Gemini Subagent

Run Google Gemini CLI for second opinions and external reviews.

Availability Check

Before using Gemini, verify it's installed:

which gemini >/dev/null 2>&1 || echo "GEMINI_NOT_INSTALLED"

If not installed, inform the user: "Gemini CLI is not installed. Skipping Gemini review."

API Key

Gemini requires GEMINI_API_KEY in the environment. Load it from the .env file in the current working directory (the folder your current agent session is running from):

GEMINI_API_KEY=$(grep '^GEMINI_API_KEY=' .env 2>/dev/null | cut -d= -f2-)
export GEMINI_API_KEY

If .env doesn't exist or doesn't contain GEMINI_API_KEY, inform the user: "GEMINI_API_KEY not found in .env file."

Execution Pattern

GEMINI_API_KEY=$(grep '^GEMINI_API_KEY=' .env 2>/dev/null | cut -d= -f2-) gemini -p "$PROMPT" --yolo 2>&1

Flags

Timeout

Gemini can take several minutes for complex prompts. Use 15 minute timeout:

timeout 900 gemini -p "$PROMPT" --yolo 2>&1

Usage Examples

Simple Question

timeout 900 gemini -p "What are the tradeoffs between Redis and Memcached for session storage?" --yolo 2>&1

Code Review

DIFF=$(git diff main...HEAD)
timeout 900 gemini -p "Review this diff for issues:

$DIFF

List concerns with severity (blocking/important/nice-to-have)." --yolo 2>&1

With Working Directory

Gemini runs in current directory by default. Change directory before running:

cd /path/to/repo && timeout 900 gemini -p "Analyze the architecture of this codebase" --yolo 2>&1

GitHub PR Review

Gemini has access to gh CLI when tools are enabled. Pass the PR URL and let it fetch the diff:

timeout 900 gemini -p "Review this PR: https://github.com/owner/repo/pull/123

Use gh CLI to get the diff and review for issues." --yolo 2>&1

Notes

• Gemini provides a different perspective from Claude and Codex
• Each call is stateless - no conversation continuity
• --yolo mode auto-approves tool use (shell commands, file reads, etc.)
• API costs apply per call