Extension authors
An extension is a sandboxed MCP server that Nimbus installs from a folder or a registry. This section walks you from an empty directory to a published version. It is a path, not the full reference: each page ends with links to the exact sections of the CLI reference.
Three things hold for every extension, and they shape the steps below:
- Installing does not run it. The owner installs a package, then approves it
to run in a separate step (
nimbus extension approve) before it runs as an extension on that machine. - It runs sandboxed. Only the paths and network your manifest declares are granted, and the owner sees them before approving. How tightly the network is limited depends on the OS: on Linux with the sandbox helper, only the declared hosts and ports; on Linux without it, the whole network or none; on macOS, the declared ports to any host; on Windows, all internet hosts whenever any network is granted.
- Every tool call asks the owner. Calls to an installed extension’s tools raise an approval prompt each time.
- Evals are the exception.
nimbus eval --packageruns your server with no run approval and no per-call prompt, but sandboxed, with no network and no credentials. Evaluating an installed extension takes oneextension.evalapproval and grants it nothing.
StartScaffold from a template or an OpenAPI document, or clone a published extension.
Build and testBuild the entry, install it from a folder, approve it and call its tools.
EvalsWrite or record a suite and score your package offline.
Sign and publishGenerate a key, sign, pack and open a pull request on a registry.
Funding and licenseDeclare how to support you and under what terms the code is offered.
Verified publishersWhat the badge means and where the verification comes from.