Altinity MCP Server

A Model Context Protocol (MCP) server that provides tools for interacting with ClickHouse databases. This server enables AI assistants and other MCP clients to query, analyze, and interact with ClickHouse databases through a standardized protocol.

Features

• Multiple Transport Options: Support for STDIO, HTTP, and Server-Sent Events (SSE) transports
• JWE Authentication: Optional JWE-based authentication with encryption for secure database access
• TLS Support: Full TLS encryption support for both ClickHouse connections and MCP server endpoints
• Comprehensive Tools: Built-in tools for listing tables, describing schemas, and executing queries
• Resource Templates: Dynamic resource discovery for database schemas and table information
• Query Prompts: AI-assisted query building and optimization prompts
• Configuration Management: Flexible configuration via files, environment variables, or CLI flags
• Hot Reload: Dynamic configuration reloading without server restart

Quick Start

Using STDIO Transport (Default)

# Basic usage with default settings
./altinity-mcp --clickhouse-host localhost --clickhouse-port 8123

# With custom database and credentials
./altinity-mcp \
  --clickhouse-host clickhouse.example.com \
  --clickhouse-port 9000 \
  --clickhouse-protocol tcp \
  --clickhouse-database analytics \
  --clickhouse-username reader \
  --clickhouse-password secret123 \
  --clickhouse-limit 5000

Using HTTP Transport with OpenAPI

./altinity-mcp \
  --transport http \
  --address 0.0.0.0 \
  --port 8080 \
  --clickhouse-host localhost \
  --openapi http

Using SSE Transport with JWE Authentication and OpenAPI

./altinity-mcp \
  --transport sse \
  --port 8080 \
  --allow-jwe-auth \
  --jwe-secret-key "your-jwe-encryption-secret" \
  --jwt-secret-key "your-jwt-signing-secret" \
  --clickhouse-host localhost \
  --openapi http

Installation

From Source

git clone https://github.com/altinity/altinity-mcp.git
cd altinity-mcp
go build -o altinity-mcp ./cmd/altinity-mcp

Using Docker

docker build -t altinity-mcp .
docker run -it altinity-mcp --clickhouse-host host.docker.internal

Using Helm

git checkout https://github.com/Altinity/altinity-mcp
cd altinity-mcp
helm install altinity-mcp ./helm/altinity-mcp \
  --set config.clickhouse.host=clickhouse.example.com \
  --set config.clickhouse.database=default \
  --set config.limit=5000

Configuration

Configuration File

Create a YAML or JSON configuration file:

# config.yaml
clickhouse:
  host: "localhost"
  port: 8123
  database: "default"
  username: "default"
  password: ""
  protocol: "http"
  read_only: false
  max_execution_time: 600
  tls:
    enabled: false
    ca_cert: ""
    client_cert: ""
    client_key: ""
    insecure_skip_verify: false

server:
  transport: "stdio"
  address: "0.0.0.0"
  port: 8080
  tls:
    enabled: false
    cert_file: ""
    key_file: ""
    ca_cert: ""
  jwt:
    enabled: false
    secret_key: ""
  openapi:
    enabled: false
    tls: false

logging:
  level: "info"

Use the configuration file:

./altinity-mcp --config config.yaml

Environment Variables

All configuration options can be set via environment variables:

export CLICKHOUSE_HOST=localhost
export CLICKHOUSE_PORT=8123
export CLICKHOUSE_DATABASE=analytics
export CLICKHOUSE_LIMIT=5000
export MCP_TRANSPORT=http
export MCP_PORT=8080
export LOG_LEVEL=debug

./altinity-mcp

Available Tools

list_tables

Lists all tables in a ClickHouse database with detailed information.

Parameters:

• database (optional): The database to list tables from

describe_table

Describes the schema of a specific table including column types, constraints, and metadata.

Parameters:

• database (required): The database name
• table_name (required): The table name

execute_query

Executes SQL queries against ClickHouse with optional result limiting.

Parameters:

• query (required): The SQL query to execute
• limit (optional): Maximum number of rows to return (default: server configured limit, max: 10,000)

Available Resources

clickhouse://schema

Provides complete schema information for the ClickHouse database in JSON format.

clickhouse://table/{database}/{table}

Provides detailed information about a specific table including schema, sample data, and statistics.

Available Prompts

query_builder

Helps build efficient ClickHouse SQL queries with context about available tables and best practices.

Arguments:

• database (required): Name of the database
• table_name (optional): Specific table to focus on
• query_type (optional): Type of query (SELECT, INSERT, etc.)

OpenAI GPTs Integration

The Altinity MCP Server supports seamless integration with OpenAI GPTs through its OpenAPI-compatible endpoints. These endpoints enable GPT assistants to perform ClickHouse database operations directly.

Authentication

• With JWE: Add the JWE token to either:
  1. Path parameter: /{jwe_token}/openapi/... (now required)
  2. Authorization header: Bearer {token} (alternative)
  3. x-altinity-mcp-key header (alternative)
• Without JWE: Use server-configured credentials (no auth needed in requests)

Available Actions

1. List Tables in Database

Path: /openapi/list_tables
Parameters:

• jwe_token (path param): JWE authentication token
• database (query param): Name of database (optional, returns all databases if omitted)

Example OpenAPI Path:

GET /{jwe_token}/openapi/list_tables?database={db_name}

2. Describe Table Structure

Path: /openapi/describe_table
Parameters:

• jwe_token (path param): JWE authentication token
• database (query param): Name of database (required)
• table_name (query param): Name of table to describe (required)

Example OpenAPI Path:

GET /{jwe_token}/openapi/describe_table?database={db_name}&table_name={table_name}

3. Execute SQL Query

Path: /openapi/execute_query
Parameters:

• jwe_token (path param): JWE authentication token
• query (query param): SQL query to execute (required)
• limit (query param): Maximum rows to return (optional, default 1000, max 10000)

Example OpenAPI Path:

GET /{jwe_token}/openapi/execute_query?query=SELECT%20*%20FROM%20table&limit=500

Configuration Example for GPTs

{
  "openapi": "3.1.0",
  "info": {
    "title": "ClickHouse SQL Interface",
    "version": "1.0.0"
  },
  "servers": [
    {"url": "https://your-server:8080/{token}"}
  ],
  "paths": {
    "/{jwe_token}/openapi/list_tables": {
      "get": {
        "operationId": "list_tables",
        "parameters": [
          {
            "name": "jwe_token",
            "in": "path",
            "required": true,
            "schema": {"type": "string"}
          },
          {
            "name": "database",
            "in": "query",
            "schema": {"type": "string"}
          }
        ]
      }
    },
    "/{jwe_token}/openapi/describe_table": {
      "get": {
        "operationId": "describe_table",
        "parameters": [
          {
            "name": "jwe_token",
            "in": "path",
            "required": true,
            "schema": {"type": "string"}
          },
          {
            "name": "database",
            "in": "query",
            "required": true
          },
          {
            "name": "table_name",
            "in": "query",
            "required": true
          }
        ]
      }
    },
    "/{jwe_token}/openapi/execute_query": {
      "get": {
        "operationId": "execute_query",
        "parameters": [
          {
            "name": "jwe_token",
            "in": "path",
            "required": true,
            "schema": {"type": "string"}
          },
          {
            "name": "query",
            "in": "query",
            "required": true
          },
          {
            "name": "limit",
            "in": "query",
            "schema": {"type": "integer"}
          }
        ]
      }
    }
  }
}

Note: For Altinity Cloud deployments, use the provided endpoint URL with your organization-specific token.

JWE Authentication

When JWE authentication is enabled, the server expects tokens encrypted using AES Key Wrap (A256KW) and AES-GCM (A256GCM). These tokens contain ClickHouse connection parameters:

{
  "host": "clickhouse.example.com",
  "port": 8123,
  "database": "analytics",
  "username": "user123",
  "password": "secret",
  "protocol": "http",
  "secure": "false"
}

Generate tokens using the provided utility.

go run ./cmd/jwe_auth/jwe_token_generator.go \
  --jwe-secret-key "your-jwe-encryption-secret" \
  --jwt-secret-key "your-jwt-signing-secret" \
  --host "clickhouse.example.com" \
  --port 8123 \
  --database "analytics" \
  --username "user123" \
  --password "password123" \
  --expiry 86400

More details in jwe_authentication.md

TLS Configuration

ClickHouse TLS

./altinity-mcp \
  --clickhouse-tls \
  --clickhouse-tls-ca-cert /path/to/ca.crt \
  --clickhouse-tls-client-cert /path/to/client.crt \
  --clickhouse-tls-client-key /path/to/client.key

Server TLS

./altinity-mcp \
  --transport https \
  --server-tls \
  --server-tls-cert-file /path/to/server.crt \
  --server-tls-key-file /path/to/server.key

Testing

Test ClickHouse Connection

./altinity-mcp test-connection \
  --clickhouse-host localhost \
  --clickhouse-port 8123 \
  --clickhouse-database default

Run Tests

go test ./...

Integration Tests

Integration tests use Docker containers and require Docker to be running:

go test -v ./cmd/altinity-mcp/...

Development

Prerequisites

• Go 1.21 or later
• Docker (for integration tests)
• ClickHouse server (for development)

Building

go build -o altinity-mcp ./cmd/altinity-mcp

Running Tests

# Unit tests
go test ./pkg/...

# Integration tests (requires Docker)
go test -v ./cmd/altinity-mcp/...

Deployment

Kubernetes with Helm

helm install altinity-mcp ./helm/altinity-mcp \
  --set config.clickhouse.host=clickhouse-service \
  --set config.clickhouse.database=analytics \
  --set config.server.transport=http \
  --set config.server.port=8080

Docker Compose

version: '3.8'
services:
  altinity-mcp:
    build: .
    ports:
      - "8080:8080"
    environment:
      - CLICKHOUSE_HOST=clickhouse
      - MCP_TRANSPORT=http
      - MCP_PORT=8080
    depends_on:
      - clickhouse
  
  clickhouse:
    image: clickhouse/clickhouse-server:latest
    ports:
      - "8123:8123"

CLI Reference

Global Flags

• --config: Path to configuration file (YAML or JSON)
• --log-level: Logging level (debug/info/warn/error)
• --clickhouse-limit: Default limit for query results (default: 1000)
• --openapi: Enable OpenAPI endpoints (disable/http/https) (default: disable)

ClickHouse Flags

• --clickhouse-host: ClickHouse server host
• --clickhouse-port: ClickHouse server port
• --clickhouse-database: Database name
• --clickhouse-username: Username
• --clickhouse-password: Password
• --clickhouse-protocol: Protocol (http/tcp)
• --read-only: Read-only mode
• --clickhouse-max-execution-time: Query timeout in seconds

Server Flags

• --transport: Transport type (stdio/http/sse)
• --address: Server address
• --port: Server port
• --allow-jwe-auth: Enable JWE authentication
• --jwe-secret-key: Secret key for JWE token decryption (must be 32 bytes for A256KW).
• --jwt-secret-key: Secret key for JWT signature verification

Commands

• version: Show version information
• test-connection: Test ClickHouse connection

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests
5. Run the test suite
6. Submit a pull request

License

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

Support

For support and questions:

• GitHub Issues: https://github.com/altinity/altinity-mcp/issues
• Email: [email protected]