PolicyEngine/policyengine-core

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Core microsimulation engine for PolicyEngine models. Forked from OpenFisca-Core.

Stars: 22
Forks: 30
Open beginner issues: 0
Indexed issues: 91
Avg merge: 14h 33m
Merged PRs (30d): 7

Dominant language: Python
License: AGPL-3.0
Last GitHub push: Sep 16, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: good first issue help wanted

Beginner friendly Everything

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91 open issues indexed

download_huggingface_dataset hardcodes repo_type="model", so it cannot fetch datasets repos Open

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

PolicyEngine/policyengine-core#549 · Opened Sep 15, 2026
`restore_simulation` silently drops memberless group entities Open

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

PolicyEngine/policyengine-core#547 · Opened Sep 10, 2026
TracingParameterNodeAtInstant never records scale/bracket parameter reads Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 74/100

PolicyEngine/policyengine-core#542 · Opened Sep 4, 2026
FullTracer records no parameter reads for yearly formulas: the at-instant node is cached before the tracing recast Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 68/100

PolicyEngine/policyengine-core#541 · Opened Sep 4, 2026
Allow metadata propagation to exclude selected fields Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

PolicyEngine/policyengine-core#537 · Opened Sep 2, 2026
download_huggingface_dataset sends no token for public+gated repos (private is the wrong predicate) Open

Difficulty 2/5 1-2 days Newbie friendliness 74/100

PolicyEngine/policyengine-core#529 · 1 comment · Opened Aug 12, 2026
Storage keys need a structured (branch, period) scheme: str(period) is lossy and separators collide with branch names Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#526 · Opened Jul 21, 2026
TaxBenefitSystem construction permanently leaks ~5,600 sys.modules entries (~55-60MB) per build — unreclaimable by gc Open

Difficulty 4/5 3-5 days Newbie friendliness 52/100

PolicyEngine/policyengine-core#520 · Opened Jul 19, 2026
Proposal: deterministic PolicyEngine YAML test -> portable fixture converter Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

PolicyEngine/policyengine-core#514 · 1 comment · Opened Jul 9, 2026
Proposal: preserve missing-input state instead of collapsing it to zero Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#513 · 1 comment · Opened Jul 9, 2026
Proposal: versioned computation trace export for household calculations Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#512 · 2 comments · Opened Jul 9, 2026
int32 / float32 default dtypes risk silent overflow and precision loss Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#467 · Opened Apr 17, 2026
Support arbitrary month periods in YAML tests Open

PolicyEngine/policyengine-core#419 · 1 assignee · Opened Jan 7, 2026
Investigate performance improvements Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-core#415 · 3 comments · Opened Dec 16, 2025
Check for outdated issues Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-core#413 · 3 comments · Opened Dec 8, 2025
Add base year support for parameter uprating Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

PolicyEngine/policyengine-core#403 · Opened Oct 16, 2025
ID variables produce fractional values when mapped between non-hierarchical entities Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#400 · Opened Oct 3, 2025
calculate_dataframe has problems when combinations of person_id and other id types are used Open

Difficulty 3/5 1-2 days Newbie friendliness 48/100

PolicyEngine/policyengine-core#398 · Opened Oct 2, 2025
Parameter uprating takes 11+ seconds per Simulation with reform (700x slowdown) Open

bug

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-core#397 · 1 comment · Opened Oct 2, 2025
Migrate GitHub Pages deployment to official actions Open

Difficulty 2/5 1-3 hours Newbie friendliness 55/100

PolicyEngine/policyengine-core#395 · Opened Aug 23, 2025
Make -core and particularly the Simulation object compatible with the new SingleYearDataset class Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-core#394 · Opened Aug 20, 2025
Add parameter extension functionality for uprating factors Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

PolicyEngine/policyengine-core#391 · Opened Aug 11, 2025
Warn when attempting to update a parameter with `start=period` Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-core#388 · Opened Aug 8, 2025
Pydantic deprecation warning: class-based config should use ConfigDict Open

Difficulty 3/5 1-2 days Newbie friendliness 48/100

PolicyEngine/policyengine-core#385 · Opened Jul 26, 2025
Remove duplicate reform application Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

PolicyEngine/policyengine-core#377 · Opened Jul 22, 2025
Weights return nans when using the `calculate_dataframe` function when mapped to any entity besides household Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 25/100

PolicyEngine/policyengine-core#384 · 1 comment · Opened Jul 18, 2025
Assert that scale parameter bracket thresholds increase monotonically Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

PolicyEngine/policyengine-core#374 · Opened Jul 11, 2025
Add year-on-year change growth factor format to parameters Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-core#373 · Opened Jul 10, 2025
Python interface to adjust uprating factors Open

Difficulty 5/5 Over a week Newbie friendliness 32/100

PolicyEngine/policyengine-core#372 · Opened Jun 25, 2025
Multi-step uprating doesn't work on `ubuntu` Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 32/100

PolicyEngine/policyengine-core#359 · Opened Apr 2, 2025
Fix subsampling Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-core#357 · 1 comment · Opened Apr 1, 2025
Add function for removing branches Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

PolicyEngine/policyengine-core#354 · Opened Apr 1, 2025
Enable `run on disk` mode or otherwise prevent OOM Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

PolicyEngine/policyengine-core#353 · Opened Apr 1, 2025
Warn when memory occupation is high Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 25/100

PolicyEngine/policyengine-core#352 · Opened Apr 1, 2025
Improve error handling in parameter operations Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-core#347 · Opened Feb 28, 2025
Fix parameter validation when using variable references in breakdown metadata Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

PolicyEngine/policyengine-core#346 · Opened Feb 25, 2025
Support amount_unit instead of rate_unit for amount scale parameters Open

Difficulty 3/5 1-2 days Newbie friendliness 38/100

PolicyEngine/policyengine-core#345 · Opened Feb 25, 2025
Support projecting non-person variables down to person in `add` Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#343 · Opened Feb 13, 2025
Add `last_reviewed_at` metadata field for variables and parameters Open

Difficulty 5/5 Over a week Newbie friendliness 15/100

PolicyEngine/policyengine-core#342 · Opened Feb 11, 2025
Allow parameters for `defined_for` Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-core#341 · Opened Feb 11, 2025
Document `Simulation.is_over_dataset` property Open

enhancement

Difficulty 2/5 1-3 hours Newbie friendliness 35/100

PolicyEngine/policyengine-core#340 · Opened Jan 31, 2025
Make Core dataset ingestion local-only and phase out remote artifact transfer Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-core#323 · Opened Dec 19, 2024
Accept json input for CLI test Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

PolicyEngine/policyengine-core#317 · Opened Dec 4, 2024
Option in `neutralize_variable` to neutralize children Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

PolicyEngine/policyengine-core#308 · Opened Nov 21, 2024
Speed up branch calculations by reimplementing `neutralize` Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-core#300 · Opened Oct 29, 2024
Uprating chaining fails Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

PolicyEngine/policyengine-core#292 · 5 comments · Opened Oct 12, 2024
Create YAML test inputs from JSON in API request Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-core#291 · Opened Oct 10, 2024
Add fully-functional `ParameterNode.__repr__` Open

enhancement help wanted

PolicyEngine/policyengine-core#274 · 1 comment · 1 assignee · Opened Sep 19, 2024
Remove unused h5 files in the data storage folder for datasets Open

Difficulty 3/5 1-2 days Newbie friendliness 30/100

PolicyEngine/policyengine-core#273 · Opened Sep 16, 2024
Macro cache loads Enum array variables incorrectly Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 45/100

PolicyEngine/policyengine-core#270 · Opened Sep 9, 2024

PolicyEngine/policyengine-core

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