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Telemetry
Feature delivery

feature_rollout_evaluated event schema

A versioned feature assignment record that makes exposure rules queryable without copying targeting expressions or personal attributes.

Reviewed by the Telemetry product team on . We checked what each event represents, which service sends it, field types, sensitive data, the example, and validation steps. Who reviews this page

Question this event answers

How do rollout cohorts differ in adoption, reliability, and customer outcomes?

Fields
9
Required
9
Send and check an event

Record and query feature_rollout_evaluated

Document what each feature_rollout_evaluated row represents and which service sends it. Send test events to check the fields, then verify that the query answers your question.

  1. 1

    Outcome becomes final

    Feature evaluation service emits only when an actor first receives an effective assignment or that assignment changes.

  2. 2

    Choose the fields

    9 required fields preserve the declared grain: One effective feature evaluation per actor, feature, assignment version, and material change.

  3. 3

    Check the test event

    Check types, UTC time, alternate outcomes, idempotency, and every pseudonymous or review-classified field.

  4. 4

    Query the result

    How do rollout cohorts differ in adoption, reliability, and customer outcomes?

Grain

One effective feature evaluation per actor, feature, assignment version, and material change.

Owner

Feature evaluation service

Emit when

When an actor first receives an effective assignment or that assignment changes.

Field contract

Field types and data to exclude

Keep field names and types stable once production queries depend on them. Document optional fields and add them only when they answer a specific question.

FieldTypeRequiredPrivacyMeaning
timestamp_utctimestampyesnon-sensitiveUTC time when the operation finishes.
event_idstringyesnon-sensitiveStable unique identifier used for deduplication.
releasestringyesnon-sensitiveApplication or service version that emitted the event.
account_idstringyespseudonymousStable internal account identifier, never an email or name.
actor_idstringyespseudonymousStable internal actor identifier.
featurestringyesnon-sensitiveStable low-cardinality feature name.
variantstringyesnon-sensitiveControl, enabled, or named experiment variant.
assignment_versionstringyesnon-sensitiveVersion of the evaluation and targeting contract.
rollout_percentagenumberyesnon-sensitiveConfigured rollout percentage at evaluation time.

Synthetic JSON event

{
  "timestamp_utc": "2026-07-29T09:34:02Z",
  "event_id": "evt_rollout_01",
  "account_id": "acct_8f31",
  "release": "2026.07.3",
  "actor_id": "user_91ac",
  "feature": "query_explanations",
  "variant": "enabled",
  "assignment_version": "rollout_2026_07_29",
  "rollout_percentage": 25
}

Privacy review

Review identifiers before ingestion

This example uses synthetic identifiers. Pseudonymous values can still be personal data, and review fields can expose business or provider context. Apply your own consent, retention, access, residency, and deletion requirements.

  • account_id: pseudonymous
  • actor_id: pseudonymous

Validation checklist

Test the schema before building a dashboard

  • Send one known feature_rollout_evaluated fixture after the documented outcome boundary.
  • Verify all 9 required fields arrive with the documented types.
  • Retry the same event identifier and confirm the chosen deduplication behavior.
  • Send a controlled failure or alternate outcome when the workflow supports one.
  • Run the related SQL over a fixed window and reconcile the result to the fixture.

Common mistakes

Record one result per row

  • Emitting feature_rollout_evaluated before feature evaluation service knows the final outcome.
  • Mixing different kinds of results in one table, which makes counts and rates ambiguous.
  • Replacing controlled categories with raw URLs, payloads, prompts, or error text.
  • Changing a field type in place after saved queries and dashboards depend on it.
  • Adding identifiers without a documented investigation, access, and retention need.

Use the contract

Query the event and set up monitoring

Related contracts

Send a test event before production traffic

Create a free API key, send the synthetic event, and inspect the inferred table before connecting a live workflow.

Test this schema