Prediction Endpoints

A Nyckel prediction endpoint is a REST API endpoint that accepts an input and returns a prediction with a confidence score. Each function (model) you create in Nyckel gets its own endpoint.

Invoke URL structure

POST https://www.nyckel.com/v1/functions/{functionId}/invoke

The functionId is found in the Nyckel console on your function’s details page.

Request format

Send the input as a JSON body with a data field.

Text input:

POST /v1/functions/{functionId}/invoke
Authorization: Bearer {token}
Content-Type: application/json

{ "data": "My subscription was cancelled without notice." }

Image input (URL):

POST /v1/functions/{functionId}/invoke
Authorization: Bearer {token}
Content-Type: application/json

{ "data": "https://example.com/photo.jpg" }

Tabular input:

POST /v1/functions/{functionId}/invoke
Authorization: Bearer {token}
Content-Type: application/json

{
  "data": {
    "age": 34,
    "plan": "pro",
    "logins_last_30d": 2
  }
}

Response format

Every invoke response includes labelName and confidence:

{
  "sampleId": "smp_abc123",
  "labelName": "Churn risk",
  "confidence": 0.88
}

The sampleId is important — store it if you plan to submit feedback later. See Build a feedback loop.

HTTP status codes