u2-mcp

Connect Claude to your Universe/UniData database using natural language.

u2-mcp is an MCP server that lets AI assistants like Claude query and interact with Rocket Universe and UniData MultiValue databases. Ask questions in plain English and get real answers from your data.

The first MCP server for the Pick/MultiValue database family.

What Can You Do With This?

Instead of writing RetrieVe queries, just ask Claude:

You Ask	Claude Does
"How many customers are in California?"	Queries the database and tells you "1,247 customers"
"Show me order ORD001"	Reads the record and displays all fields
"What files are available?"	Lists all files in your account
"Describe the CUSTOMERS file"	Shows field definitions from the dictionary

How It Works

Code

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│  Claude Desktop │◄───►│     u2-mcp      │◄───►│ Universe/UniData│
│  (You ask here) │     │  (Translates)   │     │   (Your data)   │
└─────────────────┘     └─────────────────┘     └─────────────────┘

You ask Claude a question about your database
Claude calls u2-mcp with the appropriate tool
u2-mcp queries your Universe/UniData server
Results come back through Claude in a readable format

New to MCP? See What is MCP? for a complete explanation.

Documentation

Guide	Description
What is MCP?	Understanding MCP and how u2-mcp works
Installation	Complete installation guide
Quickstart	Get running in 10 minutes
Configuration	All configuration options
Tools Reference	Detailed tool documentation
Usage Examples	Common usage patterns
OAuth Setup	Claude.ai integration with SSO

Features

Connection Management - Connect to Universe/UniData servers with connection pooling and SSL support
File Operations - Read, write, and delete records while preserving MultiValue semantics
Query Execution - Run RetrieVe/UniQuery statements with safety controls
Dictionary Access - Explore file structures and field definitions
BASIC Subroutine Calls - Execute cataloged BASIC programs
Transaction Support - Full transaction management with commit/rollback
AI-Optimized - Built-in query examples and syntax help for better LLM interactions

Installation

Terminal

pip install u2-mcp

Or using uvx for isolated execution:

bash

uvx u2-mcp

Quick Start

Prerequisites

Python 3.10+
Access to a Rocket Universe or UniData server
The uopy package (installed automatically as a dependency)

Configuration

Set environment variables for your database connection:

server.ts

export U2_HOST=server.example.com
export U2_USER=username
export U2_PASSWORD=password
export U2_ACCOUNT=MYACCOUNT
export U2_SERVICE=uvcs  # or 'udcs' for UniData

Claude Desktop Configuration

Add to your claude_desktop_config.json:

config.json

{
  "mcpServers": {
    "u2": {
      "command": "uvx",
      "args": ["u2-mcp"],
      "env": {
        "U2_HOST": "server.example.com",
        "U2_USER": "user",
        "U2_PASSWORD": "password",
        "U2_ACCOUNT": "MYACCOUNT"
      }
    }
  }
}

Usage Examples

Once connected, you can use natural language to interact with your Universe database:

"List all customers in California"
"Read record CUST001 from the CUSTOMERS file"
"Show me the dictionary for the ORDERS file"
"Count all open invoices over $1000"

Available Tools

Connection Management

connect - Establish connection to Universe/UniData server
disconnect - Close connections
list_connections - Show active connections

File Operations

list_files - List available files in the account
read_record - Read a single record by ID
read_records - Read multiple records
write_record - Write/update a record
delete_record - Delete a record
get_file_info - Get file statistics

Query Execution

execute_query - Run RetrieVe/UniQuery statements
execute_tcl - Run TCL/ECL commands
get_select_list - Execute SELECT and return record IDs

Dictionary Access

list_dictionary - List dictionary items
get_field_definition - Get field details
describe_file - High-level file description

Advanced Features

call_subroutine - Call BASIC subroutines
begin_transaction / commit_transaction / rollback_transaction - Transaction management

Knowledge Persistence

save_knowledge - Save learned information about the database
list_knowledge - List all saved knowledge topics
get_knowledge_topic - Retrieve specific topic
search_knowledge - Search across saved knowledge
delete_knowledge - Remove a knowledge topic

Configuration Options

Variable	Description	Default
`U2_HOST`	Server hostname or IP	Required
`U2_USER`	Username	Required
`U2_PASSWORD`	Password	Required
`U2_ACCOUNT`	Account name	Required
`U2_SERVICE`	Service type (`uvcs` or `udcs`)	`uvcs`
`U2_PORT`	Server port	`31438`
`U2_SSL`	Enable SSL	`false`
`U2_TIMEOUT`	Connection timeout (seconds)	`30`
`U2_READ_ONLY`	Disable write operations	`false`
`U2_MAX_RECORDS`	Maximum SELECT results	`10000`
`U2_BLOCKED_COMMANDS`	Comma-separated blocked TCL commands	`DELETE.FILE,CLEAR.FILE`
`U2_KNOWLEDGE_PATH`	Custom path for knowledge file	`~/.u2-mcp/knowledge.md`

Knowledge Persistence

The MCP server includes a knowledge persistence feature that allows Claude to save and recall learned information about your database across sessions. This eliminates repetitive discovery work and speeds up future interactions.

How It Works

When Claude discovers useful information about your database (file purposes, field meanings, working queries), it can save this knowledge using the save_knowledge tool. This information is stored in a markdown file and automatically available in future conversations via the u2://knowledge resource.

What Gets Saved

File descriptions - What each file contains (e.g., "AR-CUST is the customer master file")
Field mappings - Which fields contain what data (e.g., "Field 1 is customer name")
Query patterns - Queries that produced good results
Data formats - Date formats, code meanings, conversion notes
Relationships - How files relate to each other

Storage Location

Knowledge is stored in ~/.u2-mcp/knowledge.md by default. You can customize this location using the U2_KNOWLEDGE_PATH environment variable:

config.json

{
  "env": {
    "U2_KNOWLEDGE_PATH": "/path/to/custom/knowledge.md"
  }
}

Example Usage

After Claude discovers that AR-CUST contains customer records:

Code

Claude: I found that AR-CUST is the customer master file. Let me save this for future reference.
[Calls save_knowledge("AR-CUST file", "Customer master file. Key is customer number. Field 1=name, Field 2=address...")]

In the next conversation, Claude will already know this and won't need to rediscover it.

Centralized Deployment (HTTP/SSE Mode)

For team environments, you can run u2-mcp as a centralized HTTP server instead of local stdio mode. This allows:

Single database connection for the whole team
Shared knowledge base
Centralized credential management
Access from any MCP-compatible client

Running the HTTP Server

server.ts

# Basic HTTP server on default port 8080
u2-mcp --http

# Custom host and port
u2-mcp --http --host 0.0.0.0 --port 3000

# Or using environment variables
export U2_HTTP_HOST=0.0.0.0
export U2_HTTP_PORT=3000
u2-mcp --http

Docker Deployment

Dockerfile

FROM python:3.12-slim

RUN pip install u2-mcp

ENV U2_HOST=your-universe-server
ENV U2_USER=username
ENV U2_PASSWORD=password
ENV U2_ACCOUNT=MYACCOUNT
ENV U2_HTTP_PORT=8080

EXPOSE 8080

CMD ["u2-mcp", "--http"]

Terminal

docker build -t u2-mcp-server .
docker run -p 8080:8080 u2-mcp-server

HTTP Configuration Options

Variable	Description	Default
`U2_HTTP_HOST`	Host to bind HTTP server to	`0.0.0.0`
`U2_HTTP_PORT`	Port for HTTP server	`8080`
`U2_HTTP_CORS_ORIGINS`	Allowed CORS origins (comma-separated or `*`)	`*`

Connecting Clients

The HTTP server exposes an SSE (Server-Sent Events) endpoint at /sse. MCP clients that support remote servers can connect to:

Code

http://your-server:8080/sse

Note: As of late 2024, Claude Desktop only supports local stdio MCP servers. HTTP/SSE mode is for:

Custom MCP clients
Future Claude Desktop versions with remote server support
Integration with other AI tools that support MCP over HTTP

Claude.ai Integration (Streamable HTTP + OAuth)

Deploy u2-mcp as a Custom Connector in Claude.ai with enterprise authentication via your identity provider (Duo, Auth0, Okta, etc.).

Quick Setup

Deploy u2-mcp with OAuth enabled:

bash

u2-mcp --streamable-http --host 0.0.0.0 --port 8080

Configure OAuth in your .env:

bash

U2_AUTH_ENABLED=true
U2_AUTH_ISSUER_URL=https://u2-mcp.example.com
U2_IDP_PROVIDER=duo
U2_IDP_DISCOVERY_URL=https://sso-xxx.sso.duosecurity.com/oidc/CLIENT_ID/.well-known/openid-configuration
U2_IDP_CLIENT_ID=your_client_id
U2_IDP_CLIENT_SECRET=your_client_secret

Add to Claude.ai: Go to Settings → Connectors → Add Custom Connector → Enter your URL

Users authenticate through your IdP and can then query your database directly from Claude.ai.

Supported Identity Providers

Cisco Duo - Enterprise MFA and SSO
Auth0 - Flexible identity platform
Any OIDC Provider - Okta, Azure AD, Google Workspace, Keycloak, etc.

See the OAuth Guide for detailed setup instructions.

Security

Credentials are never logged
Configurable command blocklist prevents dangerous operations
Optional read-only mode for safe exploration
Honors Universe's built-in security model

See SECURITY.md for reporting security vulnerabilities.

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

Documentation

Getting Started

Quickstart Guide - Get running in 10 minutes
What is MCP? - Understanding MCP and how u2-mcp works
Installation Guide - Detailed installation instructions

Reference

Configuration Reference - All environment variables
Tools Reference - Complete tool documentation
Usage Examples - Common usage patterns
OAuth & Claude.ai Integration - Deploy as a Claude.ai Custom Connector

License

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

Acknowledgments

Rocket Software for the uopy package
Anthropic for the Model Context Protocol specification
The MultiValue database community