Gemini CLI Integration Skill

v2.88 Key Changes (MODEL-AGNOSTIC)

• Model-agnostic: Uses model configured in ~/.claude/settings.json or CLI/env vars
• No flags required: Works with the configured default model
• Flexible: Model-agnostic — runs on whatever model the session runs
• Settings-driven: Model selection via ANTHROPIC_DEFAULT_*_MODEL env vars

This skill enables Claude Code to orchestrate Google Gemini CLI (v0.22.0+) with Gemini 3 Pro for code generation, review, analysis, and specialized tasks including real-time web search.

What's New in v0.22.0 (December 2025)

• Gemini 3: Free tier users now have access to Gemini 3 via Preview Features toggle
• Colab Integration: Pre-installed in Google Colab, usable headlessly in notebook cells
• Extensions Support:
  • Conductor: Planning++ with context-driven development
  • Endor Labs: Code analysis, vulnerability scanning, dependency checks
• Comprehensive Quota Visibility: /stats shows all model usage
• Multi-file Drag & Drop: Proper @ prefix handling for multiple files

When to Use This Skill

Ideal Use Cases

1. Second Opinion / Cross-Validation

   • Review code after Claude writes it (different AI perspective)
   • Security audit with alternative analysis
   • Find bugs Claude might have missed

2. Google Search Grounding

   • Questions requiring current internet information
   • Latest library versions, API changes, documentation
   • Current events, recent releases

3. Codebase Architecture Analysis

   • Use codebase_investigator tool
   • Understanding unfamiliar codebases
   • Mapping cross-file dependencies

4. Parallel Processing

   • Offload tasks while continuing other work
   • Multiple code generations simultaneously
   • Background documentation generation

5. Extensions Workflows

   • Conductor for detailed planning before implementation
   • Endor Labs for security/vulnerability scanning

When NOT to Use

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

Quick Start

Prerequisites

# Verify installation
command -v gemini || which gemini

# Check version
gemini --version  # Should show v0.22.0+

Authentication

# Option 1: API Key
export GEMINI_API_KEY=your_key

# Option 2: OAuth (interactive, first run)
gemini  # Prompts for auth

Enable Gemini 3 (Free Tier)

In interactive mode:

/settings
# Toggle "Preview Features" to true

Core Commands

Basic Execution

# Human-readable output
gemini "your prompt" --yolo -o text 2>&1

# JSON structured output
gemini "your prompt" --yolo -o json 2>&1

# Faster model for simple tasks
gemini "your prompt" -m gemini-2.5-flash -o text 2>&1

Key Flags

Flag	Short	Description
--yolo	-y	Auto-approve all tool calls
--output-format	-o	Output: text, json, stream-json
--model	-m	Model selection
--resume	-r	Resume session by index
--sandbox	-s	Run in isolated sandbox
--debug	-d	Enable debug output

Important Behavior Notes

YOLO Mode: Auto-approves tool calls but does NOT prevent planning prompts. Gemini may still 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.

Model Selection

Model	Use Case	Context
gemini-3-pro	Complex tasks (default)	1M tokens
gemini-2.5-flash	Quick tasks, lower latency	Large
gemini-2.5-flash-lite	Fastest, simplest tasks	Medium

# Default (Gemini 3 Pro)
gemini "complex analysis" -o text

# Flash for speed
gemini "simple task" -m gemini-2.5-flash -o text

Unique Gemini Capabilities

1. google_web_search

Real-time internet search via Google:

gemini "What are the latest React 19 features? Use Google Search." -o text

gemini "What's new in TypeScript 5.5? Use Google Search." -o text

gemini "Best practices for Next.js 15 as of December 2025." -o text

Best for:

• Current events and news
• Latest library versions
• Recent documentation updates
• Community opinions and benchmarks

2. codebase_investigator

Deep codebase analysis:

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

gemini "Use codebase_investigator to map the authentication flow" -o text

Output includes:

• Overall architecture description
• Key file purposes
• Component relationships
• Dependency chains
• Potential issues

3. save_memory

Cross-session persistence:

gemini "Remember that this project uses Zustand. Save to memory." -o text

Extensions (v0.22.0+)

Conductor Extension

Planning++ with context-driven development:

# Install
gemini extensions install https://github.com/gemini-cli-extensions/conductor

# Use for detailed planning
gemini "Use Conductor to plan the implementation of user authentication" -o text

Conductor workflow: Plan → Pull details → Create guardrails → Implement

Endor Labs Extension

Security analysis and dependency checks:

# Install
gemini extensions install https://github.com/endorlabs/gemini-extension

# Use for security scanning
gemini "Use Endor Labs to check for vulnerabilities in this project" -o text

List Extensions

gemini --list-extensions
# or
gemini -l

Integration Patterns

Pattern 1: Generate-Review-Fix Cycle

# 1. Generate
gemini "Create a user auth module with bcrypt and JWT" --yolo -o text

# 2. Review (Gemini reviews its own work)
gemini "Review auth.js for security vulnerabilities" -o text

# 3. Fix identified issues
gemini "Fix in auth.js: XSS risk, add input validation. Apply now." --yolo -o text

Pattern 2: Background Execution

For long tasks, run in background:

gemini "Generate comprehensive tests" --yolo -o text 2>&1 &
echo $!  # Get PID

# Multiple parallel tasks
gemini "Create frontend" --yolo -o text 2>&1 &
gemini "Create backend" --yolo -o text 2>&1 &
gemini "Create tests" --yolo -o text 2>&1 &
wait

Pattern 3: Cross-Validation with Claude

# Claude generates → Gemini reviews
# (After Claude writes code)
gemini "Review this code for bugs and security issues: [paste code]" -o text

# Gemini generates → Claude reviews
gemini "Create [code]" --yolo -o text
# Then Claude reviews the output

Pattern 4: Session Continuity

# Initial task
gemini "Analyze this codebase architecture" -o text

# List sessions
gemini --list-sessions

# Resume for follow-up
echo "What patterns did you find?" | gemini -r 1 -o text

# Further refinement
echo "Focus on authentication flow" | gemini -r 1 -o text

JSON Output Processing

gemini "your prompt" -o json 2>&1

Response structure:

{
  "response": "The actual response content",
  "stats": {
    "models": {
      "gemini-3-pro": {
        "tokens": {
          "prompt": 1500,
          "candidates": 500,
          "total": 2000,
          "cached": 800
        }
      }
    },
    "tools": {
      "totalCalls": 2,
      "byName": {
        "google_web_search": {"count": 1, "success": 1}
      }
    }
  }
}

Configuration

Settings Location

Priority order:

1. /etc/gemini-cli/settings.json (system)
2. ~/.gemini/settings.json (user)
3. .gemini/settings.json (project)

Project Context (GEMINI.md)

Create .gemini/GEMINI.md in project root:

# Project Context

This is a TypeScript React app.

## Coding Standards
- Use functional components
- Prefer hooks over classes
- All functions need JSDoc

Ignore Files (.geminiignore)

node_modules/
dist/
*.log
.env

Quick Reference Commands

Task	Command
Basic query	gemini "prompt" --yolo -o text
Web search	gemini "prompt. Use Google Search." -o text
Architecture	gemini "Use codebase_investigator..." -o text
Fast model	gemini "prompt" -m gemini-2.5-flash -o text
JSON output	gemini "prompt" -o json
Resume session	echo "follow-up" | gemini -r 1 -o text
List sessions	gemini --list-sessions
List extensions	gemini --list-extensions

Rate Limit Strategies

1. Let auto-retry handle it: Default behavior with backoff
2. Use Flash for lower priority: Different quota
3. Batch operations: Combine into single prompts
4. Add delays: sleep 2 between calls in scripts

Error Handling

Common Issues

Issue	Solution
"API key not found"	Set GEMINI_API_KEY env var
"Rate limit exceeded"	Wait for auto-retry or use Flash
"Context too large"	Use .geminiignore or be specific
"Tool call failed"	Check JSON stats for details

Debug Mode

gemini "prompt" --debug -o text

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

See Also

• references/command_reference.md - Complete CLI flags
• references/tools.md - Built-in tools documentation
• references/patterns.md - Advanced integration patterns
• references/templates.md - Reusable prompt templates

---

Integration with Claude Code Task Primitive (v2.65.2)

Overview

Gemini CLI is now fully integrated with Claude Code Task Primitive. Every Gemini execution creates a traceable task in ~/.claude/tasks/<session>/tasks.json, making it visible in claude-task-viewer.

How It Works

User: /gemini-cli "Analyze authentication flow"
    ↓
Claude: TaskCreate → Task (subagent: gemini-cli)
    ↓
Hook: task-project-tracker.sh (PostToolUse)
    ↓
Task gets: project metadata, tool="gemini", session_id
    ↓
Global Sync: global-task-sync.sh → ~/.claude/tasks/<session>/tasks.json
    ↓
claude-task-viewer: Shows task with project filter

Automatic Task Creation

Tasks are created automatically via hooks when you invoke /gemini-cli:

Component	Role
task-project-tracker.sh	Adds project and tool fields to tasks
global-task-sync.sh	Syncs tasks to global ~/.claude/tasks/
project-backup-metadata.sh	Tracks session by project

Task Metadata Structure

{
  "id": "1",
  "subject": "Gemini analysis: authentication flow",
  "description": "Use codebase_investigator to map auth dependencies",
  "activeForm": "Running Gemini analysis...",
  "status": "in_progress",
  "project": {
    "path": "/Users/.../my-repo",
    "repo": "owner/my-repo",
    "branch": "main"
  },
  "tool": "gemini",
  "metadata": {
    "model": "gemini-3-pro",
    "capabilities": ["google_web_search", "codebase_investigator"]
  }
}

Viewing Gemini Tasks

# Open claude-task-viewer
npx claude-task-viewer --open

# Filter by project
# → Shows all gemini tasks with project metadata

# List tasks from CLI
ls -la ~/.claude/tasks/*/tasks.json
cat ~/.claude/tasks/ralph-*/tasks.json | jq '.tasks[] | select(.tool == "gemini")'

Integration with Adversarial Council

Gemini works seamlessly with adversarial:

# 1. Create adversarial task
/adversarial --council "Design rate limiter"

# 2. Gemini runs as one of the council members
#    → Task shows: tool="adversarial", metadata.council_mode="council"

# 3. Both adversarial and gemini tasks are tracked
#    → Full visibility in claude-task-viewer

Cross-Validation Pattern

When the user asks for it by name, Gemini can serve as an independent second opinion:

# Claude writes code
# Then Gemini reviews
/gemini-cli "Review the auth module for security issues"

# Both executions tracked separately
# → Full audit trail in claude-task-viewer

Session Continuity

Gemini sessions are preserved across Claude Code sessions:

# Session stored in: ~/.claude/tasks/<session>/tasks.json

# List previous sessions
gemini --list-sessions

# Resume with task update
echo "continue analysis" | gemini -r 1

# Task automatically updated with new session_id

Web Search Grounding

Gemini's web search is also tracked:

/gemini-cli "What are the latest React 19 features? Use Google Search."

# Task includes:
#   metadata.capabilities: ["google_web_search"]
#   → Visible in task viewer

Troubleshooting

Issue	Solution
Task not appearing in viewer	Check task-project-tracker.sh is registered in settings.json
Missing project metadata	Verify project-backup-metadata.sh ran on session start
Task sync failed	Check ~/.ralph/logs/global-task-sync.log
Gemini session not tracked	Ensure tool: "gemini" is added by hook