MCP (Model Context Protocol) is an open standard for connecting AI applications to external systems.

You need three things:

1. a Sellizer account (you log in with it during the integration),
2. the ChatGPT app with support for custom connectors (custom connector / MCP) and permission to add connectors in that app – on some plans or company accounts, adding connectors may be restricted by the person with the highest permissions in the AI application,
3. the MCP server address: https://api.sellizer.com/mcp (one and the same for everyone).
​

How you connect depends on whether you have a Solo Plan account (or a single Team account), or you operate within an organization (team) in Sellizer:
1. Solo account / single Team account → you connect using just the address and login.
2. Organization / team in Sellizer → by default, the same as Solo (address + login). However, if the organization administrator has disabled "Open connection for the team" you'll need a client_id and client_secret, which you'll receive from them.

Not sure which case applies to you? Try the solo variant. If connecting with the address alone is blocked, ask your Sellizer administrator for the keys.

​Note: To add the Sellizer plugin in ChatGPT, you must have the highest permissions in it. If you can't add a new plugin, contact the person who manages your ChatGPT.

​Note: If you are not a person with permission to add custom plugins in ChatGPT, ask someone with those permissions to add the plugin according to the instructions.
Then all you have to do in "Plugins" is find Sellizer on the list, click "+," and log in to Sellizer.

1. In ChatGPT, open [Plugins → click "+" (New plugin)].
​
​

2. In the "Connection" section, add your custom connector and paste the address: https://api.sellizer.com/mcp.

3. Click the checkbox next to "I understand and want to continue," then click "Create."
4. Log in with your Sellizer account and approve access.

If you are the person with the highest permissions and you're adding the connector for the whole organization in ChatGPT, then after adding it, each user should find the option to connect to Sellizer in their own account settings, under the connectors tab.

You'll find organization-wide options in Sellizer: go to the "Organization" panel, where three tabs are available – "MCP Server" (server address, access toggle) "MCP Clients" (key creation) and "MCP Sessions" (oversight of active connections).

​For the administrator (or a person who has a custom role in Sellizer with access to the "Organization" panel) – how to set this up for the team

By default, you don't need to do anything:
The "Open connection for the team" toggle is on, so every team member connects using just the address and login (following the instructions above for the Solo Plan and single Team account), and the chat still only sees that person's own data.

Want to restrict access to selected people (or connect a server-side integration)? Turn off the toggle and issue keys:
1. Turn off the "Open connection for the team" toggle – from this moment on, no one can connect with the address alone (including people who are already connected).
2. In the "MCP Clients" tab, click "Add integration" – a client_id and client_secret will be created.
3. Copy the client_secret right away – it's shown only once, immediately after creation, and cannot be recovered later.
4. Pass the client_id and client_secret to the people who should have access.
​

You can oversee connections in the "MCP Sessions" tab: you can see all active connections (who, through which application, until when) and revoke any of them with a single click ("Revoke access") – handy when someone leaves the company.
​
​For the user – how to connect

​The administrator hasn't changed the settings → you connect the same way as solo: using just the address and login (see the "Solo or single Team account" section above).
​The administrator has restricted access → ask them for the client_id and client_secret, then follow the same steps as in the Solo or single Team account section above – just fill in the client_id and client_secret.
​

To fill in the client_id and client_secret, select "Advanced OAuth settings" → set "Registration method" to "User-defined OAuth client" → in the "URL address call" section, enter the client_id and client_secret received from the Sellizer Administrator.

​

Note: If you are not a person with permission to add custom plugins in ChatGPT, ask someone with those permissions to add the plugin according to the instructions.
Then all you have to do in "Plugins" is find Sellizer on the list, click "+," and log in to Sellizer.

What connected ChatGPT can do

ChatGPT reaches for the right data on its own, based on your question. Benefits for you:

​1. What language can I ask in?
​Any language, and ChatGPT will reply in the same one.

​2. I don't see the "MCP Integrations" tab.
The tab is available on the Team plan with an administrator or custom role (if you have access to the "Organization" panel).