Mycelium for VS Code
Capture, organize, learn from and reuse your AI coding-agent sessions (Claude Code, Codex, Kiro, OpenCode) from the editor's sidebar. It reads and writes the same ~/.mycelium store as the Mycelium TUI and CLI.
Works in VS Code, Cursor and Windsurf, on macOS, Linux and Windows.
Requirements
Install
Search for Mycelium for VS Code in the Extensions panel, or:
code --install-extension krapie.mycelium-vscode # cursor / windsurf too
It is also on Open VSX (what Cursor, Windsurf and VSCodium use), and every release has its .vsix on GitHub for Extensions → … → Install from VSIX….
Getting started
The Get Started walkthrough opens the first time (reopen it with Mycelium: Open the Guide). In short, open the Mycelium icon in the activity bar and use Actions: scan for sessions, summarize them, smart-organize them into folders, extract a folder's knowledge, search, and start or resume sessions. Full guide: docs/vscode.md.
With the Claude Code extension installed, Claude sessions open in its panel instead of a terminal (mycelium.claudeCode.openIn; Resume in terminal keeps the terminal). Resume, Hand off and Start New Agent open in a window on the session's own project directory (this needs the extension installed in that window too; set mycelium.openSessionIn to thisWindow to always use the current one).
Settings
| Setting |
|
mycelium.path |
The mycelium executable (default: from PATH). |
mycelium.home |
Data directory (MYCELIUM_HOME); empty uses ~/.mycelium. |
mycelium.openSessionIn |
projectWindow (default) or thisWindow. |
Troubleshooting
"Mycelium can't find its command-line tool", but it is installed. An editor started from the Dock or Finder doesn't always get your shell's PATH. When VS Code can't resolve it in time it shows "Unable to resolve your shell environment…" — that message is VS Code's own and the extension can't hide it. The extension looks for mycelium on PATH, then in the usual install locations (Homebrew, npm global, nvm, Volta, asdf, %APPDATA%\npm), then asks your login shell once, and runs it with a PATH that includes the CLI's own directory so node is found too. If it still can't: run Mycelium: Show Log (it lists where it looked), set mycelium.path to the full path (which mycelium), or start VS Code from a terminal with code.
The "Unable to resolve your shell environment" message keeps appearing. VS Code runs your shell as a login, interactive shell (zsh -ilc …) and gives up after about 10 seconds. Time it with time zsh -ilc exit; the usual culprits are version-manager and conda/pyenv init, prompt plugins, and anything in your rc files that asks a question.
"…too old for this extension". The CLI is older than the extension needs (0.5.0+): npm install -g @kevinprk/mycelium, then mycelium --version. If you also have a Homebrew copy, check which one which mycelium finds.
"Node.js was not found". The CLI was found but node isn't on the PATH VS Code started with: install Node.js 22.16 or newer, or start VS Code from a terminal with code.
Privacy
No telemetry, no accounts, no network calls of its own. It runs the mycelium CLI on your machine and shows what it returns; sessions stay in ~/.mycelium. The AI steps (summarize, smart organize, folder knowledge) and Resume / Hand off / Start New Agent run your claude, codex etc. under your login, and so send session content to that provider exactly as using it directly does. The extension only runs in folders you trust.
Using several computers
Each computer has its own ~/.mycelium; the extension shows whatever store it finds on that machine.
