Jev glossary
API & ModelsPOST /v1/systemone
System One endpoint
The single HTTP endpoint that evaluates a state against typed questions: POST https://api.typesafe.ai/v1/systemone.
- Category
- API & Models
- Also known as
- POST /v1/systemone
- Reading time
- 1 min
- Related terms
- 5
- Directory entries
- 28
- Docs
- docs.typesafe.ai
- Added
- 2026-09-24
Definition
Every request carries a state, a model, and a map of typed questions. The response returns one answer per question under the same IDs, plus the model that answered and token usage.
There is no separate endpoint per primitive; Choice, Score, and Noul mix freely in one call. Official SDKs wrap this endpoint, but the HTTP contract is documented for every other language.
Tagsapicore
Related terms
Definitions that connect to this one.
API keyThe bearer credential for the TypeSafe API, created in the console and read from TYPESAFE_API_KEY by the official SDKs.API & Modelsmodel fieldThe required request field that selects which model handles the call; accepts versioned IDs and aliases.API & ModelsQuestion IDThe key you choose for a question; answers come back under the same key, and the ID is never sent to the model.PrimitivesClient SDKThe official typed clients for the API (Python and JavaScript/TypeScript), with retries and inferred answer types.API & ModelsUsageThe response field reporting input and output token counts for a request, used for cost tracking.API & Models
From the Jev directory
Directory entries that go deeper on this term.
The raw HTTP contract behind every SDK: POST a state plus typed noul, choice, and score questions to /v1/systemone, and get one answer per question, with error codes and retry guidance.
Jev Guides & ArticlesDocs#official#docs#api
Official
Everything you need to make your first request: install an SDK, get an API key, and send state plus typed questions.
Jev Guides & ArticlesDocs#docs#official#quickstart
Official
A FastAPI backend from SiliconLabAI that serves an OpenAI-compatible chat and tool-calling API plus a Jev-style POST /v1/systemone endpoint for typed decisions, powered by cactus-needle on CPU edge devices. The first request downloads the Needle weights once.
Jev Repos & SDKs#community#github#python
Community
siliconlabai/openjev-cactusPython
siliconlabai/openjev-cactusPythonAn unofficial Rust client for TypeSafe's System One API behind Jev: typed Noul, Choice, Score and Box questions, images, and both async and blocking clients. Its behaviour follows the official Python SDK, with the same environment variables, retry policy and error kinds.
Jev Repos & SDKs#community#github#rust
Community
phiat/typesafe-rust-sdkRust
phiat/typesafe-rust-sdkRustA self-hosted System One API billed as drop-in compatible with TypeSafe Jev: a bidirectional encoder with direct decision heads returns calibrated probabilities and structured choices in a single forward pass of about 33 ms.
Jev Repos & SDKs#community#github#fastapi
Community
ZulfiFazhar/system-oneHTML
ZulfiFazhar/system-oneHTMLA small HTTP service that adds a decision interface to any chat model: POST /v1/decision evaluates a finite set of candidate labels in one forward pass, reads next-token logits and returns structured JSON without model.generate() or output decoding.
Jev Tools & CLIs#community#github#python
Community
siyehua/jevPython
siyehua/jevPython22 more matching entries in the full directory.
From the Jev AI model community
Posts from builders shipping with Jev right now.