Runtimes & Harnesses

Decision interfaces without trained weights — use your own LLMs as classifiers.

These are NOT models. They extract decisions from existing LLMs via constrained decoding, logit readout, or wrapper APIs. No trained decision weights — the decision capability comes from inference-time techniques on frozen base models.

Looking for trained decision models? See the Model catalog.

bandr.ai (bandr-ai)

Bandits · Your own Jev recipe

MethodResearch

Recipe in the Bandits toolkit that LoRA-tunes Qwen3.5-4B-Base into a per-step agent-trace judge on your own labels. No checkpoint, no license, no inference server.

Why not a model

Ships a training recipe, not a model: LoRA on Qwen3.5-4B-Base, local training UI, scorecard vs Jev via /v1/systemone. No released weights, no license.

Base LLMs
Qwen/Qwen3.5-4B-Base
Types
choice
Stars
~28
Full details

classifier.dev

classifier.dev

Wrapper

HTTP/CLI/MCP wrapper over hosted Jev with smart escalation to reasoning LLMs for uncertain cases.

Why not a model

Hosted wrapper over Jev API — not a separate model, just a convenience layer.

Base LLMs
jev-1.13
Types
choice · score · boolean
Full details

Cua AI

CUA-S1-FORMS

SpecialistResearch

Lightweight specialist (~706k params) for scoring form field actions: use, check, click, skip.

Why not a model

Narrow-task specialist for form field actions — not a general-purpose System One decision model.

Base LLMs
custom-706k
Types
choice
Stars
~706
Full details

notnotsamuel

LFM2.5-350M-RLCD

MethodResearch

Research method for parallel constrained scoring on frozen LiquidAI LFM2.5-350M weights.

Why not a model

Parallel constrained scoring on unchanged LiquidAI weights — name 'RLCD' ≠ TypeSafe RLCD training method.

Base LLMs
LiquidAI/LFM2.5-350M
Types
choice
Full details

zhengxuyu

litjev

Method

Lightweight method that wraps Qwen checkpoints to serve TypeSafe-compatible decisions locally.

Why not a model

Wraps off-the-shelf Qwen checkpoints as Jev-schema decisions — probabilities are uncalibrated by default.

Base LLMs
Qwen
Types
choice · score · boolean
Full details

Ollama

Ollama

Runtime

Ollama v0.35+ adds a native, TypeSafe-compatible /v1/systemone endpoint and three decision models: nimble, tev1 and tev1:0.8b. Local only for now.

Why not a model

Inference server. Since v0.35 it serves decision models trained by others (Nimble, Tev1) on a local /v1/systemone endpoint; it has no decision weights of its own.

Base LLMs
Bespoke-Nimble-9B, Tev1-4B-experimental, Tev1-0.8B-experimental
Types
choice · noul · score
Stars
~182,000
Full details

ollaya-dev

Ollaya

Runtime

Ollama for decision models: pull and serve open decision models locally behind a TypeSafe-compatible API.

Why not a model

Serves existing open decision models locally (Laya, Decider, NLI, GLiClass, Kev, Von); no trained weights of its own — it's distribution and inference infra.

Base LLMs
Types
choice · score · boolean
Stars
~935
Full details

ikermoel (Iker Moel Tacher)

Open Alternative to Jev

Runtime

Python library (import so1) that packs several typed questions into one forward pass of a stock open LLM and reads option-letter logits. HF Transformers and vLLM backends.

Why not a model

Reads option-letter logits from stock open LLMs (Qwen) in one packed forward pass. No decision training; calibration is an optional temperature you fit yourself.

Base LLMs
Qwen3.6-27B, Qwen3.5-4B, Qwen3.5-2B…
Types
choice · boolean · score
Stars
~54
Full details

Limited-preview OpenAI API that points GPT-6 Luna at your own questions with a fixed set of answers (text or image context). Not the same product as OpenRouter's Decisions API.

Why not a model

No dedicated decision weights documented. OpenAI serves it on a version of GPT-6 Luna and it returns "a selection"; no public docs, schema or pricing yet. Re-check at broad release.

Base LLMs
GPT-6 Luna (a version of)
Types
choice
Full details

ekzhang

openjev-sglang

Runtime

SGLang-based runtime providing TypeSafe-compatible /v1/systemone endpoint over Qwen3.6-35B-A3B.

Why not a model

TypeSafe-compatible endpoint over Qwen via SGLang prefill/logprob hack — not a trained decision model.

Base LLMs
Qwen3.6-35B-A3B
Types
choice · score · boolean
Full details

alperiox

Prosodia

SpecialistResearch

Audio-native Jev-shaped decisions without ASR text decode — processes audio directly.

Why not a model

Audio modality specialist — not a text-based System One peer; different input domain entirely.

Base LLMs
whisper-encoder
Types
choice · score · noul
Full details

TheoLeeCJ

SemIf

Runtime

Browser-first runtime that extracts typed decisions from frozen open LLMs via WebGPU/wllama.

Why not a model

Reads typed option logits from frozen open LMs — no trained decision weights, just inference-time logit extraction.

Base LLMs
Qwen3.5-4B, MiniCPM5-2B, MiniCPM5-4B…
Types
choice · score · boolean
Stars
~1,900
Full details

Featherless AI

simple-jev

Runtime

Featherless stack that converts any open LLM into a typed decision classifier via next-token logits.

Why not a model

Turns any compatible open LM into a typed classifier via next-token logits — no fine-tuning required.

Base LLMs
any-open-lm
Types
choice · score · noul
Full details

TypeLLM

TypeLLM

Runtime

SGLang-based runtime for type-safe generation on autoregressive LLMs, with thinking mode and image input. Open source, and since 29 Sep 2026 also a hosted playground and API.

Why not a model

Constrained decoding layer over existing autoregressive LLMs — does not change architecture or weights.

Base LLMs
Qwen3.8-27B, Qwen3.5-0.8B, Qwen3.5-4B…
Types
choice · boolean · integer · number · string
Stars
~885
Full details

mode-io

vLLM Jev

Runtime

Native vLLM (Linux) and Apple Silicon serving for open Jev-style decision checkpoints: Choice/Noul/Score over HTTP /v1/systemone, including Valen multimodal.

Why not a model

Serving engine for existing Jev-style checkpoints (vLLM on Linux, MLX/MPS on Mac). No decision training — it selects a protocol and runs inference.

Base LLMs
ZefanCai/Open-Jev-2B, OpenJev-0.6B, Tiny-Jev…
Types
choice · boolean · score
Stars
~94
Full details