RPC requests

[leopashov]

I have seen the possibility of getting snaps to communicate with each other (https://docs.metamask.io/snaps/reference/exports/#onrpcrequest), but can't work out how to actually implement this functionality.
Are there any example projects which are making use of this? Or any code snippets one could direct me to?
Initially I'm just looking to create a simple example where I could pass some data from one snap to another.
So far I have added some custom functionality (mostly generating keys) to the snaps monorepo project, and have seen bits about the keyring handler and custom handler at https://docs.metamask.io/snaps/tutorials/custom-evm-accounts/#2-expose-the-keyring-interface-as-a-json-rpc-api, but can't figure out how to go on to use these.

I would greatly appreciate any help or guidance :)

[Montoya]

There are no good examples for this because the UX doesn't really support this yet. The way it has to be done is the user has to install both Snaps, then the caller Snap has to "connect" to the responder Snap. And endowment:rpc has to have the snaps caveat set to true.

[FrederikBolding]

@aquiladev This is not entirely accurate. You can connect to another snap but you cannot do it dynamically. The permission has to be requested like so: https://github.com/MetaMask/snaps/blob/main/packages/examples/packages/json-rpc/snap.manifest.json#L23-L27

And the other snap has to be installed, then you can invoke it.

[aquiladev]

Still does not work. Target snap is installed

"initialPermissions": {
    "endowment:rpc": {
      "dapps": true,
      "snaps": true
    },
    "wallet_snap": {
      "npm:@consensys/starknet-snap": {}
    }
  },

Code:

const res = await snap.request({
        method: 'wallet_invokeSnap',
        params: {
          snapId: 'npm:@consensys/starknet-snap',
          request: { method: 'starkNet_recoverAccounts' },
        },
 });
 console.log(res);

Error:

"Snap "npm:@consensys/starknet-snap" is not permitted to handle requests from "local:http://localhost:8080"."

[ziad-saab]

@aquiladev The StarkNet Snap doesn't allow RPC calls from other Snaps unfortunately:

https://github.com/Consensys/starknet-snap/blob/main/packages/starknet-snap/snap.manifest.json#L30

[aquiladev]

Indeed, static configuration works well. The only problem that target snaps must allow it via 'snaps: true'. Thanks for help!

[leopashov]

Thanks very much all, making more sense now :)