Frontend

Languages

Policy: One of Specified Versions

Reasoning: Adopting new versions of these technologies may have substantial impact on shared community tooling or hosting providers

Chosen Technologies:

• JavaScript
• TypeScript

Build Tools

Policy: One of Specified versions

Reasoning: Adopting new versions of these technologies may have substantial impact on shared community tooling or hosting providers

Chosen Technologies:

• Node 20
• Yarn 1

First Party Libraries / Frameworks

Policy: One of Specified versions

Reasoning: The FOLIO community has previously adopted the policy that first party technologies must be synchronized across all modules within the system for easier support

Notes: These versions are often only decided upon in the latter states of the flower release process and may be subject to change even after this document is accepted

Chosen Technologies:

• Stripes 10.0.0 or greater

Shared Third Party Libraries / Frameworks

Policy: One of Specified versions

Reasoning: These technologies are fundamental to the operation of FOLIO. Modules supporting incompatible versions would lead to an non-operational system

Chosen Technologies:

• React 18.2

During Build Automated Testing

Policy: Unspecified versions

Reasoning: These technologies are only used for automated testing within the module. It is reasonable for the versions to vary between modules as the choice does not affect other modules or centralised community tooling

Chosen Technologies:

• Jest
  • should be 29 or greater
• RTL
  • should be 14 greater

Post Build Integration Testing

Policy: TBD

Reasoning: TBD

Chosen Technologies:

• Cypress 12.0*
• * Pending verification 

Backend

Languages

Policy: One of Specified Versions

Reasoning: Adopting new versions of these technologies may have substantial impact on shared community tooling or hosting providers

Chosen Technologies:

• Java 21 / JDK 21
• Groovy (version determined by the version of Grails, below)
• OpenAPI (OAS) 3
  • see https://dev.folio.org/start/primer-oas/

Build Tools

Policy: One of Specified versions

Reasoning: Adopting new versions of these technologies may have substantial impact on shared community tooling or hosting providers 

Chosen Technologies:

• Maven 3.8 or later
• Docker
• Gradle

First Party Libraries / Frameworks

Policy: One of Specified versions

Reasoning: The FOLIO community has previously adopted the policy that first party technologies must be synchronised across all modules within the system for easier support

Notes:

• These versions are often only decided upon in the latter states of the flower release process and may be subject to change even after this document is accepted.
• A first party library/framework needs to support only one of the versions allowed in the "Third Party Libraries / Frameworks" list.

Chosen Technologies:

• folio-spring-base 8.1 or greater
• folio-vertx-lib 3.2 or greater
• raml-module-builder 35
  • deprecated. Only existing FOLIO modules may continue to use raml-module-builder
• edge-common 4.5.2 or greater
• edge-common-spring 2.3.2 or greater
• https://github.com/folio-org/folio-s3-client 2.1.1 or greater

Third Party Libraries / Frameworks

Policy: Unspecified versions

Reasoning: These technologies are only used within a module. It is reasonable for the versions to vary between modules as the choice does not affect other modules or centralized community tooling

Notes: A first party library/framework may support only one of these versions.

Chosen Technologies:

• Spring Boot
  • 3.4 or later recommended (OSS support until 2025-11)
• Spring Framework
  • 6.2 or later recommended (OSS support until 2026-08-31)
• Grails
• Eclipse Vert.x 4
  • See https://projects.eclipse.org/projects/rt.vertx and https://gitlab.eclipse.org/eclipsefdn/emo-team/emo/-/issues/760
    
• Lombok
• AWS SDK for Java
  • version 2 (version 1 will reach end-of-support on December 31, 2025)
• MinIO Client library 8.5 or higher recommended

During Build Automated Testing

Policy: Unspecified versions

Reasoning: These technologies are only used for automated testing within the module. It is reasonable for the versions to vary between modules as the choice does not affect other modules or centralized community tooling

Chosen Technologies:

• JUnit
  • 5 should be used, 4 (is in maintenance mode) may be used, however JUnit 5 vintage is preferred
• rest-assured 
• testcontainers

Post Build Integration Testing

Policy: TBD

Reasoning: These tests are run within a single repository, thus they must all use the same technology versions. However, I don't know if that version should be centrally controlled

Chosen Technologies:

• karate
• cucumber-reporting

Infrastructure

Policy: All of Specified Versions

Reasoning: These technologies are fundamental to the operation of FOLIO. Modules supporting incompatible versions would lead to an non-operational system. It may be necessary for modules to support multiple versions in the same module version e.g. in order to ease transition between infrastructure technology versions during system upgrades 

Chosen Technologies:

• Postgresql 16
• OpenSearch 2 and Elasticsearch 8
  • OpenSearch maintenance policy
  • Elasticsearch support policy, EOL dates, release history
• MSK/Kafka - 3.5.1 
• S3/MInIO - Current version of MinIO compatible with S3
  

Policies

Policies should use the language described in RFC-2119

Technology Version Policies

These policies define guidance for module developers on which versions of technologies are reasonable to use by a module version targeted for a given flower release

One of Specified Versions

When one or more versions are provided for a technology, the modules must use / work with / support one (or more) of the specified versions

For example, if Java 17 and 21 are supported, a module a may choose to support either 17, 21 or both

All of Specified Versions

When one or more versions are provided for a technology, the modules must use / work with / support all of the specified versions

For example, if Postgresql 14 and 16 are supported, a module must work with both 14 and 16

Unspecified Versions

When no versions are provided for a technology, the module should use the latest supported version where possible. Optional guidance specific to the technology may be provided within the document

Support period

Technology versions must support the full Sunflower support period that ends around Q1 2026: Sunflower will be released in Q2 2025 and will be supported until Umbrellaleaf (R1 2026) gets released around Q1 2026 (based upon assumption that future releases will follow a similar cadence to previous releases), see FOLIO support policy.

^* Current best guess