Ming Fang

building @SpaceXAI | prev. @google, @Uber, @okx, @spertainc | @CMUDB, @CarnegieMellon

[SpaceXAI @SpaceXAI]

We've open-sourced Grok Build and have reset usage limits for all users.

Open sourcing Grok Build allows anyone to support making a reliable and robust harness. Check out our code, including the Git repo for the Grok Build CLI.

https://t.co/3SSvPu2Nrz

[Ming Fang @mindbergh]

@flyflyf04862062 @lm_zheng @ying11231 @jia_xuhui @kcjacksonwang @RuohongZhang Great working with you. All the best for your next chapter!

[skcd @skcd42]

Now that Grok 4.5 is out, here are some of my workflows which I use daily

1. "use as many subagents and tokens as you need"
I end my prompts with the above to tell grok to spin up multiple subagents at the same time to divide and conquer on a hard problem. Grok is smart enough to realize when a subagent needs its own worktree and if it should inherit context from the main agent.

[Ming Fang @mindbergh]

I have been using Grok 4.5 internally to iterate on itself. It's a good model!

[SpaceXAI @SpaceXAI]

Announcing Grok 4.5, our first model trained specifically for coding and agents. It was trained with Cursor and offers frontier intelligence at leading speeds and cost efficiency.

https://t.co/i8HpU7w64k

[SpaceX @SpaceX]

SpaceX has exercised the option to acquire @cursor_ai in an all-stock transaction with the goal of building the world’s most useful AI models.

For the past few months, SpaceXAI has been jointly training a model with Cursor, which will be released in Cursor and Grok Build soon.

We look forward to working closely with the Cursor team to advance our frontier AI capabilities

[Ming Fang @mindbergh]

This is a limited edition now. 🚀🚀🚀

[Ming Fang @mindbergh]

Excited to see what Grok Build can help you achieve!

[SpaceXAI @SpaceXAI]

An early beta of Grok Build, an agentic CLI for coding, building apps, and automating workflows is now available for SuperGrok Heavy subscribers.

Through this early beta, we will improve the model and product based on your feedback.

Try it at https://t.co/bpTHpjivWD

[Toby Pohlen @TobyPhln]

At 1:30 a.m. PT on November 3, 2023 Elon sent a message to the xAI group chat saying that we need to go “extremely hardcore” for the next 36 hours; Grok will be released publicly tomorrow. You didn’t have to be in the exclusive company chat to get the message; it was also posted publicly at the same time:

https://t.co/lThuIjQvF9

What unfolded over the next day and a half was one of the best examples of engineering at pace that I’ve ever seen. All we had when we started was a somewhat fine-tuned base model and a half-baked UI. Our team of ten split up the tasks: curate data, improve the model, implement the raw prompting and RAG service, build the production infra. I took care of the latter.

At 8:51 p.m. PT the next day, we announced Grok to the world with a long-form post on X (https://t.co/9d485OLrSY). Over the past 36 hours, we came up with Fun mode (including Grok’s sunglasses), finished the whole production system, and most importantly tuned the RAG system that gave it real-time knowledge of the world through the X platform (a first in the industry). A day and a half of straight coding and shipping; no drugs, not even caffeine, just pure adrenaline. Elon gave us a mission and we delivered.

The launch went very well. We invited a couple hundred X creators and Grok’s ability to roast accounts went viral. It was the first time a publicly accessible AI was allowed to poke fun at people.

This episode is a prime example of what you can achieve by going extremely hardcore: you move and deliver results faster than any outsider could have anticipated. Within 36 hours, we took the company from silence to relevance. It was well worth it.

xAI’s hardcore culture is infamous on X. I love the tent meme that suggests we all sleep (well, slept in my case) in the office in tents. Our reputation precedes us and even new joiners hit the ground grinding hard. However, unless you understand the “why,” you are at risk of simply replicating the “how” without achieving the same results.

You need to grind with purpose and the purpose is to move fast towards a known goal. When the goal and the means of reaching it are crystal clear, a small, skilled, and highly motivated team can outcompete companies old and new, big and small.

Never grind to show off; never work late to be seen; never sacrifice without cause. There is no medal for the one who tried extremely hard but failed. There is only a medal for the winner. If all your efforts lead nowhere, you’re arguably not very productive.

Always keep your eyes firmly on the goal, do everything to reach it as quickly as possible, and make sure you're on track to win. A hardcore engineering culture is one of the most effective ways of accelerating real progress. Watch out for performative sacrifice and don’t confuse pain with progress.

[Ming Fang @mindbergh]

@flyflyf04862062 @Waymo @xai 😆😆

[Ming Fang @mindbergh]

@Waymo is blocking road in @xai office parking lot

[Ming Fang @mindbergh]

@TobyPhln @xai @elonmusk Such a sad news… It has been truly great working with you and thank you so much for the trust. Wish you all the best.

[Ming Fang @mindbergh]

@jimmybajimmyba @elonmusk It has been great working with you and learning from you, Jimmy! Best wishes!

[Ming Fang @mindbergh]

@Yuhu_ai_ All the best, Tony!

[Ming Fang @mindbergh]

My conquest is the sea of stars

[SpaceXAI @SpaceXAI]

One Team 🚀
https://t.co/8RWbk5jQIQ

[Ming Fang @mindbergh]

Besides the technical aspects, I'm really curious to see how society adapts to the development of AI.

[Dario Amodei @DarioAmodei]

The Adolescence of Technology: an essay on the risks posed by powerful AI to national security, economies and democracy—and how we can defend against them: https://t.co/0phIiJjrmz

[Ming Fang @mindbergh]

@veggie_eric I did use the code to recover one of my accounts before 😌

[Ming Fang @mindbergh]

Understand the universe one step at a time

[Paata Ivanisvili @PI010101]

Disclaimer: I had given early access to internal beta version of Grok 4.20

It found a new Bellman function for one of the problems I’d been working on with my student N. Alpay.

The problem reduces to identifying the pointwise maximal function U(p,q) under two constraints and understanding the behavior of U(p,0).
In our paper https://t.co/pgJw9MaEA1 we proved U(p,0)\geq I(p), where I(p) is the Gaussian isoperimetric profile, I(p) ~ p\sqrt{log(1/p)} as p ~ 0.

After ~5 minutes, Grok 4.20 produced an explicit formula U(p,q) = E \sqrt{q^2+\tau}, where \tau is the exit time of Brownian motion from (0,1) starting at p. This yields U(p,0)=E\sqrt{\tau} ~ p log(1/p) at p ~ 0, a square root improvement in the logarithmic factor.

Any significance of this result? It will not tell you how to change the world tomorrow. Rather, it gives a small step toward understanding what is going on with averages of stochastic analogs of derivatives (quadratic variation) of Boolean functions: how small can they be? 

More precisely, this gives a sharp lower bound on the L1 norm of the dyadic square function applied to indicator functions 1_A of sets A \subset [0,1].
In my previous tweet about Takagi function, we saw that the sharp lower bound on ||S_1(1_A)||_1 miraculously coincides with Takagi function of |A| which (surprisingly to me) is related to the Riemann hypothesis. Here, we obtain a sharp lower bound on ||S_2(1_A)||_1 given by E \sqrt{\tau}, where Brownian motion starts at |A|. This function belongs to the family of isoperimetric-type profiles, but unlike the fractal Takagi function, it is smooth and does not coincide with the Gaussian isoperimetric profile.

Finally, in harmonic analysis it is known that the square function is not bounded in L^1. The question here was more about curiosity: how exactly does it blow up when tested on Boolean functions 1_A.  Previously, the best known lower bound was |A|(1-|A|) (Burkholder—Davis—Gandy). In our paper, we obtained |A| (1-|A|)\sqrt{log(1/(|A|(1-|A|)))}. This new Grok’s Bellman function gives |A| (1-|A|) \log(1/(|A|(1-|A|))) and this bound is actually sharp.

[Ming Fang @mindbergh]

@xai 🔥🔥🔥

[Ming Fang @mindbergh]

@zjpeng94 @xai @Tesla @Tesla_Optimus Yes very impressive!

[Ming Fang @mindbergh]

Hey bro!!😎 @xai @Tesla @Tesla_Optimus