AG-UI Mastra 2.0 unifies resumable interrupts and fixes tool-result replay
AG-UI released Mastra adapter 2.0, moving interrupts to the RUN_FINISHED outcome and RunAgentInput.resume while fixing tool-result URLs, cross-turn replay, failed-tool responses, A2UI bridge calls and reasoning attribution.
Why it matters
Continuous generative interfaces depend on reliable pause, approval, resume and tool-result association. Duplicate messages, invalid media encoding or non-resumable threads directly corrupt visible state.
A closer look
The adapter now requires AG-UI 1.0. Image and document URLs remain URL items instead of being encoded as base64, resumed tool calls keep their native message IDs, failed server tools return errors, and A2UI render or bridge-owned calls are answered before the run finishes. It reports at most one interrupt per run and preserves outcomes during late stops.
Who this is for
Developers and platform teams using Mastra, AG-UI, A2UI and frontend tool-approval flows
Original sources
Revisions & corrections (1)
— Read the official AG-UI GitHub release page for release/2026-10-12. Confirmed the 2026-10-12 timestamp, @ag-ui/mastra 2.0.0 package, AG-UI 1.0 requirement, interrupt migration, tool-result URL and replay fixes, A2UI bridge behavior, and listed breaking changes. No conflicting original-source facts were found.