# Connect ChatGPT

> Turn on Developer Mode, add Stensul as an app with OAuth and your Client ID, then build emails from any chat.

Source: https://stensul.com/developers/quickstart/chatgpt/ · Last reviewed 2026-10-14

> **Not the Stensul admin?**
>
> Your **instance name** is the first part of your Stensul address (`northwind` in `northwind.stensul.com`). The [config generator](https://stensul.com/developers/config/?host=chatgpt) writes the exact settings and a message you can send your Stensul admin. Don't know who that is, or whether the MCP is turned on for your company? Ask your Stensul customer success manager, or email [help@stensul.com](mailto:help@stensul.com?subject=Stensul%20MCP%20access) from your work address.

> **ChatGPT's MCP support is in beta**
>
> OpenAI lists [MCP apps in ChatGPT as beta](https://help.openai.com/en/articles/12584461-developer-mode-and-mcp-apps-in-chatgpt) for Team and Enterprise plans, and it changes where the Developer Mode settings live from time to time. If a screen below doesn't match yours, OpenAI's guide has the current steps.

## 1. Create the API connection in Stensul

Needs admin access, the external API enabled and `access_admin_api_connections`.

1. Go to **Admin > Settings > API connections** and click **Add connection**.
2. **Authorization Type:** Authorization Code. Name: for example `mcp-chatgpt`.
3. Redirect URI: `https://mcp.stensul.com/<your-instance>/oauth/callback`
4. Enable **PKCE (Public)**.
5. Select the scopes your team needs. The first four cover drafting. The last three turn on the image gallery and audience versions; a tool whose scope is missing returns a 403. See [scopes](https://stensul.com/developers/authentication/#scopes).
   - `libraries:read`: read libraries
   - `emails:read`: read emails
   - `emails:write`: write emails
   - `images:write`: upload images (labeled **Write images**)
   - `dam:read`: browse the image gallery (labeled **Read Dam images**)
   - `dynamic-content:read`: read segment sets
   - `dynamic-content:write`: apply segment sets and write segment content

   The list shows other scopes too, such as `capabilities:read`, `modules:write`, `users:read` and `roles:read`. Leave them unchecked: the MCP doesn't use them.
6. Save. Copy the **Client ID** from the **Credentials** dialog, then click **I'm finished**. There is no secret.

## 2. Turn on Developer Mode

A ChatGPT workspace admin turns on **Developer Mode**. Apps don't appear until it's on. OpenAI moves this setting often, so follow [OpenAI's Developer Mode guide](https://help.openai.com/en/articles/12584461-developer-mode-and-mcp-apps-in-chatgpt) for where it is in your plan today.

## 3. Add the Stensul app

Only a ChatGPT workspace admin can add custom apps.

1. Open **Workspace settings > Apps** and click **Create (+)**.
2. MCP Server URL: `https://mcp.stensul.com/<your-instance>/mcp`
3. Authentication: **OAuth**.
4. Open **Advanced OAuth Settings**:

| Field | Value |
| --- | --- |
| Registration method | User-Defined OAuth Client |
| Client ID | From step 1 |
| Authorization server base | **Delete the default value. Leave empty.** |
| Registration URL | **Delete the default value. Leave empty.** |

Keep the pre-filled Auth URL, Token URL and Resource. Save.

> **The step people miss**
>
> ChatGPT pre-fills **Authorization server base** and **Registration URL**. The connection fails until both are empty. Leave **Resource** as ChatGPT fills it.

## 4. Sign in and draft an email

Each person finds the **Stensul** app in ChatGPT, connects it, logs in to Stensul and approves. You don't need to create a ChatGPT agent.

To use Stensul in a regular chat, type `@` followed by the app's name (for example `@Stensul`). ChatGPT can then call it for the rest of that chat:

```text
@Stensul Build a draft in the <library name> library announcing our new mobile
app. Start from the most relevant approved template, write real copy for every
editable text and button, and give me the edit link.
```

You're done when ChatGPT returns an edit link that opens the draft in Stensul. ChatGPT renders the preview inside the chat.

> **Use a chat, not an agent**
>
> ChatGPT agents aren't needed for Stensul, and the email preview tool doesn't work inside ChatGPT agents yet. Use the app from a regular chat.

## If something goes wrong

| What you see | Fix |
| --- | --- |
| Connection won't complete or errors on setup | Clear **Authorization server base** and **Registration URL**, keep the pre-filled Auth URL, Token URL and Resource, save, reconnect |
| No place to add an app | Developer Mode is off, or you aren't a workspace admin |
| ChatGPT answers without using Stensul | Type `@` and the app's name to add it to that chat |
| Setup asks for a client secret | Leave it blank. PKCE connections have none |
| Redirect error at sign-in | Redirect URI must be exactly `https://mcp.stensul.com/<your-instance>/oauth/callback` |
| Calls drop or fail now and then | MCP apps are in beta in ChatGPT. Wait a few minutes and try again |