Username checker template

Node.js
Express

Block offensive usernames at signup, including profanity hidden inside a longer name.

A Node.js and Express app that checks a username for profanity before someone can claim it. Type a username and it tells you whether it’s clean or offensive, even when the word is buried in a longer name with numbers or underscores. Try names by hand, or call the route from your signup form.

What it does

Finds hidden profanity: Catches offensive words inside longer usernames, like a slur followed by numbers.
One yes-or-no answer: Returns a simple flag, so your signup form can accept the name or ask for another.
Keeps your key private: The page calls your own server, which holds the key and limits each visitor to 10 checks a minute.

How it works

The route that checks a username.

server.js

// GET /api/check?username=
app.get('/api/check', async (req, res) => {
  const username = str(req.query.username, 64);
  if (!username) return res.status(400).json({ error: 'Enter a username.' });

  try {
    const data = await callApi('usernameprofanity', { query: { username } });
    res.json({ success: true, username: data.username, isProfane: data.isProfane });
  } catch (err) {
    res.status(err.status || 502).json({ error: err.message });
  }
});

See the whole file on GitHub →

Deploy it

Get a free API key
The free plan includes 200 credits a month, no card needed. Create your key.
Deploy it
Click Deploy to Vercel. Vercel copies the repo to your GitHub account and asks for APIVERVE_API_KEY: paste your key there.
Open your app
Vercel builds it and gives you a live URL, usually in about a minute. Every push to the repo redeploys it.

Try the Username Profanity API — the call this template makes

Request

GETapi.apiverve.com/v1/usernameprofanity?username=b00bs

Query parameters

usernamestring

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "username": "b00bs",
    "isProfane": true
  }
}