Home Companies Riften Riften Active · Earned intelligence. An independent AI research lab.
8 signal of 100 · rising 8
team of 5 Team size · YC's directory +4 went through YC Program · this site +4 A sum of public facts, not a judgement and not investment advice.
Competitors AI Experiential Labs Shared: reinforcement learning, infrastructure, earned AI Unify Shared: reinforcement learning, infrastructure, model AI Vibrant Labs Shared: reinforcement learning, environment, training AI Inactive Nuntius Shared: reinforcement learning, model, intelligence AI Synthetic Sciences Shared: training environment, reinforcement learning, labs Other Patronus AI Shared: environment, evaluation, training Companies closest to Riften Company Category Status Program Experiential Labs Shared: reinforcement learning, infrastructure, earned YC S26 · · AI, Devtools AI, Devtools YC S26 Unify Shared: reinforcement learning, infrastructure, model YC W23 · · AI, Devtools AI, Devtools YC W23 Vibrant Labs Shared: reinforcement learning, environment, training YC W24 · · AI, Devtools AI, Devtools YC W24 Nuntius Shared: reinforcement learning, model, intelligence YC S25 · · AI, Devtools AI, Devtools YC S25 Synthetic Sciences Shared: training environment, reinforcement learning, labs YC W26 · · AI, Devtools AI, Devtools YC W26 Patronus AI not in a program here Shared: environment, evaluation, training Elsewhere · Other Other Elsewhere
Adjacent AI Autoresearch, Inc. Shared: reinforcement learning, infrastructure, model AI Synth Shared: reinforcement learning, model, choose AI Morph Shared: model routing, workload, coding AI Twolabs Shared: coding environment, model, evaluate AI Osmosis Shared: reinforcement learning, infrastructure, model Companies next to Riften Company Category Status Program Autoresearch, Inc. Shared: reinforcement learning, infrastructure, model YC S26 · · AI, Devtools AI, Devtools YC S26 Synth Shared: reinforcement learning, model, choose YC F24 · · AI, Devtools AI, Devtools YC F24 Morph Shared: model routing, workload, coding YC S23 · · AI, Devtools AI, Devtools YC S23 Twolabs Shared: coding environment, model, evaluate YC X26 · · AI, Devtools AI, Devtools YC X26 Osmosis Shared: reinforcement learning, infrastructure, model YC W25 · · AI, Devtools AI, Devtools YC W25
Company Category Status Archal API sandboxes, built for AI agents team of 2 · AI, Devtools AI, Devtools Inkbox The identity and communication layer for AI agents team of 3 · AI, Devtools AI, Devtools Rindler The IDE for Tokenmaxxers team of 2 · AI, Devtools AI, Devtools Tokenless We find flaws in RL environments and evals and help you fix them. team of 3 · AI, Devtools AI, Devtools Agnost AI We find where AI agents fail, then train better models to run them. 2 programs team of 2 · AI, Data, Devtools AI, Data, Devtools Caution Hosting platform for software you can't afford to have hacked team of 5 · AI, Devtools AI, Devtools
Founders CS Carl Stauffer Founder/CEO About Riften Riften is an independent AI research lab exploring intelligence in software and the physical world.
We study how models learn and represent knowledge, and build systems that put that research to work. Our work spans model routing, evaluations, post-training, and physical AI.
Earned intelligence.
YC batch S26 · Summer 2026 Status, per YC Active Category AI, Developer tools Team size 5 Location San Francisco, CA, USA Founded 2026 Checked 13h ago YC tags: Developer Tools , Reinforcement Learning , Infrastructure , AI
Changes seen One-liner Nov 9, 2026
Rewrote its one-liner; it read "Earned intelligence for every company"
Tags Oct 8, 2026
No longer tagged Open Source.
Riften in S26: 229 companies, 88% AI
Riften: questions Which YC batch was Riften in? Riften was in Y Combinator's Summer 2026 batch (S26).
Is Riften still active? Y Combinator lists Riften as active.
Who founded Riften? Riften's founders, as listed on its YC page: Carl Stauffer (Founder/CEO).
Where is Riften based? Riften lists San Francisco, CA, USA as its location on YC's directory.
Startupsby Glyph