# Changelog: LitmusEdge 3.16.x to 4.0.x - LE, LEM, LUNS API Docs

> You are at https://api.litmus.io/reference/changelog-le.md.
> Parent: https://api.litmus.io/agents.md (product router: /le/agents.md)
> What changed in the LE API between 3.16.x and 4.0.x. This tree documents 4.0.x only; 3.16.x endpoints live only in the full collection JSON.

## Important note

When transitioning to API version 4.0.x, update workflows and integration points to align with the updated endpoint locations, revised folder structures, and the introduction of GraphQL implementations. Review the changes carefully to ensure a seamless transition. For APIs that are the same as version 3.16.x, verify the updated folder paths to maintain proper system alignment.

## Digital Twins

Digital Twin Parameters:

- Added APIs for Digital Twin lifecycle management (create/read/update/delete) and state transitions
- Introduced parameter schemas (type, units, defaults, validation) and per-twin parameter value management

Docs: /le/digital-twins.md

## Analytics

Move towards GraphQL:

- Migrated all Analytics REST API calls to GraphQL (queries, mutations, subscriptions). REST API calls are supported but not recommended
- Added AI model features and related APIs
- Updated upload methods for TensorFlow models
- Introduced parameter and variable features and the APIs related to them
- Migration note: update clients to the GraphQL schema and adjust to the new folder structures

Docs: /le/analytics.md, /workflows/build-analytics-pipeline.md, /workflows/upload-analytics-model.md

## Integrations

Move towards GraphQL:

- Migrated all Integrations REST API calls to GraphQL. REST API calls are supported but not recommended
- Added CloudSync APIs for configuring cloud storage connections, creating/scheduling sync jobs, and monitoring status/logs
- Migration note: replace REST integration flows with GraphQL operations and verify updated folder paths

Docs: /le/integration/agents.md, /workflows/create-integration-instance.md

## Templates (System / Device Management)

Not listed in the collection changelog, but also changed in 4.0.x: the template download/apply API moved from `/dm/template` to a new `/config/template` + `/config/session` flow. The old `/dm/template` endpoints still work but are deprecated.

Docs: /le/system/device-management.md, /workflows/apply-upload-template.md