md-redline: GUI tool for reviewing and handing off markdown docs to Claude

md-redline is a local GUI tool designed to improve the workflow of reviewing and iterating on markdown documents generated by Claude. The tool addresses the clunky feedback loop that occurs when working with raw markdown files in CLI environments.
How it works
The workflow described by the creator is:
- Claude generates a markdown document from a prompt (e.g., "write a feature spec for magic link authentication")
- Open the file with
mdr /path/to/spec.md - Review and leave inline comments directly in the GUI (examples given: "out of scope", "what does this mean?")
- Click the hand-off button which copies instructions to paste into Claude
- Claude addresses the comments and updates the document
- Review the diffs in md-redline
Technical details
The comments are stored as HTML markers directly within the .md file. These markers are invisible in GitHub and VS Code preview but Claude can read them with a plain file read operation. The tool runs locally with no account, cloud service, or database required. It works with Claude Code or any AI agent that can read files.
The creator mentions using this tool as a product manager who no longer writes specs or stories manually. Instead, Claude generates them, the creator reviews and provides feedback through md-redline, Claude updates based on that feedback, and then the document is handed over to developers (human or agents) for implementation.
The tool is open source with an MIT license and available on GitHub.
📖 Read the full source: r/ClaudeAI
👀 See Also

Clawdwatch: Open-source OSINT tool for real-time flight tracking, news scraping, and alerts
Clawdwatch is a CLI tool that pulls live flight data from OpenSky Network, scrapes news from Al Jazeera and AP, and can send Telegram alerts for military aircraft or emergency squawks. It runs locally with npm install and tracks 204+ flights over the Middle East in real-time.

Parallel Coding Agents with tmux and Markdown Specs
Manuel Schipper describes a system for running 4-8 parallel coding agents using tmux, Markdown files, bash aliases, and six slash commands. The setup uses Feature Design (FD) Markdown specs tracked through an 8-stage lifecycle.

First-Tree: Open-Source Daemon That Uses Claude Code to Triage GitHub Notifications While You Sleep
An open-source menu bar daemon that uses Claude Code to autonomously triage GitHub notifications – it handled 98 out of 100 notifications in a recent scan, leaving only 2 for human review.

Atlas Inference Engine Goes Open Source: Pure Rust + CUDA, 100+ tok/s on DGX Spark
Atlas is now open source — a Rust + CUDA inference engine that achieves 130 tok/s peak on Qwen3.5-35B (NVFP4) on a single DGX Spark, with no Python runtime and <2 minute cold start.