SecureContext: An MCP Plugin for Persistent Memory and Token Reduction in Claude Code

SecureContext is an open-source Model Context Protocol (MCP) plugin built specifically for Claude Code. It addresses two common pain points: context window limitations that lead to repetitive token costs, and security risks from passing full environment variables (including API keys) to every subprocess.

How Claude Code Was Used to Build It

The developer built SecureContext using Claude Code itself. Claude helped with three key aspects:

• Architecting the Security Sandbox: Designed the zc_execute logic that strips sensitive environment variables before running code, preventing exposure of credentials like ANTHROPIC_API_KEY to third-party scripts.
• Optimizing Search Logic: Implemented a hybrid BM25 + Vector search using Ollama, allowing the agent to find relevant code snippets without re-reading the entire codebase each session.
• Writing the Test Suite: Generated over 80 security test vectors to verify SSRF protection and credential isolation work as intended.

Core Features

• MemGPT-style Persistence: Remembers facts and session summaries across separate Claude Code windows.
• Token Optimization: Uses targeted "context recall" instead of native file-dumping, achieving approximately 87% reduction in input tokens for large projects.
• Credential Isolation: Creates a "clean-room" environment for shell commands to keep private keys secure.
• Multi-Agent Channel: Includes a broadcast channel so multiple running agents can sync status without overlapping context.

The developer shares this as an example of how MCP can fundamentally change how Claude manages its "thinking space," not just add tools. The architecture for hybrid search and security middleware may be useful for others building MCP servers.