Purge your Claude Code context window

README.md

Purge your Claude Code context window

Claude Code v2.1.12

Removes all system tools from the context window. Not very useful on its own, but it's a good starting point when developing Subagents. This helps to reclaim up to ~17k tokens (~8.5%) from the context window.

Before

> /context
Context Usage
⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛀   claude-haiku-4-5-20251001 · 19k/200k tokens (10%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System prompt: 2.8k tokens (1.4%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System tools: 16.7k tokens (8.3%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Messages: 8 tokens (0.0%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Compact buffer: 3.0k tokens (1.5%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛶ Free space: 178k (88.8%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛁ ⛀

After

> /context
Context Usage
⛁ ⛀ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   claude-haiku-4-5-20251001 · 2k/200k tokens (1%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System prompt: 2.1k tokens (1.0%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Messages: 8 tokens (0.0%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Compact buffer: 3.0k tokens (1.5%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛶ Free space: 195k (97.5%)
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛁ ⛀

---

Tools available to Claude

Source: https://docs.claude.com/en/docs/claude-code/settings#tools-available-to-claude

Claude Code has access to a set of powerful tools that help it understand and modify your codebase:

Tool	Description	Permission Required
AskUserQuestion	Asks multiple-choice questions to gather requirements or clarify ambiguity	No
Bash	Executes shell commands in your environment	Yes
Edit	Makes targeted edits to specific files	Yes
ExitPlanMode	Prompts the user to exit plan mode and start coding	Yes
Glob	Finds files based on pattern matching	No
Grep	Searches for patterns in file contents	No
KillShell	Kills a running background bash shell by its ID	No
MCPSearch	Searches for and loads MCP tools when tool search is enabled	No
NotebookEdit	Modifies Jupyter notebook cells	Yes
Read	Reads the contents of files	No
Skill	Executes a skill or slash command within the main conversation	Yes
Task	Runs a sub-agent to handle complex, multi-step tasks	No
TaskOutput	Retrieves output from a background task (bash shell or subagent)	No
TodoWrite	Creates and manages structured task lists	No
WebFetch	Fetches content from a specified URL	Yes
WebSearch	Performs web searches with domain filtering	Yes

Tools missing from official documentation (generated by Claude)

Tool	Description	Permission Required
EnterPlanMode	Requests permission to enter plan mode for complex tasks requiring exploration and design	No

settings.local.json

{
  "permissions": {
    "allow": [],
    "deny": [
      "Read",
      "Write",
      "Edit",
      "AskUserQuestion",
      "Bash",
      "TaskOutput",
      "EnterPlanMode",
      "ExitPlanMode",
      "Glob",
      "Grep",
      "KillShell",
      "MCPSearch",
      "NotebookEdit",
      "Skill",
      "Task",
      "TodoWrite",
      "WebFetch",
      "WebSearch"
    ]
  }
}