Custom RCS Chat Client for Android (FOSS Google Messages)

[ReallyNotPikachu]

Project description

"RCS has been designed as an industry open standard to provide improved capabilities over basic text messaging, based on the Internet Protocol (IP)." (from the wikipedia article for RCS)

Unfortunately, the only RCS client avaliable on android is google messages, which is a privacy nightmare that also eats up a lot of ram. It should be possible to create a custom client for RCS, and there are even libraries to do so such as https://crates.io/crates/rust-rcs-client but no one's done it. I don't want to keep having to use Google's proprietary and probably spyware-filled messaging app in order to keep in touch in people, and I doubt many do. I could use any old SMS/MMS app, but then I'd lose access to features like having reasonable filesize limits for uploads.

The full protocol specification is public and the standard is "open", so this really really should be a thing. It might take a lot of work, as there's only one library available for it (I don't even think that library implements everything), and it's written in rust which doesn't work well with other languages.

Relevant Technology

RCS, Rich Communication Service, a communication protocol developed as the successor to SMS/MMS using IP.

Complexity and required time

Complexity

• Beginner - This project requires no or little prior knowledge of the technolog(y|ies) specified to contribute to the project
• Intermediate - The user should have some prior knowledge of the technolog(y|ies) to the point where they know how to use it, but not necessarily all the nooks and crannies of the technology
• Advanced - The project requires the user to have a good understanding of all components of the project to contribute

Required time (ETA)

• Little work - A couple of days
• Medium work - A week or two
• Much work - The project will take more than a couple of weeks and serious planning is required

Categories

• Mobile app
• IoT
• Web app
• Frontend/UI
• AI/ML
• APIs/Backend
• Voice Assistant
• Developer Tooling
• Extension/Plugin/Add-On
• Design/UX
• AR/VR
• Bots
• Security
• Blockchain
• Futuristic Tech/Something Unique

[TheFlayka]

It's interesting project. I have question. You want to create open-source chat client? If yes i can help with it =)

[HughZurname]

Yeah I have been thinking about this a lot as well. As far as I understand it, I don't think it's as straightforward as building a client; It seems like there is some degree of server implementation that needs to happen and that likely requires hosting etc. from what I can tell google limit how much of the RCS api can be used on android, but that isn't really relevant here. I think the hard problem to solve here is the trust element. There are some players in this space https://www.gsma.com/solutions-and-impact/technologies/networks/rcs/the-rcs-ecosystem/

I am currently waiting for a LightPhone 3 and there is ongoing conversations about the lack of RCS support there, so I am guessing there is some hidden complexity in general, the information seems pretty hard to find outside of the open standards.

further ref: https://www.fierce-network.com/tech/how-apple-holding-back-rich-communication-services

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Edit: some further reading

Many carriers lack the resources to develop and maintain their own RCS systems, instead relying on Google’s Jibe platform. In recent years, Google has actively promoted RCS, seeing a major opportunity to expand its Jibe services. However, this raises concerns about carrier independence and control over messaging infrastructure.

and

Another challenge lies in RCS client implementation. Developing an RCS client is significantly more complex than SMS/MMS due to GSMA certification requirements. Any RCS client must undergo GSMA’s Network Vendor Accreditation (NVA) and Client Vendor Accreditation (CVA) processes, adding cost and complexity for developers and device manufacturers. To illustrate the difficulty, Samsung recently announced that it will discontinue RCS support in its Samsung Messages app starting June 1, 2025.

source: https://www.smseagle.eu/2021/11/15/sms-and-rcs-what-to-expect-in-the-coming-decade/

(obviously these guys have an entire business depending on sms so they may be somewhat biased in their reporting)