The Experiment Object

An object that represents an experiment, including its variants and per-variant story mappings.

Properties

• id number

  Numeric ID of the experiment.

• name string

  Technical name of the experiment. Lowercase letters, numbers, and underscores only. Immutable after creation.

• display_name string

  Human-readable display name of the experiment.

• description string

  Description of the experiment. null if there’s no description.

• status string

  Status of the experiment. One of draft, running, paused, or completed.

• started_at string

  The experiment’s first activation date and time (ISO 8601). null until activating the experiment.

• ended_at string

  The experiment’s completion date and time (ISO 8601). null until completing the experiment.

• created_at string

  The experiment’s creation date and time (ISO 8601).

• updated_at string

  The experiment’s latest update date and time (ISO 8601).

• story_ids number[]

  Array of story IDs associated with the experiment.

• winning_variant_id number

  Numeric ID of the winning variant. null until the experiment is completed with a winning variant.

• experiment_variants object[]

  Array of variants that belong to the experiment.

  Show child properties

  • id number

    Numeric ID of the variant.

  • name string

    Technical name of the variant. Lowercase letters, numbers, and underscores only.

  • display_name string

    Human-readable display name of the variant.

  • public_id string

    Public identifier of the variant. Used by client-side experimentation logic to reference the variant.

  • weight number

    Traffic weight of the variant in percent (0–100). The sum of all variant weights in an experiment must equal 100.

  • is_control boolean

    true if the variant is the control. The control is the baseline for measurements against other variants.

  • story_mappings object[]

    Array of mappings from original stories to variant stories.

    Show child properties

    • experiment_variant_id number

      Numeric ID of the variant the mapping belongs to.

    • original_story_id number

      Numeric ID of the original (main) story.

    • variant_story_id number

      Numeric ID of the variant story that replaces the original story when the loading the variant.

    • original_slug string

      full_slug of the original story.

    • variant_slug string

      full_slug of the variant story. Storyblok derives the variant slug from the original slug, the experiment’s technical name, and the variant’s technical name, joined with hyphens.

    • variant_story object

      The variant story object.

Example Response

{
"experiment": {
  "id": 176070002766742,
  "name": "a_simple_experiment",
  "display_name": "A simple experiment",
  "description": null,
  "status": "running",
  "started_at": "2026-01-15T10:00:00.000Z",
  "ended_at": null,
  "created_at": "2026-01-10T09:00:00.000Z",
  "updated_at": "2026-01-15T10:00:00.000Z",
  "story_ids": [176024833123843],
  "winning_variant_id": null,
  "experiment_variants": [
    {
      "id": 1001,
      "name": "control",
      "display_name": "Control",
      "public_id": "var_uhjedoghzx68",
      "weight": 70,
      "is_control": true,
      "story_mappings": []
    },
    {
      "id": 1002,
      "name": "test",
      "display_name": "Test",
      "public_id": "var_xhicas8uin5l",
      "weight": 30,
      "is_control": false,
      "story_mappings": [
        {
          "experiment_variant_id": 1002,
          "original_story_id": 176024833123843,
          "original_slug": "home",
          "variant_story_id": 176070141098149,
          "variant_slug": "home-a_simple_experiment-test"
        }
      ]
    }
  ]
}
}