Agent Skills: Gemini CLI

Gemini CLI

Interact w/ Google's Gemini CLI locally. Run queries, get responses, compare outputs.

Prerequisites

Gemini CLI must be installed & configured:

1. Install: https://github.com/google-gemini/gemini-cli
2. Auth: Run gemini & sign in w/ Google account
3. Verify: gemini --version

When to Use

• User asks to "run/ask/use gemini"
• Compare Claude vs Gemini responses
• Get second AI opinion
• Delegate task to Gemini

Usage

IMPORTANT: Use -p flag for non-interactive (headless) one-shot queries. Without -p, gemini opens interactive mode which hangs in automation.

# One-shot query (MUST use -p for non-interactive)
gemini -p "Your prompt"

# Specific model
gemini -p "prompt" -m gemini-3-pro

# JSON output
gemini -p "prompt" -o json

# YOLO mode (auto-approve tool use)
gemini -y -p "prompt"

# File analysis
cat file.txt | gemini -p "Analyze this"

Models (Gemini 3+ only)

| Model | Use case | |-------|----------| | gemini-3-pro | Default, best all-round | | gemini-3-flash | Fast, lightweight tasks |

Omit -m to use the CLI default (latest stable).

CLI Options

| Flag | Desc | |------|------| | -p | Required for headless. Non-interactive prompt | | -m | Model selection | | -o | Output: text/json/stream-json | | -y | Auto-approve all actions (YOLO) | | -d | Debug mode | | -s | Sandbox mode | | -r | Resume session | | -i | Execute prompt then continue interactive |

Comparison Workflow

1. Provide Claude's response first
2. Run same query via gemini -p "prompt"
3. Present both for comparison

Best Practices

• Always use -p for automation/one-shot queries
• Quote prompts w/ double quotes
• Use -o json for parsing
• Pipe files for context