Evaluators API

Evaluators define the scoring functions applied to traces. Evaluator lists group multiple evaluators together and are referenced when creating experiments and evaluation executions.

Evaluator Lists

Create Evaluator List

POST /api/public/evaluator-lists

Field	Type	Required	Description
`name`	`string`	Yes	Unique name for the evaluator list
`description`	`string`	No	Description
`evaluators`	`array`	Yes	At least one evaluator config
`evaluators[].evaluatorId`	`string`	Yes	ID of the evaluator
`evaluators[].params`	`array`	Yes	Parameter bindings
`evaluators[].params[].key`	`string`	Yes	Parameter key
`evaluators[].params[].value`	`string`	No	Parameter value
`evaluators[].params[].dataType`	`string`	Yes	One of: `string`, `integer`, `float`, `boolean`, `string[]`, `integer[]`, `float[]`, `boolean[]`, `list`, `dict`

curl -X POST https://evals-api.browserstack.com/api/public/evaluator-lists \
  -u "pk-lf-...:sk-lf-..." \
  -H "Content-Type: application/json" \
  -d '{
    "name": "rag-evaluators",
    "description": "Evaluators for RAG pipeline",
    "evaluators": [
      {
        "evaluatorId": "correctness-evaluator-id",
        "params": [
          { "key": "threshold", "dataType": "float", "value": "0.7" }
        ]
      },
      {
        "evaluatorId": "faithfulness-evaluator-id",
        "params": [
          { "key": "strict", "dataType": "boolean", "value": "true" }
        ]
      }
    ]
  }'

Response:

{
  "id": "eval-list-uuid-1",
  "name": "rag-evaluators",
  "description": "Evaluators for RAG pipeline",
  "projectId": "proj-xyz",
  "createdAt": "2026-04-03T10:00:00.000Z",
  "updatedAt": "2026-04-03T10:00:00.000Z",
  "evaluatorConfigs": [
    {
      "id": "config-uuid-1",
      "evaluatorId": "correctness-evaluator-id",
      "evaluator": {
        "id": "correctness-evaluator-id",
        "name": "Correctness",
        "description": "Measures factual accuracy",
        "order": 1,
        "createdAt": "2026-01-01T00:00:00.000Z",
        "updatedAt": "2026-01-01T00:00:00.000Z"
      },
      "params": [
        { "key": "threshold", "value": "0.7", "dataType": "float" }
      ]
    }
  ]
}

List Evaluator Lists

GET /api/public/evaluator-lists

Parameter	Type	Description
`page`	`integer`	Page number (default: `1`)
`limit`	`integer`	Items per page (default: `50`)
`orderBy`	`object`	`{ column: string, order: "ASC" \| "DESC" }`

curl "https://evals-api.browserstack.com/api/public/evaluator-lists?page=1&limit=20" \
  -u "pk-lf-...:sk-lf-..."

Response:

{
  "evaluators": [
    {
      "id": "eval-list-uuid-1",
      "name": "rag-evaluators",
      "description": "Evaluators for RAG pipeline",
      "projectId": "proj-xyz",
      "createdAt": "2026-04-03T10:00:00.000Z",
      "updatedAt": "2026-04-03T10:00:00.000Z",
      "evaluatorConfigs": [...]
    }
  ],
  "totalCount": 1
}

Get Evaluator List

GET /api/public/evaluator-lists/{evaluatorListId}

curl "https://evals-api.browserstack.com/api/public/evaluator-lists/eval-list-uuid-1" \
  -u "pk-lf-...:sk-lf-..."

Delete Evaluator List

DELETE /api/public/evaluator-lists/{evaluatorListId}

curl -X DELETE "https://evals-api.browserstack.com/api/public/evaluator-lists/eval-list-uuid-1" \
  -u "pk-lf-...:sk-lf-..."

Evaluators

Individual evaluator definitions are managed via the evaluators endpoint.

List Evaluators

GET /api/public/evaluators

curl "https://evals-api.browserstack.com/api/public/evaluators" \
  -u "pk-lf-...:sk-lf-..."

Get Evaluator

GET /api/public/evaluators/{evaluatorId}

curl "https://evals-api.browserstack.com/api/public/evaluators/correctness-evaluator-id" \
  -u "pk-lf-...:sk-lf-..."

Parameter Data Types

`dataType`	Description
`string`	Single string value
`integer`	Integer number
`float`	Floating-point number
`boolean`	`true` or `false`
`string[]`	Array of strings
`integer[]`	Array of integers
`float[]`	Array of floats
`boolean[]`	Array of booleans
`list`	Generic list
`dict`	Generic object/dictionary

Evaluators API

On this page