Replit Agent 4 Is Here: Everything You Need to Know

Hey everyone. All right, I'm back today with another no hype review. This time of Replet's agent 4 which just launched today. Now agent 4 lets you plan, design, and build an app with multiple AI agents all at the same time. And here's three new features that agent 4 has. You can design multiple variations on an infinite canvas. You can build using multiple AI agents in parallel. And finally, you can go beyond generating apps to generating slide decks, animations, and more. But let's put agent 4 to the test. Can I actually

generate something good? So, here's the thing. I've always wanted an app where I can easily track my habits. So, basically, I can open the app to see a calendar view to create and check off up to three habits. And I can also see streaks to help me stay motivated. All right, so let's go ahead and use replet agent 4 to build this app right now and let's use this prompt that I have here and paste it into replet. Okay, so here I am in replet and I paste the prompting. Let's take a look at this prompt. It's pretty simple. We want a mobile habit tracker. We want two tabs, a calendar and a habits view and we want to start with four design variants for the calendar tab using canvas which is new to agent 4. All right. So, we want to have a glass morphic variant, RPG quest gaming variant. We want to have a botanical variant where you're kind of growing plants and forming habits. And we want agent 4 to surprise us to see what it comes up with. So, let's go ahead and submit this prompt now and see what happens next. All right. And now we have the canvas view. And what it's doing is basically it spun up four separate design agents and each of them is designing the different variant that we want. So now let's skip ahead and see what kind of designs it comes up with. Okay, so that took about two minutes to generate and now we have our four design variants. Let's take a look. So Glass Morphic looks pretty good Apple style. RPG Quest looks really fun. I love how it has a skull when I don't complete my habits. And let's see there the botanical variant with flowers. And it surprised me with this variant that's pretty bold and in your face. So which variant should we go with? I'm a gamer at heart. So, I think I'm going to go with the RPG variant. And the problem is it only generated the calendar view. So, what I wanted to do now is to generate the other view, which is the quest view. Right? So, how are we going to generate a quest view? It's as simple as hitting the plus button here and saying now generate the quest view and then submitting. And now the agent is going to get to work to generate another frame that has the view to create and edit habits or quests. All right. So now we have the RPG quest calendar tab and the habits tab side by side. And let's do one more change. Instead of saying quest log, let's change this to Peter's quest. So how would I change this? Well, basically I have to click on this thing. And now you notice H1 here. I have to say change to Peter's quest and submit it and hopefully it will make the change. And I kind of wish that replet build a feature to let me change the copy directly instead of having to submit it through the chat, but I'm sure that's coming soon. All right, so here's my quick review of this canvas view. I think it's perfectly functional and it works great. I think if Replet wants to improve this, they could make this more delightful. Adding AI agent cursors on the screen to generate each component at a time so you can actually see it work and also making it easier for you to make manual edits yourself. But overall

this is a big improvement over what they had before. Now, let's move on to the next feature, which is getting multiple agents to actually build. So, you can see here on the left, let me just zoom in a little bit. There's actually a plus button here, right? So let's go ahead and hit the plus button and right here. And now we can plan a new task. And each task can be assigned to a different agent. So let's click this thing and just say build the calendar view and submit. And let's make a new agent or task and select this habits tab and just say build the habits tab and submit. All right. So now you can see here that we have two agents working for us, right? One building the counter tab and one building the habits tab. And before you skip ahead to see what kind of output they have, let's take a look at this pretty unique view here. So I can hit open in taskboard and it will open up a Trello style taskboard with draft active, ready and done. Let's click into the draft to see what it's up to. All right. So the draft is basically it's making a plan on what to build. And you can see here that it's created a task plan. So implement the calendar tab. Currently your task crab has content. Start building. All right, let's start building. And same for this. Let's say start building. And because we hit start building, now it's moved the task over to active. And now it's in active development. So now let's skip ahead until both of these agents finish their work. Okay. Uh that took about five minutes to generate and now it's saying the tasks are complete. Let's take a look at the task port again. So basically after it finishes coding a task, it wants you to review and play with it first before it marks as done. Right? So let's go back here and here I have the preview. Let's make sure both tabs are working correctly. On the calendar tab, we have things we can turn on and off. All quest complete. And then on the quest tab, we can also edit our quest. So we can change the icon for the quest which is pretty fun. And then we can save quest and yeah overall it seems to be working fine. All right. So let's go ahead and mark this task as

complete. And now how are we going to publish this app? Because Replet is vertically integrated. It has a front end database back end and everything built in. All we got to do is just hit publish. And let's see what it comes up with. Okay. So now it's starting the publish process. And I love how there's a security scan step built right in. And uh let's just wait a little bit until it finishes building. All right, it's finished publishing my app. And here it is. Let's take a look. See if it works. So I can add check off habits here. I can Let's see. The streaks don't seem to work. So we have to fix that bug later. But I can abandon quests. I can accept new quests. Let's just say eat enough protein. Let's see which one should we pick. Fire and legendary because I almost never eat enough protein. So, let's actually add 150 XP for doing this and accept quest. And now, let's go back here. And if we check things off, we have enough protein here. Looks like the text is getting cut off. So, we can improve that too. But bottom line is we got this app 90% working by first exploring a bunch of variations in the design canvas and then get multiple agents to build each screen. And finally, we published the app in one go

thanks to Replet's full stack. All right, let's have some more fun. So here's something that I realized. Code is the foundation of all knowledge work. You know, with code, you can generate not just apps, but also slide decks, animations, documents, and pretty much anything else. So, for example, I have a whole blog post that's basically this tutorial. And let me go ahead and paste this in here as text. So, these are all the text about how to uh use Repention 4. And let's just go ahead and pick slide deck here and hit generate. And it's going to go off and generate a slide deck. So, let's skip ahead and see what it comes up with. All right, we're back. That took a few minutes and now we have a beautiful slide deck that's generated using code. See, replication 4, a new way to build. All right, let's take a look. So, we built a habit tracker live. It's got my three habits here. It's got the four different variants that we explored. It's got build faster with parallel agents, a new paradigm. You're the team lead, not the pair programmer, and so on and so forth. And these are like pretty beautiful slides, right? That's generated purely through code. So, that's pretty impressive. But now, let's actually make a new window. And again, let's paste in the same copy that I have for the tutorial. And let's ask it to generate a animation. Let's go ahead and submit and see what it comes up with. Okay, we're back. And this is the video that agent 4 generated. It's got really awesome animations. It's got a helix style background. It made it graphics. The video is going a little bit too fast. Maybe I asked you to slow it down a little bit. But it's pretty much got everything. It's got my habit tracker and code is the foundation of everything, which is the point I'm trying to make. So yeah, so this is

pretty impressive. And now let's have some real talk about where agent 4 fits in the AI coding space. All right, let's go back to the slides that I manually made. Okay, so here's my honest take. I think the AI coding market has split into two segments. tools for engineers and developers and tools for everyone else. For engineers, in my opinion, it's right now a two-horse race between Claw Code and OpenAI's codecs. They're powerful, fast, deeply integrated with the model and developer workflows. For everyone else, and this is arguably the larger market, Replet is doing something different, right? I think there's two bets at play with agent 4. So the first bet is that nontechnical people will collaborate directly with AI agents. Designers will get AI to generate design variations instead of doing it manually. PMS will use a Treer board interface to see what agents are doing and manage them like a team. And the second bet is that again code is the foundation of all knowledge work. If an agent can write code, it can also generate apps, presentations, animations, documents and much more. You know, this is a really big market, right? Think about how many people use Microsoft Office, Google Workspace and traditional design and animation tools. Now, overall, I think agent 4 is a big step forward on both bets. There's some things that I still need more polish, like the canvas. It could be more delightful, but I think the direction is clear. You know, we're going to be all working with AI agents to build all kinds of things in the future, not just apps. So, I think this is a great launch from Replet and I highly encourage you to try Agent for yourself and I'll see you next time in my next tutorial. And be sure to like and subscribe and I'll see you next time.