Apache Pinot + LibreChat: Complete MCP Integration

Apache Pinot is a MCP server that MCP server for Apache Pinot real-time analytics database with SQL query capabilities and metadata access.

When integrated with LibreChat, you can:

• List and inspect Apache Pinot tables
• View and analyze table segments
• Retrieve and analyze table schemas

This guide provides step-by-step instructions to set up Apache Pinot in LibreChat, including configuration, examples, and troubleshooting.

What You'll Achieve

After completing this setup:

• Apache Pinot will be fully integrated and operational
• You can use Apache Pinot tools directly in LibreChat
• All Apache Pinot capabilities will be available for your workflows
• Access to 5 different tools

Prerequisites

Before starting, ensure you have:

• Apache Pinot broker hostname
• Apache Pinot broker port
• LibreChat installed and configured
• Compatible operating system (Docker (Recommended), Kubernetes, Local Installation, Cloud Platforms)

Installation

Step 1: Install Apache Pinot

Configuration

Step 2: Configure LibreChat

1. Open LibreChat settings
2. Navigate to MCP server configuration
3. Add Apache Pinot server with appropriate settings
4. Save and restart if needed

Examples

Once configured, you can use Apache Pinot in LibreChat:

List All Tables

Get overview of available Pinot tables

Ask LibreChat: "Show me all the tables available in the Pinot cluster"

Expected Result: List of table names with basic metadata and schema information

Execute Analytics Query

Run SQL query for real-time analytics

Ask LibreChat: "SELECT COUNT(*) FROM events WHERE timestamp > now() - 3600000"

Expected Result: Query results showing event count for last hour

Analyze Table Structure

Get detailed schema information for a table

Ask LibreChat: "Show me the schema and structure of the user_events table"

Expected Result: Table schema with column names, types, and index information

Generate Data Visualization

Create histogram plots from query results

Ask LibreChat: "Create a histogram showing user activity distribution by hour"

Expected Result: Histogram visualization with data aggregated by time buckets

Testing Your Setup

1. Launch LibreChat
2. Verify Apache Pinot is available in the tools list
3. Test basic Apache Pinot functionality

Troubleshooting

Common Issues

uv Command Not Found

Symptoms: Command not found error, uv: command not found

Cause: uv package manager not installed

Solution:

• Install uv using: curl -LsSf https://astral.sh/uv/install.sh | sh
• Restart terminal or source shell configuration
• Verify installation with: uv --version

Pinot Connection Failed

Symptoms: Connection refused, Broker unreachable, Network timeout

Cause: Invalid Pinot broker configuration or cluster not running

Solution:

• Verify PINOT_BROKER_HOST and PINOT_BROKER_PORT in .env file
• Check Pinot cluster is running and accessible
• Test connection: telnet <broker_host> <broker_port>
• Ensure firewall allows connections to Pinot broker

Environment Variables Not Loaded

Symptoms: Config missing errors, Default values being used

Cause: .env file not found or incorrectly formatted

Solution:

• Create .env file in repository root directory
• Copy from .env.example and modify values
• Ensure no spaces around = in variable assignments
• Restart MCP server after configuration changes

Claude Desktop Not Recognizing Server

Symptoms: Server not appearing, Connection errors in Claude

Cause: Incorrect claude_desktop_config.json configuration

Solution:

• Verify path to uv binary in command field
• Ensure correct path to mcp-pinot repository
• Restart Claude Desktop after configuration changes
• Check Claude Desktop logs for error messages

MCP Server Not Connecting

Symptoms: Status shows "Disconnected" or "Error", Server not appearing in list, Connection timeout

Cause: Invalid configuration, missing dependencies, or server startup failure

Solution:

• Check librechat.yaml syntax is valid YAML
• Verify npx and Node.js are available (for stdio/command-based servers)
• Check server command and args are correct
• Review LibreChat logs for error messages: docker logs librechat
• Increase timeout value if server takes longer to initialize
• Ensure required ports are not blocked (for HTTP-based servers)

OAuth Authentication Failing

Symptoms: Status shows "OAuth Required", Redirect loop during auth, Token refresh errors

Cause: OAuth credentials not configured or redirect URLs incorrect

Solution:

• Verify OAuth clientId and clientSecret in librechat.yaml
• Check redirect URL is correctly set in OAuth provider settings
• Ensure authorizationUrl and tokenUrl are accessible
• Complete OAuth flow by clicking "Initialize" in MCP Settings panel
• Check browser console for OAuth-related errors

User Credentials Not Working

Symptoms: Prompts for credentials not appearing, Variables not substituted, Authentication errors

Cause: User credential variables incorrectly formatted or not entered

Solution:

• Use correct format: {{USER_VARIABLE_NAME}} in librechat.yaml
• Enter credentials through MCP Settings panel in UI
• Verify variable names match between config and UI
• Check credentials are saved per-user (not shared globally)

Tools Not Appearing in Chat

Symptoms: No tool dropdown available, MCP tools missing from interface, Server connected but tools unavailable

Cause: MCP server not properly integrated with chat endpoint or agent

Solution:

• Verify you are using an endpoint that supports MCP (not all models do)
• Check if Agent Builder is enabled and MCP tools are assigned to agent
• Restart chat session after adding new MCP servers
• Verify MCP server actually provides tools (some servers are resource-only)
• Check server logs to confirm tools are being discovered

Docker Deployment Problems

Symptoms: Container fails to start, Database connection errors, Port conflicts

Cause: Docker configuration issues or missing environment variables

Solution:

• Verify .env file is properly configured with all required variables
• Check MongoDB connection string is correct
• Ensure ports 3080 (frontend) and 3081 (backend) are available
• Run docker compose logs to view detailed error messages
• Verify Docker and Docker Compose versions meet minimum requirements

Performance Issues with MCP

Symptoms: Slow tool execution, Timeout errors, UI freezing during tool calls

Cause: Server timeout too short, inefficient MCP server, or network latency

Solution:

• Increase timeout values in librechat.yaml (both init and operation timeouts)
• Use HTTP transport instead of stdio for remote servers
• Monitor MCP server performance independently
• Consider caching for frequently accessed resources
• Use Streamable HTTP transport for production environments

Apache Pinot not appearing in LibreChat

Symptoms: Server not listed, Tools not available

Cause: Configuration or installation issue

Solution:

• Verify configuration syntax
• Check Apache Pinot installation
• Restart LibreChat
• Check logs for error messages

Next Steps

Now that Apache Pinot is integrated with LibreChat:

• Explore all Apache Pinot capabilities through LibreChat
• Check out other MCP servers that work with LibreChat
• Join the MCP community for tips and support
• Consider contributing to Apache Pinot development

Need Help?

• Search for Apache Pinot documentation
• Check the LibreChat MCP guide
• Join the MCP community discussions