Mastra stepExecutionPath + supportsConcurrentUpdates: Hardening Parallel Agent Workflows Against State Corruption

Mastra·high signal

Mastra v1.0's March 2026 changelog adds stepExecutionPath to all workflow results—a list of step IDs that actually ran, available mid-execution and persisted across resume/restart cycles—enabling precise post-mortem analysis of which branches fired in parallel. More critically, storage backends now expose supportsConcurrentUpdates() as a capability check: without verifying this, simultaneous tool calls hitting the same workflow state produce subtle data corruption that only manifests under load in production. Both features are essential for any multi-step TypeScript agent workflow with branching or parallel execution patterns.