Ash Prabaker

member of technical staff @ anthropic

doing some things across applied ai and rl

views are my own duhh...

[Ash Prabaker @AshPrabaker]

fable 5 is the real deal. of course the benchmarks are great but *qualitatively* it’s a real pleasure to use and the biggest step up in model performance since opus 4.5

it was also one the first models i had the pleasure of working on at Anthropic, so it’s amazing to see it go live and have people try it out.

🧡

[Claude @claudeai]

Introducing Claude Fable 5: a Mythos-class model that we’ve made safe for general use.

Its capabilities exceed those of any model we’ve ever made generally available.

[roon @tszzl]

if you watched a stupid power scaling anime growing up it was the best preparation you can get for 2026 model scaling

[Ash Prabaker @AshPrabaker]

@bercankilic wen london!!!

[Ash Prabaker @AshPrabaker]

@ycombinator @revnu_app @artfreebrey active

[jacky @jjacky]

i have become middle manager

orchestrator of agents

[Ash Prabaker @AshPrabaker]

i recently did a talk on this at @swyx 's ai engineer conference - i think i did a pretty bad job at delivering it (jetlag rip)

the ideas from it were pretty good tho so just surfacing the post in case anyone is curious - (core work done by @rgb_prithvi)

https://t.co/HckWJmpzTc

[Ash Prabaker @AshPrabaker]

@tomasmenezesp 😮‍💨

[Ash Prabaker @AshPrabaker]

this is definitely one of the coolest things to happen at work recently

[Andrej Karpathy @karpathy]

Personal update: I've joined Anthropic. I think the next few years at the frontier of LLMs will be especially formative. I am very excited to join the team here and get back to R&D. I remain deeply passionate about education and plan to resume my work on it in time.

[Ash Prabaker @AshPrabaker]

@denpoint1 one of the main reasons research became interesting to me!

[Ash Prabaker @AshPrabaker]

@SwishMoe hashira training arc

[Ash Prabaker @AshPrabaker]

@BloggersVerse top 5

[Ash Prabaker @AshPrabaker]

@karpathy am i still allowed to ask you dumb research questions in slack instead of YouTube comments

[Sholto Douglas @_sholtodouglas]

When do you reach for other models instead of Claude? What can we do better? Hit me with all of your frustrations. dms open.

If you can give me detail (e.g. specifics/transcipts) - it'll help a lot in finding out exactly what we need to do to improve the next model

[Ash Prabaker @AshPrabaker]

there’s a lot of terrible takes out there but this isn’t one of them. captures a lot of feel for the London startup ecosystem that takes years to develop - nice work @Zainmbrk

https://t.co/otbTNXI45f

[Prime Intellect @PrimeIntellect]

Automating AI research is the next major step in AI

We let Claude Code (Opus 4.7) and Codex (GPT 5.5) run autonomously on the nanoGPT speedrun optimizer track using our idle compute. ~10k runs, ~14k H200 hours

Opus now holds the record at 2930 steps vs the 2990 human baseline

[Ash Prabaker @AshPrabaker]

@tokengobbler chilankan?!!!!

[Claude @claudeai]

We’ve agreed to a partnership with @SpaceX that will substantially increase our compute capacity.

This, along with our other recent compute deals, means that we’ve been able to increase our usage limits for Claude Code and the Claude API.

[Ash Prabaker @AshPrabaker]

a lot of startups should be more ambitious what what they think an intelligence unconstrained version of their products look like

beyond automating what a human doing the task end to end would do even

lots of alpha here

[Ash Prabaker @AshPrabaker]

@georgecurtiss goes to stockholm -> first stop irish pub ;)