---
title: "System One"
method: POST
path: "/v1/systemone"
tags: ["systemone"]
---

# System One

`POST /v1/systemone`

## Request

- The document declares no server URL.
- Auth: none declared

Answer typed questions about one state (System One-compatible).

Clients written for the System One API work by changing their base URL.

## Headers

- `X-SIE-MACHINE-PROFILE` string, nullable
- `X-SIE-Remote` string, nullable: The only accepted value is `forbid`. It keeps the request off remote upstreams: local capacity serves or refuses it, and a model served only by an upstream answers 400. Any other value answers 400.

## Request body

- SystemOneRequest: A System One request: one state and its typed questions.
  - `model` string, required: SIE model id of a decision model, e.g. fastino/GLiNER2.5-Decide.
  - `state` union, required: The text to judge, or a JSON object, or a list of conversation turns.
    - string
    - object
    - unknown[]
      - unknown
  - `questions` object, required: Typed questions by id: {"type": "noul" | "choice" | "score", "instructions"?, "criteria"?}.

## Response `200`

Every question answered

- SystemOneResponse: Answers by question id, in the System One response shape.
  - `model` string, required
  - `answers` object, required
  - `usage` SystemOneUsage, required: Tokens the model read. Decision models generate no tokens.
    - `input_tokens` integer, required
    - `output_tokens` integer

## Other responses

- `404`: Model not found
- `422`: Invalid request: a malformed question, a model that does not answer typed questions, or a state or question set that does not fit the model's window
- `503`: Model loading or server busy; retry after Retry-After (at most 60 seconds)

## Changes

- **2026-10-16** `4f2089ca60f2`: 1 info
  - endpoint added
- **2026-10-16** `4b25a7ab2caf`: 1 breaking
  - api path removed without deprecation
- **2026-10-15** `106a86a48776`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/superlinked/apis/sie-server/changes/v1/systemone/post.md)

---

[API](https://skmtc.dev/superlinked/apis/sie-server.md) - [All operations](https://skmtc.dev/superlinked/apis/sie-server/llms.txt) - [OpenAPI document](https://skmtc.dev/superlinked/apis/sie-server/revisions/4ab6736e44c1?raw)