RGB v0.11 beta 6

LNP/BP Standards Association is happy to announce the sixth beta release of RGB version 0.11.

The release marks a reference point for public audit of RGB v0.11. The APIs are now stable, and
feature-freeze has been reached: no further consensus-level or standard library breaking changes are
planned (unless they would become required as a result of newly discovered bugs/issues by the
community or auditors).

Our main focus with Beta 6 was:

• ensure with end-to-end tests that any execution routes and user stories doesn't contain bugs and
  preform correctly;
• refactor consensus and security-critical code in order to decrease its size and reduce potential
  attack surface as much as possible;
• make sure that RGB will be able to evolve in the future without introducing backward-incompatible
  changes.

All developers working with RGB are urged to update to the new version and use it to ensure
cross-application interoperability between assets, invoices, consignments and other RGB exchange
data.

Unless required, no further beta releases are planned and RGB v0.11 enters public testing and
pre-production preview cycle.

What's new in Beta 6

Beta 6 contain one of the largest changelog: we have fixed, closed and merged more than 120 issues
and pull requests. More than 20 engineers, both from LNP/BP Standards Association member companies
and independent third-parties has contributed since last Beta 5 release by reviewing, discussing and
proposing PRs to the RGB codebase across ~50 repositories related to the project.

The complete list of all closed issues and pull requests can be found on the [public RGB roadmap
page][proj]; below we review the most important of them:

Consensus-level changes

Beta 6 implements four proposals for consensus-level changes coming from the
[RGB change proposals][RCP]:

• [RCP-240227A]: Make timestamp part of genesis
• [RCP-240227B]: Make issuer identity part of genesis
• [RCP-240313B]: Move script and type libraries outside of schema, interfaces and operations
• [RCP-240326A]: Multiple metadata fields in contract operations

Other than that, we have:

• Moved information about asset tags, used in homomorphic encryption of the contract state, from
  standard library to contract genesis and adding them to the contract commitments; also
  significantly simplifying making contract operations which involve these tags;
• Improved multichain support, such that RGB contracts can run on top of multiple layer 1 soultions.
  This gives contract users ability to do cheaper and faster transactions using Liquid network,
  and benefit from the new client-side validated layer 1 called Prime, scheduled for the release
  later;
• New virtual machine op-codes for introspecting smart contract state and simplified branching
  op-codes making scripts more streamlined;
• More RGB macro assembly instructions allowing to write complex verification code;
• Improved checking and handling of strings with restricted character set, like the ones used for
  RGB20 asset tickers and names;
• Refactored mechanism for combining different types of single-use seals (like tapret- and
  opret-based) in inputs of a state transitions;
• Removed legacy schema inheritance feature in favor of new advanced interface inheritance, which
  is implemented outside of consensus code (see below).

Additionally, we have put a consensus changes required to make the following proposals
fast-forwards, which means that they can be implemented in a future releases (like v0.12 etc)
without consensus-breaking changes:

• [RCP-240313A]: SPV proofs for anchor transactions
• [RCP-240327A]: Computed state
• [RCP-240406A]: Fallback single-use-seal

We have also adjusted the complexity counter for reserved RGB op-code values, which ensures that
adding more op-codes to the virtual machine can be done in a backward-compatible manner.

Overall, with all those changes the size of consensus code in RGB Core library has decreased from
7170 to 6726 lines of Rust code (LORC), excluding comments and blank lines, which is
>6% reduction.

Interfaces and inheritance

Interface inheritance is the brand-new way of designing RGB smart contract interfaces which brings
much better modularity, audibility and upgradeability for the contracts.

Interfaces are defined at the level above consensus and specify how software or a user can interact
with a given contract. Interface defines a semantic for a business logic of a contract, and
contract developers write an implementations linking that business logic to the semantics. In
other words, interface explains to the user the meaning of a smart contract. One example is RGB20:
an interface (which becomes a family of interfaces in beta 6) which all contracts with a fungible
tokens can implement to be supported by any RGB wallet. The fact that interfaces are not a part of
the consensus level allows contract developers to gradually provide more and more advanced APIs
without a need to re-issue an assets or create new contract versions. On the other hand, users may
interact with smart contracts using newly released interfaces without the need of a wallet software
to be upgraded.

Previously RGB v0.11 beta 6 there were no interface inheritance, meaning that a contract can
implement a given interface only once; and must provide all of its functionality at once. Now, with
interface inheritance, this can become a gradual process. For instance, today RGB20 standard defines
what fungible assets can do. In a future a new features can be added to the standard (like reserves
or vesting), implemented as a new interfaces inheriting existing RGB20 interfaces and implemented
by existing assets which had that functionality in their business logic – and wallets will be able
to handle them in a correct way without any software upgrades.

As a part of the work on interfaces and inheritance, we have refactored the way errors can be
reported from smart contract validation scripts. Now, you can provide detailed error messages as
strings inside interface definitions and link them to raised errors via integer codes in
implementations.

At the same time interface inheritance brings much better modularity and audibility: you can compare
RGB20 standard
before the inheritance was introduced
and [now][RGB20].

We have re-implemented all previosly-defined interface standards (RGB-20, 21 and 25) as standard
sets ("families") of related interfaces and re-designed the APIs for working with them.

Finally, with beta 6 we added a number of interface and implementation integrity and validity
checks, which should simplify the work of developers and debugging.

The details of how the inheritance works can be found in
[RCP-240325A: Interface inheritance][RCP-240325A] proposal.

Invoicing

We also have made few changes to the invoicing. In RGB, invoices are form of URIs (like URLs), and
thus can be opened with one-click in your favorite wallet.

With beta 6 we changed the format for displaying asset amount inside the invoice. RGB20 standard,
like many other asset standards in other systems (ERC20 etc) allow to specify a precision for asset
amounts. Invoices contain information about the amount with no precision, creating a lot of
confusion for users, as well as a attack surface. Starting from the current release we hide the
amounts behind custom latin letter encoding (modified Base32 encoding with no numbers used),
removing the problem. To read an invoice a user must use wallet or other software, which will parse
it for the user using correct precision from the contract information. To simplify working with such
amounts we provide a new CoinAmount type which embeds information about precision and is handy for
presenting asset values in the UI.

Finally, invoices has changed they way a pay-to-address requests are handled. Previously, an
explicit bitcoin address was used; now we standardized that with usual blind seal definitions using
the same encoding, chunking and supporting incorporation of custom seal close method information.

Last, but not least, we have optimized identities we use across RGB (like contracts, interfaces etc)
– it was switched from Baid58 to Baid64 encoding, which resulted in shorter fixed-length identifiers,
robust chunking, and solved few issues with its URI standard compatibility and chunking.

Data containers

With client-side validation, all the contract state, new state transitions and history are sent
between peers, in a P2P way. This is quite different from the blockchain-bases systems and require
specific methods of storing and sharing the data: data containers.

There are several types of data containers in RGB. In v0.11 beta 6 we have put a lot of
optimizations into the way containers work, making them more compact and secure.

Previously, information for smart contract developers – interfaces, schemata and interface
implementations were always present as a separate files. With beta 6 we introduce kits: new data
container type which may store multiple interfaces, schemata, implementations and other data in one
single package. We have also made sure that repeated information – like data type or script
libraries which can be re-used by different interfaces and contracts – is shipped only once,
reducing the size of data containers for about a dozen of percents.

Another type of data containers are consignments, used to distribute smart contracts, assets and do
transfers. Consignments has also become smaller, since they also include all related interfaces and
implementations and thus do benefit from aggregation of data type and script libraries.

Previosly containers were packed with mechanism called bindles. With beta 6, we deprecate...

RGB v0.11 beta 5

LNP/BP Standards Association is happy to announce the fifth beta release of RGB protocol version 0.11.

This is another milestone on the stabilization of the new v0.11 RGB version. It is the first
complete beta release of both consensus-level libraries, standard libraries and tools happening
in 2024, opening a way for independent developers integrating with RGB to test all the new
functionality.

What's new in Beta 5

In preparing Beta 5 release we were focusing on performing internal audit of all consensus-critical
code, ensuring both its security and ability to do a protocol upgrades in the future versions
without introducing any incompatibilities with the assets and software using v0.11.

The internal audit was performed by two teams: the dev team and documentation team. The developer
team was reviewing the source code and modelling different types of attacks; while the doc team
was independently creating formal specification explaining how the protocol actually works (basing
on the source code), which was later compared to the expected protocol behaviour.

Let's walk through the major areas of the improvements shipping in v0.11 beta 5.

Commitments

Cryptographic commitments, which go into Bitcoin blockchain in hidden form, are the core of RGB
security and anti-double-spending protection. They are a part of so-called “single-use seals”,
which you may have heard of before.

During the last three months (since Beta 3) we have passed through an extensive internal audit
of the commitment procedures and wrote a lot of tests. We have improved the security and safety
of many aspects of them and made sure they will be a proper foundation for the RGB.

One of the main changes which the end-users will notice is that now contracts (and assets) will
commit to the issuer identity, simplifying the verification by the wallets and preventing scam
attacks.

Contractum language and scripting

With v0.11 one of our main focuses was simplification of RGB developer experiences.

First, we have introduced more opcodes allowing scripts in RGB contracts to access the contract
state and use that information in validation. We have also developed RGB assembly, which can be
compiled using macro rgbasm directive right from the Rust!

Finally, we are moving fast in finalizing the initial Contractum version: the language intended
for RGB smart contract developers. In this release we add a Contractum representation for all
standard interfaces used by RGB (RGB20 fungible assets, RGB21 NFTs and RGB25 fungible collections).

Wallet functionality

With v0.11 RGB is integrated with wallet functionality out of the box. This solves one of the
major dev and user headaches.

With Beta 5, we are going even further: now the command-line tool and RGB runtime can filter and
present the information specific to a wallet of user choice and ignore the rest of the contract
state.

Another new feature is the support for legacy Electrum RPC API, in addition to Esplora REST APIs,
supported before.

Containers

In this beta we have refactored the concept of containers. Containers are they way user exchange
RGB data, for instance when they do distribute assets, perform transfers, -- or when developers
distribute new code and interfaces for asset issuers.

In Beta 5 we have improved ASCII armoring of container data, so all of them now use more compact
Base85 encoding and standard set of headers. We have simplified programming API for working with
containers, and made sure their IDs are uniquely reflect their content - such that even the same
contract disclosing different parts of information will have a distinct id.

We also simplified a life of devs and testers by providing an ability to convert any container
into a human-readable YAML representation, edit it and convert back into a binary form, which
can go into RGB system. This will simplify audit and debugging, allowing us to model different
kinds of attacks on the system.

Details on changes in this repository:

• Release v0.10.1 by @dr-orlovsky in #28
• Fix force accept of invalid consignments by @dr-orlovsky in #29
• Initial work on v0.11 by @dr-orlovsky in #25
• Support for YAML export for consignments and stash dumps by @dr-orlovsky in #31
• fixed crates.io link by @ftdgoodluck in #34
• Support for asset tags by @dr-orlovsky in #36
• Use automatic asset tags by @dr-orlovsky in #38
• Command-line improvements by @dr-orlovsky in #37
• Select correct assignment name by @crisdut in #68
• Ongoing bugfixing work for v0.11 release by @dr-orlovsky in #80
• Update secret seals to be cross-chain by @dr-orlovsky in #81
• Support WPKH descriptors by @dr-orlovsky in #88
• Fungible operation history by @dr-orlovsky in #92
• invoice error for blind with no outpoint by @nicbus in #123
• Fix opret support in construct_psbt() by @dr-orlovsky in #130
• Add electrum support by @dr-orlovsky in #131
• Complete YAML inspection for consignments and stash by @dr-orlovsky in #140
• Support reconstruction of consignments using new ASCII armoring by @dr-orlovsky in #143
• replace electrum-client with bp-electrum by @zoedberg in #150
• complete electrum support by @nicbus in #142
• replace panic with error for unsupported layer1 by @zoedberg in #152
• docs: RGB Wallet (CLI) Manual by @bitlightlabs-dev in #153
• Pay: fix duplicated PSBT inputs by @dr-orlovsky in #136
• Update to match the refactored interfaces by @dr-orlovsky in #154

About RGB v0.11

RGB v0.11 is an evolution of the protocol coming with a lot of bug fixes and improvements, further
enhancing RGB smart contracting capabilities. It will be the first version which will be audited by
independent auditors, after which it can be considered by third-party issuers for the use in
production.

The main features shipping in v0.11 will be:

• Wallet integration right into RGB runtime and command-line tool;
• Basic support for Liquid sidechain, with ability to add more alternative scalability layers in the
  future;
• Scripting, with new state introspection codes and RGB assembly compiler;
• Initial support for Contractum language;
• Ability to inherit interfaces (multiple inheritance!);
• Support of Electrum RPC additionally to Esplora REST, present before;
• Commitments to issuer and developer identities embedded into contracts, interfaces, libraries;
• More compact consignments and better ASCII armoring.

What's next

With Beta 5 release RGB development enters a new phase of preparation for a public preview of
the RGB v0.11. The public preview will be a feature-complete version which will be used by
external auditors for evaluating the safety of the protocol. At the same time app devs and users
will be able to complete integration of RGB without expecting major API or consensus break with
the release.

Once there will be results of an audit, the preview version will become an official release (if
the audit will find any major issues however, they will be fixed even if the fixes will contain
a breaking changes).

You can track us on our journey towards v0.11 release with this GitHub dashboard.

Acknowledgements

We are grateful to Fulgur Ventures, providing another year of support for our efforts in
developing RGB. This year they were joined by Bitlight Labs, who had become a new full member of
the Association.

We have received a number of important contributions and bugfixes coming from commercial
companies, such as Pandora Prime, Bitfinex and DIBA. We are also grateful for individual
contributors, who do their small -- but still highly valuable and welcomed input in making RGB
better.

New Contributors

• @ftdgoodluck made their first contribution in #34
• @bitlightlabs-dev made their first contribution in #153

Full Changelog: v0.10.0...v0.11.0-beta.5

RGB v0.10 (stable)

It's been 5 month since the first alpha of RGB v0.10 - and today we a thrilled to make a final release of the RGB command-line tool and runtime library for desktop and mobile integration. The library was extensively tested by several independent teams and powers three different wallets (MyCitadel on Desktop, Iris on Android, BitMask in Web); it also has stable results on end-to-end tests, including performing multiple complex transfers of multiple assets.

What's Changed since alpha:

• Get correct server parameters by @crisdut in #6
• Add default resolver for regtest by @nicbus in #7
• Fix spelling by @rct-k in #11
• Add set-host command by @nicbus in #14
• Fx for consecutive transfers (dependency update) by @dr-orlovsky in #13
• Resolver Height (get by spent script) by @crisdut in #15
• Update to the resolver new APIs by @dr-orlovsky in #21
• Remove required electrum resolver by @dr-orlovsky in #23
• Update README.md by @Dimi8146 in #5

Full Changelog: v0.10.0-alpha.1...v0.10.0

RGB v0.10 alpha 1

Initial release of RGB library and command-line tool