How to Think about Context Engineering in Cline

A note: we frequently are asked how to "optimize" Cline. We've built it such that you don't have to. Out of the box, Cline is built to optimize context without you doing anything (provided you are using a quality coding model).

If that assurance is good enough for you, get back to the IDE. If you'd like to learn about all the tools at your disposal to wield context, this blog is for you.

Cline is a context engineering harness. Every turn, it assembles the right instructions, tools, environment details, file previews, and history, then manages that state as the task evolves. Bigger context windows help, but the harness matters more – how well the right tokens are curated, summarized, and handed off. The goal is simple: keep only what matters in view, at every step.

Default settings you should keep on

Focus Chain
Focus Chain should stay on. It is enabled by default in v3.25. Cline generates a todo list at task start and reinjects it into context on a cadence so the thread does not drift. You can set the reminder interval in settings; the default is every 6 messages. Treat the list like living scope; edit the markdown to add or reorder steps and Cline will adapt.
Docs: Focus Chain
Release note context: Cline v3.25
Why it matters: Focus: attention isn’t enough

Auto Compact
Auto Compact always on. As the context window reaches its limit, Cline creates a comprehensive summary, replaces the bloated history with that summary, and continues where it left off. Decisions, code changes, and state are preserved. With Focus Chain on, the todo list persists through summarizations so progress stays anchored.
Docs: Automatic Context Summarization

Tools to pull when you need them

Deep Planning
Use this when you start a substantial feature, refactor, or integration. Cline silently investigates your codebase, asks targeted questions, then writes implementation_plan.md. It spins up a fresh task that references the plan so implementation begins with distilled, high‑value context. If you expect more than a couple back‑and‑forths to clarify scope, start with /deep-planning. You avoid polluting the execution window with exploration.
Docs: /deep-planning

Editing Messages and Checkpoints
Use this the instant you realize the request needs to be rewritten, not patched. Edit the earlier message that sent the task off course, then choose Restore Chat to keep workspace state or Restore All to rewind files and chat. This resets the conversation to a clean trajectory. Do not argue with a polluted thread; rewrite the prompt and restore, then continue.
Docs: Editing Messages
Deep dive: Message Checkpoints

Smol (/smol or /compact)
Use this when you want to compress in place and keep momentum. It condenses the conversation inside the same task so you can continue without a handoff. Ideal during deep debugging or exploratory spikes when you do not want to break flow.
Note: this is the same action as Auto Compact but can be triggered manually.
Docs: /smol

New Task (/newtask)
Use this at natural transition points. It packages only what matters -- plan, decisions, relevant files, and next steps -- into a fresh task. This is a clean slate for implementation after research, or a crisp handoff between teammates. Think of it like bringing a new developer onto the project with exactly the context they need.
Docs: /newtask
Why it enables persistent progress: Persistent Memory via new_task

Memory Bank + .clinerules
Make this your baseline on any non‑trivial project. The Memory Bank captures product intent, system patterns, tech context, active context, and progress as Markdown in your repo. .clinerules are version‑controlled instructions that Cline reads -- and can edit on request -- to align behavior with your team. This is how you retain durable knowledge across sessions and teammates without bloating prompts.
Docs: Cline Memory Bank
Reference rule: memory-bank.md
Background on .clinerules: .clinerules blog

Why this works

Models degrade as conversations stretch and instructions get sharded across turns. Tool outputs, detours, and mid‑stream clarifications bury the signal. The answer is not “send everything”; it is to curate, compress, and reset deliberately. Focus Chain keeps the task anchored; Auto Compact preserves decisions while discarding noise; /smol and /newtask give you precise control over how to free space; Deep Planning front‑loads clean context so implementation starts sharp. If you want the mechanics behind cost and window dynamics, read: Cline’s context window explained.

BONUS Tidbits

• you can @ links and have the webpage's context added to Cline (i.e. docs, blogs)
• utilize MCP servers to pull in context from your external knowledge bases
• screenshots can be used as context for models which are able to inject images

How to run this in practice

Feature development
Start with /deep-planning to explore and produce implementation_plan.md. Execute from a fresh task with Focus Chain as your working checklist. Let Auto Compact handle rollover as the window fills. When you enter a new phase or the history feels heavy with exploration, use /newtask to carry forward just the essentials and keep implementation sharp. If you drift, edit the message that missed the requirement, Restore All, and regenerate from the corrected prompt.

Bug investigation
Begin normally; if the thread balloons with logs and detours, use /smol to condense in place. When you identify the root cause, use /newtask to start clean with a short summary of cause, files, and fix steps. Keep Focus Chain on so the fix lands; write the tests; close the loop.

Multi‑day or multi‑person work
Keep the Memory Bank current while you work, especially activeContext.md and progress.md. At a stopping point, run /newtask to create a clean, scoped follow‑up task. The next person begins by having Cline read the rules and memory bank, then opens the new task with a fresh window and the Focus Chain plan preloaded.

Practical guardrails

• Think in high‑value tokens; requirements, decisions, exact file paths, function signatures, next steps.
• Prefer reset over correction when the thread goes sideways; edit the divergent message, then restore.
• Use large windows as buffer, not a crutch; Auto Compact exists for a reason.
• Treat .clinerules as code; version them, share them, and let Cline refine them for you.

Opinionated defaults

• Keep Focus Chain on. It is enabled by default in v3.25, and you can configure its reminder cadence in settings; the default is every 6 messages.
• Use /deep-planning for anything beyond a trivial change; it beats course‑correcting later.
• Choose /smol when you need space mid‑flow; choose /newtask when you want a crisp handoff or preserved history.
• Maintain a Memory Bank that is light but current; Cline will read it at the start of every task.

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. This playbook adds discipline on top of that harness so the model stays sharp from turn one to turn fifty.

-Nick

Docs: docs.cline.bot
Community: Reddit and Discord