Which ChatGPT plans can do this?" below).
An Assindo account. Free to create in the Assindo app (iOS, Android, or web at web.assindo.com). Calls use your Assindo plan's minutes.
The Assindo MCP server: https://mcp.assindo.com/mcp (Streamable HTTP, OAuth sign-in).

How to Connect It

1. Open ChatGPT on the web and go to ChatGPT Plugins (chatgpt.com/plugins). 2. Select the plus button, then Add custom MCP server. 3. Enter a name, for example Assindo, and optionally a description. 4. Under Connection, enter this Server URL: https://mcp.assindo.com/mcp 5. For authentication, choose OAuth. 6. Review the risk warning and select I understand and want to continue. 7. Select Create as a plugin, then review the tools ChatGPT found on the server. 8. Install the plugin and sign in with your Assindo account (Google, Apple or email, the same login as the app).

Assindo supports dynamic client registration, so there is no client ID or secret to paste: ChatGPT registers itself when you sign in. The Assindo sign-in page shows chatgpt.com with a Verified badge, so you know the request came from ChatGPT.

Let Assindo answer your calls and make them for you.

Get Assindo

To use it, type @ in the prompt box and select the Assindo plugin, then ask for the call.

Try It

"Call a bakery near me and ask if they can do a cake for 12 by Saturday."
A few minutes later: "How did the bakery call go?"
"Tomorrow at 9am, have Assindo call my internet provider and ask why my bill went up."

ChatGPT should ask the questions a good assistant would (which bakery, when is the party), then create the task. Assindo phones the bakery, asks about the cake, the price and how much notice they need, and the result shows up in the Assindo app and back in ChatGPT.

What ChatGPT Can Ask Assindo to Do

Assindo gives ChatGPT three tools, the same things you do in the Assindo app:

Create a task (create_task). A phone call (book, ask, cancel, follow up), a post on X or LinkedIn, something at a set time, or research. The task description is all Assindo sees, so ChatGPT should include the business, its number if known, exactly what to ask, and anything to avoid ("info only, do not book").
Check a task's result (get_task_result). The status, what Assindo found out, and the call summary. A call usually takes 2 to 5 minutes.
Send Assindo a message (send_chat_message). Ask what happened on a call, what is on your task list, or hand over a request in plain words.

Troubleshooting

I do not see "Add custom MCP server"

Custom MCP servers are a ChatGPT web feature, and whether you can add one depends on your plan and, in a workspace, on what your admin allows. Workspace permissions and security settings (including Lockdown) apply. If the option is missing, ask your workspace admin or check OpenAI's current plan details.

Which ChatGPT plans can do this?

OpenAI's help center describes custom MCP apps on ChatGPT on the web for Business, Enterprise and Edu workspaces, where admins control who can create them. Availability on other plans has changed several times, so check OpenAI's help center for your plan.

The sign-in keeps coming back

Create your Assindo account in the Assindo app first. The connector signs you in to an existing account; it does not create one, and a new login shows "no Assindo account for this sign-in".
Use the same sign-in method as the app (Google, Apple or email). A different Google account is a different Assindo account.
Finish the sign-in in the window ChatGPT opened, then return to ChatGPT. If it still loops, remove the plugin and add it again: a fresh sign-in replaces the old one.

A call did not happen

Calls follow the same rules as the app: business hours only, no redialing someone who just declined, and your Assindo plan's minutes. If your plan has run out of minutes, the task result says so; check your plan in the Assindo app.

FAQs

Does ChatGPT dial the number itself?

No. ChatGPT hands the job to Assindo as a task, and Assindo's own assistant places the call with the same rules as the app.

Does it cost extra?

No. Calls and tasks count against your normal Assindo plan, exactly as if you made them in the app.

Does it work in the ChatGPT desktop app or Codex?

The ChatGPT desktop app, the Codex CLI and the Codex IDE extension share Codex's MCP settings instead: see Use Assindo in Codex.

Does Assindo work with other AI apps?

Yes. The same server works in Claude, Meta Muse, OpenClaw and several coding tools: see the list of AI apps that work with Assindo. Assindo is also listed in the official MCP Registry as com.assindo/assindo.

---

Want ChatGPT to make your next phone call? Get Assindo and connect it.