remix-run/react-router · error · Error

Could not find package.json in

Error message

Could not find package.json in ${rootDirectory} or any of its parent directories. Please add a package.json, or provide a custom entry.server.tsx/jsx file in your app directory.

What it means

When the app has no custom entry.server file, resolveEntryFiles() walks rootDirectory and all parent directories looking for package.json: it reads dependencies to choose between the node and web default entry.server and to auto-install isbot if missing. If no package.json exists anywhere above the root, it throws this error suggesting either a package.json or a custom entry.server.

Solutions

1. Add a package.json at the project root (npm init -y, then install react-router dependencies)
2. Or provide your own app/entry.server.tsx (or .jsx) so the default resolution and isbot check are skipped
3. Verify the rootDirectory passed to the tooling points at your React Router app package

Example fix

# before: bare directory, no manifest
react-router dev  # -> Could not find package.json ...

# after: add a manifest and deps, or add app/entry.server.tsx
npm init -y && npm install react-router @react-router/dev @react-router/serve
# or: create app/entry.server.tsx to bypass default resolution

import { existsSync } from "node:fs";
import path from "node:path";

function hasPackageJsonAtOrAbove(dir: string): boolean {
  let cur = path.resolve(dir);
  for (;;) {
    if (existsSync(path.join(cur, "package.json"))) return true;
    const parent = path.dirname(cur);
    if (parent === cur) return false;
    cur = parent;
  }
}

const hasCustomEntryServer = ["entry.server.tsx", "entry.server.jsx"]
  .some((f) => existsSync(path.join(appDirectory, f)));

if (!hasPackageJsonAtOrAbove(rootDirectory) && !hasCustomEntryServer) {
  throw new Error("Add a package.json above the app root, or provide app/entry.server.tsx");
}

When it happens

Trigger: Invoking @react-router/dev build/dev APIs with a rootDirectory that has no package.json above it (bare directory, deleted manifest, wrong root passed by a generator); unusual workspaces where the app root sits outside any package tree.

Common situations: Experimental setups and custom scaffolds calling the dev package programmatically; monorepo tooling misconfiguring the root directory; package.json accidentally removed.

Related errors

• React Router presets must have a `name` property defined.
• Route config file not found at
• Could not find a root route module in the app directory
• Could not find a root route module in the app directory as
• Could not find the routes directory

AI-assisted analysis of remix-run/react-router@6beaca3952 (2026-08-18). Data as JSON: /api/errors/43fced40773cdd45. Report an issue: GitHub.

Appendix: source

Thrown at packages/react-router-dev/config/config.ts:1047

  );

  let userEntryClientFile = findEntry(appDirectory, "entry.client");
  let userEntryServerFile = findEntry(appDirectory, "entry.server");

  let entryServerFile: string;
  let entryClientFile = userEntryClientFile || "entry.client.tsx";

  if (userEntryServerFile) {
    entryServerFile = userEntryServerFile;
  } else {
    let packageJsonPath = findEntry(rootDirectory, "package", {
      extensions: [".json"],
      absolute: true,
      walkParents: true,
    });

    if (!packageJsonPath) {
      throw new Error(
        `Could not find package.json in ${rootDirectory} or any of its parent directories. Please add a package.json, or provide a custom entry.server.tsx/jsx file in your app directory.`,
      );
    }

    let packageJsonDirectory = Path.dirname(packageJsonPath);
    let pkgJson = await readPackageJSON(packageJsonDirectory);
    let deps = pkgJson.dependencies ?? {};

    if (!deps["isbot"]) {
      console.log(
        "adding `isbot@5` to your package.json, you should commit this change",
      );

      await updatePackage(packageJsonPath, (pkg) => {
        pkg.dependencies ??= {};
        pkg.dependencies.isbot = "^5";
        sortPackage(pkg);
      });

View on GitHub (pinned to 6beaca3952)