fix(flags): load shared definitions without a secret key

[dustinbyrne]

💡 Motivation and Context

Like PostHog/posthog-python#1039, a worker consuming shared feature flag definitions should not need a privileged secret key. Existing initialization gates prevent that supported cache-consumer configuration from evaluating flags locally.

Changes

• Permit the configured definition cache provider to supply definitions without a secret/personal API key.
• Keyless consumers read the shared cache directly, without invoking the fetch-decision callback or publishing definitions. They cannot claim fetch leadership they are unable to use.
• With privileged credentials, retain the existing decision flow: false reads the cache; true fetches definitions and publishes them. Direct definition requests remain authenticated.
• Add public-entry regressions, update active credential/provider docs, and include scoped patch release metadata.

Cache-only readers bypass the shared loader specification's decision-first provider step; credentialed consumers retain that step.

Existing sync/async initialization and TimerTask polling are retained. Unscoped evaluate_flags still performs its existing remote discovery; scoped/conclusive local evaluation avoids remote requests.

💚 How did you test it?

• Focused provider/version/reload suites: 395 examples passed.
• Full standard and optional-OpenTelemetry suites: 1,277 examples each, zero failures. Standard suite has two expected optional-OTel pending cases; the OTel suite has none.
• RuboCop and public API snapshot check: passed.
• Shared-leadership regression fails against the prior loader and passes with the fix.
• Actual Redis example/Lua reproduction, with mocked PostHog HTTP: four publisher requests, fresh reader/publisher/cache values and no keyless lease ownership.
• Local validation used Ruby 3.4.7.

Release scope

Patch release for posthog-ruby. Existing signatures, capture defaults and wire formats are unchanged.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Implemented with Pi worker agents and reviewed by separate fresh-context Pi reviewers. A simplify pass covered the scoped source/tests/docs before final local validation. Human review remains required.

[github-actions]

posthog-ruby-sync Compliance Report

Date: 2026-10-10T04:15:40.327214+00:00
Duration: 94093ms

⚠️ Some Tests Failed

45/47 tests passed, 2 failed

---

Capture Tests

⚠️ 29/30 tests passed, 1 failed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	8ms
Format Validation.Event Has Uuid	✅	6ms
Format Validation.Event Has Lib Properties	✅	4ms
Format Validation.Distinct Id Is String	✅	8ms
Format Validation.Token Is Present	✅	7ms
Format Validation.Custom Properties Preserved	✅	6ms
Format Validation.Event Has Timestamp	✅	6ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	6ms
Retry Behavior.Retries On 503	✅	5338ms
Retry Behavior.Does Not Retry On 400	✅	2009ms
Retry Behavior.Does Not Retry On 401	✅	2011ms
Retry Behavior.Respects Retry After Header	✅	8015ms
Retry Behavior.Implements Backoff	✅	15311ms
Retry Behavior.Retries On 500	✅	5159ms
Retry Behavior.Retries On 502	✅	5115ms
Retry Behavior.Retries On 504	✅	5145ms
Retry Behavior.Max Retries Respected	✅	15653ms
Deduplication.Generates Unique Uuids	✅	20ms
Deduplication.Preserves Uuid On Retry	✅	5115ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10248ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5119ms
Deduplication.No Duplicate Events In Batch	✅	16ms
Deduplication.Different Events Have Different Uuids	✅	8ms
Compression.Sends Gzip When Enabled	✅	5ms
Batch Format.Uses Proper Batch Structure	✅	5ms
Batch Format.Flush With No Events Sends Nothing	✅	2ms
Batch Format.Multiple Events Batched Together	❌	14ms
Error Handling.Does Not Retry On 403	✅	2007ms
Error Handling.Does Not Retry On 413	✅	2007ms
Error Handling.Retries On 408	✅	5114ms

Failures

batch_format.multiple_events_batched_together

Expected 1 requests, got 5

Feature_Flags Tests

⚠️ 16/17 tests passed, 1 failed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	7ms
Request Payload.Flags Request Uses V2 Query Param	✅	5ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	6ms
Request Payload.Flags Request Omits Authorization Header	✅	7ms
Request Payload.Token In Flags Body Matches Init	✅	7ms
Request Payload.Groups Round Trip	✅	8ms
Request Payload.Groups Default To Empty Object	✅	7ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	5ms
Request Payload.Disable Geoip Omitted Defaults To False	❌	6ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	6ms
Request Lifecycle.No Flags Request On Init Alone	✅	1ms
Request Lifecycle.No Flags Request On Normal Capture	✅	5ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	8ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	6ms
Retry Behavior.Retries Flags On 502	✅	150ms
Retry Behavior.Retries Flags On 504	✅	145ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	7ms

Failures

request_payload.disable_geoip_omitted_defaults_to_false

Field 'geoip_disable' not found in /flags request body at path 'geoip_disable'. Available keys: ['distinct_id', 'groups', 'person_properties', 'group_properties', 'flag_keys_to_evaluate', 'token']

[github-actions]

posthog-ruby-async Compliance Report

Date: 2026-10-10T04:15:39.858594+00:00
Duration: 98214ms

⚠️ Some Tests Failed

46/47 tests passed, 1 failed

---

Capture Tests

✅ 30/30 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	10ms
Format Validation.Event Has Uuid	✅	105ms
Format Validation.Event Has Lib Properties	✅	109ms
Format Validation.Distinct Id Is String	✅	106ms
Format Validation.Token Is Present	✅	107ms
Format Validation.Custom Properties Preserved	✅	107ms
Format Validation.Event Has Timestamp	✅	108ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	9ms
Retry Behavior.Retries On 503	✅	5411ms
Retry Behavior.Does Not Retry On 400	✅	2109ms
Retry Behavior.Does Not Retry On 401	✅	2109ms
Retry Behavior.Respects Retry After Header	✅	8017ms
Retry Behavior.Implements Backoff	✅	15523ms
Retry Behavior.Retries On 500	✅	5212ms
Retry Behavior.Retries On 502	✅	5212ms
Retry Behavior.Retries On 504	✅	5212ms
Retry Behavior.Max Retries Respected	✅	15622ms
Deduplication.Generates Unique Uuids	✅	112ms
Deduplication.Preserves Uuid On Retry	✅	5213ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10319ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5214ms
Deduplication.No Duplicate Events In Batch	✅	111ms
Deduplication.Different Events Have Different Uuids	✅	107ms
Compression.Sends Gzip When Enabled	✅	106ms
Batch Format.Uses Proper Batch Structure	✅	106ms
Batch Format.Flush With No Events Sends Nothing	✅	6ms
Batch Format.Multiple Events Batched Together	✅	110ms
Error Handling.Does Not Retry On 403	✅	2108ms
Error Handling.Does Not Retry On 413	✅	2109ms
Error Handling.Retries On 408	✅	5211ms

Feature_Flags Tests

⚠️ 16/17 tests passed, 1 failed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	107ms
Request Payload.Flags Request Uses V2 Query Param	✅	108ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	109ms
Request Payload.Flags Request Omits Authorization Header	✅	108ms
Request Payload.Token In Flags Body Matches Init	✅	108ms
Request Payload.Groups Round Trip	✅	107ms
Request Payload.Groups Default To Empty Object	✅	107ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	106ms
Request Payload.Disable Geoip Omitted Defaults To False	❌	107ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	107ms
Request Lifecycle.No Flags Request On Init Alone	✅	3ms
Request Lifecycle.No Flags Request On Normal Capture	✅	105ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	112ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	105ms
Retry Behavior.Retries Flags On 502	✅	209ms
Retry Behavior.Retries Flags On 504	✅	257ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	109ms

Failures

request_payload.disable_geoip_omitted_defaults_to_false

Field 'geoip_disable' not found in /flags request body at path 'geoip_disable'. Available keys: ['distinct_id', 'groups', 'person_properties', 'group_properties', 'flag_keys_to_evaluate', 'token']