⚠️ Check the Kusama proposal instead

Background

My name is Daniel, senior Ambassador and head of the VaLibreNetwork development, this will be my first attempt to address the Polkadot council for a spending proposal so feedback will be very much welcomed.
The VLN has been initially created to serve as the future financial infrastructure of Valiu, a company serving thousands of users in Latin America giving them access to stable and secure money. VLN is now an independent more general purpose project that aims to become the decentralized infrastructure for on&off ramps in the Polka-verse becoming its parachain "bridge to the real world".

While developing the VLN the past year we've identified and kept several pieces of our system generic so that they can work with any Substrate based chain that can benefit from our focus on usability(we don't have crypto-savy users), keeping components lightweight(our users tend to have low end phones and poor connectivity) and our need to stay censorship resistant like being light-node friendly and having off-chain tools and components being also decentralizable(to operate in authoritarian governments known to be censor heavy).
This proposal is about the first stable version of one of those core building blocks.

Sube v1.0 spending proposal

License: Apache-2.0
Requested amount: 600 DOT
Timeline for this milestone: 4 weeks
Sister proposal

Sube is a library for submitting extrinsics to a Substrate based chain, unlike subxt, Sube focuses on being extremely lightweight and doing just one thing well, submitting extrinsics(well two things if querying storage feature is enabled). It leaves behind other functionalities that can be served by other more specialized tools(like key management and signing of extrinsics) or dependencies on runtime specific types making use of the upcoming version of frame-metadata to automatically encode/decode binary(SCALE) data to a human readable format(e.g. JSON). It is also developed with WebAssembly compatibility as a priority to not leave behind browsers and other light clients that are crucial to VLN's success.

Budget detail and timelines

The requested 600 DOT(along with the sister proposal's KSM) at an approximate current rate of 1DOT = 17€, will go to two engineer's time full-time at an approximate rate of 60€/hour plus minor infrastructure costs of the CI pipeline.

Check the Github milestone for more details and updates

• Websockets backend + storage subscription interface ~ 1 week
• Runtime agnostic auto encoding/decoding of SCALE<->JSON types ~ 2 weeks
  • (Depends on v14 metadata added to Substrate types to which we would be happy to contribute if needed).
• Documentation, tests, bug fixing and CLI adaptation ~ 1 week

Future Sube milestones

The following are future improvements to the project not covered by the current proposal.

• v1.1: Sube as a plugin of Valor for "decentralizable" HTTP API support.
  • This would mostly depend on Valor v1. Valor is a lightweight plugin runtime that allows plugins to be exposed as HTTP APIs that can run in a server environment as well as in the browser thanks to "faking" the HTTP API using Service Workers. In the context of Sube this means that a simple client side application(e.g. a simple HTML form) can first be handled by a server running Sube as plugin and progressively enhance and decentralize the experience installing the runtime and plugin in the client side without the client application requiring any change.
  • Higher level APIs can be developed as other Valor plugins that depend on Sube to offer even more convenience of use to users.
• v1.2: Smoldot backend for Sube for light-node support.
  • Smoldot is designed to be lightweight and composable without enforcing specific client facing APIs. Sube would become a wrapper of the node so it can be used as a library.
  • When using Sube as a Valor plugin clients would have access to the light node via the HTTP API. Following the idea of progressive enhancement/decentralization, after clients install the runtime with say the lighter weight HTTP back-end they could opt-in to swap the HTTP based Sube instance for a Smoldot based one which is heavier but offers greater decentralization.

More of VLN and the longer term

VLN sits at an interesting intersection between the on-chain and off-chain world, which brings the challenge of keeping real world peer to peer interactions decentralized and easy to use, a regular user doesn't want to deal with any blockchain related complexity, they just want to freely interact with another party in a secure and simple way.

Our fiat-to-cryto specialized parachain runtime comes with a set pallets that enable those peer-to-peer interactions in a trustless manner like multi asset support, fiat and crypto oracles, escrow system, a rates pallet for users to agree on exchange rates, lending pools and several other conveniences. Then to make the lower level on-chain interactions simpler, Valor and its plugins will provide a decent level of abstraction that when paired with our Summa(Substrate meets Matrix) initiative can help filling the gap between convenience of use and decentralization. Summa will be a particularly interesting concept to bring to the community for future proposals as it leverages Matrix as a well established decentralized communications protocol to for example have chat enabled wallets with abstracted blockchain account identifiers where users can send secure end-to-end encrypted data like payment information or files related to an off-chain transaction before they release an escrow.
As a final step, with the VLN toolset maturing and having a compelling integrated on&off ramps experience we would bring the project to the scrutiny of the community to consider supporting it to become a Parachain via a crowdloan or as a common good Parachain as we believe it will greatly give Polkadot exposure in local communities of non crypto-native users.