> ## Documentation Index > Fetch the complete documentation index at: https://docs.basemode.ai/llms.txt > Use this file to discover all available pages before exploring further. # Extensions > What an extension is, installing one without a build toolchain, checking a manifest before you trust it, writing your own, and what happens when a plugin command collides with a built-in. An extension adds commands to base. A manifest declares them, a handler implements them, and once installed `base ` works like anything else. ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} base extension list ``` `base ext` is the short alias, and it works everywhere the full name does. ## Installing one someone published ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} base extension add ./base-extension.toml ``` **Why it works.** This reads the manifest's `[dist]` block, fetches the prebuilt binary for your machine from its GitHub release, verifies the checksum, unpacks it and installs it. No Rust, no build step, no toolchain. **The gotcha.** If no prebuilt asset matches your machine, it falls back to building from local source, which does need a toolchain. That fallback is why the command sometimes takes minutes instead of seconds. ## Installing one from a local manifest ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} base extension validate ./base-extension.toml base extension install ./base-extension.toml base extension install ./base-extension.toml --bundle ``` **Why `--bundle` matters.** Without it, the installed manifest points back at wherever the handler currently sits on disk. Move that folder, delete the repository, or clean a build directory, and the command breaks. With `--bundle`, the handler is copied into `~/.base-gbl/plugins//` and the manifest is repointed there, so the install is self-contained. Use `--bundle` for anything you intend to keep. **The gotcha.** Validate anything you did not write. `base extension validate` reads the manifest and reports whether it conforms without installing it, and it costs one command. ## Writing one ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} base extension scaffold weather base extension scaffold weather --path ~/dev --build --git base extension scaffold weather --bootstrap ``` **Why it works.** The scaffold writes a conformant cross-platform plugin skeleton. The name you pass becomes the command, so `base extension scaffold weather` gives you `base weather`. `--bootstrap` is the whole kickoff in one flag: write the files, build them, initialize a repository, create a private GitHub repository, wire the remote and push. It is the same as passing `--build --git --create-repo` together. **Next rung.** `--repo owner/name` sets where releases come from, defaulting to `ChristopherKahler/-cli`. Set it before your first release rather than after. ## When a name collides ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} base extension run weather ``` **Why it works.** This runs a plugin command explicitly by name, and everything after the name is forwarded to the handler untouched. Where the bare `base weather` might be ambiguous, this form never is. **The gotcha.** Collisions are quiet. If a plugin command shares a name with a built-in, the built-in is what you get. `base extension run` is the way to reach the plugin anyway. ## Extensions and domains An installed extension can declare domains of its own. They merge into the same pool as yours, at the lowest priority, so a domain you define with the same name wins. **Why this matters.** It means installing an extension can change what gets injected, not just what commands exist. `base domain list` shows the merged result, so check there after installing something that ships domains. ## Removing one ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} base extension remove weather ``` No preview. The manifest goes; a bundled handler under `~/.base-gbl/plugins/` goes with it. ## Next Protocols that fire when you edit a matching file. Every `base extension` verb and flag.