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R3 MCP Server

by N3wth
Developer ToolsUse Caution3.2MCP RegistryLocal
Free

Server data from the Official MCP Registry

Local Redis memory MCP for AI apps with hybrid caching and optional Mem0 cloud backup.

About

Local Redis memory MCP for AI apps with hybrid caching and optional Mem0 cloud backup.

Security Report

3.2
Use Caution3.2High Risk

The r3 MCP server is a memory management system with generally sound architecture but contains several security and code quality concerns. The server supports optional cloud sync via Mem0 API and uses local Redis/embedded storage, which is appropriate for its purpose. However, there are issues with unauthenticated access to memory operations, overly broad permissions, lack of input validation on memory content, and potential credential exposure in environment variables. The intelligence mode implementation suppresses error messages in ways that could mask security issues. Supply chain analysis found 15 known vulnerabilities in dependencies (0 critical, 5 high severity). Package verification found 1 issue.

4 files analyzed · 27 issues found

Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.

Permissions Required

This plugin requests these system permissions. Most are normal for its category.

File System Read

Reads files on your machine. Normal for tools that analyze or process local data.

File System Write

Writes or modifies files on your machine. Check that this is expected for the tool.

HTTP Network Access

Connects to external APIs or services over the internet.

env_vars

Check that this permission is expected for this type of plugin.

process_spawn

Check that this permission is expected for this type of plugin.

network_socket

Check that this permission is expected for this type of plugin.

What You'll Need

Set these up before or after installing:

Optional Mem0 API key for cloud backup (get free at mem0.ai).Required

Environment variable: MEM0_API_KEY

Redis connection URL. Uses embedded Redis if unset.Optional

Environment variable: REDIS_URL

How to Install

Add this to your MCP configuration file:

{
  "mcpServers": {
    "io-github-n3wth-r3": {
      "env": {
        "REDIS_URL": "your-redis-url-here",
        "MEM0_API_KEY": "your-mem0-api-key-here"
      },
      "args": [
        "-y",
        "@n3wth/r3"
      ],
      "command": "npx"
    }
  }
}

Documentation

View on GitHub

From the project's GitHub README.

r3

npm version npm downloads License: MIT

Persistent memory for MCP clients (Claude Desktop, Claude Code, Cursor) that runs entirely on your machine, with no accounts, no API keys, and no cloud service required to start.

Memory persisting across two separate server processes

Quick start

npx @n3wth/r3

That single command starts an MCP server backed by an embedded Redis instance and a local vector index. There is no separate database to install and no signup step.

How it works

MCP client (Claude Desktop / Claude Code / Cursor)
        |
        v
   r3 MCP server (stdio)
        |
   +----+-----------------------+
   |                            |
embedded Redis            vectra local index
(redis-memory-server,      (on-disk vector store
 auto-downloaded binary,    for semantic search,
 no external service)       no external service)
   |
   +--- optional ---> Mem0 cloud API (MEM0_API_KEY)
                       cross-device sync, off by default
  • Embedded Redisredis-memory-server downloads and manages a local Redis binary for you. It stores memory content and metadata. If it cannot start, r3 falls back to an in-process store.
  • vectra — a local, file-backed vector index used for semantic search. No network calls, no external vector database.
  • Mem0 (optional) — if MEM0_API_KEY is set, r3 also syncs to Mem0's cloud API so memories can follow you across machines. Without a key, nothing leaves your machine.

MCP client configuration

Claude Desktop

Edit claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "r3": {
      "command": "npx",
      "args": ["@n3wth/r3"]
    }
  }
}

Claude Code

claude mcp add r3 "npx @n3wth/r3"

Cursor

Add to .cursor/mcp.json in your project (or the global Cursor MCP config):

{
  "mcpServers": {
    "r3": {
      "command": "npx",
      "args": ["@n3wth/r3"]
    }
  }
}

Restart the client after editing config. In a new conversation:

You: Remember that I prefer TypeScript and dark mode.
AI: I'll remember that.

[new conversation]

You: What are my preferences?
AI: You prefer TypeScript and dark mode.

Tools

ToolDescription
add_memoryStore content with optional metadata and priority
search_memoryQuery memories using semantic or keyword search
get_all_memoriesList stored memories with pagination
get_memoryRetrieve a specific memory by ID
update_memoryModify existing memory content or metadata
delete_memoryRemove a memory
deduplicate_memoriesFind and merge duplicate memories
cache_statsReport cache hit rate and storage stats
sync_statusReport Mem0 cloud sync status
optimize_cacheRun cache maintenance
import_memoriesBulk import memories

Enhanced mode (default, INTELLIGENCE_MODE=enhanced) adds:

ToolDescription
extract_entitiesExtract named entities from text
get_knowledge_graphReturn the entity/relationship graph
find_connectionsFind entities connected to a given entity

Configuration

Environment variables, all optional:

VariableDescriptionDefault
REDIS_URLUse an external Redis instead of the embedded oneembedded server
MEM0_API_KEYEnables Mem0 cloud syncunset (local only)
MEM0_USER_IDNamespace for memoriesdefault
INTELLIGENCE_MODEenhanced or basicenhanced

Example with cloud sync enabled:

{
  "mcpServers": {
    "r3": {
      "command": "npx",
      "args": ["@n3wth/r3"],
      "env": {
        "MEM0_API_KEY": "mem0_..."
      }
    }
  }
}

Comparison

r3mem0 (OSS)zep
Runs fully local with zero configyes (embedded Redis + vectra)requires a Postgres/vector DB you configurerequires a Postgres instance you configure
Needs an API key to try itnono (self-hosted) / yes (cloud)yes (cloud), or self-hosted setup
Optional cloud syncyes, via Mem0n/a (is the cloud option)yes

This table only reflects setup requirements observed in each project's own documentation, not benchmark performance or feature completeness. Verify against current upstream docs before relying on it.

Known issues

See LAUNCH_AUDIT.md for current limitations, including a native module build failure on some macOS setups.

Documentation

Full documentation at r3.n3wth.com.

License

MIT

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