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Overview

Jean supports three AI CLI backends (Claude CLI, Codex CLI, and OpenCode) with flexible model selection, thinking levels, and customizable system prompts. All AI interactions run locally through your installed CLI tools.

Key Capabilities

Backend Selection

Jean supports three CLI backends: Claude CLI (Anthropic):
  • Claude Opus 4.6, Opus 4.5
  • Claude Sonnet 4.6, Sonnet 4.5
  • Claude Haiku
  • Extended thinking (Think, Megathink, Ultrathink)
  • Adaptive thinking with effort levels (Opus 4.6)
Codex CLI (OpenAI):
  • GPT 5.3 Codex
  • GPT 5.2 Codex
  • GPT 5.1 Codex Max
  • GPT 5.2
  • GPT 5.1 Codex Mini
  • Reasoning effort levels (low, medium, high, xhigh)
  • Multi-agent collaboration (experimental)
OpenCode (Community):
  • Model routing through opencode/ prefix
  • Community-driven development
  • Compatible with OpenCode CLI
Backend configuration:

Model Selection

Claude Models:
Codex Models:
OpenCode Models:

Thinking Levels

Claude extended thinking:
Token allocations:
  • Off: No extended thinking
  • Think: 4,000 thinking tokens
  • Megathink: 10,000 thinking tokens
  • Ultrathink: 32,000 thinking tokens
Adaptive thinking (Opus 4.6 only):
Codex reasoning effort:

Provider Profiles

Route requests through alternative API providers: Predefined profiles:
Configuration:

Custom System Prompts

Global system prompt:
Default global prompt:
Project-specific prompts:
Example project prompt:

Parallel Execution

Optional system prompt to encourage sub-agent parallelism:

How to Use

Selecting Backend & Model

Global defaults:
  1. Open Settings (Cmd/Ctrl + ,)
  2. Navigate to AI section
  3. Choose default backend (Claude/Codex/OpenCode)
  4. Select default model
  5. Set thinking/effort levels
Per-session:
  1. Open chat session
  2. Use toolbar dropdowns
  3. Change model, thinking level, backend
  4. Settings persist for session
Per-project:
  1. Right-click project → Settings
  2. AI pane
  3. Set default backend and provider
  4. New sessions inherit these settings

Configuring Thinking Levels

When to use each level: Off:
  • Simple refactors
  • Straightforward implementations
  • Following clear patterns
  • Quick fixes
Think (4K):
  • Standard development tasks
  • Code review
  • Testing strategies
  • Documentation
Megathink (10K):
  • Complex algorithms
  • Architecture decisions
  • Performance optimization
  • Edge case analysis
Ultrathink (32K):
  • Novel problem solving
  • Research and exploration
  • Security analysis
  • Deep debugging

Using Adaptive Thinking

Opus 4.6 effort levels: Low:
  • Quick questions
  • Obvious solutions
  • Pattern following
Medium:
  • Normal development
  • Code generation
  • Light problem solving
High:
  • Complex logic
  • Multiple constraints
  • Performance critical
Max:
  • Unlimited reasoning
  • Novel approaches
  • Research problems

Setting Up Providers

Adding custom provider:
  1. Settings → Providers
  2. Click “Add Profile”
  3. Enter name and settings JSON
  4. Configure environment variables:
  5. Save profile
Using provider:
  1. Session toolbar → Provider dropdown
  2. Select custom profile
  3. Or set as default in Settings

Customizing System Prompts

Global prompt:
  1. Settings → AI → Magic Prompts
  2. Find “Global System Prompt”
  3. Edit in text editor
  4. Applies to all future messages
Project prompt:
  1. Project Settings → AI pane
  2. Enter project-specific prompt
  3. Appended after global prompt
  4. Inherited by all sessions in project
Testing prompts:
  1. Create test session
  2. Ask AI to explain its instructions
  3. Verify prompts are working
  4. Adjust as needed

Configuration Options

Settings → AI

Claude Settings:
Codex Settings:
OpenCode Settings:
Provider Settings:
Prompt Settings:

Per-Session Settings

Configurable in chat toolbar:
  • Model selection
  • Thinking level
  • Effort level (if supported)
  • Backend
  • Provider profile

Mode-Specific Overrides

Build mode:
Yolo mode:

Best Practices

Model Selection Strategy

By task complexity:
By project phase:

Thinking Level Guidelines

Match to problem type:
  • Deterministic tasks → Off
  • Creative tasks → Think+
  • Research → Megathink/Ultrathink
  • Debugging → Megathink
Token budget awareness:
  • Thinking tokens count against limits
  • Ultrathink = expensive
  • Start lower, increase if needed

System Prompt Design

Keep prompts actionable:
Layer prompts:
Test with examples:
  • Ask AI to implement something
  • Verify it follows guidelines
  • Adjust prompt if needed
  • Iterate until consistent

Provider Configuration

When to use providers:
  • Lower costs (OpenRouter)
  • Regional models (MiniMax, Z.ai)
  • Custom deployments
  • Rate limit management
Provider selection:
  • Performance: Anthropic direct > OpenRouter > Others
  • Cost: Regional providers < OpenRouter < Anthropic
  • Reliability: Anthropic > OpenRouter > Others

Performance Optimization

Reduce latency:
  • Use appropriate thinking levels
  • Choose closest provider
  • Batch related questions
  • Clear unused context
Control costs:
  • Use Haiku for simple tasks
  • Disable thinking when not needed
  • Archive finished sessions
  • Monitor token usage

Multi-Backend Workflows

Leverage strengths:
  • Claude Opus: Architecture & planning
  • Codex: Code generation
  • Sonnet: Code review & testing
  • Haiku: Quick questions
Example workflow:

Advanced Configuration

Per-magic-prompt overrides:
Use cases:
  • Expensive models for investigation
  • Fast models for commit messages
  • Specific backends for specific tasks
Configuration:
  1. Settings → AI → Magic Prompts
  2. Expand advanced options
  3. Set model/backend per prompt type
  4. Falls back to session defaults