What if my ChatGPT client does not support MCP?

Use the REST API instead. autoMessage publishes an OpenAPI 3.1 spec, which is exactly what a custom GPT Action consumes. Point a GPT at the spec, add your API key, and ChatGPT can call send, read, and search endpoints directly — no MCP required.

Do I need a Twilio number for ChatGPT to text?

No, and that is the point. Twilio and similar SMS APIs give you a new number, so your messages arrive as green-bubble SMS from a stranger. autoMessage sends through the Apple ID on your own Mac, so texts arrive as blue-bubble iMessages from the number your contacts already know.

Does this work with ChatGPT on mobile?

Indirectly. A custom GPT with an Action configured works anywhere you can use that GPT, including mobile, because the API call happens on OpenAI servers rather than on your phone. The send itself still runs through your Mac, which needs to be awake and signed in.

Can I use ChatGPT and Claude against the same account?

Yes. One autoMessage account, one Mac connector, and any number of clients on top. Many people run Claude for drafting and a scripted workflow for scheduled sends against the same iMessage account with no extra configuration.

Guide

Can ChatGPT send iMessages?

Yes — through a connector. ChatGPT can't reach Messages.app on its own. autoMessage bridges the gap two ways: an MCP server for ChatGPT clients that support MCP, and a REST API with a published OpenAPI spec for everything else — including custom GPT Actions. Both send from your own Mac and your own phone number.

Which connection method should you use?

Pick based on your client. If it supports MCP, use MCP — it's one config entry and the tools show up automatically. If it doesn't, the REST API covers the same ground and works from a custom GPT Action, a shell script, or any language that speaks HTTPS.

Option A — MCP server

Best for desktop clients with MCP support. Thirteen tools appear in the tool picker; no code to write. Same server that works with Claude, Cursor, Codex, and Cline.

MCP setup →

Option B — REST API + GPT Action

Best for custom GPTs and anything without MCP. Point the Action at our OpenAPI 3.1 spec, add your API key as an auth header, and ChatGPT can call the endpoints directly.

API reference →

How do you set up a custom GPT that sends iMessages?

Create a GPT, add an Action, and import the autoMessage OpenAPI spec. ChatGPT reads the spec and generates the tool definitions for you — send a message, list conversations, search history, manage contacts. Authentication is a single API key header.

1. Install the Mac connector and grab your key. The connector is a menu bar app that does the actual iMessage work. Your API key comes from the dashboard and is rotatable at any time.
2. Create a GPT and add an Action. In the GPT editor, choose Create new action, then Import from URL and paste the spec URL below.
3. Set authentication. Auth type API Key, custom header name X-API-KEY, value is your key. Save, and the GPT can text.

https://automessage.app/openapi.yaml

How is this different from using Twilio with ChatGPT?

Twilio gives ChatGPT a new phone number and sends SMS. autoMessage gives ChatGPT your number and sends iMessage. That changes three things that matter: the bubble is blue, the sender is someone your contact already trusts, and there's no per-message fee.

Sender identity: Your existing number, not a new one your contacts don't recognize.
Message type: Blue-bubble iMessage with read receipts and typing indicators, falling back to SMS only when the recipient isn't on iMessage.
Cost model: Flat monthly, no per-message charge.
Requirement: A Mac that stays awake and signed in — the tradeoff for sending as yourself.

Common questions

Can ChatGPT send iMessages?: Yes, with a connector. ChatGPT has no native access to Messages.app, but autoMessage exposes your iMessage account two ways ChatGPT can reach: as an MCP server for clients that support MCP, and as a plain REST API that works from a custom GPT Action or any code you write. Either path sends from your own Mac and your own number.
What if my ChatGPT client does not support MCP?: Use the REST API instead. autoMessage publishes an OpenAPI 3.1 spec, which is exactly what a custom GPT Action consumes. Point a GPT at the spec, add your API key, and ChatGPT can call send, read, and search endpoints directly — no MCP required.
Do I need a Twilio number for ChatGPT to text?: No, and that is the point. Twilio and similar SMS APIs give you a new number, so your messages arrive as green-bubble SMS from a stranger. autoMessage sends through the Apple ID on your own Mac, so texts arrive as blue-bubble iMessages from the number your contacts already know.
Does this work with ChatGPT on mobile?: Indirectly. A custom GPT with an Action configured works anywhere you can use that GPT, including mobile, because the API call happens on OpenAI servers rather than on your phone. The send itself still runs through your Mac, which needs to be awake and signed in.
Can I use ChatGPT and Claude against the same account?: Yes. One autoMessage account, one Mac connector, and any number of clients on top. Many people run Claude for drafting and a scripted workflow for scheduled sends against the same iMessage account with no extra configuration.

Let ChatGPT text from your number

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