[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 condition that depends on a flag with experience continuity is inconclusive locally. A later condition can still resolve the flag.

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 (2007 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: 2026-10-29T17:20:04.739245+00:00
Duration: 56025ms

⚠️ 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	✅	11ms
Format Validation.Event Has Uuid	✅	6ms
Format Validation.Event Has Lib Properties	✅	9ms
Format Validation.Distinct Id Is String	✅	5ms
Format Validation.Token Is Present	✅	6ms
Format Validation.Custom Properties Preserved	✅	5ms
Format Validation.Event Has Timestamp	✅	8ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	7ms
Retry Behavior.Retries On 503	✅	5326ms
Retry Behavior.Does Not Retry On 400	❌	10ms
Retry Behavior.Does Not Retry On 401	❌	6ms
Retry Behavior.Respects Retry After Header	✅	8016ms
Retry Behavior.Implements Backoff	❌	351ms
Retry Behavior.Retries On 500	✅	5117ms
Retry Behavior.Retries On 502	✅	5118ms
Retry Behavior.Retries On 504	✅	5120ms
Retry Behavior.Max Retries Respected	❌	542ms
Deduplication.Generates Unique Uuids	✅	18ms
Deduplication.Preserves Uuid On Retry	✅	5115ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10308ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5128ms
Deduplication.No Duplicate Events In Batch	✅	20ms
Deduplication.Different Events Have Different Uuids	✅	9ms
Compression.Sends Gzip When Enabled	✅	5ms
Batch Format.Uses Proper Batch Structure	✅	6ms
Batch Format.Flush With No Events Sends Nothing	✅	3ms
Batch Format.Multiple Events Batched Together	❌	16ms
Error Handling.Does Not Retry On 403	❌	5ms
Error Handling.Does Not Retry On 413	❌	5ms
Error Handling.Retries On 408	✅	5112ms

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	✅	10ms
Request Payload.Flags Request Uses V2 Query Param	✅	7ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	7ms
Request Payload.Flags Request Omits Authorization Header	✅	7ms
Request Payload.Token In Flags Body Matches Init	✅	9ms
Request Payload.Groups Round Trip	✅	8ms
Request Payload.Groups Default To Empty Object	✅	8ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	6ms
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	✅	2ms
Request Lifecycle.No Flags Request On Normal Capture	✅	6ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	11ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	6ms
Retry Behavior.Retries Flags On 502	✅	147ms
Retry Behavior.Retries Flags On 504	✅	139ms
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: 2026-10-29T17:20:38.170955+00:00
Duration: 98205ms

⚠️ 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	✅	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	✅	111ms
Format Validation.Event Has Timestamp	✅	106ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	8ms
Retry Behavior.Retries On 503	✅	5309ms
Retry Behavior.Does Not Retry On 400	✅	2109ms
Retry Behavior.Does Not Retry On 401	✅	2110ms
Retry Behavior.Respects Retry After Header	✅	8013ms
Retry Behavior.Implements Backoff	✅	15509ms
Retry Behavior.Retries On 500	✅	5213ms
Retry Behavior.Retries On 502	✅	5212ms
Retry Behavior.Retries On 504	✅	5209ms
Retry Behavior.Max Retries Respected	✅	15623ms
Deduplication.Generates Unique Uuids	✅	112ms
Deduplication.Preserves Uuid On Retry	✅	5213ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10412ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5214ms
Deduplication.No Duplicate Events In Batch	✅	113ms
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	✅	2109ms
Error Handling.Does Not Retry On 413	✅	2109ms
Error Handling.Retries On 408	✅	5213ms

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	✅	108ms
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	✅	109ms
Request Payload.Groups Round Trip	✅	108ms
Request Payload.Groups Default To Empty Object	✅	108ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	107ms
Request Payload.Disable Geoip Omitted Defaults To False	❌	108ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	107ms
Request Lifecycle.No Flags Request On Init Alone	✅	4ms
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	✅	107ms
Retry Behavior.Retries Flags On 502	✅	210ms
Retry Behavior.Retries Flags On 504	✅	249ms
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']

[posthog]

PostHog Review · Standard · reviewed fa4eb3d: no findings. This pull request is large, so the review ran in 4 parts with less depth than usual.

[dustinbyrne]

The unresolved-flag diagnostics and supporting coverage look sound overall. One compatibility issue remains: returned failed flags now lose their documented false snapshot value. Please preserve that behavior or explicitly resolve the contract and release change described inline.

AI-assisted review.

[dustinbyrne]

The returned-failed-record compatibility issue is fixed, including caller defaults and capture enrichment. No required findings remain; one optional release-note clarification is inline.

AI-assisted review.