Val Names

Vals are named like a variable export let myName = .... If you don’t supply a name, one will be assigned.

You can only have a single-top level value export in a Val, and as many type exports as you’d like.

Publishing a Val

There are three states for a Val:

🌎 Public (anyone can view or run)

🔗 Unlisted (anyone with the name or link can view or run)

🔒 Private (only you can view or run)

All Vals default to private. You can publish a Val by clicking the 🔒 next to its name.

Publishing your Val as either Public or Unlisted makes it accessible via the Run API. Be careful about publishing a function val that has access to your secrets — your secrets will be used if others call that function via the Run API. Publishing a val makes it a public API.

Referencing a Val

A val can reference other vals, much like a tweet can reference other tweets. For example, this val references the the prior example:

Once you type @ you will get helpful autocomplete on handles and then val names.

Referencing Private Vals

Anyone can reference public vals. Private vals can only be accessed by their authors. For example, I created a private val, example3. You won’t be able to see or reference example3 but I can! I can publish a val that uses example3, still without making example3 public as shown below.

Versions

Vals are immutable but you can publish new versions of vals. Versions start at v0 and go up from there. When you reference a val, you always get the most recent version. You can toggle which version you’re looking at via the drop down menu next to the val’s name.

When you import one of your own vals, it will be imported unpinned, so you will automatically get all new changes. When you import another user’s val, it will pin your import to the most recent version of that val (ie it will end it ?v=7 or whatever the current version number is), so if they change it, you won’t get automatic updates. This makes your code more stable and protects you against code injection attacks. You can override this default behavior if you trust the user not to break your code: remove the v query param in the import statement, and your code will always use the latest version of that val.

Deleting a Val

You can delete a val you created via the 🗑️ button. You can either delete a specific version or all versions. You can restore any deleted val version at /settings/versions.

Linking to a Val

You can get a link to a val in the Share menu or via val.town/v/username/valName.

Embedding a Val

You can get an embed link to a val in the Share menu or via val.town/embed/username/valName. You can paste that link into a tool like Notion and it’ll just work. For other context, you may need to use an iframe.

Included environment

Vals are evaluated on a limited subset of deno. It includes:

fetch to make HTTP requests

import from npm and https

You can view the entire environment we support here.

Keyboard Shortcuts

ctrl/cmd-enter to run a val

ctrl/cmd-k to search for a val

ctrl/cmd-click to go to a val reference or URL

ctrl+space to trigger autocomplete in the code editor

Limitations

The limitations on vals can be found on our pricing page.

What’s a Val?