Support `--config` options in Vitepress cli

[cocoich]

Is your feature request related to a problem? Please describe.

I need to deploy different outputs from the same source for multiple environments.
In my project, I maintain about 4 VitePress config files:

• .vitepress/config.base.mts
• .vitepress/config.prd.mts (mergeConfig with config.base.mts)
• .vitepress/config.dev.mts (mergeConfig with config.base.mts)
• .vitepress/config.prd-c.mts

Currently, in CI, I overwrite config files before running VitePress commands with ~10 lines of script.
This works, but it is fragile and hard to maintain.

Describe the solution you'd like

Please support a CLI option to specify a config file path, for example:

• vitepress dev --config .vitepress/config.dev.mts
• vitepress build --config .vitepress/config.prd.mts
• vitepress build --config .vitepress/config.prd-c.mts

This would remove the need for file overwrite steps in CI and make multi-environment workflows much simpler and safer.

Describe alternatives you've considered

• Overwriting .vitepress/config.mts in CI before each build process
• Keeping modified .vitepress/config.mts in another branch (worst)

Additional context

currently using vitepress@2.0.0-alpha.17

Found related:

• How can I change default config path, like /projectRoot/config/vitepress.config.ts. #2084

_{Im not good at English, Describes translated by AI 🙏🏻}

Validations

• Follow our Code of Conduct
• Read the docs.
• Read the Contributing Guidelines.
• Check that there isn't already an issue that asks for the same feature to avoid creating a duplicate.

[its-miroma]

I suggest using environment variables directly in .vitepress/config.ts:

import * as process from "node:process";
import { defineConfig } from "vitepress";

export default defineConfig({
  title: process.env.MODE === "production" ? "My Docs" : "[WIP] My Docs",
});

then, you can just run MODE="production" pnpm docs:build (or set MODE="production" && pnpm docs:build on Windows) (ofc, replace pnpm with your package manager)

[cocoich]

I suggest using environment variables directly in .vitepress/config.ts:

@its-miroma While this is a valid workaround for overriding a single option, it may not be very effective for multiple or nested options.

[its-miroma]

You could totally export your different configs based on a variable, if you have a central .vitepress/config.mts:

import * as process from "node:process";

export default await (
  process.env.MODE === "production"
  ? import("./config.prd.mts")
  : import("./config.dev.mts")
).then(config => config.default);

Tip

If the only distinction you want to make is between vitepress build and vitepress dev, you may also use a function like this:

import { defineConfig } from "vitepress";

export default defineConfig(({ mode }) => {
  if (mode === "production") {
    // vitepress build
  } else {
    // vitepress dev
  }
});

[cocoich]

You could totally export your different configs based on a variable, if you have a central .vitepress/config.mts:

@its-miroma
Central config-wrapper is also a nice workaround, but I think the cli --config arg is a more user-friendly solution. Passing the file path directly is more explicit and lowers cognitive load. so I feel it would be a nice-to-have for better DX.