Cursor

One JSON entry in mcp.json, global or per project, and your coding agent reads the company brain while it works.

With the brain connected, Cursor's agent reads your company's technical decisions, conventions and system cards before it edits a file, and it can file what it learns back. One JSON entry, one login.

At a glance

Works on	Cursor on macOS, Windows and Linux
Plans	Any plan with MCP support (all current plans)
Sign-in	OAuth. Cursor shows a login button next to the server
Time	Two minutes
Instructions live in	User Rules (global) or `.cursor/rules/` (per repo)

Step 1: add the brain to mcp.json

Global, for every project: ~/.cursor/mcp.json. Per repo, shared with your team: .cursor/mcp.json at the repo root.

json

{
  "mcpServers": {
    "lan-brain": {
      "url": "https://YOUR-BRAIN.brain.lanbrain.ai/mcp"
    }
  }
}

Replace the URL with your MCP URL from the dashboard (Your brain, then Connect AI client). More than one brain: add one entry per brain with distinct names.

Open Cursor settings and go to the MCP section (Tools and MCP in the Customize sidebar on recent builds).
lan-brain appears with a Needs login badge or a Login button. Click it.
Your browser opens the LAN Brain sign-in page. Approve with your usual account.
Back in Cursor the server turns green and lists its tools.

Schematic of Cursor's Tools and MCP settings: lan-brain with its tools and a Login button. Labels as of September 2026.

Step 3: put the instructions in your rules

Copy the instructions block from the dashboard's Connect AI client tab.
For everything you do in Cursor: Cursor settings, then Rules, then User Rules. Paste it there.
For one repo, shared with the team: create .cursor/rules/company-brain.mdc with the block as its body and alwaysApply: true in the frontmatter:

markdown

---
description: Use the company brain as the source of truth
alwaysApply: true
---
My LAN Brain connector (Acme) is the source of truth about me and my work.
Before answering anything that depends on my context, call search_brain first.
If the brain has nothing, say so instead of guessing. When the brain conflicts
with what you think you know, the brain wins; cite the page path.
Do NOT use the connector for general knowledge: definitions, public facts,
coding help, anything you could answer without knowing me.

Why this step matters.

Try it

In the agent chat:

"Check the brain for our API conventions before you scaffold this endpoint."
"What did we decide about database migrations? Link the decision and follow it."
"We just settled the logging format in this session. File it in the brain under engineering conventions."

If something is off