Phosphor Capital invests in the top founders in each Y Combinator batch. Typical check size is $100k - $500k.
San Francisco
Joined March 2025
- Tweets161
- Following230
- Followers219
- Likes324
Phosphor Capital retweeted
Agent memory gets harder the longer a chat runs.
We wondered: how well does Observational Memory hold up at 100K, 1M and 10M tokens? So we ran it on BEAM, the long-term memory benchmark, with default settings.
Turns out it has the top published scores at 100K and 1M:
Phosphor Capital retweeted
Introducing Astraeus.
High mobility. Long duration operations. Greater freedom to maneuver.
Redefining what spacecraft can do in orbit.
Built by Orbital Operations.
Concept video produced by London Studio @ZeroOneCreative and a special thanks their team @ashkan01C, @Rupert01C and @james_01c
Phosphor Capital retweeted
Finally, you can get real healthcare directly from your Claude, ChatGPT, GrokBot, Muse, or Instinct.
Just tell them to use FutureClinic. Agents welcome.
Healthcare will never be the same again.
Backed by @ycombinator
Phosphor Capital retweeted
today, we're launching the General Video Agent.
GVA edited this entire launch video. 👇🏽
public beta is now live at motion.so/gva. no waitlist.
comment “GVA” for 1,000 free credits.
examples & capabilities in thread 🧵
Phosphor Capital retweeted
1) Today we're announcing Atomwell, our state-of-the-art foundation model for predicting experimental outcomes, alongside scaling laws for molecular discovery.
We trained models from 800M to 9B parameters on ~80M experimental measurements, and found clean scaling laws in both model size and data.
Phosphor Capital retweeted
the newest frontier is agent swarms. watch us launch 700 sandboxes -- all connected to the same file system -- in 10s, then have them collaborate and build a city on that file system
i used sandboxes here, but if i used serverless tool calling? the total cost of this compute would be $0.28
the future is packing agents 40x tighter on each CPU and giving them access to the same shared file system context
could it run like this but kind of on the 'same' file system? nitter.cf/AniC_dev/status/211120…
Phosphor Capital retweeted
we were in pivot hell 6 months ago around when cursor announced composer 2.5, a high quality post-train of an oss base
made this diagram internally in May, earmarking open space in what will be a much larger category than coding
Phosphor Capital retweeted
We are building reusable heavy-lift rockets to take on SpaceX, powered by an engine designed with 90% fewer parts. First engine hot-fired 4 months in, from a basement, for under $30K. $400M in launch reservations signed. Satellite operators: let’s talk @ycombinator
Phosphor Capital retweeted
Congrats on your YC launch RATLOG @_charlieweise!
An extremely fast moving, resourceful team I was very excited to fund for the F26 batch with @ycombinator.
In 4 months they went from first build to a hot-fired engine, spending under $30K.
$400M in launch reservations already signed (so much demand that they skipped the usual LOI step that hardware companies go through).
We are building reusable heavy-lift rockets to take on SpaceX, powered by an engine designed with 90% fewer parts. First engine hot-fired 4 months in, from a basement, for under $30K. $400M in launch reservations signed. Satellite operators: let’s talk @ycombinator
Very cool launch!
Excited to be a part of it.
Phosphor Capital retweeted
We are releasing Ultramarine 1 Flash, a frontier-class model built for knowledge work. It is open-source and achieves similar performance to Fable 5, while being 60x cheaper.
It was post-trained by a team of 5 for ~$300k all-in. Available on API now, with weights releasing in 2 weeks.
Phosphor Capital retweeted
Very excited about this one: Today we're launching the b12 Foundry in partnership with the High-Throughput Experimentation Lab at the University of Zurich. AI can now design a molecule in seconds, but making it can still take a chemist several weeks. b12 Foundry closes that gap. b12-labs.com/foundry
Phosphor Capital retweeted
HIRING: I'm looking for an AI SEO Lead for the Sunflower Clinic that's going to work IRL in Buenos Aires directly working with me. 🌻
At Rupa we executed a 0 - 500k clicks/mo SEO strategy that propelled us from $5M - $75M/yr rev
This will change your life. Join us.
ALT Rupa Health organic traffic
Phosphor Capital retweeted
Introducing DeepRSI, a new industry standard for measuring recursive self-improvement.
On preexisting benchmarks, tasks are contributor-based and short-horizon (~12 hrs). In DeepRSI, we push agents to work 48 hours on ML tasks actually derived from ongoing proprietary research.
Phosphor Capital retweeted
We built an 8000 sqft. high-throughput wet-lab in 30 days, to solve molecular discovery - starting with pesticides.
Most teams in drug-discovery don’t receive target-organism verification until clinical trials. Pesticides allow us to rapidly validate our model in the target organism directly. With the help of our high-throughput lab, we were able to generate compounds that killed a $13 billion pest, the Fall Armyworm.
We believe that the bitter lesson is coming for biology.
Phosphor Capital retweeted
Robotics has a distribution problem. Today, Ultra is announcing $62M in funding to solve it, including a $50M Series A led by @hiFramework.
We believe that deployment is the bottleneck in robotics.
It’s relatively easy to make a robot look impressive in a controlled environment. It’s much harder to put a robot into the open world, make it useful, keep it running, earn the trust of the people working alongside it, and do that over and over and over again.
So that’s what we’re focusing on.
Phosphor Capital retweeted
Introducing AgentID by @agentmail, "Sign in with Google" for AI Agents
Millions of agents already use AgentMail. AgentID lets them sign in to your app.
Integrate with the prompt below, reply with a screenshot, and we'll give you 3 months free of any AgentMail plan.
Phosphor Capital retweeted
Introducing Agentic Payments on Brainbase. We’ve partnered with @stripe to allow Brainbase agents to make purchases for you using secure Link checkout flows. This enables everything from proactive agents that can book travel, order office supplies and subscribe to software.
Try it out today at brainbaselabs.com.
Phosphor Capital retweeted
Brainbase is now on AWS Marketplace. This means that the entire Brainbase platform is deployable in a single click, runs entirely inside your network, and spends from your existing AWS commitment.
To learn about how enterprises can use our AWS Marketplace offering, read more here: brainbaselabs.com/blog/brain…
Phosphor Capital retweeted
The world spends roughly $100 billion a year on experimentation in Life-Science. Yet, 93% of drug programs entering Phase I never reach approval.
Halmos Labs is changing that
See how at halmoslabs.com