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Connect ModelBrain to Devin Desktop

Devin Desktop's Cascade agent reads MCP servers from one JSON file, so connecting ModelBrain means adding one entry to it.

Devin Desktop is Windsurf renamed, and its MCP file still lives in a folder called windsurf. The old name is the one to look for, and a guide that points you at a folder called devin will send you to the wrong place.

Where the program lives

This client needs the full path to ModelBrain's mcp_server program. The commands and snippets on this page show the macOS path; on Windows or Linux, put the path for your system in the same place. Write the full path rather than a variable such as %LOCALAPPDATA% or ~, because a client may not expand it.

macOS

/Applications/ModelBrain.app/Contents/MacOS/mcp_server

Windows

C:\Users\you\AppData\Local\Programs\ModelBrain\mcp_server.exe (that is %LOCALAPPDATA%\Programs\ModelBrain\mcp_server.exe, with your own user name). Inside JSON, TOML or a quoted YAML string, double each backslash.

Linux

/home/you/.local/lib/modelbrain/mcp_server, with your own home folder. The install script puts ModelBrain in ~/.local/lib/modelbrain.

Steps

Install ModelBrain if you haven't yet (macOS, Windows or Linux).
Open the file from inside Devin Desktop. In the Cascade panel, click the MCPs icon at the top right, then choose Configure. That opens mcp_config.json. The file normally lives at ~/.codeium/windsurf/mcp_config.json, and you can create it there if it does not exist.

Add ModelBrain inside mcpServers. Keep any servers already listed.

{
  "mcpServers": {
    "modelbrain": {
      "command": "/Applications/ModelBrain.app/Contents/MacOS/mcp_server"
    }
  }
}

Save, then restart Devin Desktop.
Check it is connected. Look at the MCPs icon: a red mark means a server failed to connect. Then ask Cascade to remember something and recall it in a new chat.

Or use the setup wizard

Available in 0.5.0. Setup for Devin Desktop is in ModelBrain 0.5.0 and later. It is tested on sample files only, and the config location comes from the vendor's docs. We have not yet tried it on a real Devin Desktop install. If anything differs on your machine, use the manual steps above and tell us through the Support page.

Open Setup guide from the ModelBrain menu bar or tray icon.
Find the Devin Desktop card and click Set up Devin Desktop. The card appears only when Devin Desktop or its Windsurf folder is found. The wizard never creates a client's folders for you.
Let it write the entry. It adds modelbrain to ~/.codeium/windsurf/mcp_config.json, keeps your other servers, and saves a one-time copy of the original file next to it with the suffix .bak-original. If the file cannot be read as valid, the wizard stops and leaves it alone.
Restart Devin Desktop, then check that ModelBrain appears in its MCP servers.

Running the wizard twice is safe: it recognises its own entry and does nothing. The uninstaller removes only the entry that points at ModelBrain.app.

Questions

Does this cover Devin Local too?

No. Devin Desktop has two agents, the older Cascade and a newer Devin Local. This guide is for Cascade. Devin Local reads its own command line configuration, which we have not covered.

Why is the folder called windsurf?

The product was renamed but, as far as we can tell, the settings folder was not. If you cannot find the file, use the Configure button in the MCPs panel, which opens whichever file your version reads.

How do I undo it?

Remove the modelbrain entry and restart. Your memories are not stored in that file.

Has this been tested?

We have tested this configuration against sample files and the ModelBrain setup code, but not yet by hand on a real install of Devin Desktop. If ModelBrain does not appear in Devin Desktop after you follow these steps, tell us through the Support page and we will fix this guide.

Not installed yet?

Start with the install guide.

Install ModelBrain →

Then

A 10-minute walkthrough: add a folder, ask something that needs two notes, see the citation.

Quickstart →