Brian Sigafoos

Techno-optimist. “Win and help win” context engineer, 2x founder. e/acc

[Brian Sigafoos @BrianSigafoos]

We believe in the words of @DavidDeutschOxf : “We have a duty to be optimistic. Because the future is open, not predetermined and therefore cannot just be accepted: we are all responsible for what it holds. Thus it is our duty to fight for a better world.”

[Marc Andreessen 🇺🇸 @pmarca]

The Techno-Optimist Manifesto -- please read and Ask Me Anything! Post questions as replies to this xeet. https://t.co/5ZKjiUG8de

[Mark Kretschmann @mark_k]

Origin is Cursor’s attempt at an agent-native GitHub competitor: a Git-compatible forge built around the assumption that lots of AI agents will be cloning, branching, committing, rebasing, reviewing, and fixing failures in parallel.

That also makes the Graphite acquisition much more interesting. Graphite brings stacked PRs, review flow, merge queues, and cleaner collaboration. Origin adds the hosting layer underneath it.

So Cursor is no longer just "VS Code with AI". They’re trying to own the whole AI software factory: write code in Cursor, run agents in parallel, review with Graphite-style workflows, host and merge on Origin.

GitHub was built for human-scale development. Origin is being framed around the next bottleneck: coordinating, reviewing, and safely merging agent-generated code at massive scale.

[a16z @a16z]

Cursor CEO Michael Truell on the future of writing code: "Our goal with Cursor is to invent a new type of programming."

"It looks like a world where you have a representation of the logic of your software that does look more like English."

"You can imagine kind of an evolution of programming language towards pseudocode. You have written down the logic of the software, and you can edit that at a high level."

"It won't be the impenetrable millions of lines of code, it'll instead be something that's much terser and easier to understand and easier to navigate."

@mntruell with @lennysan on Lenny's Podcast

[Cursor @cursor_ai]

We're launching code storage and git hosting.

Origin gives teams and agents a place to host, review, and collaborate on code.

Available this fall. Join the waitlist.

https://t.co/uamaIarJXY

[Rick Pitino @RealPitino]

The Knicks should teach every team from high school to college how important work ethic and chemistry are! Besides having the best player in the NBA this year, they had an attitude of never relenting, and never giving up. Amazing run. Champions we can all look up to!

[@jason @Jason]

This isn’t illegal, but it should be.

We need to pay politicians properly so they don’t do this kind of stuff

Senators and Representatives: $174,000 should be $500,000

President: $400,000, should be $10m

Vice President: $235,100, should be $5m

Total change from today?

Only $188m

That’s .001% v .004% of the Federal Budget

Also, give a housing stipend of $100,000 a year while in office so folks have all pressure and blockers taken away from serving our government

[Eoghan McCabe @eoghan]

We’re excited to share that we just signed an agreement for @salesforce to acquire @fin_ai for ~$3.6B. The transaction is expected to close in the fourth quarter of Salesforce’s fiscal year 2027.

Fin started as Intercom 15 years ago. We changed our name to cap our transformation just weeks ago. We were a darling of the SaaS era and invented so many of the patterns you see in software today. Nearly four years ago, in need of a reboot, we jumped on weeks-old modern LLMs to create and define the category we know as Customer Agents today.

Salesforce invented modern software and SaaS. And @benioff is like the final boss of tech founder CEOs. In seat for 27 years, he’s one of the last of his era. Still pushing, pivoting, placing big bets. It’s a privilege for @destraynor and I to get to partner with him and join forces with Salesforce upon close at this most fascinating time. And will be very fun to get their help bringing Fin to magnitudes more consumers.

To our customers: Over the past few years we’ve been shipping intensely. Including recently our groundbreaking model, Apex, and our paradigm-defining internal agent, Operator. With the resources of Salesforce this will only accelerate. And yet little will practically change. I’ll still be CEO, Des will still be running R&D, we’ll both still be committed to continuing to lead this category. Thank you very sincerely and deeply for your belief in us.

To all of our friends, our families, and our employees, past and present: While this is not the end, it is a major, pivotal, special, and emotional moment for us. From the bottom of our hearts, thank you. For everything.

To my cofounders, my exec team: Look what we built. Four young lads with a dream and nothing to lose. And a home grown exec team who pulled off the greatest and arguably only late stage software company pivot to AI, and invented one of the most important categories in AI. Thank you for sticking through all of this with me.

And now, time to get back to work. See you at our next product launch in a couple weeks. (:

[Andrew Curran @AndrewCurran_]

https://t.co/yUVogvdruU

[Satya Nadella @satyanadella]

https://t.co/vLmiBKTtX3

[Jared Friedman @snowmaker]

If you want to find a truly impactful idea, a good place to look is in the trash bin of history.

Most of the ideas that have most broken out in the last 5 years aren't new. They're old ideas that got written off too early.

examples:
1) AI: When Sam started OpenAI, saying "AGI" got you laughed at
2) Space: Elon started SpaceX after people had written off the 1960s-era dreams as sci-fi
3) Supersonic flight: Blake started Boom after everyone assumed Concorde already proved it couldn't work
4) Nuclear energy: fission and fusion are roaring back decades after ambitious people stopped studying nuclear physics
5) GLP-1's: After the fen-phen disaster, weight loss drugs were synonymous with snake oil.

There's a good reason this keeps happening. When a hyped idea fails, there's a backlash. It becomes embarrassing to work on - anyone still working on it is assumed too dumb to know better.

So, if you want to work on something like this, you have to teach yourself to feel the tinge of that embarrassment and push past it.

[David Sacks @DavidSacks]

I’ve had a number of conversations with folks inside and outside government about the current situation with Anthropic, and here is what I believe to be true:

— As we know, Anthropic publicly released its Mythos class models earlier this week under the commercial name Fable.

— Fable is Mythos with guardrails. But if those guardrails fail, then you’ve exposed Mythos and its advanced cyber capabilities to people who shouldn’t have them. (Keep in mind that Anthropic itself widely promoted the idea that Mythos was a cyberweapon and needed to be regulated as such. They asked for government regulation of Mythos and championed the guardrails on Fable. If there is a vulnerability — big or small — it is Anthropic’s responsibility to patch.)

— A highly credible trusted partner of both Anthropic and the USG who was testing Fable came forward with a jailbreak of those guardrails. The Admin asked Dario to fix the jailbreak or de-deploy the model. Dario refused.

— In their blog post, Anthropic defended its decision by saying the jailbreak isn’t serious. That is not what the trusted partner and the USG believe; nor is that kind of minimizing language consistent with Anthropic’s brand as the AI safety company. It’s difficult to fathom how they could claim a jailbreak allowing operability of a cyber weapon could be defined as not “serious.”

— In the past, Anthropic has always said that safety must be top priority and taken super seriously. In this case, Anthropic prioritized the continued offering of the consumer model over safety.

— In reaction, the Admin issued the export control. The Admin did this reluctantly. It’s been very surprised that Anthropic hasn’t wanted to cooperate with a reasonable safety request (ie fixing the jailbreak issue). Anthropic’s reaction is very much at odds with their branding and ethos as a safe AI research community.

— The Admin’s hope now is that Anthropic remediates the safety issue, the export control is lifted, and Fable goes back into general release. The Admin wants all of this to happen as soon as possible. It is frankly bewildered that Anthropic hasn’t wanted to comply with safety requests that it previously said were its highest priority.

— Those trying to misdirect and tie this action to the prior DoW/Anthropic issues are wrong. The Admin values Anthropic’s technical capabilities and feels that this issue, while serious, should be easily resolved. The ball is in Anthropic’s court.

[Kevin Patrick Mahaffey @dropalltables]

Oh yes, I remember that Bond film where the villain decarbonized the auto industry, brought fast internet to everyone on the planet, and helped paralyzed people interact with the world again.

[Erik Voorhees @ErikVoorhees]

No, you don't get it.

He does not have $1 trillion sitting in cash, it is 99% stock in his companies.

To make that wealth liquid would mean selling all that stock which would swiftly destroy *both* the companies (Tesla, SpaceX, others) and the wealth. If he sold it all, he'd end up with maybe $100b max, several hundred thousand people would be out of work, the companies ruined and many of their suppliers also ruined.

Okay, but now Elon has $100b in cash, and can "solve the world's problems".

$100b divided by the world's 8 billion people is $12

If you were in charge, several of the most innovative industrial companies in the world would be destroyed, hundreds of thousands out of work, and space would again close to human civilization for another generation.

But everyone on earth could have one nice meal and you could revel in your altruism.

[Robert Sterling @RobertMSterling]

> you’ll never start a rocket company
> you’ll never build your own engines
> you’ll never be able to use off-the-shelf parts
> you’ll never survive three launch failures
> you’ll never reach orbit
> you’ll never win NASA’s trust
> you’ll never launch cargo to the ISS
> you’ll never compete with Boeing
> you’ll never compete with Lockheed
> you’ll never make rockets reusable
> you’ll never land a rocket vertically
> you’ll never land one on a drone ship
> you’ll never reuse a booster
> you’ll never fly the same booster 10 times
> you’ll never fly the same booster 20 times
> you’ll never fly the same booster 30 times
> you’ll never recover and reuse the fairing
> you’ll never lower launch costs
> you’ll never launch every month
> you’ll never launch every week
> you’ll never launch multiple times a week
> you’ll never carry astronauts
> you’ll never replace Roscosmos
> you’ll never fly civilians to orbit
> you’ll never manufacture satellites at scale
> you’ll never build the biggest constellation ever
> you’ll never make satellite internet work
> you’ll never make satellite internet fast
> you’ll never make satellite internet affordable
> you’ll never serve rural customers
> you’ll never serve aircraft and ships
> you’ll never build a methane rocket engine
> you’ll never make full-flow staged combustion work
> you’ll never build the most powerful rocket ever
> you’ll never build a rocket bigger than Saturn V
> you’ll never build it out of stainless steel
> you’ll never launch Starship
> you’ll never separate Super Heavy and Starship
> you’ll never relight Raptor in space
> you’ll never bring Super Heavy back
> you’ll never catch a booster with Mechazilla tower arms
> you’ll never launch 85% of mass to orbit worldwide
> you’ll never change the economics of space
> you’ll never force the entire industry to copy you
> you’ll never win
> you’ll never IPO

Congratulations to @elonmusk and the SpaceX team. You did what countless people said was impossible, and you did it time and time again.

Today is your day. You deserve this. May it be a glorious one.

[John Suh @john_ssuh]

Increasingly, I believe companies may need to be rebuilt from the ground up, where you have a single timeline of all observability + product metrics + file changes laid out in a retrievable system, like Datadog + Posthog + Google Drive + Slack (really unified filesystem of Claude Code chats + Codex chats). This might be the new data foundation for any and all companies to maximize AI. Needs to be rebuilt because keeping track of diffs on existing system basically impossible to produce longitudinal information on decisions and rollbacks, something coding agent storage companies are actively trying to figure out, but this should extend to businesses as a whole.

Highly skeptical existing businesses will adopt this though because it means overhauling everything about their instrumentation and business data, but I think businesses built on this foundation probably can execute 100x better and faster

[Joshua Kushner @JoshuaKushner]

in markets, to go long on something is to bet it grows more valuable over time. much of the conversation today is short on humans, wagering that ai makes people redundant. we believe the opposite is true for the industries @ThriveHoldings operates in.

we are long humans.

https://t.co/oqygDJKZGO

[ESPN @espn]

OmG.

[Dario Amodei @DarioAmodei]

Today I'm publishing a new essay, Policy on the AI Exponential. AI is progressing extremely fast—much faster than the policy process was built to handle. The essay lays out where I think the technology is now, and the action needed to close the gap: https://t.co/Lh6PWae178

[Derek Thompson @DKThomp]

This has quietly been a miracle month in medicine.

In the last 5 weeks we’ve got news on:

- retatrutide, the triple agonist GLP-1 from Lilly, basically melting fat and body-wide inflammation at record levels
- RevMed’s new pancreatic cancer drug showing unprecedented abilities to extend life
- small trial of a one-and-done PCSK9 gene editing therapy for slashing LDL cholesterol
- Mayo’s AI-assisted radiology showing vastly improved cancer detection
- this new therapy for metastatic solid tumors

This stuff is at varying levels of evidence. Retatrutide is ~100% on its way, other stuff needs more clinical trial data. But put it together and we’re maybe on the verge of majorly reducing the mortality of heart disease and cancer, the two leading causes of death in America.

[Taelin @VictorTaelin]

this is my personal singularity moment

this post may sound like a paid ad. I only wish. I'm concerned, more so than happy. the world is changing, and, among the scenarios where AI goes terribly wrong, inequality is the most realistic, yet, the one Anthropic seems to be the least concerned about. I'm glad OpenAI is taking the opposite stance: *personal AGI for everyone*. I think this is a commendable position in the times we live. but who am I in the queue of the bread?

anyway, Fable is here, so I'll just report my first-hour experience

first of all, all my pet prompts are solved.
→ λ-calculus puzzles
→ bug questions
→ one-shot apps
all are trivial to it.

I don't have anything harder other than my
ongoing work

so, in the last several days, I've been toying with HVM5, a new interaction net evaluator with a faster loop.

after writing the first version, I left 32 GPT-5 agents working for ~20 hours each. this resulted in up to 2x speedups, but the file size increased by 2-fold and quality decreased significantly.

I then simplified the whole thing into an even simpler core, and left Opus 4.8 and GPT 5.5 optimizing it for 8 hours. Opus got a legit 6% - 34% speedup in most benches. GPT got better results, but, sadly, an unusable file.

I then asked Fable to optimize it.

2 hours later, it landed a 1770% speedup in one case, 100%+ in other 4, and 22% in average. yes, in 2 hours it outperformed me, opus 4.8 and a swarm of gpt 5.5 agents, by one order of magnitude.

that could not possibly be legit. "it must be hardcoding the benchmarks" (GPT trauma). so I read its explanation and what it did was, indeed, the most high impact optimization one could try first. seems like HVM5 was wasting a lot of time garbage-collecting unused branches of pattern-match nodes. I had optimized that for static mats, but not for dynamic mats. skill issue. Fable figured how to do it for these, resulting in a massive speedup in some benches

but wait, is that *correct*? I'm not sure yet, it is credible, but this is the kind of thing that is very easy to get wrong on interaction nets. the problem is, when I was ready to start auditing Fable's solution so I could tell whether it was buggy or legit, it interrupted me to tell me it had found a massive bug on the code *I* had written.

... wait, what?

so... for garbage collection purposes, I stored a bit on lambda term pointers that meant "the variable bound by this lambda has been freed, so, its lambda must free whatever argument it is applied to". that's fine. yet, on duplicator nodes, I also used the same bit to mean "one of the duplicated variables was freed, so, treat this dup as a passthrough no-op". so, if a lambda entered a duplicator, it would mistake the lambda's collection bit for its own, resulting in corrupted interaction!

that's a mouthful, why I'm writing this?

just so you can appreciate the sheer absurdity of what just happened. I didn't ask it to find bugs. I asked it for an optimization. and even if I did ask it to find bugs, this bug is so astonishingly subtle and specific, identifying it takes mastering the domain to an extent that it beyond even me. I'd easily need hours or days to fix it, *if* I ever came across it. chances are it would just go unnoticed. and Fable found it and fixed it like it was nothing, while it was busy adding a 17x speedup to a file that neither I, nor Opus 4.8, nor a fleet of GPT 5.5 managed to barely make 2x faster.

oh and there is also another tab where it is also ripping through Bend's codebase and finishing everything I had to do

I don't know what to say anymore

this isn't about Anthropic or OpenAI, this is about our collective future as a species. the world is changing, and we need to be aware of it, and discuss how to handle this change.

receipt below . . .

[SpaceX @SpaceX]

Watch @ElonMusk provide a technical update on SpaceX’s capability to manufacture, launch, and operate AI satellites at scale → https://t.co/PSCyWrNsOg