@headlessly/experiments

LaunchDarkly manages feature flags. Optimizely runs A/B tests. Neither knows what your customers are paying or why they churn.

import { Experiment, FeatureFlag } from '@headlessly/experiments'

await Experiment.create({
  name: 'Pricing Page CTA',
  type: 'ABTest',
  hypothesis: 'Changing CTA to "Get Started" increases conversions by 15%',
  primaryMetric: 'signup_conversion',
  trafficAllocation: 100,
})
await Experiment.start('experiment_fX9bL5nRd')

// An experiment concludes — billing, CRM, and marketing react instantly
Experiment.concluded(async (experiment, $) => {
  await $.FeatureFlag.enable(experiment.winner)
  await $.Campaign.create({ name: `Roll out ${experiment.name}`, type: 'Email' })
  await $.Event.create({ type: 'experiment.concluded', value: experiment.winner })
})

No LaunchDarkly SDK. No Optimizely webhook relay. No Split analytics pipeline. Experiments, feature flags, and the entire business graph — in one typed system your agent can operate autonomously.

The Problem

LaunchDarkly charges per seat for feature flags that live in complete isolation from your business data. Optimizely runs A/B tests that require custom analytics instrumentation to measure anything meaningful. Split gives you both but needs three integrations to connect flags to metrics to users.

None of them were built for an AI agent to operate.

Your agent doesn't need a flag management dashboard. It needs FeatureFlag.enable(). It doesn't need an experiment results page with confidence interval charts. It needs Experiment.conclude(). It doesn't need a "targeting builder" GUI with drag-and-drop rules. It needs a BEFORE hook:

Experiment.starting((experiment) => {
  if (!experiment.hypothesis) throw new Error('No experiment without a hypothesis')
})

And none of them connect to the rest of your business. When an experiment concludes in Optimizely, does your CRM know which contacts saw which variant? Does your billing system know if the winning variant increased conversion to paid? Does your marketing team know it's time to announce the change?

Not without custom instrumentation, webhook handlers, and a prayer.

One Typed Graph

When an experiment concludes in headless.ly, your analytics already know. Your CRM already knows. Your billing already knows. Because they're the same system:

import { Experiment, FeatureFlag } from '@headlessly/experiments'

Experiment.concluded(async (experiment, $) => {
  await $.FeatureFlag.enable(experiment.winner)
  const contacts = await $.Contact.find({ segment: experiment.targetAudience })
  for (const c of contacts) {
    await $.Event.create({ type: 'variant.won', contact: c.$id, value: experiment.winner })
  }
  await $.Campaign.create({ name: `${experiment.name} winner`, type: 'Announcement' })
})

FeatureFlag.enabled(async (flag, $) => {
  await $.Event.create({ type: 'flag.enabled', value: flag.key })
  await $.Metric.create({ name: `${flag.key}_rollout`, value: flag.rolloutPercentage, type: 'Gauge' })
})

FeatureFlag.disabled(async (flag, $) => {
  await $.Ticket.create({ subject: `Flag "${flag.key}" killed — investigate regressions`, priority: 'High' })
})

Experiments measure conversion using the same analytics events, against the same CRM contacts, tied to the same billing subscriptions. Feature flags control behavior for real customer segments — not just user IDs in a separate system. When an experiment concludes, the winning variant can trigger campaigns, update products, or adjust pricing — all in the same graph.

No webhooks. No Zapier. No analytics pipeline glue. One graph.

Install

npm install @headlessly/experiments

Entities

Experiment

A/B tests, multivariate tests, and ML/prompt experiments with hypothesis tracking, variant definitions, and statistical results.

import { Experiment } from '@headlessly/experiments'

const experiment = await Experiment.create({
  name: 'Pricing Page CTA',
  slug: 'pricing-page-cta',
  type: 'ABTest',
  hypothesis: 'Changing the CTA from "Start Free" to "Get Started" increases conversions by 15%',
  variants: JSON.stringify([
    { key: 'control', name: 'Start Free', weight: 50 },
    { key: 'treatment', name: 'Get Started', weight: 50 },
  ]),
  primaryMetric: 'signup_conversion',
  trafficAllocation: 100,
})

await Experiment.start(experiment.$id)
await Experiment.pause(experiment.$id)
await Experiment.conclude(experiment.$id)

Experiment.concluded((experiment, $) => {
  $.FeatureFlag.enable(experiment.winner)
})

Verbs: start() · starting() · started() · startedBy · conclude() · concluding() · concluded() · concludedBy · pause() · pausing() · paused() · pausedBy

Relationships: → Organization, → Owner (Contact), ← FeatureFlags[]

FeatureFlag

Feature flags with targeting rules, gradual rollout, and evaluation tracking.

import { FeatureFlag } from '@headlessly/experiments'

const flag = await FeatureFlag.create({
  key: 'new-dashboard',
  name: 'New Dashboard',
  description: 'Redesigned analytics dashboard',
  type: 'Boolean',
  defaultValue: 'false',
  rolloutPercentage: 25,
  status: 'Active',
})

await FeatureFlag.rollout(flag.$id)
await FeatureFlag.enable(flag.$id)
await FeatureFlag.disable(flag.$id)

FeatureFlag.rolledOut((flag) => {
  console.log(`"${flag.key}" rolled out to ${flag.rolloutPercentage}%`)
})

Verbs: rollout() · rollingOut() · rolledOut() · rolledOutBy · enable() · enabling() · enabled() · enabledBy · disable() · disabling() · disabled() · disabledBy

Relationships: → Organization, → Experiment

Agent-Native

Your agent connects to one MCP endpoint. It can run your entire experimentation stack:

{ "type": "Experiment", "filter": { "status": "Running", "confidence": { "$gte": 95 } } }

{ "type": "Experiment", "id": "experiment_fX9bL5nRd", "include": ["owner", "organization"] }

const mature = await $.Experiment.find({ status: 'Running', confidence: { $gte: 95 } })
for (const experiment of mature) {
  await $.Experiment.conclude(experiment.$id)
  await $.FeatureFlag.enable(experiment.winner)
  await $.Campaign.create({
    name: `Ship ${experiment.name}`,
    type: 'Announcement',
  })
}

Three tools. Not three SDKs.

Cross-Domain Operations

Query results are standard arrays — chain operations with familiar JavaScript:

const completed = await Experiment.find({ status: 'Completed' })
const winners = completed.filter((e) => e.confidence >= 95)
for (const experiment of winners) {
  await FeatureFlag.enable(experiment.winner)
  await Campaign.create({ name: `Ship ${experiment.name}`, type: 'Announcement' })
}

License

MIT