Evaluate (System One)

POST 
https://api.knox.chat/v1/systemone

Evaluate a state against a map of typed questions and return structured answers from Jev. This is not chat completion and does not stream. Guide: Jev.

Authenticate with a Knox API key. The same route is also served under /api/v1/systemone.

Request

Request Headers

Name	Type	Required	Description
Authorization	String	Yes	Bearer <token> Knox API key from Keys.
Content-Type	String	Yes	application/json.

Request Body

Name	Type	Required	Description
state	String, Object, Array, or null	Yes	Content to evaluate. Text only. A string, JSON object, array of text, or JSON null.
questions	Object	Yes	Non-empty map of question ID → question. Answers come back under the same IDs. IDs are not sent to the model.
model	String	No	jev-1.13.0, jev-latest, or jev-preview. Default jev-latest. Unknown IDs return 422.

Extra properties are forwarded upstream.

Question object

Every question requires type and instructions.

Name	Type	Required	Description
type	String	Yes	noul, choice, or score.
instructions	String, Object, Array, or null	Yes	The judgment to make about state.
criteria	Object or Array	Conditional	Required object map for choice. Required array of ≥ 2 levels for score. Optional { true, false } object for noul.

Noul — yes/no. Optional criteria: { "true": "...", "false": "..." }.

Choice — pick one option. criteria is a map of option ID → description (string or null).

Score — ordered rubric. criteria is an array of at least two level descriptions.

cURL Example

curl -X POST https://api.knox.chat/v1/systemone \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
  "state": "Hi, I have been trying to connect my Stripe account for 3 days and it keeps failing. I am losing sales. Please help ASAP.",
  "model": "jev-latest",
  "questions": {
    "department": {
      "type": "choice",
      "instructions": "Which team should handle this",
      "criteria": {
        "billing": "Payment or subscription issues",
        "technical": "Bugs or integration problems",
        "sales": "Pricing or account questions"
      }
    },
    "frustration": {
      "type": "score",
      "instructions": "How frustrated the customer appears",
      "criteria": [
        "Calm, just stating facts",
        "Frustrated but civil",
        "Very angry, strong language"
      ]
    },
    "is_urgent": {
      "type": "noul",
      "instructions": "The message conveys urgency or time-sensitivity"
    }
  }
}'

Response

Success Response (200)

model is the versioned ID that ran (for example jev-1.13.0), even if the request sent an alias.

{
  "model": "jev-1.13.0",
  "answers": {
    "department": {
      "type": "choice",
      "choice": "billing",
      "probabilities": {
        "billing": 0.84,
        "technical": 0.159,
        "sales": 0.001
      },
      "confidence": 0.596
    },
    "frustration": {
      "type": "score",
      "score": 1.035,
      "legend": {
        "0": "Calm, just stating facts",
        "1": "Frustrated but civil",
        "2": "Very angry, strong language"
      },
      "probabilities": {
        "0": 0.12,
        "1": 0.73,
        "2": 0.15
      },
      "confidence": 0.842
    },
    "is_urgent": {
      "type": "noul",
      "noul": 0.999
    }
  },
  "usage": {
    "input_tokens": 312,
    "output_tokens": 48
  }
}

Name	Type	Description
model	String	Versioned model that produced the answers.
answers	Object	One answer per question ID.
usage.input_tokens	Integer	Billed tokens. Knox charges $0.042 / million, minimum $0.0001 on success.
usage.output_tokens	Integer	Present and free.

Answer objects

type	Fields
noul	noul (0–1) — probability the statement is true.
choice	choice (selected option), probabilities (option → float, sums to 1), confidence (0–1).
score	score (can fall between levels), legend (index → description), probabilities, confidence.

Errors

Bodies are TypeSafe-shaped: { "detail": "..." } or a 422 field list.

{
  "detail": [
    {
      "loc": ["body", "questions"],
      "msg": "questions is required",
      "type": "value_error"
    }
  ]
}

Status	Meaning
401	Missing or invalid Knox token.
402	Insufficient credits.
403	Token model allowlist does not include this jev-* ID.
404	No Jev channel is available.
422	Validation failed (missing field, bad question, unknown model).
429	Rate limited. Honor Retry-After when present.
502	Failed to connect to provider.
529	Upstream overloaded. Retry with backoff.

Failed upstream calls are not billed. Knox does not automatically retry 429 / 529.