Anyone juggling multiple AI coding assistants knows the pain: you hit a wall in one tool, switch to another, and spend five minutes re-explaining what you were doing. rses fixes that with a single command.
The open-source CLI tool reads session history from Claude Code, Codex CLI, or OpenCode, packages it into a structured handoff, and launches the target assistant with full context already loaded. It works in all six directions between the three tools. Run rses claude with codex --last and Claude Code launches pre-loaded with your Codex session's task description, recent git changes, and conversation history.
The tool is lightweight by design - around 1,200 lines of code, one npm dependency, and zero configuration. It requires Node.js 22+ because it uses Node's built-in SQLite support to read session indexes. Each assistant stores sessions differently (Claude Code uses JSONL transcript files, Codex CLI uses SQLite databases, OpenCode uses its own SQLite format), and rses handles the parsing for all three.
Power users get shorthand aliases: rses cc w cdx --last does the same thing as the full command. A --dry-run flag lets you preview the handoff without launching anything, and --turns controls how much conversation history gets included (default is 6 turns).
One limitation: it's macOS and Linux only for now, with Windows support planned. Install with npm i -g rses-cli. The project is MIT licensed and available on GitHub.