pyrefly configuration: provide additional settings

[PicoJr]

I would like to provide the following additional settings to pyrefly via the coc-settings.json:

"settings": {
  "pyrefly": {
    "analyzer": true,
    "diagnostics": true,
    "typechecking": "strict"
  }
}

How can I provide these settings in my coc-settings.json ?

my current configuration:

{
    "rust-analyzer.serverPath": "/usr/lib/rustup/bin/rust-analyzer",
    "languageserver": {
        "pyrefly": {
            "command": "pyrefly",
            "args": ["lsp"],
            "filetypes": ["python"],
            "rootPatterns": ["pyrefly.toml", "pyproject.toml", ".git"]
        }
    }
}

coc.nvim wiki explains how to setup pyrefly but I am unsure how to provide these additional settings.

Why I wish to provide these parameters ? because of this pyrefly issue (facebook/pyrefly#1633)

At the moment, unless I provide these settings in each of my pyproject.toml diagnostics are not enabled:

[tool.pyrefly]
diagnostics = true

I would like to provide these settings globally instead.

CocInfo output:

vim version: NVIM v0.11.5
node version: v25.2.0
coc.nvim version: 0.0.82-d425554 2025-06-01 02:02:45 +0800
coc.nvim directory: /home/<user redacted>/.local/share/nvim/plugged/coc.nvim
term: xterm-kitty
platform: linux

I am using pyrefly built from source: a4d0bfa8abb78ef1ecffbf6c5eae765be1998c5b

[fannheyward]

From the commit the pyrefly will read initializationOptions, try this:

  "languageserver": {
    "pyrefly": {
      "command": "pyrefly",
      "args": ["lsp"],
      "filetypes": ["python"],
      "rootPatterns": ["pyrefly.toml", "pyproject.toml", ".git"],
      "initializationOptions": {
        "pyrefly": {
          "disableLanguageServices": true
        }
      }
    }
  },

[PicoJr]

I asked the pyrefly project about this issue, I'll keep this discussion updated.

[fannheyward]

I've checked the issue you posted, just one question: are you sure the pyrefly has diagnostics configuration? The https://pyrefly.org/en/docs/configuration/#configuration-options page doesn't have this, and I don't know why the [tool.pyrefly] section works.

[PicoJr]

I have the same concern as you, I checked the source code of pyrefly, it does not look like the diagnostics can be configured via initialization options, I have taken the issue on pyrefly side, I think we can close this discussion for now.

Thanks for helping me configuring initializationOptions, it seems what I want to configure is simply not supported on pyrefly for now.

[PicoJr]

Ok, I finally managed to configure it, here is my configuration:

{
    "languageserver": {
        "pyrefly": {
            "command": "pyrefly",
            "args": ["lsp"],
            "filetypes": ["python"],
            "rootPatterns": ["pyrefly.toml", "pyproject.toml", ".git"],
            "initializationOptions": {
                "pyrefly": {
                  "displayTypeErrors": "force-on"
                }
            }
    }
}

After checking pyrefly source code I could not find the diagnostics setting but I found the documentation I was looking for: https://pyrefly.org/en/docs/IDE/#customization, it describes the option I was looking for displayTypeErrors.

Thanks @fannheyward for your help.