Connect SellerLegend MCP to ChatGPT
This guide walks you through adding SellerLegend as a custom MCP app inside ChatGPT.
Prerequisites
- An active SellerLegend account (guest users cannot create connectors)
- A ChatGPT Plus, Pro, Business, Enterprise, or Edu subscription
Step 1: Enable Developer Mode
- Open ChatGPT
- Go to Settings (profile icon)
- Navigate to Apps & Connectors
- Scroll to Advanced Settings
- Toggle Developer Mode ON
INFO
Developer Mode is required to add a custom MCP app.
Step 2: Create the App in ChatGPT
- Go to Settings > Apps & Connectors
- Click Create → New App
- Fill in:
| Field | Value |
|---|---|
| Name | SellerLegend MCP |
| Description | (optional) Access Amazon seller data and analytics |
| MCP Server URL | https://dashboard.sellerlegend.com/mcp |
| Authentication | OAuth |
- Expand Advanced settings
Recent change (2026)
ChatGPT no longer uses a single fixed callback URL. Each custom app now gets its own per-connector callback URL that you must copy back to your OAuth client in SellerLegend. The legacy fixed URL (https://chatgpt.com/connector_platform_oauth_redirect) only continues to work for apps that were already published.
- Configure the advanced settings as follows:
| Field | Value |
|---|---|
| Registration method | User-Defined OAuth Client |
| Token endpoint auth method | client_secret_post |
| Default scopes | mcp:use (leave only this checked) |
- Copy the Callback URL ChatGPT shows in this section — it will look like:
https://chatgpt.com/connector/oauth/XXXXXXXXXXXX
WARNING
Keep this dialog open. You'll come back to paste the Client ID and Client Secret in a moment.
Step 3: Create the OAuth Client in SellerLegend
- In a new tab, log in to your SellerLegend account
- Go to Admin > Developers
- Click Create New Client
- Fill in:
| Field | Value |
|---|---|
| Name | ChatGPT MCP (or any name you prefer) |
| Redirect URL | paste the per-connector callback URL you copied from ChatGPT |
- Save. SellerLegend will generate a Client ID and Client Secret.
Step 4: Finish in ChatGPT
- Switch back to the ChatGPT New App dialog
- Paste the Client ID and Client Secret into the OAuth fields
- Click Create
- Click Connect / Authorize
- You'll be redirected to SellerLegend — log in and click Authorize
- You'll be returned to ChatGPT and the connector should show Connected
Verify
- Go to Settings > Apps & Connectors and open SellerLegend
- You should see the available tools listed (click Refresh if not)
- Start a new ChatGPT conversation and ask: "What Amazon accounts do I have connected?"
Start a new conversation
Existing chats will not see newly added tools. Always start a fresh conversation after connecting (and after enabling/disabling tools).
What to Do Next
- Read Example Prompts for ideas on what to ask
- Browse the Available Tools reference
- Check Troubleshooting if you run into issues