Rules and rollouts

Rules let you choose who sees a value before the default applies.

Tenant targeting

Use tenant targeting when one customer should receive a feature early.

checkoutV2: flag.boolean({
  default: false,
  rules: [
    flag.tenants(["tenant_acme"]).value(true),
  ],
})

Pass the tenant ID when you evaluate the flag.

const enabled = await flags.enabled("checkoutV2", {
  tenantId: tenant.id,
})

User targeting

Use user targeting for a direct allow list or a narrow beta.

waitlistAccess: flag.boolean({
  default: false,
  rules: [
    flag.users(["user_123"]).value(true),
  ],
})

Attribute targeting

Use attributes for app-owned facts such as plan, region, or tier.

advancedReports: flag.boolean({
  default: false,
  rules: [
    flag.attribute("plan").equals("enterprise").value(true),
  ],
})

Pass attributes from the current request, tenant, or domain object.

const enabled = await flags.enabled("advancedReports", {
  attributes: {
    plan: tenant.plan,
    region: tenant.region,
  },
})

Percentage rollouts

Use a percentage rule when you want gradual exposure.

checkoutV2: flag.boolean({
  default: false,
  rules: [
    flag.percentage(10, { stickiness: "userId" }).value(true),
  ],
})

The stickiness key keeps the same subject on the same side of the rollout as the percentage changes.

Common choices:

• userId
• tenantId
• sessionId

Rule order

When a flag has multiple rules, Layeron checks them in the order they appear in your code. Put the most specific rule first.

checkoutV2: flag.boolean({
  default: false,
  environments: {
    preview: true,
  },
  rules: [
    flag.tenants(["tenant_acme"]).value(true),
    flag.users(["user_123"]).value(true),
    flag.percentage(10, { stickiness: "userId" }).value(true),
  ],
})

When to use which rule

• Use tenant targeting for account-level access.
• Use user targeting for internal testers or narrow betas.
• Use attribute targeting for product tiers or plans.
• Use percentage rollouts for gradual launches.