qmcp 0.7.0

MCP Server for q/kdb+ integration (Cloud-connected client)

qmcp Server

A Model Context Protocol (MCP) server for q/kdb+ integration with AI coding assistants.

MCP is an open protocol created by Anthropic that enables AI systems to interact with external tools and data sources. While currently supported by Claude (Desktop and CLI), the open standard allows other LLMs to adopt it in the future.

Why qmcp? Performance Results

The best LLMs have 57% failure rates on q/kdb+ programming tasks (26% with Pass@10). qmcp gives LLMs interactive access to q servers, reducing failures to 6.71% on the full HumanEval corpus. With optional Qython translation (Python-like syntax → q code), failure rates drop to 0.61%.

📊 Full benchmark results

🎥 Installation tutorial for Claude Code CLI (4m30s)

What is Qython?

Qython is a Python-like language that compiles to q/kdb+ code. Instead of learning q's unfamiliar syntax, AI assistants can write familiar Python-like code that gets translated to efficient q.

qmcp provides the infrastructure for AI assistants to work with q/kdb+ databases, with optional cloud-based Qython translation.

Deployment Options

Local Mode (Default)

Privacy-First • Zero Cloud Dependencies

• Direct q connection with raw q console output
• Your code never leaves your machine
• Open source and fully auditable
• Perfect for: Sensitive/proprietary code, production systems
• Configuration: cloud_enabled = false (default)

Cloud-Enhanced Mode

With Qython Translation & Enhanced Formatting

• Qython code translator: AI writes Python-like code → cloud translates to q
• Enhanced output formatting: Raw q results → cloud formats for readability
• Your code AND query results are sent to our cloud service
• Free for evaluation, learning, and non-commercial use (API key via email)
• Production/commercial use requires enterprise license
• Perfect for: Learning q, evaluating Qython, non-sensitive development
• Configuration: cloud_enabled = true + API key

Enterprise On-Premise

For organizations requiring Qython translation with complete data sovereignty, we offer on-premise deployment where all translation happens in your infrastructure. Contact for licensing information.

Core Features

• Connect to q/kdb+ servers
• Execute q queries and commands
• Persistent connection management
• Intelligent async query handling with configurable timeouts
• Programmatic query cancellation (Ctrl+C equivalent)
• Graceful handling of long-running queries
• Table introspection tools (list tables, describe schema)

Qython Features (Cloud or Enterprise)

• Qython language translator: Write Python-like syntax that compiles to q
• Enhanced output formatting: Beautiful display of q data structures
• Rich type handling: Proper representation of q nulls, infinities, and special values
• QythonDB: SQL-like table operations with Python syntax
• Comprehensive documentation: Built-in help resources for Qython syntax

Windows Users: WSL Recommendation

⚠️ Important for Windows users: For optimal functionality, it is highly recommended to run both the MCP server and your q session inside WSL (Windows Subsystem for Linux). This ensures the server can interrupt infinite loops and runaway queries that LLMs might accidentally generate.

Running the MCP server on Windows (outside WSL) disables SIGINT-based query interruption functionality, which is critical for escaping problematic queries during AI-assisted development sessions.

Architecture & Design Philosophy

Intended Goals

qmcp is designed to provide AI coding assistants with controlled access to q/kdb+ databases for development and debugging workflows:

1. Development-Focused: Optimized for coding tools working with debug/dev q servers
2. Query Control: AI can interrupt long-running queries (equivalent to developer Ctrl+C)
3. Predictable Behavior: Sequential execution prevents resource conflicts during development
4. Configurable Timeouts: Customizable timing for different development scenarios

Design Logic

The server architecture makes deliberate choices for AI-assisted development workflows:

Single Connection Model

• Why: Simplifies development debugging - one connection, clear state
• Benefit: Matches typical developer workflow with single q session
• Implementation: One persistent connection per MCP session

Sequential Query Execution

• Why: Development environments don't need concurrent query support
• Benefit: Predictable resource usage, easier debugging, prevents query interference
• Implementation: New queries rejected while another is running

Smart Async Switching with Configurable Timeouts

Fast Query (< async switch timeout)  →  Return result immediately
Slow Query (> async switch timeout)  →  Switch to async mode
                                     →  Auto-interrupt after interrupt timeout (if configured)

• Why: Keeps AI coding sessions responsive while allowing complex development queries
• Benefit: Immediate feedback for quick queries, progress tracking for analysis
• Customization: All timeouts configurable via MCP tools

AI-Controlled Query Interruption

• Why: AI coding tools need ability to cancel runaway queries (like developer Ctrl+C)
• How: MCP server locates q process by port and sends SIGINT after configurable timeout
• Benefit: Prevents development sessions from hanging on problematic queries
• Limitations: SIGINT functionality disabled when:
  • MCP server runs on Windows (outside WSL)
  • MCP server and q session run on opposite sides of WSL/Windows divide

Development-Oriented Process Management

• Why: Coding tools work with user-managed development q servers
• Benefit: Developer controls q server lifecycle, AI controls query execution
• Design: MCP server provides query interruption capability without server lifecycle management

Why This Design Makes Sense for Coding Tools

1. Development Workflow: Matches how developers interact with q - single session, iterative queries
2. AI Safety: Prevents AI from overwhelming development environments with concurrent requests
3. Debugging-Friendly: Sequential execution makes it easier to trace issues
4. Responsive: Async handling prevents AI coding sessions from blocking
5. Configurable: Timeouts can be tuned for different development scenarios

This architecture provides AI coding assistants with effective q/kdb+ access while maintaining the predictable, controlled environment that development workflows require.

Requirements

• Python 3.8+
• Access to a q/kdb+ server
• uv (for lightweight installation) or pip (for full installation)

Quick Start

For first-time users, the fastest way to get started:

1. Start a q server:

   q -p 5001
   

2. Add qmcp to Claude CLI:

   claude mcp add qmcp uvx qmcp
   

3. Start using Claude CLI:

   claude
   

   Then interact with qmcp:

   > connect to port 5001 and compute 2+2
   
   ● qmcp:connect_to_q (MCP)(host: "5001")
     ⎿  true
   
   ● qmcp:query_q (MCP)(command: "2+2")
     ⎿  4
   

Installation

Prerequisites: Installing uv (Recommended)

If you don't have uv installed, install it first:

Linux/macOS/WSL:

curl -LsSf https://astral.sh/uv/install.sh | sh

Windows (PowerShell):

powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"

This adds uv (and uvx) to your PATH automatically.

MCP Server Installation (Primary Use)

Recommended: uvx (simplest)

claude mcp add qmcp uvx qmcp

Benefits:

• One command setup after uv is installed
• Auto-downloads qmcp from PyPI when needed
• No virtual environment management
• Uses efficient global cache

For Claude Desktop/VSCode/Cursor:

{
  "mcpServers": {
    "qmcp": {
      "type": "stdio",
      "command": "uvx",
      "args": ["qmcp"]
    }
  }
}

Alternative: pip (if you already have Python in PATH)

On modern Linux systems (Ubuntu 22.04+, Debian 12+, WSL), use --user to avoid system Python restrictions:

pip install --user qmcp
claude mcp add qmcp qmcp

Or use a virtual environment:

python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate
pip install qmcp
claude mcp add qmcp venv/bin/qmcp

On other systems:

pip install qmcp
claude mcp add qmcp qmcp

For Claude Desktop/VSCode/Cursor (pip-installed):

{
  "mcpServers": {
    "qmcp": {
      "type": "stdio",
      "command": "qmcp"
    }
  }
}

Advanced: Python Library Usage

If you need to import qmcp functions in your Python code:

# Using pip
pip install qmcp

# Using uv (recommended for projects)
uv add qmcp

Then in your code:

from qmcp import <functionality>  # Library API documentation coming soon

Advanced: Running from Source

For development or contributing:

# Clone the repository
git clone https://github.com/gabiteodoru/qmcp.git
cd qmcp

# Claude CLI
claude mcp add qmcp uvx --from . qmcp

# Claude Desktop
# Add this to your config file:

{
  "mcpServers": {
    "qmcp": {
      "command": "uv",
      "args": [
        "--directory",
        "/absolute/path/to/qmcp",
        "run",
        "qmcp"
      ]
    }
  }
}

Configuration

Default Configuration

By default, qmcp operates in local mode (privacy-first, no cloud dependencies):

[default]
cloud_enabled = false  # No cloud services, your code stays local
output_format = "q"    # Raw q console output

To find your configuration file location, ask your AI assistant: "Where is my qmcp config file?"

Enabling Cloud Features

Cloud services provide two types of enhancement:

1. Code Translation: When you use translate_qython_to_q and related tools

   • Python-like code → q code translation
   • Requires cloud_enabled = true

2. Output Formatting: When you run ANY q code with output_format = "qython"

   • Raw q output → beautifully formatted display
   • Handles q nulls, infinities, tables, lists, etc. with proper formatting
   • Applies to all q expressions: calculations, function results, data queries
   • Requires cloud_enabled = true AND output_format = "qython"

Both features send data to the cloud. To enable them:

Step 1: Request an API Key

Ask your AI assistant:

Can you get me a qmcp API key? My email is [e-mail]

The AI will call the request_api_key tool and send you an email with your API key.

Step 2: Configure API Key

Your AI assistant can automatically add the API key to your config, or you can add it manually:

[cloud]
api_key = "sk_xxxxxxxxxxxxx"  # Paste your API key from email

Step 3: Enable Cloud Services

[default]
cloud_enabled = true       # Enable cloud features
output_format = "qython"   # Use enhanced formatting

That's it! Qython translation is now available.

Privacy Note

What gets sent to the cloud:

When cloud_enabled = true:

• Code translation tools: Your Qython code is sent for translation to q
• Output formatting (if output_format = "qython"): All q output (function results, calculations, data, etc.) is sent for formatting
• API keys: Stored locally in plain text in your config file (never sent over network except as auth header)
• All requests may be logged for service improvement

For production use or proprietary code: Keep cloud_enabled = false (raw q output only) or contact us about on-premise deployment.

Terms of Service: By using the cloud API, you agree to our terms:

• ✅ Free for: Personal projects, evaluation, learning, testing
• ⚠️ Production/commercial use requires enterprise license
• See full terms in your API key email or contact for details

Configuration Reference

[default]
# Enable cloud services for Qython code translation and enhanced output formatting
cloud_enabled = false  # Set to true to enable cloud features

# Output format for query results
# "q" = raw q console output (local, no cloud)
# "qython" = enhanced formatting (requires cloud_enabled = true)
output_format = "q"

# LLM mode (reserved for future use)
LLM = "claude"  # claude, copilot

[cloud]
# API key for cloud services (obtain via request_api_key tool)
api_key = "your-key-here"

Usage

Starting the MCP Server

After full installation:

qmcp

With lightweight installation: The server starts automatically when Claude CLI uses it (no manual start needed).

Configuration

qmcp creates a configuration file in your default user directory for server settings, credentials, and behavior. For advanced use cases requiring multiple configurations, you can override this by placing qmcp.toml or .qmcp.toml in the directory where you start qmcp.

Configuration structure:

[default]
# Operational defaults (can be overridden per-server)
connection_timeout = 2      # Seconds to wait for connection
async_timeout = 1           # Seconds before switching to async mode
interrupt_timeout = 10      # Seconds before auto-interrupt (0 to disable)
print_to_async = true       # true = async IPC (LLM), false = console
# console_size = [25, 80]   # [rows, cols] - omit or [] to not change on connect

[servers.default]
host = "localhost"
port = 5001
user = ""  # blank means no authentication
password = ""
# Inherits all [default] operational settings

[servers.prod]
host = "prod-server.com"
port = 5001
user = "produser"
password = "prod-secret"
print_to_async = false      # Override: production uses console
interrupt_timeout = 30      # Override: longer timeout for prod
# Other settings inherit from [default]

Get config path: Use get_config_file_path() tool to find your config file location.

Connection Logic

The connect_to_q(host) tool uses flexible connection modes:

1. No parameters: Load servers.default from config
   • connect_to_q() → Uses all default settings
2. Port number: Load servers.default, override port
   • connect_to_q("5002") → localhost:5002 with default auth
3. Server name: Load servers.{name} from config
   • connect_to_q("prod") → Full prod server config
4. Connection string (has :): Use as-is, bypass config
   • connect_to_q("myhost:5001:user:pass") → Direct connection

Auto-configuration: After connecting, qmcp automatically:

• Sets print mode from server's print_to_async setting
• Configures console dimensions if console_size = [rows, cols] is set (omitted by default)
• Applies timeout settings for async operations and interrupts

Configuration inheritance: Servers inherit operational settings from [default] but can override any setting. Server identity fields (host, port, user, password) never inherit between servers.

Available Tools

Core Tools

Configuration:

• get_config_file_path - Get the path to the qmcp configuration file
• reload_config - Reload configuration from file after manual edits

Connection Management:

• connect_to_q - Connect to q/kdb+ server with flexible fallback logic
• set_timeout_connection - Configure connection timeout

Query Execution:

• query_q - Execute q queries with intelligent async timeout control
• get_current_task_result - Retrieve result of completed async query
• interrupt_current_query - Send SIGINT to interrupt running queries (Ctrl+C equivalent)
• get_last_query_result_q_view - Get the q console view of the last query result
• set_maximum_console_view - Set maximum console view dimensions (rows, cols)

Timeout Configuration:

• set_timeout_switch_to_async - Configure when queries switch to async mode
• set_timeout_interrupt_q - Configure when to auto-interrupt long queries
• get_timeout_settings - View current timeout configuration

Table Introspection:

• list_tables - List all tables with metadata (type, row count, columns, partitioning)
• describe_table - Get column names and types for a table

Cloud Authentication

• request_api_key - Request API key via email for cloud services

Qython Tools

Translation:

• translate_qython_to_q - Translate Python-like syntax to q code

  • ⚠️ EXPERIMENTAL: Limited vocabulary, may produce incorrect code
  • Requires cloud services (cloud_enabled = true) or enterprise installation
  • Please verify all output before use

• translate_q_to_qython - Translate q code to Python-like syntax with AI disambiguation

  • ⚠️ EXPERIMENTAL: Uses ParseQ + AI to convert q to readable Qython
  • Requires q connection first - run connect_to_q before using
  • Namespace Impact: Creates variables/functions in .parseq namespace
  • May produce incorrect translations for complex expressions
  • Please verify all output before use

• translate_and_run_qython - Translate Qython code and execute it via IPC

  • Requires active q connection

File Operations:

• translate_qython_file_to_q - Translate Qython file to q code (returns string)
• translate_qython_to_q_file - Translate Qython code string, write to q file
• translate_qython_file_to_q_file - Translate Qython file, write to specified q file path
• run_qython_file_via_IPC - Translate and execute Qython file via IPC
• run_q_file_via_IPC - Execute q file via IPC
• export_qython_namespace - Export Qython runtime dependencies to file

Setup & Documentation:

• setup_qython_namespace - Load Qython runtime utilities into q session
• qython_help - Get Qython documentation and help

Report bugs at GitHub Issues

Known Limitations

When using the MCP server, be aware of these limitations:

Query Interruption (SIGINT) Limitations

• Windows Platform: Query interruption disabled when MCP server runs on Windows (outside WSL)
• Cross-Platform Setup: Query interruption disabled when MCP server and q session run on opposite sides of WSL/Windows divide
• Impact: LLM cannot automatically escape infinite loops or cancel runaway queries in these configurations

Data Conversion Limitations

• Keyed tables: Operations like 1!table may fail during pandas conversion
• String vs Symbol distinction: q strings and symbols may appear identical in output
• Type ambiguity: Use q's meta and type commands to determine actual data types when precision matters
• Pandas conversion: Some q-specific data structures may not convert properly to pandas DataFrames

For type checking, use:

meta table           / Check table column types and structure
type variable        / Check variable type

WSL2 Port Communication (Windows Users)

Skip this section if you're not on Windows.

Since Claude CLI is WSL-only on Windows, but you might want to use Windows IDEs or tools to connect to your q server, you need proper port communication between WSL2 and Windows.

WSL2 Configuration for Port Communication

.wslconfig File Setup

Location: C:\Users\{YourUsername}\.wslconfig

Add mirrored networking configuration:

# Mirrored networking mode for seamless port communication
networkingMode=mirrored
dnsTunneling=true
firewall=true
autoProxy=true

Restart WSL2

Run from Windows PowerShell/CMD (NOT from within WSL):

wsl --shutdown
# Wait a few seconds, then start WSL again

Verify Configuration

Check if mirrored networking is active:

ip addr show
cat /etc/resolv.conf

Test Port Communication

Test WSL2 → Windows (localhost):

# In WSL2, start a server
python3 -m http.server 8000

# In Windows browser or PowerShell
curl http://localhost:8000

Test Windows → WSL2 (localhost):

# In Windows PowerShell
python -m http.server 8001

# In WSL2
curl http://localhost:8001

What Mirrored Networking Provides

• ✅ Direct localhost communication both ways
• ✅ No manual port forwarding needed
• ✅ Better VPN compatibility
• ✅ Simplified networking (Windows and WSL2 share network interfaces)
• ✅ Firewall rules automatically handled

⚠️ Port 5000 Special Case

Issue: Port 5000 has limited mirrored networking support due to Windows service binding.

Root Cause:

• Windows svchost service binds to 127.0.0.1:5000 (localhost only)
• Localhost-only bindings are not fully mirrored between Windows and WSL2
• This creates an exception to the general mirrored networking functionality

Port 5000 Communication Matrix:

• ✅ Windows ↔ Windows: Works (same localhost)
• ❌ WSL2 ↔ Windows: Fails (different localhost interpretation)
• ✅ WSL2 ↔ WSL2: Works (same environment)

Solutions for Port 5000:

1. Use different ports: 5001, 5002, etc. (recommended)
2. Stop Windows service: If not needed
3. Traditional port forwarding: For specific use cases

Common Services That May Have Localhost-Only Binding

• Flask development servers (default 127.0.0.1:5000)
• UPnP Device Host service
• Windows Media Player Network Sharing
• Various development tools

Known Limitations of Mirrored Networking

1. Localhost-only services: Not fully mirrored (as confirmed with port 5000)
2. mDNS doesn't work in mirrored mode
3. Some Docker configurations may have issues
4. Requires Windows 11 22H2+ (build 22621+)

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Note: The cloud translation service has separate Terms of Service provided when you request an API key.