worker-w3up-client-example

Cloudflare Workers introduce some challenges on how to load wasm code compared to other environments.

In CF workers, wasm bytecode must be imported, as all other paths are disallowed by embedder.

Other environments do not behave like this, and sometimes even forbid what is the default within Cloudflare.

What is needed?

We essentially need to perform a custom esbuild instead of relying on default wrangler build. With this, we can use esbuild-plugin-w3up-client-wasm-import to transform the build to use wasm imports, instead of default behaviour. See build.js for the custom build details.

Setup environment to run this example

1. Open src/index.js and modify INSERT_YOUR_KEY to your secret_key (you can see below how to generate one)
2. Open src/index.js and modify INSERT_YOUR_PROOF to your proof (you can see below how to generate one)
3. Run npm run deploy and login with your Cloudflare Account.
4. Make KEY and PROOF Cloudflare bindings so that they are not hardcoded
5. ⚠️ unfortunately CF Workers secrets do not support large secrets like needed for PROOF

Generating a secret_key and proof

On your dev machine, use [w3cli] to generate a secret_key and proof to allow this action to upload to a space.

Install it from npm and login as described here https://web3.storage/docs/quickstart/ then create a key like this:

# Use the `did` in the input to the next command. 
# Use `key` as your `secret_key` for add_to_web3.
$ w3 key create --json
{
  "did": "did:key:z6Mk...",
  "key": "MgCaT7Se2QX9..."
}

Keep the key safe. Save it as a secret on your repo.

Copy the did for use in the next command. The output is a base64 encoded ucan proof that delegates capabilities to store/add and upload/add on your current space to the key generated above.

# Delegate capabilities to the `did` we created above.
$ w3 delegation create did:key:z6Mk... -c 'store/add' -c 'upload/add' --base64
mAYIEAP8OEaJlcm9vdHOAZ3ZlcnNpb24BwwUBcRIg+oHTbzShh1WzBo9ISkonCW+KAcy/+zW8Zb...

The capabilies store/add and upload/add are the minimum required to upload files to web3.storage.