Myelin: MD Extractor and Evaluator for Claude Code Procedural Memory
Myelin: MD Extractor and Evaluator for Claude Code
Myelin is a tool that addresses two specific problems developers face when working with Claude Code and procedural memory files: manually writing .md procedure files after successful sessions, and lacking visibility into whether Claude actually follows those procedures.
Core Features
The tool operates through three main functions:
- Extraction: When a session succeeds with no existing procedure, Myelin extracts a .md file from the trace. You review, approve or edit it, eliminating the need to hand-write procedures from memory.
- Observability: When a session follows an existing procedure, Myelin tracks step-by-step what Claude actually did, categorizing actions as Followed, Skipped, or Diverged. Across sessions, patterns emerge, and Myelin suggests diffs.
- Evaluation: Every session receives a verdict: Success, Partial, or Failure. This provides actual success rates per procedure rather than relying on gut feeling.
Technical Implementation
Myelin hooks into Claude Code via PostToolUse and captures every tool call. The output is plain .md files that can be downloaded and kept in your repository, or left in Myelin where it serves the right procedure via search when matching tasks come up.
Setup and Access
Setup requires just an MCP server plus one hook in settings.json. The tool offers a free tier with 50 sessions/month.
Resources
- SDK: https://github.com/yahnyshc/myelin-sdk
- Site: https://myelin.vercel.app
- HN Discussion: https://news.ycombinator.com/item?id=47545239
This tool is particularly useful for developers who use Claude Code for deployment, running migrations, handling tickets, and other procedural tasks where maintaining accurate documentation and verifying execution is important.
📖 Read the full source: r/ClaudeAI
👀 See Also
Claude Code's Local Memory Integration with Shodh: Enhancing Context Retention Over Time
Explore Claude Code's integration with Shodh memory for long-term project context retention using a local memory server.
Vibeyard: Open-Source Dashboard That Launches Claude Sessions from PRs, Issues, and Kanban Cards
Vibeyard is an open-source (MIT) home screen with draggable widgets for PRs, issues, kanban, and Claude sessions. Click any card to spawn a pre-scoped Claude Code session for review, fix planning, or resumption.
PreToolUse Hook Fixes Claude Code Image Crash Problem
A developer created a PreToolUse hook that intercepts Claude Code's Read calls on images, converts them safely, and proxies them through a Haiku subprocess to prevent API Error 400 crashes from problematic images.
Deblank: Tool to Strip Code Formatting for LLM Token Reduction
Deblank is an open-source tool that strips code formatting (indentation, whitespace, line breaks) before sending to LLMs, reducing tokens by ~30% for Java/C++ and ~9% for Python with ~76ms latency. It supports Python, Java, C/C++, C#, JS/TS, and Go.