What is the key difference between Robrain and Lean Memory?

Robrain belongs to the Knowledge & Memory category with local stdio execution, while Lean Memory belongs to the Knowledge & Memory category with local stdio execution.

How do I install Robrain or Lean Memory in Claude Desktop or Cursor?

Copy the mcpServers JSON configuration snippet provided on this page into your claude_desktop_config.json or ~/.cursor/mcp.json file and restart your AI client.

Are Robrain and Lean Memory free or paid?

Robrain operates under a Freemium model (API Key required). Lean Memory operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

Robrain lists 6 tools with 2 views and 81 GitHub stars. Lean Memory lists 6 tools with 1 views and 47 GitHub stars.

Can I use both Robrain and Lean Memory together in the same MCP host?

Yes! MCP hosts like Claude Desktop, Cursor, Windsurf, Cline, and VS Code support configuring multiple servers under the mcpServers object simultaneously.

How do I install Robrain or Lean Memory in Claude Desktop, Cursor, or Windsurf?

Both servers follow the standard Model Context Protocol configuration format. Simply copy the JSON block from the configuration section above and paste it into your AI client's mcpServers configuration object (for instance in claude_desktop_config.json or ~/.cursor/mcp.json ), then completely restart or refresh the application.

Are Robrain and Lean Memory free to use, or do they require API keys?

Robrain is listed under a Freemium model with API Key required . Lean Memory operates under a Free / Open Source model with No auth required . If environment variables are required (such as API keys), be sure to define them under the env key in your MCP client's configuration file.

Can I run both Robrain and Lean Memory at the same time in my AI client?

Yes! MCP clients support multi-server orchestration. You can include both adelinamart-robrain and wuesteon-lean-memory as distinct keys inside the single mcpServers object in your configuration file. Your AI assistant will automatically select and call the appropriate tool from either server during chat sessions.

Which MCP server has higher directory engagement and quality ratings?

On AllMCPs, Robrain has a Quality Score of 49 /100 ( Fair ) with 2 views, 0 installs, and 81 GitHub stars. Lean Memory holds a Quality Score of 52 /100 ( Good ) with 1 views, 0 installs, and 47 GitHub stars.

Side-by-Side Model Context Protocol Comparison

Robrain vs Lean Memory

In-depth architectural comparison of the Robrain and Lean Memory MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

At a Glance & Executive Verdict

Robrain

Knowledge & Memory · Local stdio

Quality: 49/100 (Fair) | Auth: API Key required

Lean Memory

Knowledge & Memory · Local stdio

Quality: 52/100 (Good) | Auth: No auth required

Verdict Summary: Choose Robrain if you need specialized Knowledge & Memory tools running via a local process. Choose Lean Memory if your workspace requires Knowledge & Memory integration with local subprocess execution. Both servers can be configured concurrently in your client's mcpServers manifest.

Which MCP Server Should You Choose?

Choose Robrain when:

You need dedicated capabilities in the Knowledge & Memory domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: API Key required (Freemium).
You have access to required keys: ANTHROPIC_API_KEY, OPENAI_API_KEY, PERCEPTION_API_KEY, POSTGRES_PASSWORD.
Primary tools included: Passive capture of session turns and decisions, Structured rejected[] field for vetoed alternatives, Corpus-wide contradiction and stance drift detection.

Explore Robrain Details

Choose Lean Memory when:

You need dedicated capabilities in the Knowledge & Memory domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
You have access to required keys: LM_DATA_ROOT, ANTHROPIC_API_KEY.

Feature & Specification Comparison

Specification	Robrain adelinamart Knowledge & Memory	Lean Memory Wuesteon Knowledge & Memory
Summary	Self-hosted decision memory for AI coding agents. Passively captures architectural decisions with the alternatives you rejected (structured rejected[]), then warns the agent before it re-proposes a rejected approach. Postgres + pgvector; cross-tool across Claude Code, Cursor, Copilot, and Codex. Install: npx robrain up && npx robrain install.	Embedded, local-first agent memory in a single SQLite file per namespace (vec0 + FTS5 hybrid retrieval). ADD-only history queryable as-of any past time; offline sleep-time maintenance stages dedupe/summarize/evict proposals a human reviews. No Docker, no server, no cloud key. pip install 'lean-memory[mcp]'
Category & Scope

Tools & Capabilities Breakdown

Robrain Tools (6)

Passive capture of session turns and decisions

Structured rejected[] field for vetoed alternatives

Corpus-wide contradiction and stance drift detection

Postgres + pgvector backend for persistent storage

Cross-tool integration with Claude Code, Cursor, Copilot, Codex CLI

Self-hosted or managed cloud deployment options

Lean Memory Tools (6)

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

Robrain Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "adelinamart-robrain": {
      "command": "npx",
      "args": [
        "-y",
        "robrain"
      ],
      "env": {
        "ANTHROPIC_API_KEY": "YOUR_ANTHROPIC_API_KEY_HERE",
        "OPENAI_API_KEY": "YOUR_OPENAI_API_KEY_HERE",
        "PERCEPTION_API_KEY": "YOUR_PERCEPTION_API_KEY_HERE",
        "POSTGRES_PASSWORD": "YOUR_POSTGRES_PASSWORD_HERE"
      }
    }
  }
}

Lean Memory Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "wuesteon-lean-memory": {
      "command": "uvx",
      "args": [
        "lean-memory"
      ],
      "env": {
        "LM_DATA_ROOT": "YOUR_LM_DATA_ROOT_HERE",
        "ANTHROPIC_API_KEY": "YOUR_ANTHROPIC_API_KEY_HERE"
      }
    }
  }
}

Frequently Asked Questions

Robrain is categorized under Knowledge & Memory and uses a local stdio subprocess. In contrast, Lean Memory belongs to Knowledge & Memory using local stdio subprocess. Select Robrain when you need capabilities focused on knowledge & memory and Lean Memory when you require tools for knowledge & memory.

More alternatives to Robrain More alternatives to Lean Memory Knowledge & Memory category hub