Get experiment score histogram with filters

POST

https://api.respan.ai/api/v2/experiments/:experiment_id/histogram/

POST

/api/v2/experiments/:experiment_id/histogram/

$ curl -X POST "https://api.respan.ai/api/v2/experiments/experiment_id/histogram/?evaluator_id=eval_456" \
>      -H "Authorization: Bearer <respanApiKey>" \
>      -H "Content-Type: application/json" \
>      -d '{}'

1 {
2   "evaluator_id": "eval_789:grader_v1",
3   "bins": [
4     {
5       "lower": 0,
6       "upper": 0.2,
7       "count": 15,
8       "label": null
9     },
10     {
11       "lower": 0.2,
12       "upper": 0.4,
13       "count": 30,
14       "label": null
15     },
16     {
17       "lower": 0.4,
18       "upper": 0.6,
19       "count": 45,
20       "label": null
21     },
22     {
23       "lower": 0.6,
24       "upper": 0.8,
25       "count": 60,
26       "label": null
27     },
28     {
29       "lower": 0.8,
30       "upper": 1,
31       "count": 50,
32       "label": null
33     }
34   ],
35   "stats": {
36     "min": 0.05,
37     "max": 0.98,
38     "mean": 0.65,
39     "total": 200
40   },
41   "evaluator_slug": "accuracy",
42   "evaluator_name": "Accuracy Evaluator"
43 }

Compute histogram aggregation for experiment evaluation scores. The backend reads evaluator_id and bins from query parameters; it does not consume a request body.

Authentication

AuthorizationBearer

Use your Respan API key for Respan API authentication. Enter only the Respan API key value; clients send Authorization: Bearer <RESPAN_API_KEY>. For /api/responses, OpenAI or Azure OpenAI provider credentials go in Settings -> Providers or the request body credential_override field, not in this auth field.

AuthorizationBearer

Use a dashboard JWT only for dashboard-authenticated endpoints. Respan API-key endpoints use the respanApiKey auth field instead.

Path parameters

experiment_idstringRequired

Experiment ID returned as id in experiment responses.

Query parameters

evaluator_idstringRequired

Evaluator ID, optionally including a grader suffix such as eval_123:grader_name.

binsintegerOptional1-50Defaults to 20

Number of histogram bins for numerical scores. Maximum 50.

Response

Experiment score histogram.

evaluator_idstring

binslist of objects

statsobject

evaluator_slugstring or null

evaluator_namestring or null

Errors

400

Bad Request Error

401

Unauthorized Error

404

Not Found Error