AI library

Source · repo

Context Mode: keep raw tool output out of the context window

Author
mksglu
Published
26 October 2026
Added
26 October 2026
Original
https://github.com/mksglu/context-mode

Summary

Context Mode is an MCP server and Claude Code plugin that runs large tool calls in a sandbox. Only what the code prints goes back to the model, and the raw output stays out. It also records session events in SQLite so the agent can recover its working state after compaction. It was a "rising" repo in today's GitHub trends (+1,402 stars in 7 days, about 32,000 in total, over 2,200 commits). It is source-available under the Elastic License 2.0, not an OSI open-source licence. date_published is the date the README was read; the project is older.

Key points

  • Install in Claude Code (plugin, with hooks and slash commands): /plugin marketplace add mksglu/context-mode, then /plugin install context-mode@context-mode, then /reload-plugins (needs Claude Code 1.0.33 or later). Check it with /context-mode:ctx-doctor.
  • MCP only (no automatic routing): claude mcp add context-mode -- npx -y context-mode.
  • Other agents: the README lists 17 platforms, including Codex CLI, Gemini CLI, Copilot (VS Code, JetBrains, CLI), Cursor, OpenCode, Kiro, and Zed. Hook support differs between them.
  • What it is good for: long sessions where logs, test output, large files, or web pages would fill the context. ctx_execute runs code in 12 language runtimes and returns only stdout. ctx_fetch_and_index fetches a page, indexes it, and caches it for 24 hours, so the agent can search it instead of reading all of it.
  • Session memory: file edits, git operations, tasks, and errors go into SQLite and are found again after compaction with full-text search (FTS5/BM25 plus trigram matching).
  • Claimed savings: the README gives one example in which 315 KB of output became 5.4 KB (about 98% less). This is self-reported.

Why it matters

It deals with the other half of context bloat: tool results, not tool definitions. Tool search and code-mode proxies such as MCPtoCodeMode cut the definitions. The two approaches can be combined.