Gemini CLI for the Enterprise

This document outlines configuration patterns and best practices for deploying and managing Gemini CLI in an enterprise environment. By leveraging system-level settings, administrators can enforce security policies, manage tool access, and ensure a consistent experience for all users.

A Note on Security: The patterns described in this document are intended to help administrators create a more controlled and secure environment for using Gemini CLI. However, they should not be considered a foolproof security boundary. A determined user with sufficient privileges on their local machine may still be able to circumvent these configurations. These measures are designed to prevent accidental misuse and enforce corporate policy in a managed environment, not to defend against a malicious actor with local administrative rights.

Centralized Configuration: The System Settings File

The most powerful tools for enterprise administration are the system-wide settings files. These files allow you to define a baseline configuration (system-defaults.json) and a set of overrides (settings.json) that apply to all users on a machine. For a complete overview of configuration options, see the Configuration documentation.

Settings are merged from four files. The precedence order for single-value settings (like theme) is:

1. System Defaults (system-defaults.json)
2. User Settings (~/.gemini/settings.json)
3. Workspace Settings (<project>/.gemini/settings.json)
4. System Overrides (settings.json)

This means the System Overrides file has the final say. For settings that are arrays (includeDirectories) or objects (mcpServers), the values are merged.

Example of Merging and Precedence:

Here is how settings from different levels are combined.

• System Defaults system-defaults.json:

  {
    "ui": {
      "theme": "default-corporate-theme"
    },
    "context": {
      "includeDirectories": ["/etc/gemini-cli/common-context"]
    }
  }

• User settings.json (~/.gemini/settings.json):

  {
    "ui": {
      "theme": "user-preferred-dark-theme"
    },
    "mcpServers": {
      "corp-server": {
        "command": "/usr/local/bin/corp-server-dev"
      },
      "user-tool": {
        "command": "npm start --prefix ~/tools/my-tool"
      }
    },
    "context": {
      "includeDirectories": ["~/gemini-context"]
    }
  }

• Workspace settings.json (<project>/.gemini/settings.json):

  {
    "ui": {
      "theme": "project-specific-light-theme"
    },
    "mcpServers": {
      "project-tool": {
        "command": "npm start"
      }
    },
    "context": {
      "includeDirectories": ["./project-context"]
    }
  }

• System Overrides settings.json:

  {
    "ui": {
      "theme": "system-enforced-theme"
    },
    "mcpServers": {
      "corp-server": {
        "command": "/usr/local/bin/corp-server-prod"
      }
    },
    "context": {
      "includeDirectories": ["/etc/gemini-cli/global-context"]
    }
  }

This results in the following merged configuration:

• Final Merged Configuration:

  {
    "ui": {
      "theme": "system-enforced-theme"
    },
    "mcpServers": {
      "corp-server": {
        "command": "/usr/local/bin/corp-server-prod"
      },
      "user-tool": {
        "command": "npm start --prefix ~/tools/my-tool"
      },
      "project-tool": {
        "command": "npm start"
      }
    },
    "context": {
      "includeDirectories": [
        "/etc/gemini-cli/common-context",
        "~/gemini-context",
        "./project-context",
        "/etc/gemini-cli/global-context"
      ]
    }
  }

Why:

• theme: The value from the system overrides (system-enforced-theme) is used, as it has the highest precedence.

• mcpServers: The objects are merged. The corp-server definition from the system overrides takes precedence over the user’s definition. The unique user-tool and project-tool are included.

• includeDirectories: The arrays are concatenated in the order of System Defaults, User, Workspace, and then System Overrides.

• Location:

  • Linux: /etc/gemini-cli/settings.json
  • Windows: C:\ProgramData\gemini-cli\settings.json
  • macOS: /Library/Application Support/GeminiCli/settings.json
  • The path can be overridden using the GEMINI_CLI_SYSTEM_SETTINGS_PATH environment variable.

• Control: This file should be managed by system administrators and protected with appropriate file permissions to prevent unauthorized modification by users.

By using the system settings file, you can enforce the security and configuration patterns described below.

Restricting Tool Access

You can significantly enhance security by controlling which tools the Gemini model can use. This is achieved through the tools.core and tools.exclude settings. For a list of available tools, see the Tools documentation.

Allowlisting with coreTools

The most secure approach is to explicitly add the tools and commands that users are permitted to execute to an allowlist. This prevents the use of any tool not on the approved list.

Example: Allow only safe, read-only file operations and listing files.

{
  "tools": {
    "core": ["ReadFileTool", "GlobTool", "ShellTool(ls)"]
  }
}

Blocklisting with excludeTools

Alternatively, you can add specific tools that are considered dangerous in your environment to a blocklist.

Example: Prevent the use of the shell tool for removing files.

{
  "tools": {
    "exclude": ["ShellTool(rm -rf)"]
  }
}

Security Note: Blocklisting with excludeTools is less secure than allowlisting with coreTools, as it relies on blocking known-bad commands, and clever users may find ways to bypass simple string-based blocks. Allowlisting is the recommended approach.

Disabling YOLO Mode

To ensure that users cannot bypass the confirmation prompt for tool execution, you can disable YOLO mode at the policy level. This adds a critical layer of safety, as it prevents the model from executing tools without explicit user approval.

Example: Force all tool executions to require user confirmation.

{
  "security": {
    "disableYoloMode": true
  }
}

This setting is highly recommended in an enterprise environment to prevent unintended tool execution.

Managing Custom Tools (MCP Servers)

If your organization uses custom tools via Model-Context Protocol (MCP) servers, it is crucial to understand how server configurations are managed to apply security policies effectively.

How MCP Server Configurations are Merged

Gemini CLI loads settings.json files from three levels: System, Workspace, and User. When it comes to the mcpServers object, these configurations are merged:

1. Merging: The lists of servers from all three levels are combined into a single list.
2. Precedence: If a server with the same name is defined at multiple levels (e.g., a server named corp-api exists in both system and user settings), the definition from the highest-precedence level is used. The order of precedence is: System > Workspace > User.

This means a user cannot override the definition of a server that is already defined in the system-level settings. However, they can add new servers with unique names.

Enforcing a Catalog of Tools

The security of your MCP tool ecosystem depends on a combination of defining the canonical servers and adding their names to an allowlist.

Restricting Tools Within an MCP Server

For even greater security, especially when dealing with third-party MCP servers, you can restrict which specific tools from a server are exposed to the model. This is done using the includeTools and excludeTools properties within a server’s definition. This allows you to use a subset of tools from a server without allowing potentially dangerous ones.

Following the principle of least privilege, it is highly recommended to use includeTools to create an allowlist of only the necessary tools.

Example: Only allow the code-search and get-ticket-details tools from a third-party MCP server, even if the server offers other tools like delete-ticket.

{
  "mcp": {
    "allowed": ["third-party-analyzer"]
  },
  "mcpServers": {
    "third-party-analyzer": {
      "command": "/usr/local/bin/start-3p-analyzer.sh",
      "includeTools": ["code-search", "get-ticket-details"]
    }
  }
}

More Secure Pattern: Define and Add to Allowlist in System Settings

To create a secure, centrally-managed catalog of tools, the system administrator must do both of the following in the system-level settings.json file:

1. Define the full configuration for every approved server in the mcpServers object. This ensures that even if a user defines a server with the same name, the secure system-level definition will take precedence.
2. Add the names of those servers to an allowlist using the mcp.allowed setting. This is a critical security step that prevents users from running any servers that are not on this list. If this setting is omitted, the CLI will merge and allow any server defined by the user.

Example System settings.json:

1. Add the names of all approved servers to an allowlist. This will prevent users from adding their own servers.

2. Provide the canonical definition for each server on the allowlist.

{
  "mcp": {
    "allowed": ["corp-data-api", "source-code-analyzer"]
  },
  "mcpServers": {
    "corp-data-api": {
      "command": "/usr/local/bin/start-corp-api.sh",
      "timeout": 5000
    },
    "source-code-analyzer": {
      "command": "/usr/local/bin/start-analyzer.sh"
    }
  }
}

This pattern is more secure because it uses both definition and an allowlist. Any server a user defines will either be overridden by the system definition (if it has the same name) or blocked because its name is not in the mcp.allowed list.

Less Secure Pattern: Omitting the Allowlist

If the administrator defines the mcpServers object but fails to also specify the mcp.allowed allowlist, users may add their own servers.

Example System settings.json:

This configuration defines servers but does not enforce the allowlist. The administrator has NOT included the “mcp.allowed” setting.

{
  "mcpServers": {
    "corp-data-api": {
      "command": "/usr/local/bin/start-corp-api.sh"
    }
  }
}

In this scenario, a user can add their own server in their local settings.json. Because there is no mcp.allowed list to filter the merged results, the user’s server will be added to the list of available tools and allowed to run.

Enforcing Sandboxing for Security

To mitigate the risk of potentially harmful operations, you can enforce the use of sandboxing for all tool execution. The sandbox isolates tool execution in a containerized environment.

Example: Force all tool execution to happen within a Docker sandbox.

{
  "tools": {
    "sandbox": "docker"
  }
}

You can also specify a custom, hardened Docker image for the sandbox by building a custom sandbox.Dockerfile as described in the Sandboxing documentation.

Controlling Network Access via Proxy

In corporate environments with strict network policies, you can configure Gemini CLI to route all outbound traffic through a corporate proxy. This can be set via an environment variable, but it can also be enforced for custom tools via the mcpServers configuration.

Example (for an MCP Server):

{
  "mcpServers": {
    "proxied-server": {
      "command": "node",
      "args": ["mcp_server.js"],
      "env": {
        "HTTP_PROXY": "http://proxy.example.com:8080",
        "HTTPS_PROXY": "http://proxy.example.com:8080"
      }
    }
  }
}

Telemetry and Auditing

For auditing and monitoring purposes, you can configure Gemini CLI to send telemetry data to a central location. This allows you to track tool usage and other events. For more information, see the telemetry documentation.

Example: Enable telemetry and send it to a local OTLP collector. If otlpEndpoint is not specified, it defaults to http://localhost:4317.

{
  "telemetry": {
    "enabled": true,
    "target": "gcp",
    "logPrompts": false
  }
}

Note: Ensure that logPrompts is set to false in an enterprise setting to avoid collecting potentially sensitive information from user prompts.

Authentication

You can enforce a specific authentication method for all users by setting the enforcedAuthType in the system-level settings.json file. This prevents users from choosing a different authentication method. See the Authentication docs for more details.

Example: Enforce the use of Google login for all users.

{
  "enforcedAuthType": "oauth-personal"
}

If a user has a different authentication method configured, they will be prompted to switch to the enforced method. In non-interactive mode, the CLI will exit with an error if the configured authentication method does not match the enforced one.

Putting It All Together: Example System settings.json

Here is an example of a system settings.json file that combines several of the patterns discussed above to create a secure, controlled environment for Gemini CLI.

{
  "tools": {
    "sandbox": "docker",
    "core": [
      "ReadFileTool",
      "GlobTool",
      "ShellTool(ls)",
      "ShellTool(cat)",
      "ShellTool(grep)"
    ]
  },
  "mcp": {
    "allowed": ["corp-tools"]
  },
  "mcpServers": {
    "corp-tools": {
      "command": "/opt/gemini-tools/start.sh",
      "timeout": 5000
    }
  },
  "telemetry": {
    "enabled": true,
    "target": "gcp",
    "otlpEndpoint": "https://telemetry-prod.example.com:4317",
    "logPrompts": false
  },
  "advanced": {
    "bugCommand": {
      "urlTemplate": "https://servicedesk.example.com/new-ticket?title={title}&details={info}"
    }
  },
  "privacy": {
    "usageStatisticsEnabled": false
  }
}

This configuration:

• Forces all tool execution into a Docker sandbox.
• Strictly uses an allowlist for a small set of safe shell commands and file tools.
• Defines and allows a single corporate MCP server for custom tools.
• Enables telemetry for auditing, without logging prompt content.
• Redirects the /bug command to an internal ticketing system.
• Disables general usage statistics collection.