[gustavohstrassburger]

💡 Motivation and Context

Why: sdk-specs #85 defines how a server SDK reports flags that local evaluation could not resolve. Today such a flag is absent from the evaluate_flags snapshot, so it looks the same as a flag that does not exist, and $feature_flag_called reports flag_missing for both. With only_evaluate_locally: true this is permanent. posthog-node already implements this (PostHog/posthog-js#5234); posthog-python (#1133) and posthog-server (#896) are in review.

Changes:

• FeatureFlagEvaluations#unresolved_flags maps each unresolved flag to a PostHog::UnresolvedFlagReason (experience_continuity, unsupported_definition, unresolved_dependency, missing_context). When several causes apply, the spec's fixed precedence picks one. only / only_accessed snapshots have no entries, and reading the hash is not an access.
• A snapshot read of an unresolved flag reports local_evaluation_inconclusive instead of flag_missing.
• InconclusiveMatchError and RequiresServerEvaluation take an optional reason:, set at every raise site. A bad person value is missing_context; a bad filter value is unsupported_definition.
• When definitions load, the SDK logs a WARN line for flags local evaluation can never resolve. Each flag warns once until its definition changes; 304 and repeated shared-cache loads do not repeat it.

Behavior changes (all in the changeset):

• A condition or cohort property group no longer stops at the first filter it cannot check. If another filter does not match, the flag can resolve locally. A static cohort still forces the fallback only when it is the first filter in its condition that cannot be checked, as in posthog-node.
• An inactive flag with experience continuity resolves to false locally.
• A flag that depends on a flag with experience continuity no longer resolves locally.
• A flag that depends on a flag that needs the server becomes inconclusive (unresolved_dependency) at that condition instead of forcing the fallback, as in posthog-node. A later condition can now resolve it.
• When local evaluation left a flag unresolved and the remote fallback marks it as failed, the snapshot no longer holds it as false; it is absent and listed as unresolved. A failed flag with no local definition keeps its false value.

Divergences from the spec or posthog-node:

• The SDK has no device-id bucketing, so the device-id acceptance row does not apply. A missing group key still resolves to false, as in posthog-node.
• A regex that only the server can evaluate reports unsupported_definition, even when the person value causes the deferral. Patterns that always need the server are in the load-time warning; posthog-node does not warn about regexes.

💚 How did you test it?

New RSpec examples mirror every scenario tagged @unresolved_flags_capable and @unresolvable_flag_warning_capable in acceptance/public/evaluate-flags.feature, plus precedence, the condition loop, dependencies, warning dedup, failed fallback and unexpected errors. Run locally:

• bundle exec rspec (1988 examples, 0 failures, 40 pending for the optional OpenTelemetry bundle)
• bundle exec rubocop
• bundle exec rake public_api:check

No manual testing in an app.

📝 Checklist

• All commits are signed
• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm changeset to generate a changeset file

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

• Written with Claude Code in PostHog Desktop, from a cross-SDK plan to apply sdk-specs Add Action workflow for publishing Ruby gem #85 to all server SDKs. It follows posthog-node and the posthog-python and posthog-server PRs from the same plan.
• PostHog::Utils.convert_to_datetime (@api private) now takes a required reason: so date parsing can tell a bad person value from a bad filter value.

---

Created with PostHog Desktop

🤖 Generated with Claude Code

[github-actions]

posthog-ruby-sync Compliance Report

Date: 2026-10-28T03:57:10.598571+00:00
Duration: 56051ms

⚠️ Some Tests Failed

39/47 tests passed, 8 failed

---

Capture Tests

⚠️ 23/30 tests passed, 7 failed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	10ms
Format Validation.Event Has Uuid	✅	7ms
Format Validation.Event Has Lib Properties	✅	9ms
Format Validation.Distinct Id Is String	✅	7ms
Format Validation.Token Is Present	✅	7ms
Format Validation.Custom Properties Preserved	✅	7ms
Format Validation.Event Has Timestamp	✅	10ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	7ms
Retry Behavior.Retries On 503	✅	5322ms
Retry Behavior.Does Not Retry On 400	❌	8ms
Retry Behavior.Does Not Retry On 401	❌	6ms
Retry Behavior.Respects Retry After Header	✅	8015ms
Retry Behavior.Implements Backoff	❌	339ms
Retry Behavior.Retries On 500	✅	5116ms
Retry Behavior.Retries On 502	✅	5115ms
Retry Behavior.Retries On 504	✅	5116ms
Retry Behavior.Max Retries Respected	❌	427ms
Deduplication.Generates Unique Uuids	✅	17ms
Deduplication.Preserves Uuid On Retry	✅	5115ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10319ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5150ms
Deduplication.No Duplicate Events In Batch	✅	20ms
Deduplication.Different Events Have Different Uuids	✅	10ms
Compression.Sends Gzip When Enabled	✅	7ms
Batch Format.Uses Proper Batch Structure	✅	7ms
Batch Format.Flush With No Events Sends Nothing	✅	4ms
Batch Format.Multiple Events Batched Together	❌	19ms
Error Handling.Does Not Retry On 403	❌	6ms
Error Handling.Does Not Retry On 413	❌	5ms
Error Handling.Retries On 408	✅	5139ms

Failures

retry_behavior.does_not_retry_on_400

500, message='Internal Server Error', url='http://sdk-adapter:8080/capture'

retry_behavior.does_not_retry_on_401

500, message='Internal Server Error', url='http://sdk-adapter:8080/capture'

retry_behavior.implements_backoff

500, message='Internal Server Error', url='http://sdk-adapter:8080/capture'

retry_behavior.max_retries_respected

500, message='Internal Server Error', url='http://sdk-adapter:8080/capture'

batch_format.multiple_events_batched_together

Expected 1 requests, got 5

error_handling.does_not_retry_on_403

500, message='Internal Server Error', url='http://sdk-adapter:8080/capture'

error_handling.does_not_retry_on_413

500, message='Internal Server Error', url='http://sdk-adapter:8080/capture'

Feature_Flags Tests

⚠️ 16/17 tests passed, 1 failed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	9ms
Request Payload.Flags Request Uses V2 Query Param	✅	8ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	9ms
Request Payload.Flags Request Omits Authorization Header	✅	10ms
Request Payload.Token In Flags Body Matches Init	✅	11ms
Request Payload.Groups Round Trip	✅	7ms
Request Payload.Groups Default To Empty Object	✅	8ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	7ms
Request Payload.Disable Geoip Omitted Defaults To False	❌	8ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	8ms
Request Lifecycle.No Flags Request On Init Alone	✅	3ms
Request Lifecycle.No Flags Request On Normal Capture	✅	7ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	10ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	8ms
Retry Behavior.Retries Flags On 502	✅	112ms
Retry Behavior.Retries Flags On 504	✅	151ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	9ms

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: 2026-10-28T03:57:47.336313+00:00
Duration: 98515ms

⚠️ 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	✅	11ms
Format Validation.Event Has Uuid	✅	106ms
Format Validation.Event Has Lib Properties	✅	110ms
Format Validation.Distinct Id Is String	✅	107ms
Format Validation.Token Is Present	✅	107ms
Format Validation.Custom Properties Preserved	✅	112ms
Format Validation.Event Has Timestamp	✅	106ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	8ms
Retry Behavior.Retries On 503	✅	5312ms
Retry Behavior.Does Not Retry On 400	✅	2109ms
Retry Behavior.Does Not Retry On 401	✅	2108ms
Retry Behavior.Respects Retry After Header	✅	8117ms
Retry Behavior.Implements Backoff	✅	15818ms
Retry Behavior.Retries On 500	✅	5213ms
Retry Behavior.Retries On 502	✅	5212ms
Retry Behavior.Retries On 504	✅	5208ms
Retry Behavior.Max Retries Respected	✅	15622ms
Deduplication.Generates Unique Uuids	✅	112ms
Deduplication.Preserves Uuid On Retry	✅	5212ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10318ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5216ms
Deduplication.No Duplicate Events In Batch	✅	112ms
Deduplication.Different Events Have Different Uuids	✅	108ms
Compression.Sends Gzip When Enabled	✅	106ms
Batch Format.Uses Proper Batch Structure	✅	107ms
Batch Format.Flush With No Events Sends Nothing	✅	5ms
Batch Format.Multiple Events Batched Together	✅	111ms
Error Handling.Does Not Retry On 403	✅	2107ms
Error Handling.Does Not Retry On 413	✅	2109ms
Error Handling.Retries On 408	✅	5212ms

Feature_Flags Tests

⚠️ 16/17 tests passed, 1 failed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	108ms
Request Payload.Flags Request Uses V2 Query Param	✅	107ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	108ms
Request Payload.Flags Request Omits Authorization Header	✅	109ms
Request Payload.Token In Flags Body Matches Init	✅	110ms
Request Payload.Groups Round Trip	✅	107ms
Request Payload.Groups Default To Empty Object	✅	107ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	108ms
Request Payload.Disable Geoip Omitted Defaults To False	❌	107ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	108ms
Request Lifecycle.No Flags Request On Init Alone	✅	3ms
Request Lifecycle.No Flags Request On Normal Capture	✅	106ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	111ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	108ms
Retry Behavior.Retries Flags On 502	✅	210ms
Retry Behavior.Retries Flags On 504	✅	243ms
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']