No.
No. This was also never really the requirement (modulo host functions, which didn’t changed for quite some time). For sure you will need the SDK version to get this feature. Depending on the need, we could discuss about backporting.
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any ETA on the app being available to download? looking forward to using all parachains on my ledger! the last article i read said early q2.
That seems to be the last eta.
- The app is currently in audit.
- Talisman, Subwallet, and Nova wallet are in the progress of integrating.
- We are taking the approach of a simultaneous Ledger live integration along with the launch of the app itself. This makes things significantly easier in terms of ecosystem application support.
- The relay chain will need to be upgraded to support the new app, as will any parachain that wants to use it. This I do not have certain ETA on yet, though previously informed latest June for the relay chain.
- There are a good few components here across different teams that need to be lined up and executed simultaneously in order for this to be a success, code freezes etc, so one could estimate a full launch of the app by the 3rd-4th week of June.
We will be reaching out to Parachains soon to inform you as to the steps that need to be taken in order to prepare your parachains for use with the app.
It would make sense to have a general how-to for parachain teams to follow since this is considered a major thing.
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thanks for sharing the update. so end of june, maybe early july.
can you give clarity on the following:
“The relay chain will need to be upgraded to support the new app, as will any parachain that wants to use it. This I do not have certain ETA on yet, though previously informed latest June for the relay chain.”
does this mean each individual parachain will have to talk to polkadot devs to integrate?
or is the app plug and play? and will work for any parachain without the parachain needing to upgrade or change anything on their side?
Each parachain will need to integrate some changes to their runtime. They don’t need to talk to Polkadot devs. There exists a guide etc and the integration is quite easy.
The pull request that implements the feature in polkadot-sdk was merged today: Implement `CheckMetadataHash` extension by bkchr · Pull Request #4274 · paritytech/polkadot-sdk · GitHub
We aim to integrate this into 1.2.5 on the relay chain side (hopefully before decoded).
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I’m hijacking this thread here now 
The CheckMetadataHash signed extension and all the required integrations were merged as part of this pr. This means that chains can now get access to the generic ledger app by integrating the signed extension into their runtime. I have written a guide on how to integrate the signed extension etc into your runtime. It would be nice to get some feedback on the guide if there is something that can be improved to make it more easier to use this! Ty!
As promised, I also backported the pull request back to 1.1.0: Pull requests · paritytech/polkadot-sdk · GitHub
If you need to have this put onto crates.io, please comment here for which release you need this!
For the production runtimes of Polkadot/Kusama and all its system chains the plan is to integrate this change into 1.2.5 which should be released before end of june.
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Will this be available to standalone Substrate chains, or just parachains/relay chains? VERY excited–ledger is important to the userbase!
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It will be available for every FRAME based chain.
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Great! Is the generic Ledger app already available somewhere to test together with the extension integration?
@ainhoa-a is probably the best to answer this, but I assume it is not yet public anywhere.
Hi @erkkonet the app is on its last phase of testing & audit and will be available officially for installation through Ledger Live. We expect this to happen during this month of June. We are already collaborating with wallets like Nova, Subwallet, Talisman, to be ready/compatible with this new app for launch.
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The pull request for adding support to Polkadot/Kusama and all the system parachains got merged. Thus, with the next runtime upgrade the Generic ledger app should be usable 
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From r/dot: “Presumably this app will use the same Ledger derivation path when creating keys?”
Yes, the new app will use the derivation path of Polkadot.
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Thank you for confirming! Greatly appreciate you! 
Thanks. I added the extension to my runtime without issues using one of your backports, was quite straightforward.
I was able to submit transactions with the new mode byte using polkadot-js/apps (set to 0) but the polkadot-js/extension does not seem to support authoring transactions with the extension enabled in the runtime (?).
Is there any tool available to test submitting an extrinsic with a metadata hash? I looked at subxt and it also does not seem to support it other than disabled mode.
Yeah we are aware of this. There will probably be a new extension in the next week that will also bring support for this.
The ledger implementation can do this You could also build something with subxt that uses GitHub - bkchr/merkleized-metadata to generate the metadata hash for you.
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While waiting for the ledger app, I took your advice 
and built something with subxt and it works fine to submit extrinsics with the metadata hash included also, test-metadatahash.
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Nice @erkkonet. If you upstream this, I think the ecosystem would be happy!
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