remotion-dev/remotion · error · Error

Config.addElementLibrary() only supports HTTP and HTTPS URLs

Error message

Config.addElementLibrary() only supports HTTP and HTTPS URLs, got ${JSON.stringify(url)}

What it means

Even if the URL parses, addElementLibrary only accepts http: and https: protocols. Other schemes such as file:, data:, or ftp: are rejected.

Source

Thrown at packages/cli/src/config/element-libraries.ts:39

	const {url, displayName} = options;
	if (typeof url !== 'string') {
		throw new Error(
			`Config.addElementLibrary() expects "url" to be a string, got ${typeof url}`,
		);
	}

	let parsedUrl: URL;
	try {
		parsedUrl = new URL(url);
	} catch {
		throw new Error(
			`Config.addElementLibrary() expects an absolute URL, got ${JSON.stringify(url)}`,
		);
	}

	if (parsedUrl.protocol !== 'http:' && parsedUrl.protocol !== 'https:') {
		throw new Error(
			`Config.addElementLibrary() only supports HTTP and HTTPS URLs, got ${JSON.stringify(url)}`,
		);
	}

	if (displayName !== undefined && typeof displayName !== 'string') {
		throw new Error(
			`Config.addElementLibrary() expects the display name to be a string, got ${typeof displayName}`,
		);
	}

	const trimmedDisplayName = displayName?.trim() ?? null;
	if (trimmedDisplayName === '') {
		throw new Error(
			'Config.addElementLibrary() expects the display name to not be empty',
		);
	}

	elementLibraries.push({

View on GitHub (pinned to 8f97758157)

Solutions

Serve the library over http(s) (e.g. via a local static server) and use that URL
For local development, use a localhost http URL rather than file://

Example fix

// before
Config.addElementLibrary({url: 'file:///libs/library.json'});

// after
// serve ./libs via: npx serve libs
Config.addElementLibrary({url: 'http://localhost:3000/library.json'});

Defensive patterns

Strategy: validation

Validate before calling

const proto = new URL(url).protocol;
if (proto !== 'http:' && proto !== 'https:') { /* serve over http instead */ }

Type guard

const isHttpUrl = (u: string) => { try { const p = new URL(u).protocol; return p === 'http:' || p === 'https:'; } catch { return false; } };

Prevention

Never use file:// or data: URLs for element libraries
Run a local static server for development assets

When it happens

Trigger: Passing 'file:///Users/me/library.json' or 'data:application/json,...' as the url option.

Common situations: Pointing at a local file during development instead of serving it over HTTP, or pasting a data URL.

Related errors

AI-assisted analysis of remotion-dev/remotion@8f97758157 (2026-08-28). Data as JSON: /api/errors/f2cdd4b9ead9a6a5. Report an issue: GitHub.