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Code-owned definitions and `.drip.config.ts`

Define experiments and feature flags in TypeScript, then pair them with Apex CLI GitOps push.

The SDK exports helpers for typed, validated code-owned experiment definitions. Use them when experiments live near application code or when feature flags need typed values.

defineExperiment

ts
import { defineExperiment, init } from "@drip-apex/sdk";
 
const productBadge = defineExperiment({
  slug: "product-page-trust-badge",
  name: "Product page trust badge",
  trafficAllocation: 0.5,
  variations: [
    {
      id: "control",
      weight: 0.5,
      isControl: true,
      mutations: []
    },
    {
      id: "badge",
      weight: 0.5,
      mutations: [
        {
          selector: "[data-add-to-cart]",
          action: "insertAfter",
          html: "<p data-apex-trust-badge>Secure checkout and fast support.</p>"
        }
      ]
    }
  ],
  goals: [
    { id: "add-to-cart-click", type: "click", selector: "[data-add-to-cart]" }
  ]
});
 
init({
  experiments: [productBadge],
  endpoint: "https://events.drip-apex.com"
});

defineExperiment returns a frozen Experiment object with the slug as the experiment ID. It throws ExperimentDefinitionError when required fields, variation weights, control variation rules, or click goal selectors are invalid.

defineExperiments

ts
import { defineExperiments } from "@drip-apex/sdk";
 
export const experiments = defineExperiments([
  {
    slug: "homepage-proof-copy",
    name: "Homepage proof copy",
    variations: [
      { id: "control", weight: 0.5, isControl: true },
      { id: "proof", weight: 0.5, mutations: [] }
    ]
  },
  {
    slug: "cart-empty-state",
    name: "Cart empty state",
    variations: [
      { id: "control", weight: 0.5, isControl: true },
      { id: "helpful-links", weight: 0.5, mutations: [] }
    ]
  }
]);

defineFlagExperiment

ts
import { defineFlagExperiment } from "@drip-apex/sdk";
 
export const progressUiFlag = defineFlagExperiment({
  slug: "checkout-progress-ui",
  name: "Checkout progress UI",
  rolloutPercent: 25,
  offValue: false,
  onValue: true
});

defineFlagExperiment creates a two-variation experiment where control is off and enabled is on. rolloutPercent is clamped between 0 and 100.

.drip.config.ts

Pair code-owned definitions with the CLI when you want GitOps sync into Apex:

ts
import { defineExperiments, defineFlagExperiment } from "@drip-apex/sdk";
 
export default {
  experiments: [
    ...defineExperiments([
      {
        slug: "homepage-proof-copy",
        name: "Homepage proof copy",
        variations: [
          { id: "control", weight: 0.5, isControl: true },
          { id: "proof", weight: 0.5, mutations: [] }
        ]
      }
    ]),
    defineFlagExperiment({
      slug: "checkout-progress-ui",
      name: "Checkout progress UI",
      rolloutPercent: 25
    })
  ]
};

Then push with the CLI:

bash
apex push --config ./.drip.config.ts --dry-run
apex push --config ./.drip.config.ts