Claude Desktop

Claude Desktop supports MCP natively. Once configured, Claude can create, search, and manage memories without any additional setup.

Prerequisites

• Claude Desktop installed
• A MemNexus API key (sign up)
• Node.js 18+ installed

Setup

1. Edit the Claude Desktop config

Open or create the config file:

• macOS: ~/.config/claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Add the MemNexus MCP server:

{
  "mcpServers": {
    "memnexus": {
      "command": "npx",
      "args": ["@memnexus-ai/mcp-server"],
      "env": {
        "MEMNEXUS_API_KEY": "cmk_live_xxx.yyy"
      }
    }
  }
}

Replace cmk_live_xxx.yyy with your actual API key.

2. Restart Claude Desktop

Close and reopen Claude Desktop. The MemNexus tools should now appear in the tools menu.

3. Verify

Ask Claude:

"Search my memories for recent notes"

If configured correctly, Claude will use the search_memories tool and show results (or confirm no memories exist yet).

Custom instructions

Add these to Claude Desktop's custom instructions for the best experience:

You have access to MemNexus, a persistent memory system. Use it proactively:

SAVING: When I share preferences, decisions, or important project context,
save it using create_memory with relevant topics and importance scores.

SEARCHING: Before answering questions about my projects or past conversations,
search memory first. Search by meaning — "deployment preferences" finds
memories about CI/CD and hosting.

TOPICS: Use consistent topics for categorization:
- Project names (lowercase, hyphenated)
- Types: preferences, decisions, architecture, debugging, context
- Importance: 0.9 for decisions, 0.7 for context, 0.5 for general info

Available tools

Once connected, Claude has access to 19 MemNexus tools. The most commonly used:

Tool	What Claude uses it for
create_memory	Saving important context from conversations
search_memories	Finding relevant past information
get_conversation_timeline	Reconstructing past work sessions
graphrag_query	Answering complex questions across your knowledge
discover_related_topics	Finding connections between topics

See MCP Integration for the full tool reference.

Tips

• Be explicit initially — Tell Claude "remember this" or "search your memory" until it learns your patterns
• Use topics — Mention project names and categories so memories are easy to find later
• Cross-platform — Memories created in Claude Desktop are searchable from Claude Code, Cursor, or any other MCP client

Troubleshooting

Tools not appearing

1. Verify the config file path is correct
2. Check JSON syntax (trailing commas are not allowed)
3. Ensure npx is available in your PATH
4. Restart Claude Desktop completely (not just the conversation)

Authentication errors

1. Verify your API key format: cmk_live_<id>.<secret>
2. Test it with the CLI: mx auth login --api-key cmk_live_xxx.yyy && mx auth status
3. Check that the key is in the env section, not args

Next steps

• Claude Code — Set up memory in Claude Code
• Prompt Library — Optimize Claude's memory usage
• MCP Integration — Full MCP tool reference