cypress-io/cypress · error · Error

Could not find "vite" in your project's dependencies…

Error message

Could not find "vite" in your project's dependencies. Please install "vite" to fix this error.\n\n${err}

What it means

The outer catch in getVite, reached only for non-CJSNotSupportedError failures anywhere in the function: resolving vite/package.json from projectRoot, reading/parsing its package.json, or importing either build. The message tells the user Vite itself could not be located/resolved and appends the original error for detail. It is the canonical 'vite is not installed' signal for the dev server.

Solutions

1. Install Vite in the project Cypress is testing: `npm install -D vite` (vite 5, 6, 7, or 8).
2. Ensure vite resolves from the same projectRoot Cypress uses (cypressConfig.projectRoot).
3. If using a monorepo, make sure vite is a dependency of the workspace Cypress runs in, not only a sibling.
4. Read the appended `${err}` to diagnose non-MODULE_NOT_FOUND causes (e.g. corrupt package.json).

Example fix

// before: devServer requests vite but vite is not installed
devServer: { bundler: 'vite' }
// after
npm install -D vite@7
devServer: { bundler: 'vite' }

import { createRequire } from 'module'
function ensureViteInstalled(projectRoot: string) {
  const r = createRequire(import.meta.url)
  try { r.resolve('vite/package.json', { paths: [projectRoot] }) }
  catch { throw new Error('Run `npm install -D vite` before starting CT') }
}

const isViteResolvable = (projectRoot: string): boolean => { try { createRequire(import.meta.url).resolve('vite/package.json', { paths: [projectRoot] }); return true } catch { return false } }

try { await getVite(config) } catch (e) { if (/Could not find "vite"/.test(e.message)) { /* npm install vite, retry */ } else throw e }

When it happens

Trigger: require.resolve('vite/package.json', { paths: [projectRoot] }) throws MODULE_NOT_FOUND (vite not installed), the package.json import/parse fails, or viteExports resolution throws — and none of these is a CJSNotSupportedError. The original error is concatenated into the message.

Common situations: Running Cypress component testing with `devServer: { bundler: 'vite' }` in a project that has not installed vite; vite hoisted to a location require.resolve cannot reach from projectRoot; a yarn-workspace structure where vite is in a sibling package; a broken/partial vite install.

Related errors

• CJS builds of vite are not supported
• ${err}
• Missing vite dev server port.
• No typescript installable was found. ts-loader needs a…
• Unsupported webpackDevServer version

AI-assisted analysis of cypress-io/cypress@0d85fdc912 (2026-08-12). Data as JSON: /api/errors/c5ead670c2dbc049. Report an issue: GitHub.

Appendix: source

Thrown at npm/vite-dev-server/src/getVite.ts:92

      // if the ESM build import fails, try to import the CJS build
      debug('importing vite as ESM failed:', err)
      debug('importing vite as CJS')
      // Vite 4-6 both include the CJS distribution of Vite
      const cjsViteImportPath = path.resolve(vitePackageJsonPath, '../', cjsPath)

      debug('resolved cjsViteImportPath as %s', cjsViteImportPath)

      const viteImport = await import(`${filePrefix}${cjsViteImportPath}`)

      return viteImport.default
    }
  } catch (err) {
    if (err instanceof CJSNotSupportedError) {
      throw err
    }

    throw new Error(`Could not find "vite" in your project's dependencies. Please install "vite" to fix this error.\n\n${err}`)
  }
}

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