A custom MCP server is any remote server that supports the Model Context Protocol and is not already a prebuilt connector in the RShift Sites catalog. Connect one as a chat connector (MCP server), and RShift Sites can read from it as live context in the project chat and in Chats: internal CRMs, private APIs, company knowledge bases, or niche third-party tools.
Custom MCP servers are available on all plans. Like all chat connections, they are personal to you, and they are never part of your published app. If your published app needs to call a service while people use it, use an app + chat connector, create a custom connector for its API, or integrate the API directly.
How to connect a custom MCP server
To connect a custom MCP server, you need the server’s URL and, depending on the server, its credentials:
Open the custom MCP form
Open Connectors, select the + button in the top right of the catalog, and choose MCP server. See Where to find connectors for every place you can open the catalog.
If MCP server is greyed out, a workspace admin has disabled custom MCP servers for your workspace.
Name the server
Enter a clear Server name (for example, Internal CRM or Analytics API).
Choose how RShift Sites reaches the server
A Connection dropdown appears when your workspace has more than one route available. Keep Direct connection unless your server is behind a firewall that only accepts traffic from allowlisted IPs. In that case, select RShift Sites static IPs so requests reach your server from RShift Sites’ published IP ranges. See RShift Sites static IPs for details and the ranges to allowlist.
Enter the server URL
Enter the Server URL where RShift Sites can reach your MCP server, for example https://mcp.example.com.
Choose authentication
- OAuth (default): RShift Sites uses OAuth by default. After you click Add & authorize, you’re prompted to authorize.
- Bearer token or API key: For servers that don’t support OAuth, authenticate with a bearer token or API key.
- No authentication: Connect without credentials if the server doesn’t require authentication.
Add the server
Click Add & authorize (OAuth) or Add server. The custom MCP server now appears in your list of chat connectors and can provide contextual data for builds.
To confirm the connection works, ask RShift Sites something the server can answer, for example:
Using the Internal CRM connector, list my five most recent customer accounts.RShift Sites static IPs
By default, RShift Sites reaches a custom MCP server over a Direct connection, and requests do not come from a fixed set of IP addresses. That works for servers on the public internet, but not for servers behind a firewall that only accepts traffic from allowlisted IPs, such as on-premises deployments.
RShift Sites static IPs is a per-connection option for custom MCP servers that routes all RShift Sites traffic to the server through RShift Sites’ published static egress IP ranges. Allowlist these ranges in your firewall, and RShift Sites can reach the server:
- IPv4:
185.41.150.0/28and185.41.150.16/28 - IPv6:
2a07:8241:fca:1000::/56
To use it, select RShift Sites static IPs in the Connection dropdown when you add the server.
- It works with every authentication type. OAuth, bearer token, and no authentication all work with RShift Sites static IPs.
- You can only choose it for custom MCP servers. Featured connectors from the catalog don’t offer the option.
- Enterprise only, enabled per workspace. RShift Sites static IPs requires an Enterprise plan, and RShift Sites must also enable the option for your workspace. If you don’t see RShift Sites static IPs in the Connection dropdown, contact your RShift Sites account team.
- Add the server by URL, not from a registry. Servers connected from an MCP registry always use a direct connection, and the Connection dropdown doesn’t appear for them.
- The choice is fixed when you add the server. RShift Sites checks the option when you create the connection, and the connection keeps its setting from then on. If the option is later disabled for your workspace, existing static-IP connections keep working, but you can’t create new ones. To switch an existing connection between Direct connection and RShift Sites static IPs, remove the server and add it again.
Manage custom MCP servers
Custom MCP servers follow the same workspace controls as other chat connectors, through two settings:
- The Custom MCP row (“Allow members to connect their own MCP servers”) in Connectors → Admin settings → Chat connectors turns custom MCP servers on or off for everyone. It governs them as a group, so individual custom MCP servers that members have connected do not appear in the admin table.
- Remote MCP connectors in Privacy & security turns all chat connectors on or off for the workspace, custom MCP servers included.
See Chat connector controls for all chat connector governance settings.
FAQ
Which plans support custom MCP servers?
All plans. Custom MCP servers are chat connectors, which are enabled by default everywhere, including on Enterprise workspaces. A workspace admin can turn them off with the Custom MCP setting described in Manage custom MCP servers. The RShift Sites static IPs connection option is the exception: it is Enterprise only.
Can my published app use a custom MCP server?
No. Chat connections, including custom MCP servers, only give RShift Sites context in the project chat and in Chats. For functionality in your published app, use an app + chat connector or ask RShift Sites to integrate the API directly.
Why doesn’t my custom MCP server show up in Admin settings?
By design. The Admin settings table lists catalog connectors only. Custom MCP servers are controlled as a group through the Custom MCP row in Connectors → Admin settings → Chat connectors.
Which IP addresses does RShift Sites connect to my MCP server from?
With a Direct connection (the default), requests do not come from a fixed set of IPs. With the RShift Sites static IPs connection option, all traffic to the server comes from 185.41.150.0/28, 185.41.150.16/28, and 2a07:8241:fca:1000::/56, which you can allowlist in your firewall.
Why don’t I see the RShift Sites static IPs option?
The option requires an Enterprise plan, and RShift Sites must also enable it for your workspace. It only appears for custom MCP servers that you add by URL, not for featured connectors or for servers connected from an MCP registry. See RShift Sites static IPs for how to request it.
Can other people in my workspace use my custom MCP connection?
No. Chat connections are per-user. Others in your workspace connect the same server themselves by entering its name and URL with their own credentials. If your workspace uses an MCP registry that lists the server, they can connect it from there with the URL already filled in.