A/B Testing: Results

Curl examples for reading A/B test results, transaction logs, and enabling real-payment interception.

A/B Testing: Results

Once an experiment (see Create An Experiment) is active and taking traffic, use these endpoints to monitor it. Both routes below live under /analytics/ and require $TENANT_HEADER in addition to $AUTH_HEADER — see Environment setup.

Experiment Results

Runs a statistical significance test (two-sample z-test on expected value, or plain auth-rate when the experiment is auth-only) between the control and variant arms.

curl "$BASE_URL/analytics/experiment/routing_a1b2c3d4-1111-2222-3333-444455556666/results" \
  --header "$AUTH_HEADER" \
  --header "$TENANT_HEADER"

Optional query parameters: start_ms, end_ms, min_sample_size, guardrail_threshold_pp, evaluation_margin — override the experiment’s stored thresholds for an ad-hoc window or sensitivity check.

{
  "experiment_id": "routing_a1b2c3d4-1111-2222-3333-444455556666",
  "merchant_id": "merchant_demo",
  "control": {
    "arm": "control",
    "transaction_count": 4820,
    "success_count": 4531,
    "failure_count": 289,
    "auth_rate": 0.94,
    "first_attempt_auth_rate": 0.91,
    "total_cost_saved": null,
    "avg_latency_ms": 6.2,
    "avg_chosen_cost_bps": 182.4,
    "avg_cost_saved_bps": null,
    "net_ev_bps": 17660.0
  },
  "variant": {
    "arm": "variant",
    "transaction_count": 1204,
    "success_count": 1101,
    "failure_count": 103,
    "auth_rate": 0.914,
    "first_attempt_auth_rate": 0.887,
    "total_cost_saved": 962.3,
    "avg_latency_ms": 6.5,
    "avg_chosen_cost_bps": 150.1,
    "avg_cost_saved_bps": 32.3,
    "net_ev_bps": 17944.0
  },
  "delta_pp": -2.6,
  "p_value": 0.031,
  "confidence_interval": [-4.9, -0.3],
  "verdict": "variant_wins",
  "min_sample_size": 1000,
  "net_delta_bps": 284.0,
  "evaluation_margin": 0.2
}

Verdict Values

Verdict	Meaning
collecting_data	At least one arm hasn’t reached min_sample_size yet.
not_significant	Enough data, but the difference isn’t statistically significant.
variant_wins	Variant significantly outperforms control on net expected value.
variant_loses	Variant significantly underperforms control.
guardrail_breached	Variant’s auth rate dropped more than guardrail_threshold_pp below control — short-circuits before significance is even computed.

For an auth-only experiment (no cost data / multi-objective involved on either arm), the significance test collapses to a pure auth-rate z-test and cost-related fields (total_cost_saved, avg_cost_saved_bps, net_ev_bps, net_delta_bps) are null.

Experiment Transactions

Paginated per-transaction log — which arm each payment landed in and its outcome. Useful for spot-checking arm assignment or debugging a specific payment.

curl "$BASE_URL/analytics/experiment/routing_a1b2c3d4-1111-2222-3333-444455556666/transactions?page=1&page_size=20" \
  --header "$AUTH_HEADER" \
  --header "$TENANT_HEADER"

{
  "experiment_id": "routing_a1b2c3d4-1111-2222-3333-444455556666",
  "total": 6024,
  "transactions": [
    {
      "payment_id": "pay_9f21",
      "variant_arm": "variant",
      "gateway": "adyen",
      "status": "success",
      "created_at_ms": 1784271600000
    }
  ]
}

page_size is capped at 100. Optional start_ms narrows to a time window.

Enabling Real-Payment Interception

A newly created experiment does not affect live traffic until real-payment interception is turned on for the merchant:

curl --location "$BASE_URL/merchant-account/merchant_demo/features/ab-test-real-payments" \
  --header "$AUTH_HEADER" \
  --header "Content-Type: application/json" \
  --data '{ "enabled": true }'

See Merchant Features for the full feature-flag reference. Until this is enabled, /routing/evaluate still previews both arms for simulation purposes even though /decide-gateway traffic is unaffected.

Related

• A/B Testing: Create An Experiment
• Merchant Features
• Analytics Endpoints