Gemini CLI Reference

Complete guide to using Gemini CLI with Preloop's Safety Layer.

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Overview

Gemini CLI is Google's open-source terminal AI agent. It supports MCP out of the box, making it simple to connect to Preloop's Safety Layer.

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Installation

npm install -g @anthropic-ai/gemini-cli

Or via the official repo:

npx https://github.com/anthropics/gemini-cli

Verify:

gemini --version

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Configuration

Connect to Preloop

Step 1: Get Your API Key

1. Log in to preloop.ai
2. Settings → API Keys → + Create API Key
3. Name: "Gemini CLI"
4. Copy the key

Step 2: Add Preloop MCP Server

Edit ~/.gemini/settings.json:

{
  "mcpServers": {
    "preloop": {
      "url": "https://preloop.ai/mcp/v1",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY_HERE"
      }
    }
  }
}

Step 3: Verify Connection

gemini
> /mcp

You should see preloop listed with available tools.

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Usage

Basic Usage

gemini
> Using @preloop tools, pay alice@example.com $500

The approval flow works the same as other clients:

1. Gemini sends tool call to Preloop
2. Preloop creates an approval request
3. You approve via dashboard, mobile, or email
4. Tool executes and result is returned

Differences from Other Clients

Feature	Gemini CLI	Claude Code
Provider	Google	Anthropic
Transport	HTTP streaming	HTTP streaming
Config location	~/.gemini/settings.json	~/.claude/mcp-servers.json
MCP support	Native	Native

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Automatic Discovery

Use the Preloop CLI to automatically detect Gemini CLI:

preloop agents discover

This scans ~/.gemini/settings.json and inspects the local MCP and model configuration.

Discovery is the entry point for onboarding an existing Gemini CLI setup into Preloop:

• Existing MCP tools can be imported into your Preloop account when they can be represented there
• Existing AI model metadata can be imported or reused when the local configuration is compatible
• Supported managed rewrites can point Gemini CLI to the Preloop Gateway for model traffic and the Preloop Tool Firewall for governed MCP access

If you want discovery to stay non-mutating in scripts or CI, use the read-only flags supported by the Preloop CLI.

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