This Gemini CLI extension provides a set of tools to interact with Google Cloud Spanner instances. It allows you to manage your databases, execute queries, and explore schemas directly from the Gemini CLI, using natural language prompts.

Learn more about Gemini CLI Extensions.

• Natural Language Management: Stop wrestling with complex commands. Explore schemas and query data by describing what you want in plain English.
• Seamless Workflow: As a Google-developed extension, it integrates seamlessly into the Gemini CLI environment. No need to constantly switch contexts for common database tasks.
• Code Generation: Accelerate development by asking Gemini to generate data classes and other code snippets based on your table schemas.

Before you begin, ensure you have the following:

• Gemini CLI installed with version +v0.6.0.
• Setup Gemini CLI Authentication.
• A Google Cloud project with the Spanner API enabled.
• Ensure Application Default Credentials are available in your environment.
• IAM Permissions
  • Cloud Spanner Database Reader (roles/spanner.databaseReader)
  • Cloud Spanner Database User (roles/spanner.databaseUser)

To install the extension, use the command:

gemini extensions install https://github.com/gemini-cli-extensions/spanner

Set the following environment variables before starting the Gemini CLI. These variables can be loaded from a .env file.

• SPANNER_PROJECT: The GCP project ID.
• SPANNER_INSTANCE: The Spanner instance ID.
• SPANNER_DATABASE: The Spanner database ID.
• SPANNER_DIALECT: (Optional) The Spanner database dialect e.g. "googlesql" or "postgresql" (Default: "googlesql")

Ensure Application Default Credentials are available in your environment.

To start the Gemini CLI, use the following command:

gemini

• Explore Schemas and Data:

  • "Show me all tables in the 'orders' database."
  • "What are the columns in the 'products' table?"
  • "How many orders were placed in the last 30 days, and what were the top 5 most purchased items?"

• Generate Code:

  • "Generate a Python dataclass to represent the 'customers' tab

• list_tables: Use this tool to list tables and descriptions.
• execute_sql: Use this tool to execute any SQL statement.
• execute_sql_dql: Use this tool to execute DQL SQL statement.

Find additional extensions to support your entire software development lifecycle at github.com/gemini-cli-extensions.

Use gemini --debug to enable debugging.

Common issues:

• "failed to find default credentials: google: could not find default credentials.": Ensure Application Default Credentials are available in your environment. See Set up Application Default Credentials for more information.
• "✖ Error during discovery for server: MCP error -32000: Connection closed": The database connection has not been established. Ensure your configuration is set via environment variables.
• "✖ MCP ERROR: Error: spawn /Users/USER/.gemini/extensions/spanner/toolbox ENOENT": The Toolbox binary did not download correctly. Ensure you are using Gemini CLI v0.6.0+.
• "cannot execute binary file": The Toolbox binary did not download correctly. Ensure the correct binary for your OS/Architecture has been downloaded. See Installing the server for more information.