Short URLs

Since all code and state is stored in the URL hash, metaframe URLs can get very long. The built-in URL shortener compresses these into compact, shareable links.

How it works

1. Click the shorten button in the editor header
2. The current hash parameters (code, inputs, options) are sent to the server
3. The server stores the hash params in S3 and returns a SHA256-based short ID
4. You get a short URL like:

https://js.mtfm.io/j/8a3b1c9f...

The short URL is automatically copied to your clipboard.

Example

A full URL like this:

https://js.mtfm.io/#?js=Y29uc3QgZGl2ID0gZG9jdW1lbnQuY3Jl...&options=eyJhdXRvcnVuIjp0cnVlfQ%3D%3D

Becomes:

https://js.mtfm.io/j/8a3b1c9f4e2d7a6b5c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b

When someone opens the short URL, the page loads with all the original code and state intact — no redirect, the browser stays on the /j/... path.

API

You can also shorten URLs programmatically.

Shorten from hash params

curl -X POST https://js.mtfm.io/api/shorten \
  -H "Content-Type: application/json" \
  -d '{"hashParams": "?js=Y29uc29sZS5sb2coImhlbGxvIik%3D"}'

Response:

{
  "success": true,
  "id": "8a3b1c9f...",
  "path": "/j/8a3b1c9f..."
}

Shorten from JSON

A convenience endpoint that encodes JavaScript and options into hash params for you:

curl -X POST https://js.mtfm.io/api/shorten/json \
  -H "Content-Type: application/json" \
  -d '{"js": "console.log(\"hello\")"}'

Response:

{
  "id": "8a3b1c9f...",
  "shortUrl": "https://js.mtfm.io/j/8a3b1c9f...",
  "fullUrl": "https://js.mtfm.io/#?js=Y29uc29sZS5sb2coImhlbGxvIik%3D",
  "hashParams": "?js=Y29uc29sZS5sb2coImhlbGxvIik%3D"
}

Retrieve hash params

curl https://js.mtfm.io/api/j/8a3b1c9f...

Response:

{
  "id": "8a3b1c9f...",
  "hashParams": "?js=Y29uc29sZS5sb2coImhlbGxvIik%3D"
}

TIP

Short URLs are content-addressed — the same code always produces the same short URL. They never expire.