Building Universal Apps with Push Chain

GM, GM. Welcome to what's going to be another fantastic episode of DevNTell. So if you didn't know, DevNTell is a 30-minute podcast held every week allowing founders, hackers, and anyone in between the opportunity to come on the show and showcase what they built. And today, I am ecstatic to welcome Harsh Rajat, who is the founder of Push Chain. So if you didn't know, Push Chain is a unified settlement layer for all chains, allowing developers to build and deploy once and reach users natively from any chain. So if you stick around for today's episode, you'll get to meet Harsh, learn all about Push Chain, maybe get a little bit of alpha as well, and learn how you can get started using it today. All right, let's get into it. GM, GM. Welcome to the show, Harsh. I'm excited to have you on today, man.

GM, GM, Narb. I'm really excited to be here. DevNTell is one of my favorite shows. And I'm a developer by heart, so it really feels comfortable to be here.

Oh, thank you so much, man. Yeah, and it's wonderful to have you on. And I'm ecstatic for our audience to learn all about Push Chain. But before we get into that, I guess would you just like to give an intro about yourself?

Sure. So, I'm Harsh, co-founder and project lead of Push Chain. Co-founder and project lead basically means that I assist all the teams that are doing certain things. So, I have general idea of all the things that are going on different department. And yeah, that's my day-to-day life. That's it. Apart from that, the remaining hobbies I have outside of work is probably playing PlayStation 5 whenever Doom or something else comes out. So yeah, happy to be here.

Awesome. You said your main go-to is Doom?

Yeah, Doom and God of War. I think those are the two games I really loved.

Yeah, I agree. I was a really big God of War fan. I remember in university, I got a PlayStation 3 just to play God of War. And yeah, I loved it.

Same. I asked my friend to lend me a PlayStation 3 just so that I can play God of War.

Excellent. Yeah, love it. And you mentioned it, you being a founder and being a founder in Web3. Just curious, how did you get into technology in general and that, and crypto as well?

Oh wow. So, I started, like I've been a entrepreneur from the start, like from the start of my career. Even when startup was not very hot. I'm from India, so startup was not very hot back then. Got into technology at the time iPhone came out. I always liked technology, I always liked to play around things. Kind of realized when iPhone was out that the browser experience, it really sucked. Because one tab, you cannot have any power features, no Chrome or Firefox was there. So kind of realized that missing gap, created a power browser, right time, right place. So it worked really well, went on to become the top 10 in the US App Store. And that was my entry to my career as a technologist. Then in two, three years created some games as well, then eventually got tired with just mobile. So kind of started experimenting with things. That was around 2013 or so. Kind of experimented with AI and machine learning, was going and looking through different technology. 2016 came, BTC was all the rage, so I kind of bought, thinking it's the future without reading anything, without doing any research. That's how I think most of the people come. Of course, I bought it at $1000 and it crashed to $200. So buy high sell low, ask me, I have really useful tips. But yeah, that was my entry into crypto. Then I kind of realized that arbitrage was very powerful back then. Of course, back then I didn't know it's arbitrage, but buying from one exchange, selling on one exchange, especially if it's Europe and Asia, it was really cool arbitrage. So built a bot around it. That performed very well until others caught up. So around 2018 it started giving me losses, but it also started posting a lot of ERC-20 coins. So I was like what the hell is a ERC-20 coin? And that is when I got to know about Ethereum, the programmable money. And that's when I started learning about Ethereum, joining a company, learning about DeFi, and yeah, that's how it started in crypto.

Awesome. Yeah, that's amazing man. And yeah, it seems very, a very similar story a lot of founders have, just exploring, starting out with the speculation side, just buying something and then that kind of just sparking their curiosity to go down the rabbit holes. I guess was there any particular point when you were exploring crypto where you were like, oh, there's like a gap that inspired you to start Push?

Yes, so I think all my life whenever we have invented something or we have created something, is because I got enraged. So 2019, playing around with DeFi protocol trying to take a loan, and then yeah, for some reason for a week or so I wasn't able to check Web3. And I came back and everything was liquidated. And I was like what is this future of internet wherein you don't even have a basic alert? And then I kind of realized that Web3 didn't had that because Web3 is that your smart contracts, they only know about you as a Web3 wallet address. So unless you have a communication layer that can deliver everything out, you are not able to notify anyone. Being from the mobile first background, right, I knew about notification, I knew about the architecture. So I created a first draft of the architecture, wrote it to Ethereum Foundation, that this needs to be there. At that time I was pitching it as part of the Ethereum blockchain itself. They said that cannot be a part of Ethereum blockchain, and we also cannot fund you because it's just a idea. So that was disheartening, but it's because the way they wrote the next set of lines, which was about the research that has been done and asking me to check it out and asking me to come to ETHGlobal to create it. I still thought that let me go to ETHGlobal and try it out. And at ETHGlobal I went over there, the same guy of Ethereum Foundation, he was there. He's now one of my very cool friends. And he recognized me and it felt so special. That was the time I kind of knew that I have to basically go all in and create this out. Of course ETHGlobal is the best platform to start, we delivered the first notification for Web3 from ETHGlobal, got all the support from ETHGlobal, from Ethereum Foundation after that, and also from a lot of Web3 OGs back then. And yeah, that was basically how Push was born.

Amazing. And yeah, I mean I, we've had Push on the show before I think, if I'm not mistaken, it was in 2024. And you and you mentioned that back then it was solely a notification protocol for Ethereum, but now you guys have expanded out into a full-fledged chain. I guess what kind of prompted you guys to make that pivot to expand the vision of Push?

Sure. So as I said, like I think my trigger point is rage. I got enraged when I couldn't find a proper browser experience, then loan liquidation. This was the same thing around 2024, early 2024, like we created notification and chat. We are still the leading Web3 communication platform. But what happened in 2023 was that the vision was that you have to connect every Web3 layer. So what we were doing, like we had these set of very cool features planned out, but what we started doing was that let's go to this other blockchain that's coming up. Oh, let's go to Solana as well, let's go to Polygon as well. And what we realized was that this is not a easy feat for a Web3 developer. Because your smart contract, you have to rewrite that for a different blockchain like Polygon. If Solana then you have to hire someone who knows Rust, getting engineering, bloating your engineering team, and of course the audit cost, that just compounds. And even when you have those smart contracts, now you need a sync management. So you either use some messaging protocol and have like a controller smart contract to manage the sync, or you have nodes, which is what we did to manage everything out. On top of that, we wanted this notification and chat experience to be a very simple standard for anyone. So Solana user can come and just sign in or Ethereum user can come and just sign in. All of these things, they basically meant that we had to create different standards, we had to sync up state. And you know, while talking, there was a joke that was thrown across, that why not build a universal chain? Like this is just too messed up for months of deployment on infra and not working on app feature. And yeah, that, that joke basically turned uglier and uglier the more chains we spoke to and the more chains we launched on. And then at one point we were like this needs to stop. That was the evolution of the Push Chain vision.

Awesome. Yeah, yeah. I mean there's, you've seen, we've seen a lot of interoperability plays. I don't think I've ever seen a universal chain. So that's amazing to see and I'm glad our audience here can bear witness to this as well. I guess why don't we get into it? Did you want to share your screen and take our audience through a tour?

Of course, of course. So let me share my screen, but before that let me just talk about like what is a universal blockchain as well, just so the audience know. So what we realized was that the interoperability play that people had, it was basically passing a message from one chain to the other. But that is not what a user intent is, right? A user wants to use an app of another chain. And that is why you are basically doing a chain A to chain B transfer, and then using that app or basically buying some token whatever. It's always about using the app. So what we realized was this interop protocol that started, like someone had to start, right? So the generation zero was quite nice, but still had this problem that you're not reaching the app. So either you are telling the user that you have to reach the app or you are basically telling the developer that you create a middleware smart contract, or you are giving up and basically saying let the user figure it out. This crypto trilemma or the interop trilemma needed to be solved. And that is where the blockchain or the universal blockchain comes in. In a simplest term, it's a unified settlement layer or a universal execution layer. So it's like a L0 for all the layer ones and layer twos where any user can come and do any transaction. So with that mental model in mind, let me share my screen and let me show you how everything works. So yeah, we'll we'll basically go to Ballsy, which is a very simple example just to give you this summary of how it works.

So, this is a simple counter contract that you have seen on Ethereum. This counter contract you deploy on Push Chain because Push Chain handles interop and all your abstraction under the hood. Any app that gets deployed on Push Chain, it instantly becomes compatible with Solana, with Ethereum and so on. So let me just log out from here and let me show you the entire experience. So universal leaderboard, which means users of Ethereum, Base, Solana, Arbitrum, what not, they can come, they can log in and they can interact with the same app. So I'm going to connect with the wallet. You don't need a different wallet, whatever existing wallet you have will work. So right now I connected to Solana. You don't even need to bridge tokens out like that is also taken care for you, so native Solana will be used to fund your transaction. Over here I'm just going to sign one transaction. And that's about it. Give it a couple of seconds and it should be done. And a Solana green color ball should drop right now. Yeah. That's that's it. Like you just interacted on your EVM contract through Solana. What's more is that this Solana user never left Solana, they basically used their Solana wallet to control the entire experience, so everything is massively simplified for them. You can see this as a universal transaction like your Solana is connected to a smart account which we call universal executor account. This smart account of EVM, it only takes instructions from this Solana wallet. It verifies the Solana I think ED2559 crypto algorithm and once that payload is vetted, it basically tells to go ahead and execute. Same way if I log out, I can do the same thing on Ethereum. So all of a sudden the same app that you have, now it's accessible to all of Web3. So I connected MetaMask, I'm on Ethereum. I'm going to increment my counter, MetaMask will pop up, single transaction, and yeah. Give it a second, should be done. It's run, we'll see a Ethereum ball dropping. So yeah, it's as easy as this and of course you can see this time this universal execution layer or unified settlement layer means that a Ethereum user is also able to interact. But of course this is just a simple demo. There are few other ones that you can see. So this is one that's getting very popular, which is Last One, which is basically you send testnet PC from any chain. So right now I'm connected to Ethereum I can just bid and if no one bids before the timer runs out, then the person who is the last will get all the bidding. So payable or sending funds is also easy. And of course last is this universal DEX. I can basically now get Ethereum or get Solana just by logging over here and doing a swap. Let me just do with a small thing. So I'll swap and yeah, it should basically go through in a couple of seconds and I'll have Solana. So all of a sudden your wallet now is able to control every blockchain. All of these examples they basically showed you like if you deploy once you become instantly compatible and you can reach any user. But there are some very cool advanced features as well, which we'll go through when I walk you through the SDK. Which is basically that you can also do any chain to any chain interaction, not just to Push Chain. So yeah.

Amazing. And just a question before we get into the SDK stuff. So can a, can a smart contract, so say somebody has a dApp and they have a smart contract deployed on Ethereum and then they have a program deployed on Solana, can that smart contract talk to that program on Solana through Push?

Yes. Yes. So I'll show you the like this was the last part of the roadmap that we had to complete. It's completed the SDK is getting built on that, but I'll show you the local host version so you can see. The way it works is actually quite cool. What happens is that let's say you're a Ethereum user, right? When you come to Push Chain for the first time, Push Chain basically detects that and it deploys a smart account for you which is called your universal executor account. This universal executor account has this custom precompile or module that takes the signature from the wallet origin wallet which is Ethereum wallet. And only when that origin wallet signature they are verified, the smart account will say that okay go ahead and execute it. So on the chain side what happens? Chain only sees EVM, on the or a chain only sees Push Chain EVM. On the Ethereum side the user is still able to send the payload or instructions whatever they want. And everything simply works and then there's a connection or a on-chain smart contract wherein you can put your executor account this UEA account and it will spit out like what was the origin chain, so you are of course able to connect it as well. So that basically solves the transaction part. The other part is the gas funding part, so for that we have gateway contracts deployed on all the chains. So what you do is you pass your transaction, you sign your transaction and you pass the gas fee that's required on the universal gateway contract. It gets logged over there. The Push Chain universal validators they detect it, they basically then ask the validators to mint a equivalent version of ETH out. This P-ETH is then minted and then automatically swapped to PC and attributed to your smart account. So that is how the gas is funded before you send the transaction. So this is how from the origin account to Push Chain account works. Now what happens is this UEA that you have let's say you want to go out to a different blockchain. A similar contract is deployed on that different blockchain which is called CEA. So CEAs are then controlled by the UEAs, UEA is controlled by your origin chain whether it's Push, whether it's Ethereum, whether it's Solana. So because of that from your origin chain you're now able to control any app of any chain. So because of that even if you're on Ethereum, you can create a UEA, through UEA you can create a CEA, and now you have a route by which you can get Solana users or do anything on Solana or create universal yield, whatever you want to do.

Wow, that's quite a powerful construct allowing that that cross-chain interaction. And yeah, I guess this is a nice segue of how can people start building building with Push Chain, what SDKs, APIs are available for them to use?

Awesome. So time for me to share the screen again. So yeah, the best way is go to push.org/docs/chain to get started. I'll show you the local host version because we are going to launch this probably on Saturday or on Monday. So you'll get the basic idea. So there are two SDKs that you will need. The first one is the UI Kit SDK. The UI Kit SDK ensures that your app becomes universal. And that is how we basically have this embeddable wallet. And the second SDK is the core SDK. The core SDK is basically the backend of what you do. As I said, like the system is designed to be 100% EVM compatible. So there's no on-chain smart contract change that you have to do. What you do over here like let me just show you this counter app. Like is the same counter app that you just saw. So you just deploy this on Push Chain and right after that, that's it. Like your app is automatically now universally compatible with all the layer ones and layer twos. But right after that when you're creating front-end, you will wrap or you'll use this UI kit to basically wrap your wallet and the account button. Once you have done that, you're almost ready. The last thing that you have to do is you can use Ethers, you can use VM, whatever you are doing for your blockchain state, that simply works. But when you're sending the transaction, the last thing that you will have to do is you will have to call the universal.sendTransaction. And that enables user of Solana or user of Ethereum or any other layer one or layer two users to kind of send the entire transaction out. The way by which you construct this core SDK like if you're using UI Kit, then you don't even have to create or initialize the Push client. It is already taken care for you, so you just use a hook on the UI Kit which is Push client and you just connect through it. But the way it works is that instead of a signer, what you have is or what we have is a universal signer. So a signer is basically blockchain siloed, a universal signer simply means that it knows what chain you're coming from. So the best way to create it is in case you want to create from core like UI Kit will anyway abstract it for you, but on the backend if in case you want to create it, you just do ethers.JSONProvider and you pass whatever JSON provider you want. And that way we'll known like what is what blockchain you belong to and based on that then you convert your signer to a universal signer. Once you convert your signer to universal signer you just initialize Push client. What we have also done is because as a developer I didn't want to go ahead and install a package just to check everything out, so what we did was we created these live playgrounds right on the doc. So these live playgrounds you can just edit and play with it like however you want. And you can get everything right over here. Whether it's the core thing that you're doing or whether it's the UI Kit, you can just use this playground and you can just go ahead and do whatever you want over here. And everything basically gets instantly picked up. So so yeah, this is basically how you start. Simple steps in case you want, look look into your app, deploy your smart contract. After deploying your smart contract go to your front-end install UI Kit. From UI Kit now you have Push client access. Then find wherever you have used sendTransaction or signMessage and over there just replace it with the universal transaction or send universal transaction and that's about it. In the send universal transaction, everything is very Ethers or VMish, so it's very intuitive but you can come over here to this page and you can find out. In case you're sending a transaction directly on Push, you have to, you pass in the Push address. In case you want to send it to external chain, you just pass to.address and to.chain. In case you CEA which is basically controlled by UEA, you want to interact with that and maybe pull your funds out, you pass to address of Push and just have from.chain as the chain of the CEA. And that's it, that will basically complete your universal transaction. If you're a advanced user or you have basically a universal vault you want to pull funds from a yield of Aave on Polygon and you want let's say give it to Jupiter of Solana in one single transaction. What you do is you can create a bunch of these universal transaction by prepareTransaction. And once you have prepared all these bunch of transaction, all you do is you pass it as a array. It will create a single cohesive transaction and get it executed. In case you're a contract on Push, we have also covered you. So you can go ahead and check it out. The docs also have AI, so of course anyone who's not living in 2023, just use that and create it out. And we have several examples like every every page or every API has an example along with a playground for you to simply try. So you can just get started and you can build your app in 30 minutes, like or make your app universal in 30 minutes.

Wow, that's certainly a really solid comprehensive set of docs and SDKs you guys have built out. And I guess are you guys only live on testnet or is this also mainnet?

So right now it's testnet, but our chain audit just started today. So it's going to be mainnet very soon.

Awesome. And I guess in terms of well you guys have clearly built out quite a bit already. I guess from your vision, what what is the north star vision for Push Chain? What's the what's the roadmap and alpha or any alpha you may be able to share?

Sure, so couple of alphas like let me tell about the north star. So north star is getting killer apps. That is exactly why we are building things in the way we are building. So killer app translates to getting quality developers, which translates to making this a dev first chain. Ensuring that we spend more time on SDK rather than anywhere else. That's what we do, that's what I also do, like for the past five days I've just focused on getting the right documentation trying it out myself. But yeah, the way we see it like crypto, it's about decentralization, but more than that it's about making the best killer app. And the best killer app comes with developers and that's what we focus on. On the alpha side we just started season three of ours which will have some amazing drops. What you have to do is you can just go to portal.push.org and you can basically start trying it out. It's a invite only thing for now, so for DevNTell what I'll say is just go ahead and DM me your username or your wallet address. Not your wallet address, just DM me and say DevNTell or hi DevNTell, and for the top 10 users I'll give an invite code out. So yeah, that's how you can start. Season 3 is all about ensuring that real Web3 users, they are able to participate and they will have some very cool rewards once mainnet launches.

Right on, right on. And yeah, thank you for sharing that alpha with our audience today. And as we're coming to time here, just wanted to pick your brain a little bit. As a entrepreneur and founder, just curious if you can provide our audience who might be aspiring founders themselves, any type of advice to help them get started. Maybe it's something, some advice you'd want to give yourself maybe like four or five years back.

For sure. Like I have actually three advices that I like to share. So the first thing is be shameless in asking questions. Like Web3 is usually made of helpful people. Like they are trolls, like who doesn't have trolls? But if someone is not building, like that that is like you can simply ignore their feedback. But yeah, what you have to do is when you ask questions and ask help, most of the time people want to help you out. That's how I got in DevNTell as well, so right? So that's the thing like be shameless in asking questions. The second advice is that you have to build in public. So early founders, even me when I came over here, I thought that if I share my idea or if I share my code someone will just go ahead and copy it. The thing that you have to remember is that ideas they might be worth a million, but execution is worth a billion. Like someone can copy your 40 character tweet or 140 character tweet. They cannot copy the thought process of thousands of hours that you have spent towards your idea. But once you share it out, people genuinely will figure or discover you out, they will amplify. Even right now, like 2021 was really cool but even right now everyone is that look at this, this is really cool or what these guys have built out. So always build out in public. And the third is start from a hackathon. The reason for that is that when you're starting, right? You will not know the latest tools that are coming out. But when you go to hackathon you're meeting your peers, you're meeting Web3 leaders, there will be conversations about have you heard about let's say at my time Tenderly or have you heard about Hardhat, you can do console.log in smart contract. That was a huge deal back then. So if I didn't know about it of course my development pace and the product would have suffered. So follow these three advices, I follow this a lot myself now.

That's solid. And yeah, I would wholeheartedly agree. Definitely some pretty killer advice. And with that, Harsh, thank you so much for taking the time out of your busy day to come chat with us today. Just from your end, what's the best way for people to keep in touch with you, DM you on socials and keep up with all the latest developments with Push Chain?

Sure. So I think we'll already paste all the links down in the comments so you can go ahead and look at it. But the best way to start is push.org, just go over there. Or just go to Push Chain on Twitter. If you're going to DM me which I think you will have to for the invite code, so for that it's Harsh Rajat, H-A-R-S-H-R-A-J-A-T. And that's the best way to keep in touch.

Amazing. And yeah, as Harsh mentioned, all that information will be in the description of this podcast below. So definitely check it out if you are interested. And yeah, with that, just want to wish everybody a happy Friday, happy weekend wherever you may be. And we'll catch you back here for another great episode of DevNTell next week. Until then, have a good one folks. Cheers.

Happy weekend guys.