Cursor Code Nucleus

Connect Cursor to the same repository Nucleus used by other coding agents while keeping its reviewed outcomes in agent:cursor.

Add repository instructions

Cursor can load AGENTS.md, CLAUDE.md, and rules under .cursor/rules. Put cross-agent engineering and memory policy in AGENTS.md; use a Cursor rule only for Cursor-specific behavior.

For example, create .cursor/rules/neutron-code-nucleus.mdc without credentials:

---
description: Use scoped Neutron repository memory
alwaysApply: true
---

Follow the root AGENTS.md.
Before editing, request Neutron context for the smallest relevant scope set.
Inspect current files before applying recalled guidance.
After verification, save only safe reviewed outcomes to agent:cursor.
Never store secrets, customer data, hidden prompts, or private reasoning.

Connect Neutron over MCP

Use Cursor's user-level MCP file when the configuration includes a token. Store it at ~/.cursor/mcp.json, not in the repository:

{
  "mcpServers": {
    "neutron-memory": {
      "url": "https://mcp.neutronai.dev/mcp",
      "headers": {
        "Authorization": "Bearer <nucleus-access-token>"
      }
    }
  }
}

Protect the file with local filesystem permissions and rotate the token if it is ever exposed. Use managed authentication when your Cursor environment provides it.

Start read-only. Enable memory_remember and memory_reflect only after reviewed write-back is part of the team's workflow.

Request task context

{
  "nucleusId": "<repository-nucleus-id>",
  "scopeIds": [
    "repo:root",
    "ui:landing",
    "tests:landing",
    "agent:cursor"
  ],
  "agentId": "agent:cursor",
  "task": "Update the docs navigation and verify every changed route.",
  "tokenBudget": 1200
}

Keep the task as the primary instruction. Recalled memory can narrow the search, but it cannot replace reading the live repository.

Verify the workflow

1. Open Cursor's MCP settings and confirm neutron-memory is connected.
2. With Cursor CLI, run cursor-agent mcp list.
3. Run cursor-agent mcp list-tools neutron-memory and confirm only approved tools appear.
4. Request context for one bounded task and review the Nucleus and scope IDs.
5. Run the repository checks before saving any outcome.
6. Store one safe lesson in agent:cursor, then confirm a new unrelated task does not recall it.

Official Cursor documentation

• Cursor CLI
• Cursor rules
• Cursor MCP

For another host, use its dedicated Codex, Claude Code, Google Gemini, GitHub Copilot, or Windsurf guide.