Comparison
Worthune vs PolicyEngine
These answer different questions. PolicyEngine is open-source microsimulation of US tax and benefit policy — what a rule change does to a household — available as a hosted API or a self-hosted image under AGPL-3.0. Worthune is a productized planning API: retirement, equity comp, loans, and life decisions, with a published specification and an audit record per model. If you are studying policy, use theirs. If you are shipping a planning feature, that is what we are for.
Every claim below about PolicyEngine carries the page it was read from and the date. Oldest check on this page: .
Worthune
Financial planning models delivered as a REST API, an MCP server, and embeddable calculators, each with a published spec and a per-run audit record.
Developers and product teams at fintech, wealthtech, banking, and AI companies.
PolicyEngine
Open-source software computing the effect of tax and benefit policy on households, with a public API.
Researchers, policy analysts, and developers.
Side by side
Sourced facts only. Where a cell says a vendor does not publish something, that means we looked at the page named in the sources below on the date shown and it was not there — not that the answer is no.
| Worthune | PolicyEngine | |
|---|---|---|
| How it is delivered | REST API, MCP server, and a one-script-tag embed | A hosted REST API, or a self-hosted Docker image that runs the same model on your own infrastructure |
| Programmatic API | Yes — REST and MCP, no key required for the three sample models | Yes — household tax and benefit calculations over HTTP; hosted access is granted on request with OAuth credentials, and the Docker image needs no authentication by default |
| License | Commercial, with a free tier that requires attribution | Open source — GNU Affero General Public License v3 |
| Pricing model | Subscription; three models free with attribution, no per-run metering | Not stated publicly; hosted API credentials are requested by email, and the self-hosted image carries no stated fee |
| Published specification per calculator | Yes — three in full publicly, the rest with a subscription; every input contract public | Not verified(not checked yet) |
| Published test cases | Yes — 250 cases per model, downloadable as JSONL | Not verified(not checked yet) |
| Constants with primary sources and check dates | Yes — every constant carries a primary source and the date it was last checked | Not verified(not checked yet) |
| Per-run audit record | Yes — SHA-256 over model, spec version, inputs and outputs, returned with every run | Not verified(not checked yet) |
Where PolicyEngine is stronger
Open, deep on policy, and genuinely better at what it does
Federal and state tax-benefit microsimulation, with the source open for anyone to read, fork, or self-host. On the question of what a policy change does to a household, it goes deeper than we do and is free to inspect line by line. We are not a substitute for it, and we say so on our own comparison page because it is true.
When Worthune is the wrong choice
If you need policy analysis, state-level modeling, or open source
We model US federal rules and do not simulate policy counterfactuals, we have no state-level tax modeling, and our engine is not open source. For research, distributional analysis, or anything where reading the implementation is the point, PolicyEngine is the better tool and it is not close.
Our case
Where we think the difference actually matters
This section is our opinion rather than sourced fact, and it is marked that way on purpose — the table above is what a source URL can settle, and this is what it cannot.
We depend on them, and say so
An advisory job in our own CI cross-checks part of our tax pack against policyengine-us. Comparing ourselves favorably to a project we use as a reference would be dishonest, so this page does not try.
Productized rather than assembled
Versioned specifications, stable input contracts, a response envelope, embeds, an MCP server, and a support address. That is packaging work rather than modeling work, and it is what a product team is usually buying.
A different breadth
Retirement projections, rent-vs-buy, equity compensation, debt strategy, business decisions — planning questions that are not policy questions, and mostly outside what a microsimulation model sets out to answer.
Licensing is a real consideration
AGPL-3.0 is an excellent license for open research and a genuine question for a closed commercial product. That is a matter for your counsel rather than a mark against the project, and we mention it only because it is the thing teams most often miss.
Questions
Common questions
- Is PolicyEngine free?
- The software is open source under AGPL-3.0, read from the package classifiers on the date in the sources below. No pricing is stated for the hosted API — access is requested by email — and the self-hosted Docker image carries no stated fee. Free to use is not the same as free to embed in a closed product; check the license terms against your situation.
- Should I use PolicyEngine instead of Worthune?
- If your question is about policy — what a proposed rule does to households, or how a benefit phases out across incomes — yes, and without hesitation. If your question is about shipping a planning feature with a stable contract, versioned behavior, and a record you can hand a reviewer, that is what we built.
- Can I use both?
- We do. Running a second, independently maintained model against your own is one of the better checks available, which is exactly why our tax pack is cross-checked against theirs in CI.
- Does Worthune model state taxes?
- No. Constants and tax logic are United States federal only. If state-level modeling matters to you, that is a real gap on our side and PolicyEngine covers it.
Sources
Every claim above, and where it came from
- PolicyEngine · Pricing model — policyengine.org/us/api, checked
- PolicyEngine · License — pypi.org/project/policyengine-us/, checked — Read from the policyengine-us package classifiers. AGPL has real consequences for embedding it in a closed product; that is a licensing question for the reader's counsel, not a knock on the project.
- Worthune · Pricing model — worthune.com/pricing, checked
- Worthune · Programmatic API — worthune.com/docs, checked
- Worthune · Per-run audit record — worthune.com/proof, checked
- Worthune · License — worthune.com/terms, checked
Product names and trademarks belong to their owners and are used here only to identify the products compared. Nothing on this page implies endorsement or affiliation. Found something out of date? Tell us at support@worthune.com and we will re-check it.