Fetch Available Variants

Enterprise

This endpoint is part of Countly Enterprise. To get access, contact sales or compare versions. Existing customers can reach the support portal with questions.

Endpoint

/o/sdk?method=ab_fetch_variants

Overview

Fetch available variant names and values for active experiments (documents with status missing or status="running"), optionally filtered by parameter keys.

Authentication

Authentication Methods:

• App Key (parameter): app_key=YOUR_APP_KEY

Permissions

• No additional permissions required

Request Parameters

Parameter	Type	Required	Description
app_key	String	Yes	Application key
device_id	String	Yes	Device identifier used by the SDK request context; required by the live handler.
keys	String	No	JSON array of parameter names to filter by (empty array returns all)

Examples

Example 1: Fetch Variants for All Parameters

Request:

curl "https://your-server.com/o/sdk?method=ab_fetch_variants" \
  -d "app_key=YOUR_APP_KEY" \
  -d "device_id=DEVICE_ID"

Example 2: Fetch Variants for Specific Parameters

Request:

curl "https://your-server.com/o/sdk?method=ab_fetch_variants" \
  -d "app_key=YOUR_APP_KEY" \
  -d "device_id=DEVICE_ID" \
  -d 'keys=["button_text","header_text"]'

Response

Success Response

{
  "button_text": [
    {
      "name": "Control group",
      "value": "q"
    },
    {
      "name": "Variant A",
      "value": "w"
    }
  ]
}

Response Fields

Field	Type	Description
*	Object	Parameter name to variants array mapping
*.name	String	Variant name
*.value	Any	Parameter value for that variant

Error Responses

• Query error payload:

{
  "result": "Error while fetching ab-testing variants."
}

Behavior

• Handles /o/sdk?method=ab_fetch_variants and reads experiments from countly_out.ab_testing_experiments{appId}.
• Includes experiments whose status is missing or exactly running; draft and completed experiments are not returned.
• Parses keys as a JSON array. If omitted, it defaults to an empty array and all eligible experiment parameters are returned.
• For each experiment, the grouping key is the name of the first parameter in the first variant (variants[0].parameters[0].name).
• If keys is non-empty, an experiment is included only when that first parameter name is present in keys.
• For included experiments, the response maps the grouping key to an array of {name, value} objects, one per variant. value is taken from each variant's first parameter.
• On database errors, returns Error while fetching ab-testing variants.. Invalid keys JSON is not caught by this handler and can fail the request before a normal error payload is produced.

Limitations

• The live handler requires device_id even though this endpoint is read-only.
• keys must be a valid JSON array string.
• This endpoint uses the first parameter in the first variant as the grouping key for each experiment.

Related Endpoints

• Fetch Active Experiments
• Enroll User in Variant

Implementation details

Database Collections

Collection	Used for	Data touched by this endpoint
countly_out.ab_testing_experiments{appId}	Primary:	Experiment definitions and variants.