[marandaneto]

Problem

People can receive unexpected feature flag results when an exact filter contains boolean-like scalar values or multiple options.

The released matcher evaluates aggregate truthiness before array membership. This produces results such as:

Filter	Property	Released exact	Version 2 exact	Product analytics exact
false	\"banana\"	true	false	false
false	0	true	false	false
[\"true\", \"false\"]	\"true\"	false	true	true
[\"true\", \"false\"]	\"pro\"	true	false	false
[]	true	true	true	true
[]	[]	true	true	true

Changing is_not false globally could expand existing flag audiences. The new behavior therefore defaults to released semantics and rolls out per team.

Current flow:

flowchart TD
    A[Exact or is_not filter] --> B[Use released truthiness behavior]
    classDef phYellow fill:#f9bd2b,stroke:#f9bd2b,color:#000;
    classDef phRed fill:#f54e00,stroke:#f54e00,color:#fff;
    class A phYellow;
    class B phRed;

Loading

Proposed flow:

flowchart TD
    A[Team property matching version] --> B{Version}
    B -->|1 or missing| C[Use released truthiness behavior]
    B -->|2| D[Use explicit exact matching]
    A --> E[Expose version to local-evaluation SDKs]
    C --> F[Live flags and batch cohort evaluation]
    D --> F
    classDef phBlue fill:#1d4aff,stroke:#1d4aff,color:#fff;
    classDef phYellow fill:#f9bd2b,stroke:#f9bd2b,color:#000;
    classDef phGray fill:#e5e7eb,stroke:#c7ccd1,color:#000;
    class A phYellow;
    class B phBlue;
    class C,D,E,F phGray;

Loading

Changes

• Teams retain released matching until staff selects property matching version 2.
• Version 2 compares scalar values without truthiness coercion and matches non-empty arrays by member equality.
• Empty arrays preserve released /flags behavior, and is_not remains the complement of exact.
• Live and batch evaluation read the same durable team setting.
• Local-evaluation responses and team metadata expose the selected version for SDK discovery.
• Static cohort generation pins both flag and matching versions across pages, then stops on either conflict.
• Mechanical: add a versioned team setting, staff API validation, audit data, cache refreshes, and generated API types.
• Mechanical: add an additive smallint migration whose database default preserves version 1 for older writers.

How did you test this code?

• Regression coverage verifies released and explicit scalar, array, direct flag, dynamic cohort, and batch behavior.
• Cohort tests verify every page uses one matching version and version conflicts are not retried.
• Metadata and local-evaluation tests verify configured, default, cached, and no-flags response paths.
• Staff API tests verify updates, validation, audit behavior, and cache refresh tasks.
• uv run pytest products/feature_flags/backend/test/test_local_evaluation.py products/feature_flags/backend/test/test_staff_team_config_api.py products/feature_flags/backend/test/test_team_feature_flags_config.py posthog/storage/test/test_team_metadata_cache.py posthog/api/test/test_flags_service.py products/feature_flags/backend/api/test/test_feature_flag.py::TestCohortGenerationForFeatureFlag --reuse-db -q
• cargo test -p feature-flags --test test_batch_flag_evaluation
• cargo test -p feature-flags --lib test_match_properties
• cargo test -p feature-flags --lib test_evaluate_dynamic_cohorts
• cargo check -p feature-flags --all-targets
• cargo clippy -p feature-flags --all-targets -- -D warnings
• cargo fmt --all -- --check
• uv run mypy --cache-fine-grained .
• hogli build:openapi
• hogli ci:preflight --fix

Automatic notifications

• Publish to changelog?

Docs update

The Rust feature-flags service overview documents the durable property matching version and compatibility behavior.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Pi addressed reviewer feedback using /address-pr-comments, /django-migrations, /improving-drf-endpoints, /writing-tests, /writing-code-comments, /writing-user-facing-copy, /writing-pr-descriptions, and /running-ci-preflight.

The rollout moved from a process-local allowlist to durable team configuration so remote, local, and paginated evaluations can stay aligned. The duplicate search found no competing fix. All examples are invented.

[trunk-io]

😎 Merged successfully - details.

[github-actions]

🤖 CI report

⚠️ Trunk lane — backend Python lane

This PR is assigned to the backend Python lane. It runs backend Python tests and may merge in parallel with PRs in other lanes.

✅ Complexity (TypeScript) — clean

Cyclomatic complexity above the limit in changed typescript files (10 for production files, 15 for test files). Warn only: worth simplifying when you next touch these functions.

⚠️ Bundle size — 🔺 +409 B (+0.0%)

Uncompressed size of every built .js bundle, compared against the base branch.

Total: 68.29 MiB · 🔺 +409 B (+0.0%)

No file changed by more than 1000 B.

_{Posted automatically by build-bundle-size-report · uncompressed bytes from dist-report}

✅ Eager graph — within budget

How much code each root ships on the eager path — downloaded and parsed before the surface is interactive. Measured from the esbuild output chunks (post-tree-shake, static imports only); lazy import() / React.lazy chunks are not counted.

Root	Eager (shipped)	Δ vs base	Budget
entry (logged-out pages, app bootstrap) src/index.tsx	1.45 MiB · 22 files	no change	███░░░░░░░ 32.3% of 4.51 MiB
authenticated shell (every logged-in page) src/scenes/AuthenticatedShell.tsx	8.90 MiB · 3,268 files	🔺 +8 B (+0.0%)	█████████░ 91.6% of 9.71 MiB

🟢 node_modules/monaco-editor/ stays out of src/index.tsx
🟢 src/lib/components/ActivityLog/describers stays out of src/index.tsx
🟢 [object Object] stays out of src/index.tsx
🟢 [object Object] stays out of src/index.tsx
🟢 node_modules/monaco-editor/ stays out of src/scenes/AuthenticatedShell.tsx
🟢 src/lib/components/ActivityLog/describers stays out of src/scenes/AuthenticatedShell.tsx
🟢 [object Object] stays out of src/scenes/AuthenticatedShell.tsx
🟢 [object Object] stays out of src/scenes/AuthenticatedShell.tsx

Largest files eagerly shipped from src/index.tsx

Size	File
126.8 KiB	../node_modules/.pnpm/react-dom@18.3.1_react@18.3.1/node_modules/react-dom/cjs/react-dom.production.min.js
24.6 KiB	../node_modules/.pnpm/buffer@6.0.3/node_modules/buffer/index.js
6.3 KiB	../node_modules/.pnpm/react@18.3.1/node_modules/react/cjs/react.production.min.js
4.5 KiB	../node_modules/.pnpm/@jspm+core@2.1.0/node_modules/@jspm/core/nodelibs/browser/process.js
3.9 KiB	../node_modules/.pnpm/scheduler@0.23.2/node_modules/scheduler/cjs/scheduler.production.min.js
1.4 KiB	../node_modules/.pnpm/base64-js@1.5.1/node_modules/base64-js/index.js
1.3 KiB	src/RootErrorBoundary.tsx
912 B	../node_modules/.pnpm/ieee754@1.2.1/node_modules/ieee754/index.js
854 B	src/scenes/ChunkLoadErrorBoundary.tsx
762 B	src/index.tsx

Largest files eagerly shipped from src/scenes/AuthenticatedShell.tsx

Size	File
309.3 KiB	../node_modules/.pnpm/posthog-js@1.427.0_@types+react@18.3.27_react@18.3.1/node_modules/posthog-js/dist/rrweb.js
275.9 KiB	../node_modules/.pnpm/posthog-js@1.427.0_@types+react@18.3.27_react@18.3.1/node_modules/posthog-js/dist/module.mjs
267.7 KiB	../node_modules/.pnpm/@posthog+icons@0.38.0_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/@posthog/icons/dist/posthog-icons.es.js
255.2 KiB	src/taxonomy/core-filter-definitions-by-group.json
154.2 KiB	../node_modules/.pnpm/re2js@0.4.1/node_modules/re2js/build/index.esm.js
126.8 KiB	../node_modules/.pnpm/react-dom@18.3.1_react@18.3.1/node_modules/react-dom/cjs/react-dom.production.min.js
104.4 KiB	src/lib/api.ts
95.8 KiB	../packages/quill/packages/quill/dist/index.js
93.3 KiB	../node_modules/.pnpm/prosemirror-view@1.40.1/node_modules/prosemirror-view/dist/index.js
90.6 KiB	../node_modules/.pnpm/@tiptap+core@3.20.6_@tiptap+pm@3.20.6/node_modules/@tiptap/core/dist/index.js

_{Posted automatically by check-eager-graph · sizes are eager output bytes (shipped, post-tree-shake) from the esbuild metafile · part of #32479}

✅ Toolbar bundle — eager 2.28 MiB within budget

What the toolbar ships to customer pages, measured from the esbuild output (minified, post-tree-shake). The eager set is the entry plus everything statically imported from it — fetched before any feature runs; deferred chunks load lazily. The eager guardrail is 5.72 MiB. Each output file must also stay below 10 MB, where CloudFront stops compressing it. The module boundary is enforced separately by check-toolbar-graph.

Metric	Size	Δ vs base	Budget
Eager (shipped) entry + static imports	2.28 MiB · 18 files	no change	████░░░░░░ 39.8% of 5.72 MiB
Deferred (lazy)	2.11 MiB · 45 files	no change	n/a — loads on demand
Loader dist/toolbar.js	1.1 KiB	no change	█░░░░░░░░░ 5.8% of 19.5 KiB

Largest eagerly-shipped chunks

Size	File
754.5 KiB	dist/toolbar/toolbar-app-UB54KCUA.css
602.9 KiB	dist/toolbar/chunk-chunk-PSSB2NES.js
484.7 KiB	dist/toolbar/chunk-chunk-EL6RQSMS.js
135.6 KiB	dist/toolbar/chunk-chunk-FV2N34MB.js
131.8 KiB	dist/toolbar/chunk-chunk-FDH2IBXT.js
71.3 KiB	dist/toolbar/toolbar-app-73KR5GY4.js
69.0 KiB	dist/toolbar/chunk-chunk-TSAL54PB.js
35.6 KiB	dist/toolbar/chunk-chunk-LTYHHK34.js
21.0 KiB	dist/toolbar/chunk-chunk-JPI7DKFZ.js
6.8 KiB	dist/toolbar/chunk-chunk-DV7IWQNF.js

_{Posted automatically by check-toolbar-size · sizes are toolbar output bytes (shipped, post-tree-shake) from the esbuild metafile}

✅ Dist folder size — 🔺 +1.1 KiB (+0.0%)

Total size of the built frontend/dist folder (all assets), compared against the base branch.

Total: 1459.04 MiB · 🔺 +1.1 KiB (+0.0%)

ℹ️ MCP UI apps size — 33 app(s), 17665.2 KB JS

Built size of each MCP UI app (main.js + styles.css).

App	JS	CSS
debug	600.0 KB	195.2 KB
action	458.2 KB	195.2 KB
action-list	564.9 KB	195.2 KB
cohort	457.2 KB	195.2 KB
cohort-list	563.8 KB	195.2 KB
email-template	457.0 KB	195.2 KB
error-details	472.9 KB	195.2 KB
error-issue	457.9 KB	195.2 KB
error-issue-list	564.7 KB	195.2 KB
experiment	562.0 KB	195.2 KB
experiment-list	565.6 KB	195.2 KB
experiment-results	567.1 KB	195.2 KB
feature-flag	567.6 KB	195.2 KB
feature-flag-list	571.4 KB	195.2 KB
feature-flag-testing	461.4 KB	195.2 KB
inline-scan	457.7 KB	195.2 KB
insight-actors	563.0 KB	195.2 KB
invite-email-preview	456.4 KB	195.2 KB
llm-costs	560.0 KB	195.2 KB
session-recording	459.0 KB	195.2 KB
survey	458.8 KB	195.2 KB
survey-global-stats	562.7 KB	195.2 KB
survey-list	565.5 KB	195.2 KB
survey-stats	562.7 KB	195.2 KB
trace-span	457.6 KB	195.2 KB
trace-span-list	564.7 KB	195.2 KB
vision-observation-list	563.9 KB	195.2 KB
workflow	457.5 KB	195.2 KB
workflow-list	564.2 KB	195.2 KB
loops-review	461.9 KB	195.2 KB
query-results	756.3 KB	195.2 KB
render-ui	839.5 KB	195.2 KB
visual-review-snapshots	462.0 KB	195.2 KB

✅ Playwright — all passed

All tests passed.

View test results →

⚠️ Backend snapshots — 1 updated (1 modified, 0 added, 0 deleted)

Query snapshots: Backend query snapshots updated

Changes: 1 snapshots (1 modified, 0 added, 0 deleted)

What this means:

• Query snapshots have been automatically updated to match current output
• These changes reflect modifications to database queries or schema

Next steps:

• Review the query changes to ensure they're intentional
• If unexpected, investigate what caused the query to change

Review snapshot changes →

⚠️ Django migration SQL — 1 new migration to review

We've detected new migrations on this PR. Review the SQL output for each migration:

products/feature_flags/backend/migrations/0017_teamfeatureflagsconfig_property_matching_version.py

BEGIN;
--
-- Add field property_matching_version to teamfeatureflagsconfig
--
ALTER TABLE "feature_flags_teamfeatureflagsconfig" ADD COLUMN "property_matching_version" smallint DEFAULT 1 NOT NULL;
COMMIT;

Last updated: 2026-09-04 12:38 UTC (cde54f2)

✅ Django migration risk — migration analysis complete

We've analyzed your migrations for potential risks.

Summary: 1 Safe | 0 Needs Review | 0 Blocked

✅ Safe

Brief or no lock, backwards compatible

feature_flags.0017_teamfeatureflagsconfig_property_matching_version
  └─ #1 ✅ AddField
     Adding NOT NULL field with constant default (safe in PG11+)
     model: teamfeatureflagsconfig, field: property_matching_version

Last updated: 2026-09-04 12:39 UTC (cde54f2)

ℹ️ Docs preview — preview build triggered

Docs from this PR will be published at posthog.com.

Project	Preview	Updated (UTC)
posthog.com	Open preview	Sep 4, 2026, 12:35 PM

The preview should be ready in about 10 minutes. Open the preview at /handbook/engineering/.

[marandaneto]

found while checking PostHog/sdk-specs#51

[trunk-io]

   

View Full Report ↗︎ ⋅ Docs

[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(flags): make exact boolean matching ..." | Re-trigger Greptile}

[greptile-apps]

_{Reviews (2): Last reviewed commit: "fix(flags): make exact boolean matching ..." | Re-trigger Greptile}

[marandaneto]

maybe i should rollback the changes for [] so it'd keep as is and match the current prod analytics as well

[github-actions]

🦔 Hogbox preview · ✅ ready

▶ Open the preview

🔑 Login	test@posthog.com / 12345678 (demo data)
🧩 Running	this PR's backend and frontend, on the PostHog :master base
🔗 Link	stable across rebuilds — a re-push swaps the box underneath, the URL stays
🔒 Access	tailnet only (PostHog VPN)
🛠️ Admin	inspect & debug state in hogland
💤 Idle	sleeps after ~30 min idle (snapshot to S3, zero node cost) and wakes on your next visit in ~30s, behind a brief "waking up" screen

_{commit cde54f2 · box box-29d1529bb225 · ready in 856s (push → usable) · build log · rebuilds on every push, torn down on close}

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-09-04 15:00 UTC	Run
prod-us	✅ Deployed	2026-09-04 15:21 UTC	Run
prod-eu	✅ Deployed	2026-09-04 15:20 UTC	Run