Stabilizing the `archive_*` RPC-V2 methods

Tech Talk
1

Introduction

The V2 RPC methods are designed to provide a set of well specified and stable RPC methods in a few different groups, primarily:

  • archive_*: methods which are available on archive nodes and are capable of querying historic blocks and storage.

  • chainhead_*: methods which are available via light clients (ie nodes that do not store any data themselves and ask for it over the network) and are capable of querying head-of-chain blocks and storage entries.

  • transaction_* and transactionWatch_*: methods for broadcasting and submitting transactions to a chain.

Methods in each group are marked as unstable (ie archive_unstable_*) while they are still in flux, and when stabilized will take a version (ie archive_v1_*). Versioned methods will never change (nor will new methods be added to a given version, so valid implementations will always remain valid), but newer versions can be added which allow us to make changes as needed.

We’ve stabilized the chainHead_v1_*, transaction_v1_* and transactionWatch_v1_* groups of methods already, leaving only the archive group of methods as unstable. These methods have been implemented in Substrate for a while (modulo a small bug).

Proposal

I’m proposing to now stablize these archive_unstable_* methods in their current form to v1 (so methods will transition from archive_unstable_* to archive_v1_*). Doing so will:

  • Encourage more people to try out these methods without fear of them changing.

  • Allow tooling and other libraries to target them for the same reason.

  • Lead to more complete feedback which we can take into account for a future v2 set of methods.

I’d suggest a cut-off date of the end of March to stabilize, leaving a little time for anybody who would like to experiment prior to stabilization. If you have tried the archive_* methods already and are aware of any crucial omissions or issues, please report them here!

If you have any comments on the RPCs themselves, please leave them here instead of replying to this post, so that we keep the feedback in a single place :slight_smile:

Thankyou in advance!

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