Editors

passmcp-lsp is a stdio language server: an editor starts the passmcp-lsp program and exchanges Language Server Protocol messages with it over stdin and stdout. Any editor that can do that can use it, for JSON and JSON-with-comments files. The server recognises the MCP artefacts among those files and says nothing about the rest.

VS Code

The extension in editors/vscode starts the server for every JSON document. It does not bundle the server; install passmcp-lsp first, then build and install the extension from a checkout:

make vscode
code --install-extension editors/vscode/passmcp-lsp.vsix

Setting	Default	Meaning
passmcpLsp.path	passmcp-lsp	The server program: a path, or a name on PATH
passmcpLsp.passmcpPath	empty	The passmcp program hover asks for guidance
passmcpLsp.trace.server	off	Trace the protocol in the output panel

The two paths are machine-scoped settings. A workspace's .vscode/settings.json cannot set them, so opening a repository cannot choose which program the extension starts. Changing either restarts the server.

The extension is not published to a marketplace.

Neovim

Neovim 0.11 or later has the configuration built in:

vim.lsp.config('passmcp_lsp', {
  cmd = { 'passmcp-lsp' },
  filetypes = { 'json', 'jsonc' },
  root_markers = { '.git' },
})
vim.lsp.enable('passmcp_lsp')

To name the passmcp program for hover, add init_options = { passmcpPath = '/path/to/passmcp' }, or start the server with cmd = { 'passmcp-lsp', '--passmcp', '/path/to/passmcp' }.

Any other editor

What the editor needs	Value
Command	passmcp-lsp (it accepts --stdio, which some clients add)
Transport	stdio
Languages	json, jsonc
Initialization options	optional: {"passmcpPath": "/path/to/passmcp"}

The server asks for whole-document sync and applies incremental changes as well when a client sends them. It advertises diagnostics (pushed with textDocument/publishDiagnostics) and hover.