Start script missing error when running npm start

This error also happens if you added a second "script" key in the package.json file. If you just leave one "script" key in the package.json the error disappears.

check package.json file having "scripts" property is there or not. if not update script property like this

{
  "name": "csvjson",
  "version": "1.0.0",
  "description": "upload csv to json and insert it into MongoDB for a single colletion",
  "scripts": {
    "start": "node csvjson.js"
  },
  "dependencies": {
    "csvjson": "^4.3.4",
    "fs": "^0.0.1-security",
    "mongodb": "^2.2.31"
  },
  "devDependencies": {},
  "repository": {
    "type": "git",
    "url": "git+https://github.com/giturl.git"
  },
  "keywords": [
    "csv",
    "json",
    "mongodb",
    "nodejs",
    "collection",
    "import",
    "export"
  ],
  "author": "karthikeyan.a",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/homepage/issues"
  },
  "homepage": "https://github.com/homepage#readme"
}

If you are using babelify and watchify, go to:

package.json

and add this in "scripts":

"scripts": {
    "start": "watchify the-path-to-your-source-jsx-file -v -t [ babelify --presets [ react ] ] -o the-path-to-your-output-js-file"
}

An example would be:

"scripts": {
    "start": "watchify src/main.jsx -v -t [ babelify --presets [ react ] ] -o public/js/main.js"
}

Thanks to Mark Price from DevSlopes

should avoid using unstable npm version.

I observed one thing that is npm version based issue, npm version 4.6.1 is the stable one but 5.x is unstable because package.json will be configured perfectly while creating with default template if it's a stable version and so we manually don't need to add that scripts.

I got the below issue on the npm 5 so I downgraded to npm 4.6.1 then its worked for me,

ERROR: npm 5 is not supported yet

It looks like you're using npm 5 which was recently released.

Create React Native App doesn't work with npm 5 yet, unfortunately. We recommend using npm 4 or yarn until some bugs are resolved.

You can follow the known issues with npm 5 at: https://github.com/npm/npm/issues/16991

Devas-MacBook-Air:SampleTestApp deva$ npm start npm ERR! missing script: start

In my case, if it's a react project, you can try to upgrade npm, and then upgrade react-cli

npm -g install [email protected]
npm install -g create-react-app

Make sure the PORTS ARE ON

var app = express();
app.set('port', (process.env.PORT || 5000));

BLAL BLA BLA AND AT THE END YOU HAVE THIS

app.listen(app.get('port'), function() {
    console.log("Node app is running at localhost:" + app.get('port'))
});

Still a newbee in node js but this caused more of this.

Another possible reason: you're using npm when your project is initialized in yarn. (I did this myself). So it would be yarn start instead of npm start.

Installing create-react-app globally is now discouraged. Instead uninstall globally installed create-react-app package by doing: npm uninstall -g create-react-app (you may have to manually delete package folder if this command didn't work for you. Some users have reported they had to delete folders manually)

Then you can run npx create-react-app my-app to create react app again.

ref: https://github.com/facebook/create-react-app/issues/8086

"scripts": {
  "prestart": "npm install",
  "start": "http-server -a localhost -p 8000 -c-1"
}

add this code snippet in your package.json, depending on your own configuration.

I have the same issue. I try to write a code in package.json file as below

    "scripts": {
    "start": "<your-script-file>.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },

I have solved mine. Its not an NPM Error its related to proxy behavior.

If you are behind proxy,

MAC
 1.  Goto System Preference (gears icon on your mac)
 2.  click your network
 3.  click advanced
 4.  click proxy
 5.  check excludes simple hostnames
 6.  add this line below (Bypass Proxy Settings...) "localhost, localhost:8080"

refer to the npm echo: "Project is running at http://localhost:8080/"

Windows
 1.  Goto your browser Proxy Settings (google it)
 2.  check Bypass local address
 3.  add this line below "localhost, localhost:8080"

It looks like you might not have defined a start script in your package.json file or your project does not contain a server.js file.

If there is a server.js file in the root of your package, then npm will default the start command to node server.js.

https://docs.npmjs.com/misc/scripts#default-values

You could either change the name of your application script to server.js or add the following to your package.json

"scripts": {
    "start": "node your-script.js"
}

Or ... you could just run node your-script.js directly

In my case, it wasn't working because I used "scripts" twice. After combining - it is ok.

"scripts": {
  "test": "make test",
  "start": "node index.js"
}

Please use the below line of code in script object which is there in package.json

"scripts": {
    "start": "webpack-dev-server --hot"
}

For me it worked perfectly fine.

Take a look at your client/package.json. You have to have these scripts

"scripts": {
  "start": "react-scripts start",
  "build": "react-scripts build",
  "test": "react-scripts test --env=jsdom",
  "eject": "react-scripts eject"
}

I had this issue while installing react-js for the first time : These line helped me solve the issue:

npm rm -g create-react-app
npm install -g create-react-app
npx create-react-app my-app

source: https://stackoverflow.com/a/59260128/11652661

You might have an old (global) installation of npm which causes the issue. As of 12/19, npm does not support global installations.

First, uninstall the package using:
npm uninstall -g create-react-app

Some osx/Linux users may need to also remove the old npm using:
rm -rf /usr/local/bin/create-react-app

This is now the only supported method for generating a project:
npx create-react-app my-app

Finally you can run:
npm start

Try with these steps :

npm rm -g create-react-app

npm install -g create-react-app

npx create-react-app my-app

Definitely this works!!