---
title: "Context compaction controls"
canonical: "https://canmyagentuse.com/features/context-compaction-controls"
contentKind: "feature"
locale: "en"
description: "Trigger, inspect, configure, or disable the harness's context-compaction behavior."
llmSummary: "Compaction controls cover operator actions such as manual compaction, threshold configuration, summary inspection, retained-item pinning, and disabling automatic compaction."
publishedAt: "2026-08-28T00:00:00.000Z"
updatedAt: "2026-08-28T00:00:00.000Z"
verifiedAt: "2026-08-28"
tags: ["context","compaction","control"]
---

# Context compaction controls

Compaction controls cover operator actions such as manual compaction, threshold configuration, summary inspection, retained-item pinning, and disabling automatic compaction.

- HTML: https://canmyagentuse.com/features/context-compaction-controls
- JSON: https://canmyagentuse.com/api/v1/features/context-compaction-controls.json
- Markdown: https://canmyagentuse.com/features/context-compaction-controls.md

Terminology basis: **Common product term** — https://learn.chatgpt.com/docs/reference/slash-commands.

## Current support at a glance

Context compaction controls: 4 supported, 1 partial, 0 unsupported, 26 unreviewed across 31 cataloged products.

- Reviewed current products: 5 of 31
- Supported: 4
- Partial: 1
- Unsupported: 0
- Unreviewed: 26
- Not applicable: 0

Unknown or unreviewed means insufficient published evidence; it does not mean unsupported.

This row separates controllability from the existence of automatic compaction. Useful controls include a manual compact action, an editable instruction for the summary, threshold configuration, inspection of the compacted state, pinning of durable facts, and an opt-out.

A single manual “summarize this chat” prompt is not necessarily a harness-level compaction control. Evidence should show that the resulting state is used for subsequent requests and identify the scope of each setting.

## Catalog context

- Category: [models-context](/categories/models-context.md)
- Terminology basis: Common product term
- Aliases: manual compact, compaction settings, context pinning
- Family: [Models and context](/features/models-and-context.md)
- Siblings: [Automatic context compaction](/features/automatic-context-compaction.md), [Context usage](/features/context-usage-visibility.md), [Context window](/features/context-window.md), [Local models](/features/local-models.md), [Model fallback](/features/model-fallback.md), [Model selection](/features/model-selection.md), [Output token limit](/features/output-token-limit.md), [Prompt cache controls](/features/prompt-cache-controls.md), [Prompt cache telemetry](/features/prompt-cache-telemetry.md), [Prompt caching](/features/prompt-cache-reuse.md), [Reasoning effort controls](/features/reasoning-effort-controls.md)

## Compatibility assertions

Unknown means insufficient published evidence; it does not mean unsupported.

### ChatGPT (web)

- Harness: [ChatGPT](/harnesses/chatgpt-web.md)
- current: **Unknown**
- preview: **Unknown**

### Claude (web)

- Harness: [Claude](/harnesses/claude-web.md)
- current: **Unknown**
- preview: **Unknown**

### Gemini (web)

- Harness: [Gemini](/harnesses/gemini-web.md)
- current: **Unknown**
- preview: **Unknown**

### Copilot (web)

- Harness: [Copilot](/harnesses/copilot-web.md)
- current: **Unknown**
- preview: **Unknown**

### Grok (web)

- Harness: [Grok](/harnesses/grok-web.md)
- current: **Unknown**
- preview: **Unknown**

### Grok Bot (desktop)

- Harness: [Grok Bot](/harnesses/grok-bot-desktop.md)
- current: **Unknown**

### Perplexity (web)

- Harness: [Perplexity](/harnesses/perplexity-web.md)
- current: **Unknown**
- preview: **Unknown**

### Le Chat (web)

- Harness: [Le Chat](/harnesses/le-chat.md)
- current: **Unknown**
- preview: **Unknown**

### Devin (web)

- Harness: [Devin](/harnesses/devin-web.md)
- current: **Unknown**
- preview: **Unknown**

### Replit Agent (web)

- Harness: [Replit Agent](/harnesses/replit-agent.md)
- current: **Unknown**
- preview: **Unknown**

### ChatGPT (desktop)

- Harness: [ChatGPT](/harnesses/chatgpt-desktop.md)
- current: **Partial**
  - Target: dated-documentation — current ChatGPT desktop documentation; observed 2026-08-28
  - Environment: local-default
  - Constraint (runtime): /compact triggers compaction; summary inspection, threshold configuration, retained-item pinning, and disabling are not established by the reviewed page
  - Evidence: [OpenAI — ChatGPT desktop slash commands](https://learn.chatgpt.com/docs/reference/slash-commands) — documented; observed 2026-08-28
  - Qualification note 1: Evidence checked 2026-08-28: ChatGPT desktop exposes /compact to compact the current chat context.
- preview: **Unknown**

### Claude (desktop)

- Harness: [Claude](/harnesses/claude-desktop.md)
- current: **Unknown**
- preview: **Unknown**

### Cursor (desktop)

- Harness: [Cursor](/harnesses/cursor.md)
- current: **Unknown**
- preview: **Unknown**

### OpenWork Desktop (desktop)

- Harness: [OpenWork Desktop](/harnesses/openwork-desktop.md)
- current: **Unknown**

### Copilot Chat (desktop)

- Harness: [Copilot Chat](/harnesses/vscode-copilot.md)
- current: **Supported**
  - Target: dated-documentation — current VS Code agent-session documentation; observed 2026-08-28
  - Environment: local-default
  - Constraint (policy): /compact accepts preservation instructions and automatic compaction can be disabled; threshold selection and retained-item pinning are not documented
  - Evidence: [Microsoft — Manage agent sessions in VS Code](https://code.visualstudio.com/docs/agents/run/sessions/manage-sessions) — documented; observed 2026-08-28
  - Qualification note 5: Evidence checked 2026-08-28: VS Code exposes `/compact`, optional preservation instructions, a context-control action, and a setting that disables automatic compaction.
- preview: **Unknown**

### Chrome WebMCP origin trial (desktop)

- Harness: [Chrome WebMCP origin trial](/harnesses/chrome-webmcp-preview.md)
- current: **Unknown**

### Windsurf (desktop)

- Harness: [Windsurf](/harnesses/windsurf.md)
- current: **Unknown**
- preview: **Unknown**

### Zed Agent (desktop)

- Harness: [Zed Agent](/harnesses/zed-agent.md)
- current: **Unknown**
- preview: **Unknown**

### Continue (desktop)

- Harness: [Continue](/harnesses/continue.md)
- current: **Unknown**
- preview: **Unknown**

### Cline (desktop)

- Harness: [Cline](/harnesses/cline.md)
- current: **Unknown**
- preview: **Unknown**

### JetBrains AI (desktop)

- Harness: [JetBrains AI](/harnesses/jetbrains-ai.md)
- current: **Unknown**
- preview: **Unknown**

### Warp (desktop)

- Harness: [Warp](/harnesses/warp.md)
- current: **Unknown**
- preview: **Unknown**

### Claude CLI (cli)

- Harness: [Claude CLI](/harnesses/claude-cli.md)
- current: **Supported**
  - Target: dated-documentation — current Claude Code documentation; observed 2026-08-28
  - Environment: local-default
  - Constraint (runtime): /compact can include task-specific preservation instructions; CLAUDE.md can define reusable compact guidance
  - Evidence: [Anthropic — Manage Claude Code costs](https://code.claude.com/docs/en/costs) — documented; observed 2026-08-28
  - Qualification note 2: Evidence checked 2026-08-28: Claude Code exposes /compact with an optional preservation instruction and also accepts durable compact instructions in CLAUDE.md.
- preview: **Unknown**

### ChatGPT CLI (cli)

- Harness: [ChatGPT CLI](/harnesses/chatgpt-cli.md)
- current: **Unknown**
- preview: **Unknown**

### Codex CLI (cli)

- Harness: [Codex CLI](/harnesses/codex-cli.md)
- current: **Unknown**
- preview: **Unknown**

### OpenCode (cli)

- Harness: [OpenCode](/harnesses/opencode.md)
- current: **Unknown**
- preview: **Unknown**

### Gemini CLI (cli)

- Harness: [Gemini CLI](/harnesses/gemini-cli.md)
- current: **Supported**
  - Target: dated-documentation — current Gemini CLI documentation; observed 2026-08-28
  - Environment: local-default
  - Constraint (runtime): /compress replaces chat context with a high-level summary; model.compressionThreshold configures the automatic trigger fraction and defaults to 0.5
  - Evidence: [Google — Gemini CLI commands](https://geminicli.com/docs/cli/commands/) — documented; observed 2026-08-28
  - Evidence: [Google — Gemini CLI settings](https://geminicli.com/docs/cli/settings/) — documented; observed 2026-08-28
  - Qualification note 3: Evidence checked 2026-08-28: Gemini CLI exposes /compress and a model.compressionThreshold setting whose documented default is 0.5.
- preview: **Unknown**

### Aider (cli)

- Harness: [Aider](/harnesses/aider.md)
- current: **Unknown**
- preview: **Unknown**

### Goose (cli)

- Harness: [Goose](/harnesses/goose.md)
- current: **Unknown**
- preview: **Unknown**

### Copilot CLI (cli)

- Harness: [Copilot CLI](/harnesses/copilot-cli.md)
- current: **Supported**
  - Target: dated-documentation — current GitHub Copilot CLI context-management documentation; observed 2026-08-28
  - Environment: local-default
  - Constraint (runtime): /compact accepts optional focus instructions and manual compaction can be canceled with Escape; the automatic threshold itself is not documented as configurable
  - Evidence: [GitHub — Managing context in Copilot CLI](https://docs.github.com/en/enterprise-cloud@latest/copilot/concepts/agents/copilot-cli/context-management) — documented; observed 2026-08-28
  - Qualification note 4: Evidence checked 2026-08-28: GitHub Copilot CLI exposes `/compact` with optional focus instructions and lets the operator cancel manual compaction.
- preview: **Unknown**

### Amp (cli)

- Harness: [Amp](/harnesses/amp-cli.md)
- current: **Unknown**
- preview: **Unknown**