Introduction
Due to the updates on Safe Software's website and the upcoming release of the FME Flow (formerly FME Server) REST API V4, we are starting the deprecation process for the FME Flow JavaScript API.
Safe Software will no longer provide support for integrations utilizing the JavaScript API and has removed the publicly hosted .js libraries.
Timeline
Technical support for the JavaScript API has been discontinued with immediate effect.
The hosted .js libraries have been removed as of October 2025.
Access the Library
You can obtain the JavaScript API library (fmeserver.js) for reference by downloading it from this link: https://safe-kc.s3.us-west-2.amazonaws.com/FME-Server-Javascript-API.zip
Users have the option to self-host this file, ensuring their workflows can still reference it. Nevertheless, we strongly advise that all workflows transition to using a supported alternative over time.
It's important to note that the .js library will no longer receive updates or support from Safe Software.
Workflow Migration
We recommend that any existing workflows that use the JavaScript API be migrated to a supported alternative, such as the FME Flow REST API or FME Flow Apps.
FME Flow REST API
The FME Flow REST API is the recommended alternative to the JavaScript API. Workflows may be updated to use the REST API V3 or REST API V4 (2025.1+).
As of FME Flow 2025.1, the V3 REST API has been deprecated. The current API will remain accessible, but no new features or general bug fixes will be implemented. Starting with FME Flow 2026.1, the V3 API will be removed. We encourage all users to prepare their systems for this change.
The V4 REST API offers enhanced security and usability, including new and reorganized endpoints, as well as the removal of certain endpoints. For information on migrating from V3 to V4, please see the FME Flow REST API V4 documentation and click on the heading Migrating from REST API V4.
The REST API provides even greater flexibility compared to the JavaScript API. Thus, workflows that require custom functionality or are integrated into other applications are good candidates for this option.
See Getting Started with the FME Flow REST API and Automating Workflow Submission from a Third Party Application To FME Flow for more resources and tutorials.
FME Flow Apps
FME Flow Apps are the recommended no-code alternative to the JavaScript API.
Flow apps offer extensive customization and options for data upload and delivery, but less interactivity than coded web applications. Standalone, self-serve workflows that do not require custom functionality are good candidates for this option.
See Getting Started with FME Flow Apps for more resources and tutorials.
Support
If you have any questions or concerns about the JavaScript API deprecation, please contact Safe Software Support.