gemini-cli

Ideal Use Cases

1. Second Opinion / Cross-Validation

- Code review after writing code (different AI perspective)

- Security audit with alternative analysis

- Finding bugs Claude might have missed

1. Google Search Grounding

- Questions requiring current internet information

- Latest library versions, API changes, documentation updates

- Current events or recent releases

1. Codebase Architecture Analysis

- Use Gemini's codebase_investigator tool

- Understanding unfamiliar codebases

- Mapping cross-file dependencies

1. Parallel Processing

- Offload tasks while continuing other work

- Run multiple code generations simultaneously

- Background documentation generation

1. Specialized Generation

- Test suite generation

- JSDoc/documentation generation

- Code translation between languages

When NOT to Use

• Simple, quick tasks (overhead not worth it)
• Tasks requiring immediate response (rate limits cause delays)
• When context is already loaded and understood
• Interactive refinement requiring conversation

1. Verify Installation

```bash

command -v gemini || which gemini

```

2. Basic Command Pattern

```bash

gemini "[prompt]" --yolo -o text 2>&1

```

Key flags:

• --yolo or -y: Auto-approve all tool calls
• -o text: Human-readable output
• -o json: Structured output with stats
• -m gemini-2.5-flash: Use faster model for simple tasks

3. Critical Behavioral Notes

YOLO Mode Behavior: Auto-approves tool calls but does NOT prevent planning prompts. Gemini may still present plans and ask "Does this plan look good?" Use forceful language:

• "Apply now"
• "Start immediately"
• "Do this without asking for confirmation"

Rate Limits: Free tier has 60 requests/min, 1000/day. CLI auto-retries with backoff. Expect messages like "quota will reset after Xs".

4. Output Processing

For JSON output (-o json), parse:

```json

{

"response": "actual content",

"stats": {

"models": { "tokens": {...} },

"tools": { "byName": {...} }

}

}

```

Code Generation

```bash

gemini "Create [description] with [features]. Output complete file content." --yolo -o text

```

Code Review

```bash

gemini "Review [file] for: 1) features, 2) bugs/security issues, 3) improvements" -o text

```

Bug Fixing

```bash

gemini "Fix these bugs in [file]: [list]. Apply fixes now." --yolo -o text

```

Test Generation

```bash

gemini "Generate [Jest/pytest] tests for [file]. Focus on [areas]." --yolo -o text

```

Documentation

```bash

gemini "Generate JSDoc for all functions in [file]. Output as markdown." --yolo -o text

```

Architecture Analysis

```bash

gemini "Use codebase_investigator to analyze this project" -o text

```

Web Research

```bash

gemini "What are the latest [topic]? Use Google Search." -o text

```

Faster Model (Simple Tasks)

```bash

gemini "[prompt]" -m gemini-2.5-flash -o text

```

Rate Limit Exceeded

• CLI auto-retries with backoff
• Use -m gemini-2.5-flash for lower priority tasks
• Run in background for long operations

Command Failures

• Check JSON output for detailed error stats
• Verify Gemini is authenticated: gemini --version
• Check ~/.gemini/settings.json for config issues

Validation After Generation

Always verify Gemini's output:

• Check for security vulnerabilities (XSS, injection)
• Test functionality matches requirements
• Review code style consistency
• Verify dependencies are appropriate

Standard Generate-Review-Fix Cycle

```bash

# 1. Generate

gemini "Create [code]" --yolo -o text

# 2. Review (Gemini reviews its own work)

gemini "Review [file] for bugs and security issues" -o text

# 3. Fix identified issues

gemini "Fix [issues] in [file]. Apply now." --yolo -o text

```

Background Execution

For long tasks, run in background and monitor:

```bash

gemini "[long task]" --yolo -o text 2>&1 &

# Monitor with BashOutput tool

```

These tools are available only through Gemini:

1. google_web_search - Real-time internet search via Google
2. codebase_investigator - Deep architectural analysis
3. save_memory - Cross-session persistent memory

Project Context (Optional)

Create .gemini/GEMINI.md in project root for persistent context that Gemini will automatically read.

Session Management

List sessions: gemini --list-sessions

Resume session: echo "follow-up" | gemini -r [index] -o text

• reference.md - Complete command and flag reference
• templates.md - Prompt templates for common operations
• patterns.md - Advanced integration patterns
• tools.md - Gemini's built-in tools documentation