Context Firewall
Local MCP proxy that exposes 4 meta-tools and compresses large downstream tool outputs.
Install
npx context-firewall --config context-firewall.json
Add this to your Claude Code MCP settings or run via the CLI.
About
Context Firewall is a local MCP proxy for Claude Code, Claude Desktop, Cursor, Cline, and other MCP clients. It sits between the client and configured downstream MCP servers. The proxy exposes four meta-tools to the client: `list_tool_categories`, `search_tools`, `invoke_tool`, and `read_more`. It delays loading full downstream tool schemas until needed, which reduces startup token usage. It also compresses large tool outputs before they reach the model context window. The pipeline can strip base64, convert HTML to Markdown, summarize JSON, and truncate to a configured token budget, while preserving the full original output for later retrieval with `read_more`. The README includes Claude Code setup examples using `npx context-firewall --config ...` and a `claude mcp add` command for registering it as an MCP server.