phase4 is an embeddable Java library for sending and receiving AS4 messages. It is designed for manual integration into an existing system, rather than use as a standalone project. Built-in protocol profile support includes Peppol and CEF eDelivery; the documentation also lists BDEW, DBNAlliance, eDelivery2, EESPA, ENTSOG, EUCTP, and HR eDelivery. The library is licensed under Apache 2.0, and its open-source plan costs 0.00 USD per free. The minimum Java version is 17, with Java 21 or later recommended for performance. The maintainer says it works on Windows, Linux, Mac, and AWS. Configuration can be supplied through application.properties, system properties, or environment variables. Security setup includes keystores and truststores in JKS or PKCS12 formats. The project lists AS4 multi-hop and AS4 split and join as unimplemented. Its automated unit and integration tests cover many configurations, while testing against a real remote system is a different process. The testing guide says an official Peppol AP certificate is needed to test sending to or receiving from an existing Peppol service provider. Commercial support inquiries can be directed to the maintainer by email.
Who it is for
phase4 suits developers who need AS4 messaging in an existing Java system and can handle manual integration and configuration. It is relevant to systems using Peppol, CEF eDelivery, or the other listed profiles.
What is good
- Free library licensed under Apache 2.0.
- Built-in profiles include Peppol and CEF eDelivery.
- Works on Windows, Linux, Mac, and AWS.
- Configuration can use properties, system properties, or environment variables.
- Security configuration supports JKS and PKCS12 keystores and truststores.
What to know first
- Requires manual integration into an existing system.
- Java 17 is the minimum requirement.
- AS4 multi-hop is not implemented.
- AS4 split and join are not implemented.
Verdict
Choose phase4 when you need an open-source Java library for AS4 messaging and can integrate it into an existing system. Look elsewhere if you need a standalone project or require AS4 multi-hop, split, or join functionality.
Get started with phase4
- Open the phase4 GitHub repository.
- Prepare a Java environment with Java 17 or later; Java 21 or later is recommended.
- Manually integrate the library into an existing system.
- Configure it through application.properties, system properties, or environment variables.
- Set up keystores and truststores in JKS or PKCS12 format as needed.
- For testing with an existing Peppol service provider, obtain an official Peppol AP certificate.
What the free plan stops at
Java 17 is the minimum requirement. AS4 multi-hop and AS4 split and join are not implemented; testing with an existing Peppol service provider requires an official Peppol AP certificate.
Questions about phase4
How much does phase4 cost?
The open-source library plan is 0.00 USD per free.
Is phase4 open source?
Yes. It is licensed under the Apache 2 License.
Does phase4 work as a standalone project?
No. It is a library that must be manually integrated into an existing system.
Which operating systems does phase4 work on?
The maintainer says it works on Windows, Linux, Mac, and AWS.
What Java version does phase4 require?
Java 17 is the minimum. Java 21 or later is recommended for performance.
Does phase4 support Peppol?
Yes. Peppol is among its built-in protocol profiles. Testing with an existing Peppol service provider requires an official Peppol AP certificate.
phase4 plans and pricing
All plansCompared on electronic invoicing software
- Free plan
- No
- Peppol access
- Yes
- Tax validation
- No
- API access
- Yes
- Structured formats
- UBL
- Deployment
- on-premise
