The Problem

You check if a package name is available on npm. It says yes. You build the whole thing. You run npm publish. Boom:

403 Package name too similar to existing packages degit,pdfkit,exit

npm has an undocumented similarity filter that blocks names even if they don't exist on the registry. npm publish --dry-run doesn't catch it either. Neither does npm-name-cli.

can-i-publish actually tests publishability by checking both the registry AND the similarity filter.

npm-name-cli vs can-i-publish

Try it yourself — check dxkit, a name that looks available but is actually blocked:

# npm-name-cli says it's available (wrong — will fail on npm publish)
$ npx npm-name-cli dxkit
✔ dxkit is available

# can-i-publish catches the similarity block
$ npx can-i-publish dxkit
⚠ dxkit is blocked by npm similarity filter
  Similar to: degit, pdfkit, exit

Other names you can verify: reacto, expresss, loadash, chulk.

| | npm-name-cli | can-i-publish | |---|---|---| | Registry check | Yes | Yes | | Organization check (@org) | Yes | Yes | | Squatter detection | Yes | Yes | | Similarity filter | No | Yes | | Catches dxkit as blocked | No | Yes | | Shows similar packages | No | Yes | | Suggests alternatives | No | Yes (--suggest) |

Install

npx can-i-publish my-package

Or install globally:

npm install -g can-i-publish

Usage

# Check a single name
can-i-publish my-package

# Check multiple names at once
can-i-publish my-tool my-lib my-app

# Check an organization name
can-i-publish @my-org

# Get suggestions if blocked
can-i-publish dxkit --suggest

# JSON output (for scripting)
can-i-publish my-package --json

Output

$ can-i-publish abc123 chalk dxkit my-cool-tool @ava

⚠ abc123 is squatted (https://www.npmjs.com/package/abc123)
✖ chalk is unavailable (https://www.npmjs.com/package/chalk)
⚠ dxkit is blocked by npm similarity filter
  Similar to: degit, pdfkit, exit
✔ my-cool-tool is available
✖ @ava is unavailable (https://www.npmjs.com/org/ava)

How It Works

1. Validates the name against npm naming rules (lowercase, no spaces, under 214 chars)
2. Checks the registry to see if the package already exists
3. Detects squatters — flags packages that exist but appear abandoned (low downloads, no readme, no prod version)
4. Tests the similarity filter by attempting a publish probe against the npm registry using your npm credentials

[!NOTE] Step 4 requires npm credentials. Run npm login first, or set NPM_TOKEN as an environment variable. If you're not logged in, can-i-publish will still check steps 1-3 and let you know that similarity wasn't tested.

Options

| Flag | Description | |------|-------------| | -s, --suggest | Suggest alternative names if unavailable | | -j, --json | Output results as JSON | | -V, --version | Show version | | -h, --help | Show help |

Exit Codes

• 0 — all names are available or squatted
• 1 — one or more names are unavailable, blocked, or invalid

Useful for CI/scripting:

can-i-publish my-package && npm publish

Programmatic API

import { checkName, suggestNames } from 'can-i-publish';

const result = await checkName({ name: 'my-package' });
// { name, status: 'available' | 'taken' | 'squatted' | 'blocked' | 'invalid', reason?, similarTo? }

const suggestions = await suggestNames({ name: 'dxkit', limit: 5 });
// [{ name: 'dxkit-cli', status: 'available' }, ...]

Credits

Inspired by npm-name-cli by Sindre Sorhus.

License

MIT

Built with commandcode by @saqibameen