what is the message format used to communicate directly over `.postMessage()`?

[serapath]

@todo

• implement message format and tests to check for correct messages

---

Maybe any valid message could look like:

onmessage = event => {
  const [lid, from, path, ref, type, body] = event.data
  console.log(from)
  // => e.g. `/wallet` or `/wallet/data-wallet-feature`? or any other capability
  console.log(type) // => e.g. `"error"`, `"pay"`, `"get"` ... (meaning depends on `path`)
  console.log(path)
  // => e.g.`/dapp` or `/dapp/marketplace` or any other feature of the dapp
  console.log(from, lid) // uniquely identifies a message
  console.log(lid) // => lid>0, probably just a counter maintained by code around `from`
    // it can be used by a sender to specifically "replay" to a previously received message
  console.log(ref) // => a `lid` or a previous message where `from` was `path`
  console.log(body) // => any kind of data that makes sense in the context of `type` & `path`
}

---

example scenarios

1. dapp requests payment confirmation from wallet and returns transaction response
2. or dapp listens to events and wallet sends a lot of "responses" over time every time
3. user revokes access in wallet and it sends a message about revoked access to dapp
4. ....

"communication" - depending on wallet features - could be initiated by either:

1. the dapp
2. the wallet

every "protocol type" involves a certain amount of messages passing back and forth depending on what the communication is about and can be initiated and/or terminated by any party

so whether:

1. an API (list of methods/commands/querys/...) the wallet understands
2. an API (list of methods/commands/querys/...) the dapp understands

each method/command/query/... would:

1. start with a message
2. followed by 0 or more messages going back and forth
3. until success or fail or e.g. in case of subscribing to an event, this might go on forever...