Gemini Peer Review
Consult Gemini as a coding peer for a second opinion on code quality, architecture decisions, debugging, or security reviews.
Setup
API Key: Set GEMINI_API_KEY as an environment variable. Get a key from https://aistudio.google.com/apikey if you don't have one.
export GEMINI_API_KEY="your-key-here"Workflow
- Determine mode from user request (review, architect, debug, security, quick)
- Read target files into context
- Build prompt using the AI-to-AI template from references/prompt-templates.md
- Write prompt to file at
.claude/artifacts/gemini-prompt.txt(avoids shell escaping issues) - Call the API — generate a Python script that: Write the script to
.claude/scripts/gemini-review.pyand run it.
- Reads GEMINI_API_KEY from environment - Reads the prompt from .claude/artifacts/gemini-prompt.txt - POSTs to https://generativelanguage.googleapis.com/v1beta/models/{model}:generateContent - Payload: {"contents": [{"parts": [{"text": prompt}]}], "generationConfig": {"temperature": 0.3, "maxOutputTokens": 8192}} - Extracts text from candidates[0].content.parts[0].text - Prints result to stdout
- Synthesize — present Gemini's findings, add your own perspective (agree/disagree), let the user decide what to implement
Modes
Code Review
Review specific files for bugs, logic errors, security vulnerabilities, performance issues, and best practice violations.
Read the target files, build a prompt using the Code Review template, call with gemini-2.5-flash.
Architecture Advice
Get feedback on design decisions with trade-off analysis. Include project context (CLAUDE.md, relevant source files).
Read project context, build a prompt using the Architecture template, call with gemini-2.5-pro.
Debugging Help
Analyse errors when stuck after 2+ failed fix attempts. Gemini sees the code fresh without your debugging context bias.
Read the problematic files, build a prompt using the Debug template (include error message and previous attempts), call with gemini-2.5-flash.
Security Scan
Scan code for security vulnerabilities (injection, auth bypass, data exposure).
Read the target directory's source files, build a prompt using the Security template, call with gemini-2.5-pro.
Quick Question
Fast question without file context. Build prompt inline, write to file, call with gemini-2.5-flash.
Model Selection
| Mode | Model | Why |
|---|---|---|
| review, debug, quick | gemini-2.5-flash | Fast, good for straightforward analysis |
| architect, security-scan | gemini-2.5-pro | Better reasoning for complex trade-offs |
Check current model IDs if errors occur — they change frequently:
curl -s "https://generativelanguage.googleapis.com/v1beta/models?key=$GEMINI_API_KEY" | python3 -c "import sys,json; [print(m['name']) for m in json.load(sys.stdin)['models'] if 'gemini' in m['name']]"When to Use
Good use cases:
- Before committing major changes (final review)
- When stuck debugging after multiple attempts
- Architecture decisions with multiple valid options
- Security-sensitive code review
Avoid using for:
- Simple syntax checks (Claude handles these faster)
- Every single edit (too slow, unnecessary)
- Questions with obvious answers
Prompt Construction
Critical: Always use the AI-to-AI prompting format. Write the full prompt to a file — never pass code inline via bash arguments (shell escaping will break it).
When building the prompt:
- Start with the AI-to-AI header from references/prompt-templates.md
- Append the mode-specific template
- Append the file contents with clear
--- filename ---separators - Write to
.claude/artifacts/gemini-prompt.txt - Generate and run the API call script
Reference Files
| When | Read |
|---|---|
| Building prompts for any mode | references/prompt-templates.md |