Memvid

MCP (Model Context Protocol) server for memvid - a memory layer for AI agents.

This server wraps the memvid Rust CLI, exposing 40 tools for persistent memory management with hybrid search (lexical + vector), temporal indexing, knowledge graphs, and RAG capabilities.

Use Cases

• Agent Memory: Give AI agents persistent memory across sessions with semantic search and temporal awareness
• Document Intelligence: Ingest documents, code, and web content with automatic entity extraction and fact tracking
• Knowledge Base: Build searchable knowledge bases with hybrid lexical/vector search and knowledge graph relationships
• Audit & Compliance: Track information sources with citation generation and audit reports
• Session Replay: Record and replay agent sessions for debugging and analysis

Prerequisites

• Node.js 18+
• memvid CLI binary (see memvid for installation)
• Optional: Embedder configuration for vector search (embedder.toml)
• Optional: LLM configuration for RAG (llm.toml)

Installation

From Source

git clone https://github.com/Tapiocapioca/memvid-mcp.git
cd memvid-mcp
npm install
npm run build

Verify Installation

# Test the server starts
node dist/index.js
# Should output: "memvid-mcp server started"
# Press Ctrl+C to exit

Configuration

Environment Variables

Variable	Default	Description
MEMVID_PATH	memvid	Path to the memvid binary
MEMVID_LOG_LEVEL	warning	Log level: debug, info, warning, error
MEMVID_VERBOSE	0	Set to 1 for verbose CLI output

MCP Client Setup

VS Code (Copilot)

Add to your VS Code MCP settings:

{
  "servers": {
    "memvid": {
      "command": "node",
      "args": ["/path/to/memvid-mcp/dist/index.js"],
      "env": {
        "MEMVID_PATH": "/path/to/memvid"
      }
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "memvid": {
      "command": "node",
      "args": ["/path/to/memvid-mcp/dist/index.js"],
      "env": {
        "MEMVID_PATH": "/path/to/memvid"
      }
    }
  }
}

Cursor

Add to MCP settings:

{
  "memvid": {
    "command": "node",
    "args": ["/path/to/memvid-mcp/dist/index.js"],
    "env": {
      "MEMVID_PATH": "/path/to/memvid"
    }
  }
}

OpenCode

Add to opencode.json:

{
  "mcp": {
    "memvid": {
      "type": "stdio",
      "command": "node",
      "args": ["/path/to/memvid-mcp/dist/index.js"],
      "env": {
        "MEMVID_PATH": "/path/to/memvid"
      }
    }
  }
}

Security Considerations

Path Validation

The server implements multiple layers of path security:

1. Path Traversal Protection: Blocks .. patterns
2. System Path Blocklist: Prevents access to sensitive directories (/etc/, /proc/, \windows\, etc.)
3. MCP Roots Validation: Respects client-provided roots boundaries (when supported by client)

Encryption

Memory files can be encrypted using AES-256-GCM:

memvid_lock { "file": "data.mv2", "output": "data.mv2e", "password": "secret" }
memvid_unlock { "file": "data.mv2e", "output": "data.mv2", "password": "secret" }

Recommendations

• Store memory files in dedicated directories
• Use encrypted files (.mv2e) for sensitive data
• Configure MCP roots in your client to restrict file access
• Use separate memory files per project/context

Available Tools (40)

Lifecycle (5 tools)

Tool	Description	Annotations
memvid_create	Create a new .mv2 memory file	write
memvid_open	Open and display file metadata	read-only
memvid_stats	Show detailed statistics (frame count, index sizes)	read-only
memvid_verify	Verify file integrity with optional deep check	read-only
memvid_doctor	Diagnose and repair corrupted indexes	destructive

Content Management (7 tools)

Tool	Description	Annotations
memvid_put	Add content from file/directory with optional embeddings	write
memvid_put_many	Batch add with progress tracking	write
memvid_view	View frame content by ID	read-only
memvid_update	Replace frame content	destructive
memvid_delete	Delete a frame	destructive
memvid_correct	Amend frame with audit trail	write
memvid_api_fetch	Fetch URL content and add to memory	network

Search (5 tools)

Tool	Description	Annotations
memvid_find	Hybrid/lexical/vector search	read-only
memvid_vec_search	Vector-only semantic search	read-only
memvid_ask	RAG question answering	read-only
memvid_timeline	Chronological frame view	read-only
memvid_when	Temporal search (find when something was mentioned)	read-only

Analysis (6 tools)

Tool	Description	Annotations
memvid_audit	Generate audit report with citations	read-only
memvid_debug_segment	Debug internal index segments	read-only
memvid_export	Export to JSON/CSV/JSONL	write
memvid_tables	List internal SQLite tables	read-only
memvid_schema	Schema inference and summary	read-only
memvid_models	List available embedding models	read-only

Knowledge Graph (6 tools)

Tool	Description	Annotations
memvid_enrich	NER entity extraction	write
memvid_memories	Memory card operations	read-only
memvid_state	Show current memory state	read-only
memvid_facts	Fact extraction and listing	read-only
memvid_follow	Traverse entity relationships	read-only
memvid_who	Entity lookup	read-only

Session Management (5 tools)

Tool	Description	Annotations
memvid_session	Start/stop/list/replay sessions	write
memvid_binding	Memory binding operations	destructive
memvid_status	System status (version, model status)	read-only
memvid_sketch	SimHash sketch operations	write
memvid_nudge	Trigger background processing	write

Encryption (2 tools)

Tool	Description	Annotations
memvid_lock	Encrypt memory file (AES-256-GCM)	write
memvid_unlock	Decrypt memory file	write

Utility (4 tools)

Tool	Description	Annotations
memvid_process_queue	Process pending operations	write
memvid_verify_single_file	Verify single frame integrity	read-only
memvid_config	Show current configuration	read-only
memvid_version	Print version information	read-only

Example Workflows

Basic Memory Setup

# 1. Create a new memory file
memvid_create { "file": "project.mv2" }

# 2. Ingest documentation
memvid_put { 
  "file": "project.mv2", 
  "input": "./docs", 
  "recursive": true,
  "embed": true  # Generate vector embeddings
}

# 3. Check statistics
memvid_stats { "file": "project.mv2" }

Search and Retrieval

# Hybrid search (lexical + vector)
memvid_find { 
  "file": "project.mv2", 
  "query": "authentication flow", 
  "mode": "hybrid",
  "limit": 5 
}

# Semantic search only
memvid_vec_search { 
  "file": "project.mv2", 
  "query": "how to handle user sessions" 
}

# RAG question answering
memvid_ask { 
  "file": "project.mv2", 
  "question": "What authentication methods are supported?" 
}

Knowledge Graph Operations

# Extract entities from all frames
memvid_enrich { "file": "project.mv2", "all": true }

# Look up an entity
memvid_who { "file": "project.mv2", "query": "OAuth" }

# Follow entity relationships
memvid_follow { 
  "file": "project.mv2", 
  "entity": "AuthService", 
  "hops": 2 
}

Audit and Export

# Generate audit report with sources
memvid_audit { 
  "file": "project.mv2", 
  "query": "security requirements",
  "include_snippets": true 
}

# Export for backup
memvid_export { 
  "file": "project.mv2", 
  "output": "backup.json",
  "format": "json" 
}

Session Recording

# Start recording a session
memvid_session { "file": "project.mv2", "start": "debug-session-1" }

# ... agent interactions ...

# Stop recording
memvid_session { "file": "project.mv2", "stop": true }

# Replay later
memvid_session { "file": "project.mv2", "replay": "debug-session-1" }

Embedder Configuration

For vector search capabilities, create ~/.config/memvid/embedder.toml:

[embedder]
provider = "openai"
model = "text-embedding-3-large"
api_key_env = "OPENAI_API_KEY"
dimensions = 3072

Or for A4F/OpenRouter compatible APIs:

[embedder]
provider = "openai"
model = "provider-3/text-embedding-3-large"
base_url = "https://api.a]4f.co/v1"
api_key_env = "A4F_API_KEY"

Performance Characteristics

Operation	Typical Latency	Notes
memvid_create	< 100ms	Creates empty SQLite database
memvid_put (single file)	100-500ms	Depends on file size
memvid_put (with embed)	500ms-2s	Includes API call for embedding
memvid_find (lexical)	< 50ms	Tantivy full-text search
memvid_find (hybrid)	100-500ms	Combines lexical + vector
memvid_ask (RAG)	1-5s	Includes LLM API call

Timeouts are configured per operation type:

• Default: 120 seconds
• Heavy operations (batch put): 300 seconds
• RAG operations: 180 seconds

Development

npm run dev    # Run with tsx (hot reload)
npm run build  # Compile TypeScript
npm start      # Run compiled version
npm run clean  # Remove dist/

Troubleshooting

Server won't start

1. Check Node.js version: node --version (requires 18+)
2. Verify build: npm run build
3. Check memvid binary: memvid --version

"MEMVID_PATH not found"

Set the environment variable to the full path:

export MEMVID_PATH=/path/to/memvid
# or on Windows
set MEMVID_PATH=C:\path\to\memvid.exe

Vector search returns no results

1. Check embeddings were generated: memvid_stats shows vector_count > 0
2. Verify embedder config: memvid_config
3. Re-ingest with embeddings: memvid_put { ..., "embed": true }

Path validation errors

The server validates all paths against:

1. Path traversal patterns (..)
2. System directory blocklist
3. MCP roots (if client supports roots capability)

Ensure your paths are within allowed directories.

License

MIT