https://github.com/dynamike/snowflake-mcp-server
MCP Server for connecting to Snowflake with read-only questions
https://github.com/dynamike/snowflake-mcp-server
modelcontextprotocol snowflake
Last synced: about 1 year ago
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MCP Server for connecting to Snowflake with read-only questions
- Host: GitHub
- URL: https://github.com/dynamike/snowflake-mcp-server
- Owner: dynamike
- License: mit
- Created: 2025-03-14T13:17:25.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-04-28T19:38:02.000Z (over 1 year ago)
- Last Synced: 2025-06-22T10:15:54.922Z (about 1 year ago)
- Topics: modelcontextprotocol, snowflake
- Language: Python
- Homepage:
- Size: 143 KB
- Stars: 7
- Watchers: 1
- Forks: 6
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# MCP Server for Snowflake
A Model Context Protocol (MCP) server for performing read-only operations against Snowflake databases. This tool enables Claude to securely query Snowflake data without modifying any information.
## Features
- Flexible authentication to Snowflake using either:
- Service account authentication with private key
- External browser authentication for interactive sessions
- Connection pooling with automatic background refresh to maintain persistent connections
- Support for querying multiple views and databases in a single session
- Support for multiple SQL statement types (SELECT, SHOW, DESCRIBE, EXPLAIN, WITH)
- MCP-compatible handlers for querying Snowflake data
- Read-only operations with security checks to prevent data modification
- Support for Python 3.12+
- Stdio-based MCP server for easy integration with Claude Desktop
## Available Tools
The server provides the following tools for querying Snowflake:
- **list_databases**: List all accessible Snowflake databases
- **list_views**: List all views in a specified database and schema
- **describe_view**: Get detailed information about a specific view including columns and SQL definition
- **query_view**: Query data from a view with an optional row limit
- **execute_query**: Execute custom read-only SQL queries (SELECT, SHOW, DESCRIBE, EXPLAIN, WITH) with results formatted as markdown tables
## Installation
### Prerequisites
- Python 3.12 or higher
- A Snowflake account with either:
- A configured service account (username + private key), or
- A regular user account for browser-based authentication
- [uv](https://github.com/astral-sh/uv) package manager (recommended)
### Steps
1. Clone this repository:
```
git clone https://github.com/yourusername/snowflake-mcp-server.git
cd snowflake-mcp-server
```
2. Install the package:
```
uv pip install -e .
```
3. Create a `.env` file with your Snowflake credentials:
Choose one of the provided example files based on your preferred authentication method:
**For private key authentication**:
```
cp .env.private_key.example .env
```
Then edit the `.env` file to set your Snowflake account details and path to your private key.
**For external browser authentication**:
```
cp .env.browser.example .env
```
Then edit the `.env` file to set your Snowflake account details.
## Usage
### Running with uv
After installing the package, you can run the server directly with:
```
uv run snowflake-mcp
# Or you can be explicit about using stdio transport
uv run snowflake-mcp-stdio
```
This will start the stdio-based MCP server, which can be connected to Claude Desktop or any MCP client that supports stdio communication.
When using external browser authentication, a browser window will automatically open prompting you to log in to your Snowflake account.
### Claude Desktop Integration
1. In Claude Desktop, go to Settings → MCP Servers
2. Add a new server with the full path to your uv executable:
```yaml
"snowflake-mcp-server": {
"command": "uv",
"args": [
"--directory",
"//snowflake-mcp-server",
"run",
"snowflake-mcp"
]
}
```
Or explicitly specify the stdio transport:
```yaml
"snowflake-mcp-server": {
"command": "uv",
"args": [
"--directory",
"//snowflake-mcp-server",
"run",
"snowflake-mcp-stdio"
]
}
```
3. You can find your uv path by running `which uv` in your terminal
4. Save the server configuration
### Example Queries
When using with Claude, you can ask questions like:
- "Can you list all the databases in my Snowflake account?"
- "List all views in the MARKETING database"
- "Describe the structure of the CUSTOMER_ANALYTICS view in the SALES database"
- "Show me sample data from the REVENUE_BY_REGION view in the FINANCE database"
- "Run this SQL query: SELECT customer_id, SUM(order_total) as total_spend FROM SALES.ORDERS GROUP BY customer_id ORDER BY total_spend DESC LIMIT 10"
- "Query the MARKETING database to find the top 5 performing campaigns by conversion rate"
- "Compare data from views in different databases by querying SALES.CUSTOMER_METRICS and MARKETING.CAMPAIGN_RESULTS"
### Configuration
Connection pooling behavior can be configured through environment variables:
- `SNOWFLAKE_CONN_REFRESH_HOURS`: Time interval in hours between connection refreshes (default: 8)
Example `.env` configuration:
```
# Set connection to refresh every 4 hours
SNOWFLAKE_CONN_REFRESH_HOURS=4
```
## Authentication Methods
### Private Key Authentication
This method uses a service account and private key for non-interactive authentication, ideal for automated processes.
1. Create a key pair for your Snowflake user following [Snowflake documentation](https://docs.snowflake.com/en/user-guide/key-pair-auth)
2. Set `SNOWFLAKE_AUTH_TYPE=private_key` in your `.env` file
3. Provide the path to your private key in `SNOWFLAKE_PRIVATE_KEY_PATH`
### External Browser Authentication
This method opens a browser window for interactive authentication.
1. Set `SNOWFLAKE_AUTH_TYPE=external_browser` in your `.env` file
2. When you start the server, a browser window will open asking you to log in
3. After authentication, the session will remain active for the duration specified by your Snowflake account settings
## Security Considerations
This server:
- Enforces read-only operations (only SELECT, SHOW, DESCRIBE, EXPLAIN, and WITH statements are allowed)
- Automatically adds LIMIT clauses to prevent large result sets
- Uses secure authentication methods for connections to Snowflake
- Validates inputs to prevent SQL injection
⚠️ **Important**: Keep your `.env` file secure and never commit it to version control. The `.gitignore` file is configured to exclude it.
## Development
### Static Type Checking
```
mypy mcp_server_snowflake/
```
### Linting
```
ruff check .
```
### Formatting
```
ruff format .
```
### Running Tests
```
pytest
```
## Contributing
Contributions are welcome! Please feel free to submit a Pull Request.
## Technical Details
This project uses:
- [Snowflake Connector Python](https://docs.snowflake.com/en/developer-guide/python-connector/python-connector) for connecting to Snowflake
- [MCP (Model Context Protocol)](https://github.com/anthropics/anthropic-cookbook/tree/main/mcp) for interacting with Claude
- [Pydantic](https://docs.pydantic.dev/) for data validation
- [python-dotenv](https://github.com/theskumar/python-dotenv) for environment variable management