Hey HN! We’re Adish & Kyle from Mosaic (https://edit.mosaic.so, https://docs.mosaic.so/, https://mosaic.so). Mosaic lets you create and run your own multimodal video editing agents in a node-based canvas. It’s different from traditional video editing tools in two ways: (1) the user interface and (2) the visual intelligence built into our agent.

We were engineers at Tesla and one day had a fun idea to make a YouTube video of Cybertrucks in Palo Alto. We recorded hours of cars driving by, but got stuck on how to scrub through all this raw footage to edit it down to just the Cybertrucks.

We got frustrated trying to accomplish simple tasks in video editors like DaVinci Resolve and Adobe Premiere Pro. Features are hidden behind menus, buttons, and icons, and we often found ourselves Googling or asking ChatGPT how to do certain edits.

We thought that surely now, with multimodal AI, we could accelerate this process. Better yet, an AI video editor could automatically apply edits based off what it sees and hears in your video. The idea quickly snowballed and we began our side quest to build “Cursor for Video Editing”.

We put together a prototype and to our amazement, it was able to analyze and add text overlays based on what it saw or heard in the video. We could now automate our Cybertruck counting with a single chat prompt. That prototype is shown here: https://www.youtube.com/watch?v=GXr7q7Dl9X0.

After that, we spent a chunk of time building our own timeline-based video editor and making our multimodal copilot powerful and stateful. In natural language, we could now ask chat to help with AI asset generation, enhancements, searching through assets, and automatically applying edits like dynamic text overlays. That version is shown here: https://youtu.be/X4ki-QEwN40.

After talking to users though, we realized that the chat UX has limitations for video: (1) the longer the video, the more time it takes to process. Users have to wait too long between chat responses. (2) Users have set workflows that they use across video projects. Especially for people who have to produce a lot of content, the chat interface is a bottleneck rather than an accelerant.

That took us back to first principles to rethink what a “non-linear editor” really means. The result: a node-based canvas which enables you to create and run your own multimodal video editing agents. https://screen.studio/share/SP7DItVD.

Each tile in the canvas represents a video editing operation and is configurable, so you still have creative control. You can also branch and run edits in parallel, creating multiple variants from the same raw footage to A/B test different prompts, models, and workflows. In the canvas, you can see inline how your content evolves as the agent goes through each step.

The idea is that canvas will run your video editing on autopilot, and get you 80-90% of the way there. Then you can adjust and modify it in an inline timeline editor. We support exporting your timeline state out to traditional editing tools like DaVinci Resolve, Adobe Premiere Pro, and Final Cut Pro.

We’ve also used multimodal AI to build in visual understanding and intelligence. This gives our system a deep understanding of video concepts, emotions, actions, spoken word, light levels, shot types.

We’re doing a ton of additional processing in our pipeline, such as saliency analysis, audio analysis, and determining objects of significance—all to help guide the best edit. These are things that we as human editors internalize so deeply we may not think twice about it, but reverse-engineering the process to build it into the AI agent has been an interesting challenge.

Some of our analysis findings: Optimal Safe Rectangles: https://assets.frameapp.ai/mosaicresearchimage1.png Video Analysis: https://assets.frameapp.ai/mosaicresearchimage2.png Saliency Analysis: https://assets.frameapp.ai/mosaicresearchimage3.png Mean Movement Analysis: https://assets.frameapp.ai/mosaicresearchimage4.png

Use cases for editing include: - Removing bad takes or creating script-based cuts from videos / talking-heads - Repurposing longer-form videos into clips, shorts, and reels (e.g. podcasts, webinars, interviews) - Creating sizzle reels or montages from one or many input videos - Creating assembly edits and rough cuts from one or many input videos - Optimizing content for various social media platforms (reframing, captions, etc.) - Dubbing content with voice cloning and lip syncing.

We also support use cases for generating content such as motion graphic animations, cinematic captions, AI UGC content, adding contextual AI-generated B-Rolls to existing content, or modifying existing video footage (changing lighting, applying VFX).

Currently, our canvas can be used to build repeatable agentic workflows, but we’re working on a fully autonomous agent which will be able to do things like: style transfer using existing video content, define its own editing sequence / workflow without needing a canvas, do research and pull assets from web references, and so on.

You can try it today at https://edit.mosaic.so. You can sign up for free and get started playing with the interface by uploading videos, making workflows on the canvas, and editing them in the timeline editor. We do paywall node runs to help cover model costs. Our API docs are at https://docs.mosaic.so. We’d love to hear your feedback!

Last year, I made a YouTube documentary series showcasing the prolific corruption in a small city government. I downloaded all the city government meetings, used Whisper to transcribe them, and then set up a basic RAG so I could query across a decade of committee meetings (around 1 TB of video). Once I got the timestamps that I'm interested in, I then have to embark on a tedious manual process of locating the file, cutting out a few seconds/minutes from a multi-hour video, and then order all the clips into a cohesive narrative.

These seem like problems that LLMs are especially well-suited for. I might have spent a fraction of the time if there was some system that could "index" my content library, and intelligently pull relevant clips into a cohesive storyline.

I also spent an ungodly amount of time on animations - it felt like "1 hour of work for 1 minute of animation". I would gladly pay for a tool which reduces the time investment required to be a citizen documentarian.

I think this is a great endeavor. I was thinking about a channel that I like watching on YouTube. They travel to exotic places by boat and film themselves, nature documentary style. To make good videos requires going to these places, a ton of filming, AND a ton of editing. They put out a video every 2 weeks or so on their trips. I imagine the editing is the hard part.

This is a long winded way of saying that I think creators need what you're making! People who have hours of awesome footage but have to spend dozens of hours cutting it down need this. Then also people who have awesome footage but aren't good at editing or hiring an editor, same thing. I'd love to see someone solve this so that 90th percentile editing is available to all, and then it can be more about who has the interesting content, rather than who has the interesting content and editing skills.

Damn, you beat me to it. I was building something similar but got too caught up optimizing the context extraction. I actually ended up building a full spec for it—basically a PoC of "grep for videos."

My end goal was to let an agent make semantic changes (e.g., "remove the parts where the guy in the blue dress is seen") by simply grepping the context spec for the relevant timestamps and using ffmpeg to cut them out.

How are you extracting context from videos?

Can it work for this use-case? I have lots of 15 seconds to 1 min duration videos) of my kids and want to upload them all (let's say 10 videos) and have the agent make a single video with all the best bits of them?

As a creator who films long form content, editing (specifically clipping for short form) is such a nightmare - this solves such a huge problem and the ui is insanely clean.

Will be using this a ton in the future

Hey, this is super cool. congrats on the product and the launch!

I'm building something exactly similar and couldn't believe my eyes when I saw the HN post. What i'm building (chatoctopus.com) is more like a chat-first agent for video editing, only at a prototype stage. But what you guys have achieved is insane. Wishing you lots of success.

to healthy competition!

Been following this team from the early days. Amazing founder story, even better product. Just what people need today

I just signed up for a Creator plan, but it looks like the automated "Thank you for being a Mosaic Creator" email going out is not configured correctly. Instead of having my company name, it referenced a different business name and description (that seems to exist/be accurate, so not a placeholder).

These comments real sus.

Really interesting direction. The node-based canvas feels like a more scalable abstraction for video automation than the usual chat-only interface. I’m curious how you’re handling long-form content where temporal context matters (e.g., emotional shifts, pacing, narrative cues).

Multimodal models are good at frame-level recognition, but editing requires understanding relationships between scenes, have you found any methods that work reliably there?

I’ve had a lot of fun with Remotion and Claude Code for CLI video editing. I’ve been impressed with how much traditional video editing I can manage.

I will be checking this out!

Loom for Loom?

This is one of those ideas that seems obvious after you hear about it, yet somehow didn't exist yet. So many potential applications. Met the founder back in SF and he's one of the coolest, down to earth dudes there is. Best of luck to the team!

You can see the care in every little decision, workflow, and feature — I’ve never had this much fun editing videos.

I didn’t expect great video editing to become democratized so quickly. Kudos to the team!!

- a happy customer

I just clicked the link and encountered a non-scrollable, dark, fixed content pane with loads of flickering images and scrolling text with random font sizes without much meaning. I felt imprisoned, subjected to unexpected suffering, can't scroll away, got scared and raced for the window close button, and then breathed easy.

Very cool. It definitely feels to me that the power of pro tools should be available to more people with AI.

Would have been nice if there was a killer demo on your landing page of a video made with Mosaic.

I absolutely love your approach of "expert tools". If I understand your approach, you aren't just feeding a video into a multimodal LLM and asking it "what is the bounding box of the optimal caption region?" -- you have built tools with discrete algorithms (using traditional CV techniques) that use things like object detection boxes + traditional motion analysis techniques to give "expert opinions" to the LLM in the form of tool calls -- such as finding the regions of minimal saliency + minimal movement to be the best places for caption placement.

If the LLM needs to place captions, it calls one of these expert discrete-algorithm tools to determine the best place to put the captions -- you aren't just asking the LLM to do it on its own.

If I'm correct about that, then I absolutely applaud you -- it feels like THIS is a fantastic model for how agentic tools should be built, and this is absolutely the opposite of AI slop.

Kudos!

Agree this looks very promising.

When I see a hn post with no critical comments I assume all comments are either seeded or biased (commenting on my own bias)

this is going to save me so much time, hell yeah guys!

Good luck. I've dabbled with this myself and ultimately decided that DaVinci Resolve would end up doing this natively. But then again they haven't yet so who knows!

Good luck with it, sincerely.

Damn this is good.

Hey, good luck with Mosaic.

Some feedback initially on the landing page, looks great but I thought that there is, for me, too much motion going on on the homepage and the use cases page. May be an unpopular opinion!

this is so cool, can we see some demos of edits you'd make with it?

best of luck guys!!

Mosaic team dev here Hanging in the comments all day and pushing updates as fast as we can -really appreciate the feedback!

> We got frustrated trying to accomplish simple tasks in video editors like DaVinci Resolve and Adobe Premiere Pro. Features are hidden behind menus, buttons, and icons, and we often found ourselves Googling or asking ChatGPT how to do certain edits.

Hidden behind a UI? Most of the major tools like blade, trim, etc. are right there on the toolbars.

> We recorded hours of cars driving by, but got stuck on how to scrub through all this raw footage to edit it down to just the Cybertrucks.

Scrubbing is the easiest part. Mouse over the clip, it starts scrubbing!

I’m being a bit tongue in cheek and I totally agree there is a learning curve to NLE’s but those complaints were also a bit striking to me.

YOOOO, this is super awesome. Love this for you all. Lets make life easier for more creators.

This is so cool. Good luck with your venture.

Can you make this a desktop app?

I'm really tired of editing videos in the cloud. I'm also also tired of all these AI image and video tools that make you work over a browser. Your workflow seems so second class buried amongst all the other browser tabs.

I understand that this is how to deploy quickly to customers, but it feels so gross working on "heavy" media in a browser.

Not related to NCSA Mosaic (RIP).

Can we stop with the overloaded names? "Mosaic" is a well-known web browser.