Quick Reference
  • Context = The information Cline knows about your project
  • Context Window = How much information Cline can hold at once
  • Use context files to maintain project knowledge
  • Reset when the context window gets full

Understanding Context & Context Windows

In a world of infinite context, the context window is what Cline currently has available

In a world of infinite context, the context window is what Cline currently has available

Think of working with Cline like collaborating with a thorough, proactive teammate:

How Context is Built

Cline actively builds context in two ways:
  1. Automatic Context Gathering (i.e. Cline-driven)
    • Proactively reads related files
    • Explores project structure
    • Analyzes patterns and relationships
    • Maps dependencies and imports
    • Asks clarifying questions
  2. User-Guided Context
    • Share specific files
    • Provide documentation
    • Answer Cline’s questions
    • Guide focus areas
    • Share design thoughts and requirements
Key Point: Cline isn’t passive - it actively seeks to understand your project. You can either let it explore or guide its focus, especially in Plan Mode.

Context & Context Windows

Think of context like a whiteboard you and Cline share:
  • Context is all the information available:
    • What Cline has discovered
    • What you’ve shared
    • Your conversation history
    • Project requirements
    • Previous decisions
  • Context Window is the size of the whiteboard itself:
    • Measured in tokens (1 token ≈ 3/4 of an English word)
    • Each model has a fixed size:
      • Claude Sonnet 4: 1,000,000 tokens
      • Qwen3 Coder: 256,000 tokens
      • Gemini 2.5 Pro: 1,000,000+ tokens
      • GPT-5: 400,000 tokens
    • When the whiteboard is full, Cline automatically summarizes the conversation to free up space
Important: Having a large context window doesn’t mean you should fill it completely. Models start degrading around 400-500K tokens even if they claim higher limits. Just like a cluttered whiteboard, too much information can make it harder to focus on what’s important.

Understanding the Context Window Progress Bar

Cline provides a visual way to monitor your context window usage through a progress bar:
Context window progress bar

Visual representation of the context window usage

Reading the Bar

  • ↑ shows input tokens (what you’ve sent to the LLM)
  • ↓ shows output tokens (what the LLM has generated)
  • The progress bar visualizes how much of your context window you’ve used
  • The total shows your model’s maximum capacity (e.g., 1M for Claude Sonnet 4)

When to Watch the Bar

  • During long coding sessions
  • When working with multiple files
  • Before starting complex tasks
  • When Cline seems to lose context
Tip: With Auto Compact, Cline can now handle long conversations automatically. When combined with Focus Chain, you can work on complex projects that span multiple context windows without losing progress.

Automatic Context Management

Cline includes intelligent features to manage context automatically:

Default Settings You Should Keep On

Focus Chain - Enabled by default in v3.25. Cline generates a todo list at task start and keeps it in context so the thread doesn’t drift. You can edit the markdown to add or reorder steps and Cline will adapt. Learn more about Focus Chain. Auto Compact - Always on. As the context window reaches its limit, Cline creates a comprehensive summary, replaces the bloated history, and continues where it left off. Decisions, code changes, and state are preserved. Learn more about Auto Compact.

Advanced Context Tools

When you need more control over context management:

Deep Planning (/deep-planning)

For substantial features, refactors, or integrations. Cline investigates your codebase, asks targeted questions, then writes implementation_plan.md. It creates a fresh task with distilled, high-value context. Learn more about Deep Planning.

New Task (/newtask)

At natural transition points, packages only what matters into a fresh task. Clean slate for implementation after research, or crisp handoff between teammates. Learn more about New Task.

Smol (/smol)

Compress the conversation in place to keep momentum. Ideal during debugging or exploratory work when you don’t want to break flow. Learn more about Smol.

Memory Bank + .clinerules

For non-trivial projects. The Memory Bank captures project knowledge as Markdown in your repo. .clinerules are version-controlled instructions that align Cline’s behavior with your team. Learn more about Memory Bank and Cline Rules.

Working with Context Files

Context files help maintain understanding across sessions. They serve as documentation specifically designed to help AI assistants understand your project.

Approaches to Context Files

  1. Evergreen Project Context (Memory Bank)
    • Living documentation that evolves with your project
    • Updated as architecture and patterns emerge
    • Example: The Memory Bank pattern maintains files like techContext.md and systemPatterns.md
    • Useful for long-running projects and teams
  2. Task-Specific Context
    • Created for specific implementation tasks
    • Document requirements, constraints, and decisions
    • Example:
      # auth-system-implementation.md
      
      ## Requirements
      
      -   OAuth2 implementation
      -   Support for Google and GitHub
      -   Rate limiting on auth endpoints
      
      ## Technical Decisions
      
      -   Using Passport.js for provider integration
      -   JWT for session management
      -   Redis for rate limiting
      
  3. Knowledge Transfer Docs
    • Switch to plan mode and ask Cline to document everything you’ve accomplished so far, along with the remaining steps, in a markdown file.
    • Copy the contents of the markdown file.
    • Start a new task using that content as context.

Using Context Files Effectively

  1. Structure and Format
    • Use clear, consistent organization
    • Include relevant examples
    • Link related concepts
    • Keep information focused
  2. Maintenance
    • Update after significant changes
    • Version control your context files
    • Remove outdated information
    • Document key decisions

Practical Tips

  1. Starting New Projects
    • Let Cline explore the codebase
    • Answer its questions about structure and patterns
    • Consider setting up basic context files
    • Document key design decisions
  2. Ongoing Development
    • Update context files with significant changes
    • Share relevant documentation
    • Use Plan mode for complex discussions
    • Start fresh sessions when needed
  3. Team Projects
    • Share common context files (consider using .clinerules files in project roots)
    • Document architectural decisions
    • Maintain consistent patterns
    • Keep documentation current

Bonus Context Tips

  • You can @ links and have the webpage’s context added to Cline (docs, blogs, etc.)
  • Utilize MCP servers to pull in context from your external knowledge bases
  • Screenshots can be used as context for models that support image inputs

The Bottom Line

Cline already does a lot of context work for you - Focus Chain, Auto Compact, and the planning flow are designed to keep the thread intact across long horizons. The goal is to help Cline maintain consistent understanding of your project across sessions. Remember: The goal is to keep only what matters in view, at every step.