Compare e-invoice libraries — 15 August 2026

we looked for a rival. Here is where we looked.

This dated survey supports one claim about Attestwire. The sources and method are included so you can check the result. If it is wrong, tell us and we will publish a dated correction.

Surveyed 15 August 2026.

The claim

As of 15 August 2026 we know of no other EN 16931 rule-set validator written in TypeScript, with no JVM and no runtime dependencies.

"We know of no other" describes what this survey found. It is not a claim that no other project exists. EN 16931 is the European standard that says what an electronic invoice must contain, and a JVM is the Java runtime most tools in this space need installed.

The method

1. The starting list is the Electronic Invoicing section of the awesome-europe list — "Peppol, EN 16931, and the EU e-invoicing directive (2014/55/EU) for cross-border electronic invoicing" — read from raw.githubusercontent.com/GeiserX/awesome-europe/main/README.md on 15 August 2026. It carried 27 entries, all GitHub repositories.
2. For each entry we read the project's own README and repository to record two things only: the implementation language, and whether the project carries the EN 16931 rule set itself or delegates validation to another engine.
3. Nothing here is inferred from a project's popularity, its documentation tone, or anything a maintainer has not written down. Where a project's own docs and our reading disagreed, we recorded the project's docs.

What the section contains

One entry is a validator: gflohr/e-invoice-eu-validator, and its own documentation describes it as wrapping the Java Mustang engine.

That is the whole basis of the claim above, and you can check it against the same file we read.

A tool with broader PDF support

Mustangproject writes PDF/A-3. We do not. If what you need is a finished Factur-X or ZUGFeRD file — the container, the factur-x.xml attachment under its required name, the /AFRelationship value — that is a capability Mustangproject has and Attestwire does not. We write only the CII XML payload. If you need the finished PDF container, Mustangproject may be a better fit.

What the survey does not cover

It does not tell you what any other project lacks, and it ranks nobody. We have read their READMEs; we have not run their test suites, measured their coverage, or audited their rule sets. What it records is the language each project is written in and whether it carries a rule set — two facts a maintainer states about their own work.

It also does not include the hosted Attestwire API. This is a survey of open-source tooling, and a commercial endpoint does not belong in it.

The section is one list. A project that is not on it was not surveyed.

Scope, and how this page ages

This is a snapshot of one list on one date. Projects will change and new ones will appear. The date stays visible so readers can judge how current the result is.

Read the source list yourself: github.com/GeiserX/awesome-europe.

Corrections

If something here is wrong about your project, write to us and it changes, with the date on this page moved to the day it changed.