Nameable

Nameable checks a name on package registries, GitHub, agent and editor directories, app stores and domains, shows the evidence behind every answer, and says how sure each answer is. It runs as a CLI, as an MCP server for AI agents, and as a Claude Code plugin that also looks for prior art and recommends which name to keep.

Why

Most availability checks ask each registry whether the name exists and read "not found" as free. Not found only means nobody holds that exact name. The registry may still refuse it:

Nameable applies each registry's own rules, taken from its source code, and checks the lists those rules need: similar and reserved names, aliases and old names, recently deleted names, unpublished packages. When a rule cannot be checked, the answer says "probably" and why, instead of "available". A failed request is unknown, never free.

Use it from the terminal

Requires Node.js 22 or later. Run it in your project (or any folder under it, up to the repository root) and it checks the channels the project ships on, picked from its files:

• package.json for npm (unless it has no name, is private, or is a server or site: it starts, serves or deploys itself and declares nothing to publish), Homebrew when it has a bin; with engines.vscode, VS Code Marketplace and Open VSX instead of npm
• pyproject.toml, setup.py or setup.cfg that describe a package for PyPI, Homebrew when they declare scripts
• Cargo.toml for crates.io (unless publish = false), Homebrew when it builds a binary
• a .gemspec for RubyGems, composer.json for Packagist (unless it is a project), pubspec.yaml for pub.dev (unless publish_to: none), a .NET project or solution for NuGet (unless it builds a web app, a function, an executable or tests, or is not packable), a Dockerfile for Docker Hub, a Package.swift with an executable for Homebrew
• .claude-plugin/, .cursor-plugin/ and gemini-extension.json for those directories, a plugin.xml or the IntelliJ Gradle plugin for JetBrains Marketplace, an MCP SDK dependency for the MCP Registry and Smithery
• an Xcode project for the App Store, an Android app for Google Play, and an Expo or Flutter app for both
• at an npm, pnpm, Yarn, Lerna or Cargo workspace root, the channels of each member, read the same way

GitHub accounts and repositories and domains are always checked; a project that ships on none of these, such as a Rails app or a Go library, gets only those (and Homebrew for a Go command). Outside a project it checks a general set: npm, PyPI, crates.io, Homebrew, GitHub and domains.

npx nameable nameable --all --tlds com,dev,sh

Checking "nameable" on 25 channels
  ✗ npm                   taken              Find out if a name is free everywhere it matters for …  ✓ PyPI                  available  ✓ crates.io             available  ✓ Homebrew              available          no homebrew-core formula or cask  ✗ RubyGems              taken              A library that provides parsing and output of person …  ✓ Packagist             probably available no packages under this vendor; packages frozen for sp…  ✓ pub.dev               probably available no package with this name; moderated packages and res…  ✓ NuGet                 probably available no package with this ID; reserved prefixes and the ty…  ✓ Docker Hub            probably available no user or organization; deactivated or reserved Dock…  ✓ GitHub user/org       probably available suspended, deleted or reserved accounts also look fre…  ✗ GitHub repository     taken              clash, not a block: dwightwatson/nameable (★30, pushe…  ✓ MCP Registry          probably available no server uses this name in the registry as of 2026-10…  ✓ Smithery              probably available no public servers; a namespace with none, or with onl…  ✓ Claude plugins        available          not in the official marketplace  ✓ Cursor plugins        probably available not among Cursor's listed plugins; plugins in review …  ✓ Gemini extensions     probably available not in the Gemini CLI gallery; it lists only tagged G…  ✓ VS Code Marketplace   probably available no extension or publisher; removed extensions keep th…  ✓ Open VSX              probably available no namespace or similar one; namespaces without publi…  ✓ JetBrains Marketplace probably available no plugin with this name or ID; unapproved and hidden…  ✓ App Store             probably available no app with this name in the US store; unreleased app…  ✓ Google Play           probably available no app with this title in search results of the US st…  ✓ Trademarks (TW)       probably available no Taiwan trademark uses exactly this name as of 2026…  ✗ .com                  taken              registered 1999-02-13, expires 2027-02-13  ✓ .dev                  probably available not registered; a registry can still refuse premium o…  ✓ .sh                   probably available not registered (whois); a registry can still refuse p…
  npm                https://www.npmjs.com/package/nameable  RubyGems           https://rubygems.org/gems/nameable  GitHub repository  https://github.com/dwightwatson/nameable  .com               https://lookup.icann.org/en/lookup?name=nameable.com
  21 available (17 probably) · 4 taken

Several names show a grid to compare them:

npx nameable twinsy dupefind fclones --only crates,homebrew,github,domain --tlds com,dev,sh

                   twinsy    dupefind  fclones  crates.io        ✓         ✓         ✗  Homebrew         ✓         ✓         ✗  GitHub user/org  ✗         ✓*        ✓*  .com             ✗         ✗         ✓*  .dev             ✓*        ✓*        ✓*  .sh              ✓*        ✓*        ✓*  free             4/6       5/6       4/6
  ✓ available  ↺ reclaimable  ✗ taken  ⊘ unavailable  ? unknown  * probably available  Check one name at a time for the details behind each mark.

GitHub checks use GITHUB_TOKEN, GH_TOKEN or gh auth token when one is available, for a higher rate limit.

Use it with AI agents

Claude Code plugin

/plugin marketplace add minanyang/claude-plugins/plugin install nameable@minanyang

Then ask for a name, or run /nameable:check <names>. The skill picks the channels that matter for your project, checks them, looks for projects that already do the same thing, and gives a verdict for each candidate: use it, use it with changes (a scope, another TLD, another GitHub owner), or drop it.

The plugin carries its own copy of the CLI and runs it with Node.js 22 or later. When it installs, Claude Code adds the CLI's two dependencies, zod and @modelcontextprotocol/server, from the npm lockfile in the plugin.

MCP server

npx -y nameable mcp runs the same checks as an MCP server over stdio. It has one read-only tool, check_names (names, and optionally channels, tlds and refresh), which returns the JSON below as structured content. It is listed on the official MCP Registry as io.github.minanyang/nameable.

What the answers mean

An available answer carries a certainty. Only PyPI, crates.io, Homebrew and Claude plugins can answer confirmed; every other channel keeps something out of public view, so its free answer is probable at most. Confirmed means every rule of that registry that public data allows was checked. Probable (* in the grid) means one could not be, and note says which: GitHub hides suspended and reserved accounts, npm's similar-name rule cannot be checked for every spelling, registries can refuse premium or reserved domains, or a name list could not be downloaded. Two PyPI rules rest on data PyPI does not publish, so even a confirmed PyPI answer cannot cover them: names its admins prohibited, and names similar to a quarantined project.

Name lists

Several checks compare against registry-wide lists: every PyPI project, every Homebrew alias and old name, the reserved and recently deleted names in crates.io's daily database dump (read by byte range, under 1 MB of a 2 GB archive), every pub.dev package, every gem, every MCP server, every Open VSX namespace, and every plugin and extension in Cursor's marketplace and the Gemini CLI gallery. Each is downloaded the first time a check needs it, about 25 MB in all, and at most once a day after that. The Taiwan trademark list is split in 16 parts by name, and a check downloads only the part its name is in, about 2 MB each. This project rebuilds it twice a month from the Taiwan Intellectual Property Office's open data (Open Government Data License, version 1.0), like the MCP Registry list it rebuilds daily, and leaves out who owns each mark. They are kept compressed (about 12 MB) in ~/Library/Caches/nameable on macOS, $XDG_CACHE_HOME/nameable on Linux, %LOCALAPPDATA%\nameable\Cache on Windows, or NAMEABLE_CACHE_DIR.

JSON

{  "schema": 1,  "reports": [    {      "name": "nameable",      "results": [        {          "channel": "npm",          "label": "npm",          "status": "taken",          "url": "https://www.npmjs.com/package/nameable",          "note": "..."        },        {          "channel": "domain:dev",          "label": ".dev",          "status": "available",          "certainty": "probable",          "url": "https://lookup.icann.org/en/lookup?name=nameable.dev",          "note": "..."        }      ]    }  ]}

Exit codes: 0 every channel is available or reclaimable for every name · 1 taken or unavailable somewhere · 2 nothing taken, but some channels could not be checked, or the cache could not be cleared · 64 usage error.

Semantic versioning covers the commands and options, the exit codes, the channel IDs, the check_names tool and its inputs, the JSON fields with the values of status and certainty, the environment variables above, and the oldest Node.js version supported. A minor release may add a status; read one you do not know as unknown. The wording of label and note, what meta holds, and which channels are picked from a project can change in any release; pass --only to fix the channels.

Planned channels

Nameable checks npm, PyPI, crates.io, Homebrew, RubyGems, Packagist, pub.dev, NuGet, Docker Hub, GitHub users, organizations and repositories, the MCP Registry, Smithery, Claude Code's official plugin marketplace, Cursor's marketplace, the Gemini CLI gallery, VS Code Marketplace, Open VSX, JetBrains Marketplace, the App Store, Google Play, Taiwan trademarks, and domains today. Each channel below was tested before it was listed: a request about a name gets an answer that tells an existing name apart from a missing one.

Not every channel has an official API. Where Nameable reads a public page or an undocumented endpoint, the site can change it or block requests at any time: a free answer there is probable at most, and a blocked request is unknown. The same goes for registries that keep part of their rules private, such as reserved names and typo checks.

When a channel Nameable does not check matters for your project, the Claude Code skill lists it as not checked, so you can look yourself.

What it sends

Nameable has no server of its own and no telemetry; nothing goes to its author.

• A check sends the name, and for domains the name with each TLD, to the registry, store, directory or RDAP/whois server of each channel checked, the ones in the table under What the answers mean.
• Name lists come from those registries, and the MCP Registry's and the Taiwan trademarks' from the lists this project rebuilds on GitHub (raw.githubusercontent.com/minanyang/nameable/data/). They are cached on your machine.
• GitHub requests carry GITHUB_TOKEN, GH_TOKEN or the gh auth token when one is available, and go only to api.github.com.
• The Claude Code plugin's skill also asks Claude to look for prior art with the tools it already has, such as web search.

License

Nameable is released under the MIT License.

The Nameable name and logo are not covered by the MIT License. The logo artwork (docs/brand/ and plugins/nameable/.claude-plugin/icon.png) is © 2026 Min-An Yang (minanyang), all rights reserved. Forks and derivative works must use a different name and logo; saying a fork is "based on Nameable" is fine.