TypeSafe AI: The Company Behind Jev

At a glance

Item	Detail
Company	TypeSafe AI
Based in	San Francisco (office near the Embarcadero), in person five days a week
Product	System One models; the first is Jev
Founded	2024
Public launch	September 15, 2026, coming out of stealth
Founders	Diogo Almeida (CEO), Sasha Sheng (COO), Erik Gafni (CTO)
Funding	$40 million seed round led by DCVC, announced September 15, 2026
Website and docs	typesafe.ai, docs.typesafe.ai, console.typesafe.ai, status.typesafe.ai

Who founded TypeSafe AI?

TypeSafe AI was founded in 2024 by Diogo Almeida, Erik Gafni and Sasha Sheng. Almeida is the CEO and the public face of the company; Sheng is COO and Gafni is CTO. It is a private company and has not published an ownership breakdown.

Diogo Almeida, CEO. TypeSafe’s team page credits him with co-inventing RLHF and InstructGPT, the methods behind ChatGPT and GPT-4, and lists earlier work at Google Brain. In the launch post he writes that the work at OpenAI left him asking why chat models had not led to more automation. TechCrunch reports that he left OpenAI about two years ago to start TypeSafe.

Sasha Sheng, COO. A former research engineer at Meta’s FAIR lab who worked on News Feed and AI research, according to the team page.

Erik Gafni, CTO. A repeat founder whose earlier company, Ravel, worked on multi-modal AI for DNA sequencing, and an early employee at two unicorns, Invitae and Freenome, according to the team page.

The company says its wider team comes from OpenAI, Google Brain, Meta FAIR, Stripe, Airbnb, Plaid and Docker.

Funding

TypeSafe announced on September 15, 2026, the day Jev launched, that it had raised $40 million in seed funding led by DCVC, a venture firm that invests in deep-tech companies. DCVC general partner James Hardiman is quoted in the announcement. No other investors were named. Forbes’ launch-day article about the company calls it a “$200 million startup”; TypeSafe itself has not published a valuation.

What TypeSafe is trying to build

TypeSafe’s manifesto and documentation make one argument repeatedly: most future AI traffic will be software talking to software, not people chatting with bots, so models should behave like dependable components. The company’s phrase for it is “Build prod, not God”: narrow, testable decisions instead of one model that tries to do everything.

That shapes the product. Jev returns typed answers and calibrated probabilities instead of text, is trained with the company’s own method, RLCD, and is priced per billion input tokens with free output.

Timeline

Date	Event
Sep 15, 2026	Launch post “Introducing System One Models & Jev”; early access opens with a waitlist; $40M seed round led by DCVC announced; Vercel AI Gateway lists Jev the same day
Sep 15, 2026	The launch post draws about 1,900 points and 500 comments on Hacker News
Sep 17, 2026	Last review date of TypeSafe’s “Jev 1.13 jaggedness” page, which lists known weaknesses
Sep 18, 2026	OpenRouter adds typesafe/jev-1.13; TechCrunch profiles the company and reports that demand briefly overwhelmed the API
Sep 19, 2026	Cloudflare adds typesafe/jev to Workers AI
Sep 20, 2026	TypeSafe drops the waitlist and opens signups to everyone
Sep 21, 2026	Python SDK 0.7.1; Vercel and OpenRouter accept TypeSafe’s own request format
Sep 22, 2026	New signups paused because of demand; existing accounts keep working

For model versions, see the Jev changelog.

What TypeSafe has not disclosed

• Valuation and other investors. The $40 million seed round and its lead investor are public; the valuation and the rest of the cap table are not.
• Model details. Size, base model and training data are unpublished. See Is Jev an LLM?
• Pricing after early access. The launch post says TypeSafe expects prices to fall rather than rise, but makes no commitment.

Data and legal commitments

TypeSafe’s legal page links a Data Processing Agreement, a Master Customer Agreement and a Privacy Policy. The company states that it does not train its models on customer requests or responses, and offers zero data retention to enterprise customers. Its legal page now routes ZDR requests to [email protected]. See Does Jev train on your data?

Not to be confused with Typesafe (Lightbend)

Before 2016, the company behind the Scala programming language and the Akka toolkit was also called Typesafe; it renamed itself Lightbend. Searches for “typesafe config” or “typesafe scala” are about that older company and its libraries, not about TypeSafe AI or Jev. Programmers also use “type-safe” as an everyday term for code that the compiler checks for type errors. TypeSafe AI’s name plays on that meaning: its models’ answers always match the types you declare.

Contacting TypeSafe

This site is independent and cannot help with TypeSafe accounts. For access, billing or enterprise plans, use the console at console.typesafe.ai or the addresses in TypeSafe’s documentation ([email protected] for enterprise, [email protected] for data requests).