Using AI

RepoPrompt gives you two powerful ways to use AI with your code: copy optimized prompts to external AI services, or use the integrated Chat with professional diff editing.

Compose Mode

Build context in RepoPrompt, then use it with any AI service - ChatGPT, Claude.ai, Gemini, or any other.

Basic Copy Workflow

1. Select files and configure your context (full, slices, codemaps)
2. Write your prompt describing what you want
3. Click Copy (or ⌘+C)
4. Paste into your AI of choice
5. Get your response

Pro Edit Copy Workflow

For powerful reasoning models that can follow structured instructions:

1. Select a Pro Edit copy preset from the preset dropdown
2. Copy and paste to external AI (ChatGPT, Claude.ai, etc.)
3. The model responds with structured XML change instructions
4. Paste the response back into RepoPrompt's Apply panel
5. Review changes in professional diff view, then apply

tip

Best Models for Classic Edition (as suggested in June 2026): GPT-5.5 Pro (ChatGPT Pro web only), GPT-5.5 High via Codex CLI, Gemini 3 Pro, Claude Opus 4.6 — strong models for instruction following and reasoning.

When to Use Compose Mode

• Deep reasoning tasks: Use the most powerful models (GPT-5.5 Pro via ChatGPT Pro, Gemini 3 Pro) for architectural decisions
• Cost control: Use your existing ChatGPT Plus/Pro subscription, and add Claude Pro only if you want a second editing-focused option
• Privacy preferences: Some prefer keeping code in browser-based AI
• Specialized models: Access models not available via API

Chat Mode

Have AI conversations directly in RepoPrompt with your code context automatically included.

Starting a Chat

1. Select your files (they become the chat's context)
2. Write your prompt or question
3. Click New AI Chat (or ⌘+N)
4. Choose your model and settings
5. Send your message

Chat Modes

Mode	Purpose	When to Use
Chat	Conversation & questions	Asking questions, getting explanations
Plan	Architecture & design	Planning changes before implementing
Edit	Code modifications	Making actual code changes

Reviewing & Applying Changes

When AI suggests code changes in Edit mode:

• Changes appear in a professional diff view with syntax highlighting
• Review each file's modifications line-by-line
• Apply all changes at once, or select specific files
• Undo applied changes if needed

CLI Providers

Use your existing AI subscriptions instead of per-token API costs. This is one of RepoPrompt's most powerful features.

Available Providers

Provider	Subscription	CLI Tool	Best Models
Claude Code	Claude Pro/Max ($20-200/mo)	claude	Opus 4.6, Sonnet 4.5 (optional for light UI work / quick fixes)
Codex CLI	OpenAI Plus/Pro ($20-200/mo)	codex	GPT-5.5 Low for explore/discovery; GPT-5.5 Medium for engineer/default implementation; GPT-5.5 High for heavier planning/review/pair; GPT-5.4 Medium/High/XHigh still available
Gemini CLI	Google AI subscription	gemini	Gemini 2.5 Pro/Flash

Why Use CLI Providers?

• No per-token costs: Use models you're already paying for
• Latest models: Access new releases through official CLIs
• Works everywhere: Chat, Context Builder, Pro Edit all use CLI providers
• Familiar auth: Uses CLI's existing authentication

Setup Steps

1. Install the CLI:

   • Claude Code: npm install -g @anthropic-ai/claude-code
   • Codex: npm install -g @openai/codex
   • Gemini: npm install -g @anthropic-ai/gemini-cli

2. Login: Run claude login, codex login, or gemini login

3. Connect: In RepoPrompt, go to Settings → CLI Providers → Connect

4. Test: Verify connection with the test button

API Keys

For direct API access without CLI providers:

1. Go to Settings → API Keys
2. Add keys for your providers (OpenAI, Anthropic, Google, DeepSeek, etc.)
3. Keys are stored securely in macOS Keychain
4. Select your provider and model in Chat settings

June 2026 Recommended Models

Based on current performance and value:

Fast & Affordable

• Gemini 2.5 Flash: Excellent speed and quality balance
• GPT-5 Mini: Fast, capable, good for simple edits
• DeepSeek Chat: Very cheap with strong diff capabilities

Complex Reasoning & Coding (as suggested in June 2026)

• GPT-5.5 High (Codex CLI): Best all-around in-app coding and reasoning model in our current testing
• GPT-5.5 Pro (ChatGPT Pro web): Best for deep planning and high-value reasoning sessions — use ChatGPT Export
• Claude Opus 4.6: Still great for editing-heavy work and UI polish
• Grok 4: Capable alternative with diff support

Best Value (as suggested in June 2026)

• GPT-5.5 Low/Medium (Codex CLI): Best value split for explore and Context Builder/discovery (Low) plus engineer/default implementation (Medium) if you already use Codex CLI via ChatGPT Plus/Pro
• Claude Sonnet 4.5: Reliable, diff-capable, great balance for quick fixes
• Gemini 3 Pro Preview: Strong performance with speed

Context Window Champions (as suggested in June 2026)

• Gemini 3.0: 200K standard, 1M+ at higher pricing
• Claude models: 200K tokens
• GPT-5.4 family: 272K–1M tokens depending on interface (still the family behind the OpenAI API and OpenRouter)

tip

Where GPT-5.5 lives: GPT-5.5 Low/Medium/High are Codex CLI-only. GPT-5.5 Pro is ChatGPT Pro web only. Neither is available via the OpenAI API, Azure OpenAI, or OpenRouter — those endpoints continue to serve GPT-5.4.

Choosing the Right Approach (as suggested in June 2026)

Use Case	Recommended Approach
Quick questions, explanations	Chat mode with fast model (Gemini Flash, GPT-5 Mini)
Simple single-file edits	Chat mode in Edit mode
Complex multi-file refactors	Chat mode with Pro Edit enabled
Deep architectural planning	Compose + GPT-5.5 Pro (ChatGPT Pro) for plan → Chat with GPT-5.5 High (Codex CLI) for implementation
Cost-sensitive usage	CLI Providers with existing subscription
Large codebase context	Context Builder → Pro Edit with high-context models

tip

Pro Workflow: Use Context Builder (default: GPT-5.5 Low via Codex CLI) to select files → Compose with GPT-5.5 Pro on ChatGPT Pro for a detailed plan → Chat with GPT-5.5 Medium via Codex CLI in RepoPrompt to implement (or High for heavier review/pair sessions) → optionally use Claude Code on Claude Pro for light UI polish or quick fixes.

Video Tutorials

Learn these concepts in action:

What is RepoPrompt for? Prompt building essentials. Try the interactive demo at repoprompt.com/prompt-anatomy

Rapid Iteration with RepoPrompt Multi-file edits via XML modes. Best with GPT 4.1, Claude Sonnet 4.5

Fitting RepoPrompt into Agent Workflows Context Builder → GPT-5.5 Pro plan → GPT-5.5 High (Codex) implementation → review