termi-link

termi-link

Clickable links for terminals that support them, and readable plain text for the ones that do not. It is an alternative to terminal-link with an almost matching API and semantics, differing in a few places, so you can move an existing import over with a small edit rather than a rewrite.

The exact contracts, the version history and a glossary of the terminal jargon live in README.details.md.

Installation

npm install termi-link

Usage

import { terminalLink } from 'termi-link';

terminalLink('example.com', 'https://example.com');
terminalLink('example.com', 'https://example.com', { fallback: (_text, url) => `${url}` });

Here is what each call renders, where url is https://example.com. The supported-terminal column is imitated with a markdown link, because that is exactly what a supporting terminal shows you: a clickable label with the url hidden inside the escape sequence.

Call	Supported terminals	Unsupported terminals
terminalLink('example.com', url)	example.com	example.com https://example.com
terminalLink('', url)	https://example.com	https://example.com
terminalLink('example.com', url, { fallback: false })	example.com	example.com
terminalLink('example.com', url, { fallback: (t, u) => t + ' <' + u + '>' })	example.com	example.com <https://example.com>

The supported-terminal column never changes. fallback only decides what a terminal without link support prints. Leave text empty and the url becomes the label on both paths.

Text formatting

You can pass text formatting, such as color, to either argument. red and blue below stand for whichever color helper you use; this library ships none.

terminalLink(red('termi-link'), blue('https://github.com/king8fisher/termi-link'));
// fallback: red text, blue url, and the link target itself stays byte-clean

A supported terminal renders the text, not the url, so the url color shows up only in the fallback. To give both parts the same color, wrap the whole return value:

red(terminalLink(text, url));

Url encoding

Encoding your urls is up to you. Once a url is a single string, only you know whether an & separates two query parameters or is part of the data inside one, so build your urls with new URL() and URLSearchParams instead of gluing strings together, then hand the finished result to terminalLink.

The library takes care of the rest. It removes anything from your url that could break or hijack the link, and encodes the characters the escape sequence cannot carry, both in the link itself and in the text it prints. Color is the deliberate exception: the formatting you wrapped the url in survives into whatever gets printed, which is what makes the colored example above show blue. Your text is a different matter, printed exactly as you give it, so clean it yourself if it can carry anything you did not put there.

Ten characters fall between those two cases: space, ", <, >, \, ^, `, {, | and }. A url is not supposed to contain any of them, but the escape sequence accepts them, so the library passes them through as you wrote them. strictUrlEncoding encodes them for you, and it stays off unless you ask for it. Turn it on when a url can reach you already unescaped, say from the filesystem or a config file. A space is the one that does visible damage, cutting your link short in the plain-text fallback:

terminalLink('report', 'file:///Users/me/My Documents/report.pdf');
// fallback linkifies only  file:///Users/me/My

terminalLink('report', 'file:///Users/me/My Documents/report.pdf', { strictUrlEncoding: true });
// fallback linkifies       file:///Users/me/My%20Documents/report.pdf

One thing to know before you turn it on: inside the path of an https or file style url, a backslash works as a path separator, so encoding it changes where the link points. In a query or a fragment it is just a character. Read url safety if that could affect your urls.

API

Three exports:

terminalLink(text: string, url: string, options?: {
  fallback?: false | ((text: string, url: string) => string),
  strictUrlEncoding?: boolean,
} | undefined): string

terminalLink returns a clickable link when the terminal supports one, and the configured fallback when it does not.

• fallback: false keeps text unchanged and drops the url
• fallback: fn replaces the whole fallback string with fn(text, url), where url arrives sanitized and keeps its color

The table above shows what each form outputs. By default the url is left delimited by whitespace, so the terminal's own url detector picks it up intact.

isSupported(): boolean

isSupported() reports whether the current terminal supports links.

TERMI_LINK_HYPERLINK

This environment variable lets you force links on or off at runtime. It is checked before every detection branch, so it overrides both terminalLink and isSupported:

• 1, true, always, enabled force links on
• 0, false, never, disabled force links off

Matching is exact and case-sensitive. Anything else, including TRUE and the empty string, falls through to normal detection.

Supported terminals

Detection is built in. The library reads only the environment variables a terminal sets about itself, with no runtime dependency, no network call and no round-trip to the terminal. Every terminal it recognizes, the release each is supported from and the variables each is read from are listed in README.details.md.

Differences from terminal-link

This is an alternative with a different API. The surface differs in three places:

	terminal-link v5	termi-link (this library)
entry	default export, callable	named export terminalLink
support check	terminalLink.isSupported (boolean property)	isSupported() (function)
stderr	terminalLink.stderr(...)	none

Behavior differs in three ways:

• No runtime dependencies, because terminal detection is built in.
• Urls are made safe for the escape sequence, so a crafted url cannot break or hijack the link.
• The fallback contract differs twice: terminalLink('', url) returns the url alone, and a custom fallback receives the sanitized display value rather than the raw url.

Reason

The terminal-link library, long the go-to for outputting links, added zero-width spaces around urls, which made links lead to 404 in Windows terminals. Issue #18 was opened in February 2022 and stayed open for more than three years. That, plus a supported-terminal list that needed updating more often than upstream released, led me to create this alternative.

terminal-link v5.0.0 (2025-09-08) fixed this issue and removed the zero-width spaces entirely.

License

MIT