05 / Evidence record

TypeSafe, Jev & the evidence.

TypeSafe AI is the developer and commercial operator of Jev. The company position is that general-purpose autoregressive LLMs are structurally ill-suited for high-throughput software decision routing due to hallucination, non-determinism, and slow token generation. Jev was built to replace generative reasoning with calibrated, non-autoregressive decision classification.

Editorial Disclosure: Jev FYI is an independent technical reference. We are not TypeSafe AI, we do not receive compensation from TypeSafe AI, and this page distinguishes official vendor claims from officially documented operational behavior.

Documented specifications & integrations

Status: Verified against primary documentation

System One API endpoint contract

Officially Documented (TypeSafe)

POST /v1/systemone accepts shared state string and keyed questions object, returning strict JSON evaluation objects with structured answers.

Non-autoregressive decision architecture

Documented Architecture

TypeSafe documents that Jev outputs only categorical selections, probability distributions, continuous rubric scores, and binary truth probabilities. It does not generate prose, chat, or free-form token sequences.

Context window limit architecture

Officially Documented

TypeSafe documents a 64k-token total budget per request across state plus all questions combined, with a 32k-token cap for state plus the single longest question. OpenRouter lists Jev 1.13 with a 32,000-token context window in its model catalog.

Third-party platform integrations

Documented by Platforms

Available on OpenRouter via model ID 'typesafe/jev-1.13' (and alias '~typesafe/jev-latest'), on Vercel AI Gateway via 'typesafe-ai/jev', and on Cloudflare Workers AI via 'typesafe/jev'.

Published token pricing

Documented by Platforms

Billed at $0.042 per 1,000,000 input tokens; $0.00 for output tokens across both TypeSafe direct and OpenRouter.

Vendor Claims & Evaluation Metrics

Status: TypeSafe reported metrics; independent audits pending

Reinforcement Learning for Calibrated Decisions (RLCD)

TypeSafe Training Methodology

TypeSafe reports that Jev was trained using a custom RLCD framework to align output probabilities directly with empirical ground-truth error frequencies. See our complete technical analysis of the RLCD training paradigm and calibration metrics.

Reported 70ms to 500ms latency envelope

TypeSafe Performance Claim

TypeSafe reports internal cluster response times of 70ms to 500ms on early-access infrastructure. TypeSafe notes that published evals were run from laptops on the West Coast. Independent multi-region latency benchmarks have not been conducted by Jev FYI.

Workflow evaluation gains (up to 193.6× faster, 444.6× cheaper)

TypeSafe Evaluation Results

TypeSafe reports that in internal workflow evaluations comparing decomposed multi-step agent decisions, Jev was up to 193.6× faster and 444.6× cheaper than external LLM baselines wrapped in structured adapters. TypeSafe notes these figures represent the high end of achievable gains on decomposed workloads.

Guaranteed schema matching & type safety

Architecture Constraint (TypeSafe)

TypeSafe states that schema matching is guaranteed rather than empirical because Jev is constrained to predefined Choice, Score, or Noul structures. However, structural schema adherence eliminates JSON parsing syntax errors but does not guarantee semantic correctness or protect against misclassification.

TypeSafe Leadership Team

Verified from official TypeSafe company disclosures (September 2026).

typesafe.ai/team ↗
CEO
Diogo Almeida
CEO. Former OpenAI researcher and Google Brain engineer; co-inventor of RLHF (Reinforcement Learning from Human Feedback) and InstructGPT.
COO
Sasha Sheng
COO. Former research engineer at Meta/FAIR working on News Feed and AI Experiences; published work at NeurIPS and ECCV.
CTO
Erik Gafni
CTO. Repeat founder (Ravel) and early employee at Invitae and Freenome; specializing in production AI inference systems.