Loved that zed-inspired landing pages.

What does pricing look like?

free, oss, and local-only right now! we are working on a hosted solution but honestly aren't sure yet; we mostly made this for ourselves to fix our own gripes with agentic coding :)

Oh WOW, cool to see a technique that'll be everywhere in 12 months (the fake pen drawing animations + streaming diagrams as they're produced) first be announced. Do we still do "First!" comments, y'all?

~~[EDIT: you need to put "only for macOS" in way more prominent places, all over -- that offends my soul greatly and may Linus frown upon you all]~~ [EDIT2: I was mistaken!]

This all looks really solid. That said, two remarks:

1. The integration with OS LSPs is quite fun and commendable. Is it possible that the diagrams might get their own LSP, someday? Or is better just staying as direct TS callsites?

2. The choice of the word "IDE" seems like it might get you in trouble, given the small "cannot edit files" detail. Any comments on the decision there, as opposed to, say... "brainstorming tool"? Or hell, "[architectonic] harness"?

3. The psuedocode "semantic diff" thing is an incredible idea, wow. Props there.

4. This language kinda concerns me: "how the requirements that you set were implemented". In my highly-arbitrary development flow, it ideally goes `idea -> spec/reqs -> plan -> test -> impl -> eval -> land -> review`, and this kind of tool seems explicitly targeted towards just the second and third with some partial coverage of their neighbors on either side. More concretely: by adding implementation, don't you lose a powerful specificity selling point and now have to compete with all full harnesses?

5. Suggesting "GPT-6 Luna and Claude Opus 5.5" is presumably a typo? Cause the equivelant of Opus 5.5 is Astra, and even then not really.

There are a lot of emerging tools like this for which we will need a name. A similar one I randomly came across (https://github.com/Maksim-Burtsev/merl) calls itself a "Code Navigator."

Along similar lines, I also don't know what we're calling tools like T3 or Superset. They're basically harnesses for harnesses.

They are usually called orchestrators, sometimes Agentic Development Environments (i.e. IDE for agents) if they are complex enough

hmm - those tools are great, but I don't think orchestrator / ADE is quite right either, since this is explicitly not opinionated about where your coding agent is living.

Whiteboard is targeted at almost the opposite problem of the ADE (which is targeted to context switching) - having a dedicated tool to help you understand & participate in the development process in places where humans are high leverage.

maybe also useful: https://x.com/ThePrimeagen/status/2101869827266596973?s=20

thank you! really appreciate it.

1. Yeah, we've thought about this too - at the minimum, we're going to implement a vibe-codeable extension system so that you can add your own diagram types without rebuilding the app. definitely hopeful for some sort of common schema or lsp-shaped thing in the future

2. this is a good point and is something we've considered and struggled with. we ultimately settled on the term 'IDE' because we've found that most people use vscode to review code nowadays, almost exclusively (so it makes it a bit easier to draw the comp in your mind). we're also strongly considering adding an editing feature, but not sure what the exact shape of it is, so decided to go in favor of not shipping it yet - editing tends towards a conductor / superset shape of product. maybe we could try "canvas" instead of "ide" or something? will mull it over more.

4. Yeah, this is definitely tricky. This is why we didn't end up shipping edits as part of this release. Part of the solution here, we think, is tighter integration with the "spec" part of the lifecycle - where whiteboard makes it easier to understand if a spec (like a formal proof) is extensible, generalizable, etc. will mull on this more.

5. yes that's a typo! we're fixing right now - we meant "GPT 6 Sol" (basically, fast TPS, don't need the limits of intelligence really).

Edit: we do have a Fedora Linux build out if that's what you use! releasing stuff on every distro requires some care, so please let us know what you'd want to see it on (re: appimage lol) Edit 2: (5) is fixed! thank you

I don't have much to say, other than these were interesting & helpful responses to understand what you've learned and where you're going. So thanks!

I'll be honest that my initial belief it was for OSX exclusively left me feeling indignant, so knowing I was just mistaken (based on the link up top, tbf) turns me around completly. I do in fact run Fedora, so I'll be trying this ASAP!

I feel Fedora+Debian+Ubuntu+Arch covers all but the long tail of devs, based on vibes alone? You might get bullied if you don't support Nix, but you'll probably be bullied by them anyway lol so no advice on navigating those waters.

https://install.dev.fast/linux ! we added the fedora build because one of our friends swears by it! (was hoping you wouldnt say omarchy lol)

Vibe-coded landing pages are an instant “no thanks” for me.

I did, for what it's worth, spend a painfully long amount of time designing this website, but unfortunately none of us are great frontend devs, so we lean on the models here for sure (definitely am working on getting better at frontend dev).

we've put in a lot of time and attention into the app especially and hope it shows in the details - e.g. the diff viewer, the rendering animations - we want development to feel human again while still enjoying the speed boost of agents

This is definitely getting at least some things right about how we work with agents today, specifically that we often work at the architecture level, and we need a better alternative to the current Plan Mode offered by coding agents to efficiently architect software at a high level, which is more visual and offers better back-and-forth incrementation with the agent than simply "reject final plan with X message".

From the website demos i definitely think this is a clean interface, although I don't know how much better this is compared to some simple custom Mermaid format, which the agent can write as artifact files and present to users. Zooming out, this app seems like 1 feature (a MCP with a GUI attached to it) rather than an entire product.

Also, I don't know if asking the agent to write specific code changes into the plan is a good idea. I think maybe that a "plan -> approve -> write code" would let the agent write higher quality code than "plan which contains code -> approve". But maybe you can make it work when combined with some specific prompting marking the code as clearly work-in-progress and subject to change, and that the agent should surface any parts implemented differently relative to the plan to the user, etc.

thanks for the feedback! two points:

1. "is this a feature" - it could be! in fact, we will expose this as an MCP UI next so that you can view the info directly in Codex Desktop or Superset/Conductor/Emdash for example. that aside, we found that the big things that matter for us are: (1) good code navigation (diagram/spec -> code), (2) beautiful diff viewing, and (3) visualizing agent traces as they connect to code. we found that these problems were hard enough, and enough folks that were using platforms that didn't easily map to these requirements - e.g. TUIs like claude code - that a dedicated product that was just focused on these problems exclusively makes sense.

2. "using whiteboard for plan mode": hmm, i think our wires are crossed a bit here. how people mostly use whiteboard today is:

plan -> approve -> agent codes -> use whiteboard to explain the code.

(or just omit the plan phase as a formal artifact -> just emit a plan + code together, like a golang design draft [A]).

we are exploring an explicit "put the plan in whiteboard first" mode (there's a scratchpad feature that's experimental right now), but it's definitely not ready for prime time yet.

[A] we were heavily influenced by golang's practice of "design drafts" as a way of scaling engineering velocity, e.g.: https://go.googlesource.com/proposal/+/master/design/draft-i... (thanks to Russ Cox, the legend)

how people mostly use whiteboard today is: plan -> approve -> agent codes -> use whiteboard to explain the code.

I guess it's interesting and useful for now, but I don't think people are going to work at the code level much longer.

In my opinion current coding agents + automatic review systems are already at superhuman reliability during the implementation phase (as in they will not fail something in the plan during implementation and not tell you about it, so there's no need to look at the actual code beyond maybe a cursory glance). I literally just use plan mode + CC's /code-review in each task so it's not like I'm doing anything special. So I think the main human interaction surfaces to target in the future will be in the planning process.

So I think the main human interaction surfaces to target in the future will be in the planning process.

yes, agreed. we're working on more stuff in that direction (a plan / scratchpad mode), but what i personally like the most is eliminating / shrinking the plan/review gap.

i think reviewing a plan without an implementation doesn't feel that useful anymore, at least to me, because key tradeoffs often only surface during implementation that effect the top-level spec.

in some sense, the code writing process is just a cheap effort which makes the spec better and more thorough?

a better alternative to the current Plan Mode

An easy upgrade (ime) is to be intentional about a process, move the planning artifact to a file, use multiple research/propose/review sessions to dial it in. Still tuning my vibes for when to add in some actual exploratory implementation elements, because there's always something you didn't foresee when getting to the actual implementation, while also not having them implement the solution as a "plan" in markdown

be intentional about a process, move the planning artifact to a file, use multiple research/propose/review sessions to dial it in

Yeah, I think we need something like that as well. I am actually working on an virtual artifact filesystem in my orchestrator to enable this. So agents can create a persistent, versioned plan artifact separate from the codebase (maybe a HTML) and iterate it alongside the user, much like what ChatGPT/claude.ai can already do but for a coding agent. Then you'd need to define a process and get the agent to follow it, but that's much easier and mostly a mix of prompt and orchestration primitives.

exploratory implementation elements

This is a good point, I've ran into a lot of instances as well where my agents in plan mode would like to explore something but can't because of permissions. I wonder if there should be some kind of system like a "experiment subagent" to handle it.

We need LESS of AI and more HUMAN thinking. The process of thought and the increased difficulty with increased complexity is a feature not a bug.

AI note taking is a scourge on society and needs to go.

i am not sure to be honest if you're agreeing with us or not! but we do think that human thinking is both necessary and important in the future.

wrote a blog about this if you're interested! https://dev.fast/blog/youre-still-going-to-have-a-job-in-5-y...

736mb on macOS

/facepalm

Does it have a terminal and panes? These are things I do not ever see giving up

it's meant to be used as a complement to your existing terminal! your agent uses the mcp or api from the terminal to draw on the Whiteboard

Looks cool :-)Linux wen plz so I can play with it?

https://install.dev.fast/linux ! we just have a fedora build right now, but if you're looking for another distro let me know and i can put it on our roadmap.

Thanks! Sorry if I missed it. I had clicked ok the download on the page and it only pointed me at Mac.

If you can create an aur it'd be awesome for the arch crowd :-)

I think the issue with this type of product is it creates an N+1 source of truth for teams alongside their other tools. Inherently, this will get out of date as a project progresses. You could have an agent update based on changes, but that would likely degrade the design doc/artifact into unintelligible slop which wouldn't be useful in the future. This is a behavioral/structural problem of software design in general, which I don't think can be solved by software. Perhaps if this is mainly focused on collaboration at design time, but then that begs the question if teams will really want this tool versus using Notion, Linear, Google Docs.

I was confused for a moment by the name "Sid" in new coding tools.

Sid of GitLab raised for Kilo, and GitLab is also of YC

https://capwolf.com/former-gitlab-ceo-launches-kilo-in-ai-co...

Interesting idea for sure. But as a software engineer, I’m struggling to map out what this would replace today. I use Cursor pretty heavily, but it’s not entirely clear what would make me jump to a new IDE based on what you’ve built so far.

Maybe I’m missing something.

sorry, yeah the word IDE is a misnomer - we will fix, looking for something better. It's really a canvas that your agent can use to help you understand an implementation, what tradeoffs were made, etc. Whiteboard is meant to be used in conjunction with tools like Cursor / an ADE.

Edit: just updated the GitHub + marketing site to reflect this!

very cool. Congrats on the launch. first half of 2026 was the year when every one made such internal tools one way or another. I am happy you guys could build a product out of it.

The cool thing is even though this tool addresses a few, use case for reducing cognitive load, they happen so frequently that they add up.

I think they key with cognitive load is that the agents often produce a lot of trace/docs etc, in the end only a small % of the traces really are important to the final changes, because concise changes are typically very small and self contained.

One thing i see this becoming important with is maintaining internal tooling built using this. I maintain an internal docs system that helps me do designing before i build code, that docs system is completely vibe coded and i can add features to it very fast, but now its all grown up. A challenge then is can i understand just enough about a new proposed change to approve it? That is key to the doc system not becoming a burden in of itself, while maintaining a tight core feature set.

One concern about accuracy of the diagrams. In the example, there is a transition back to the session service labelled "wait for release" after the "no" decision. I'm not seeing that in the shown diff.

Looking at the code the "no" seems to relate to the context expiring, so you wouldn't want to wait more if the context already expired, you'd want to stop. Is there a reason that label exists?

I'm pretty wary of LLM development tools hallucinating and wasting my time, is that whats happening in the lease broker example?

Hey! oops, that gif is a notional one we were using for design, and we forgot to update it.

Real diagrams are all linked to code, so hallucinations don’t really happen in practice (hallucinated architecture really bothers me too!)

Will update shortly with an actual gif of the app. Sorry about that!

Okay great timing because I was having the exact same idea, but mine was just a skill that was building a website with the flow mapped out and the relevant code, which seems that you are doing as well, definitely going to follow this, good luck guys!

Plans for Windows version?

For that there's Python: with30 lines you can automate this task. If you want I can send you the script I use. DM me if interested.

As an architect, how do you envision me using this?

Cool open-source project. Vut why are we trying to build so many no code tools?

not no-code at all (a big part of this project has been our semantic diffing engine)! check out the demo - in fact if anything it's meant you bring more into touch with the code, rather than less. :)

  You cannot currently edit files in Whiteboard. If this is something that you find yourself wanting to do, please file an issue!

Do you still consider this an IDE? Curious

more than anything it's valid enough as a frame of reference for what many people want to do. if they went and invented a new term for it i'd reckon a lot of people just wouldn't even click on it

yes, this is tricky and something we’ve struggled with too. We chose IDE because the closest comp is probably VSCode - lots of folks seem to just use it for code browsing / review these days!

regardless, we ended up renaming “ide” -> “canvas” in on gh + website. hope that’s less confusing. will mull it over in the meantime.

Awesome, keen to see where this goes. Can we have light mode for the whiteboard and dark mode for the code?

Echoing the wish for a Windows version. This is the first piece of software I've attempted to download in my ~2 years on this site. 90% of the software engineers I know are on Windows :-)

Throw in some tla+, eventb, p and modp for formal guarantees

make it possible to link to and comment on github PRs - this would be a sweet reviewing tool

for sure, we're thinking of doing something along those lines for our hosted product-- auto-trigger reviews upon opening PR, link to them from gh, etc. feel free to shoot me a message (ketan at dev dot fast) if you're interested in that!

If you make it hosted only, my guess is you will lose out on a number of users who cannot convince their corporate overlords to authorize yet another GitHub app. Charge the user and use their local gh access to make it work!

"Known limitations You cannot currently edit files in Whiteboard. If this is something that you find yourself wanting to do, please file an issue!"

Seems like a big limitation for an "IDE"

Seems more like IDE is "I Don't Edit" in this case

Thanks! The project looks great and I am definitely interested in this approach. I hope it will help me with my usual issue - I review a lot of code these days and it's really hard to understand what changes about and why they even needed usually, without deep analysis and AI sessions. It's always good to have such a visual method to check briefly what's there on architecture and design level - these mistakes are hardest to find in other people's code, as it is for me.

I especially like your way to connect agents - I'm basically using what I wish to use, without limitations or pay walls. At my work, all AI tools should be reviewed and approved before usage but here I just use my coding agent and this is "plugin" for visualisation, so I guess it will be approved in no time. Thanks to not keeping a forced data collection, it will really help to promote your tool in corporate environments.

No reasons to not try it for me! I am looking closely at what will come next and will try to share my feedback, if there will be some.

For now, I just feel that it will be good to have a way to trigger review creation from the app itself, not to create a new agent session for this. Kinda a bit counterintuitive but I understand why it works this way and it's not a real issue.

Was excited to try this, but my company moved from Claude to Copilot CLI. Any plans for Copilot support?

Is a new IDE really required for this? Wouldn't Markdown already cover a shared "canvas" for documentation/planning, when accompanied by something like Mermaid?

I think some of the presented ideas are pretty cool, but am thinking that you'll get slown down by the IDE approach.

So it's an electron app but you don't support editing or even viewing on the web? And no windows client?

Looks interesting! Side question: how do you plan to make money out of it?

we plan to launch a complementary hosted, multiplayer product as well; here's some of the ideas we're thinking about: https://dev.fast/about/

but that's all a bit far in the future; lots to iterate on here right now to get the ux right.

I can see the value of having the agent and the human looking at the same design. The thing I'd worry about is the diagram becoming another thing that slowly diverges from the code. Would be interesting to see how you handle that once the implementation starts moving.

How do you compare to https://likec4.dev/ and https://erode.dev/ , which are currently fully open-source and community driven?

C4 gives the text-based representation needed for LLMs to generate and maintain large architecture diagrams - why not build off that heritage?

This is really cool! I'm pumped for anything that makes it easier to review generated code. I, like many people these days, am searching for ways to stay close to the code whilst not being overwhelmed... and as a visual personal i like your idea to semantically link code to diagrams

I've been working on a (semi-)similar thing, a TUI for narrative code reviews - https://github.com/mtford90/revue - the idea being to generate "guided tours" of a change as opposed to a big wall of files.

Codex warns me - "Whiteboard requires uploading/exposing repository data to its authoring server".

Is this expected? I had a different take on "local" and "works as a plugin with your existing harness". What might I be missing?

the authoring server is referring to the stdio mcp server running on your machine! so its all still local and private, we should clarify that nomenclature though.

all of the facets we track are in the repo's TELEMETRY.md! for errors and crashes, any specifics about your machine+repo are redacted. We only collect repository information when you submit a bug report and opt into it, or share a whiteboard session, also totally optional.