vitejs/vite · error · Error

Cannot print server URLs before server.listen is called.

Error message

Cannot print server URLs before server.listen is called.

What it means

ViteDevServer.printUrls at packages/vite/src/node/server/index.ts:800 throws when resolvedUrls is still null in non-middleware mode. resolvedUrls is filled only after the http server actually listens (the listening callback resolves host/port/urls), so calling printUrls before server.listen() cannot print anything meaningful.

Source

Thrown at packages/vite/src/node/server/index.ts:800

      }
    },
    async close() {
      if (!closeServerPromise) {
        closeServerPromise = closeServer()
      }
      return closeServerPromise
    },
    printUrls() {
      if (server.resolvedUrls) {
        printServerUrls(
          server.resolvedUrls,
          serverConfig.host,
          config.logger.info,
        )
      } else if (middlewareMode) {
        throw new Error('Cannot print server URLs in middleware mode.')
      } else {
        throw new Error(
          'Cannot print server URLs before server.listen is called.',
        )
      }
    },
    bindCLIShortcuts(options) {
      bindCLIShortcuts(server, options)
    },
    async restart(forceOptimize?: boolean) {
      if (!server._restartPromise) {
        server._forceOptimizeOnRestart = !!forceOptimize
        server._restartPromise = restartServer(server).finally(() => {
          server._restartPromise = null
          server._forceOptimizeOnRestart = false
        })
      }
      return server._restartPromise
    },

View on GitHub (pinned to 89620f09af)

Solutions

1. Await server.listen() (or call printUrls inside its callback) so resolvedUrls is populated.
2. Move printUrls() to the point where you know the server is listening.
3. Omit the call entirely if Vite's default listen already prints URLs for you.

Example fix

// before
const server = await createServer({})
server.printUrls() // throws

// after
const server = await createServer({})
await server.listen()
server.printUrls()

function assertServerListened(server: { resolvedUrls: unknown }) {
  if (!server.resolvedUrls) {
    throw new Error('Await server.listen() before calling printUrls()')
  }
}

function isServerListened(server: { resolvedUrls: unknown }): boolean {
  return server.resolvedUrls != null
}

When it happens

Trigger: Calling server.printUrls() synchronously right after createServer without awaiting server.listen(); calling printUrls inside an error handler when listen failed; test fixtures that create the server and immediately print.

Common situations: Custom dev scripts that forget the listen step; race conditions where printUrls runs before the listen promise resolves; refactoring that moved listen into an async branch but left printUrls at the top.

Related errors

• Cannot print server URLs before server is listening.
• There is already a server associated with the config.
• Cannot print server URLs in middleware mode.
• Vite module runner has been closed.
• [module runner] HMR client was closed.

AI-assisted analysis of vitejs/vite@89620f09af (2026-08-03). Data as JSON: /data/errors/69b57a924b474f6c.json. Report an issue: GitHub.