Fetch

epos.fetch() gives you a way to make cross-origin requests.

When normal fetch() fails because of CORS restrictions, epos.fetch() can still make the request.

Why It Exists

If your code runs on a page like https://example.com and tries to fetch another origin like https://epos.dev, the request will usually fail because of CORS restrictions. This is normal web page security.

Extensions can bypass that restriction. If your extension has permission to access https://epos.dev, it can make the request. Use epos.fetch() instead of fetch(), and Epos will route it through the extension.

Which URLs It Can Fetch

epos.fetch() can fetch URLs that your project has permission to access.

That access can come from these epos.json fields:

• matches
• hostPermissions
• optionalHostPermissions, requested at runtime

If your project does not have permission for a URL, epos.fetch() will fail.

Basic Usage

epos.fetch() uses the same API as fetch():

const res = await epos.fetch('https://api.example.com/data')
const data = await res.json()

Limitations

epos.fetch() is similar to normal fetch(), but it is not identical.

• Streaming responses are not supported.
• Some RequestInit fields are missing.
• Some Response fields and methods are missing.

All supported fields and methods are typed in TypeScript, so your editor can help you avoid unsupported features.