Maestro 4.6 Adds React Flow Editor, Visual Tracing and ToolRunner Integration

Maintainers released Maestro 4.6.0 on 4 November 2026, adding a React Flow workflow editor and visual tracing tools to the Drupal contributed module. The official release notes also identify changes to Tool API integration, trace archiving, task management and orchestration controls.

The changes affect how Drupal administrators build workflow templates, inspect running processes and manage automated task execution. Updated Maestro documentation describes new inspection capabilities alongside changes to the account context used when workflows invoke Drupal tools.

The React Flow editor supports drag-and-drop task creation, zoom controls, a minimap and tools for arranging workflow tasks. Maestro's existing Diagram.js editor remains available, with both interfaces editing the same workflow templates. Both use native Drupal forms for task configuration. The editor documentation also warns that changing templates while processes are running can cause execution problems.

Maestro's visual trace viewer allows administrators to inspect running and completed workflows through a read-only diagram. The interface displays task statuses, execution paths and repeated workflow steps, with separate views for individual loops. Administrators can select tasks to examine execution details and enable automatic refresh every five, ten, 30 or 60 seconds. The visual trace viewer requires the React Flow Template Builder submodule.

The release notes also list trace archiving and pruning changes. According to the tracing documentation, the archive records process variables and linked entity identifiers before and after individual tasks. These snapshots allow administrators to examine changes made during execution. The default retention period is one week, with configurable retention and scheduled pruning through cron. The documentation also references archive availability in Maestro 4.5.1 and later, so not all archive functionality can be attributed exclusively to version 4.6.

Another change updates Maestro's Tool Task integration to use the runner introduced in Tool API 1.0.0-beta12. The runner provides a shared execution sequence covering declared permissions, input validation, access checks and tool execution. Maestro's documentation states that failed tool calls receive a Cancelled task status and are recorded in the logs. Administrators can configure a subsequent IF task to handle failures.

The ToolRunner change follows an integration gap identified in The DropTimes' 2 November report on the Rosetta workflow tracing proposal. The proposal, presented by ECA maintainer Jürgen Haas, identified Maestro among systems invoking tools outside a shared execution path. Maestro 4.6 documents adoption of the updated runner, but the release does not establish support for cross-engine OpenTelemetry tracing or shared workflow replay.

Maestro 4.6 also introduces a configurable account for running the orchestrator. The Tool Task documentation recommends assigning a dedicated account with only the permissions required by workflow tools. If no account is configured, tools execute under the identity associated with the request or command that triggers orchestration. Tool API continues to apply permission and access checks when invoking tools.

Maestro 4.6 supports Drupal 10.3 and later within Drupal 10, as well as Drupal 11. However, the updated Tool Task requires Tool API beta12 or later, and beta12 supports Drupal 10.5 and Drupal 11. Administrators using earlier Drupal 10 versions must therefore distinguish Maestro's general compatibility from the requirements of its updated Tool API integration.

Additional release changes include task-console interface improvements, enhanced Content Type Task functionality, Drush orchestration fixes and process-variable relationships in Views. Further information is available in the official Maestro 4.6.0 release notes.