stack.pulse
#stacks/mastra/ai

Mastra release notes, breaking changes, and upgrade notes.

TypeScript agent framework with workflows, RAG, and evals StackPulse turns upstream changelogs into scannable summaries with risky changes, deprecations, migration notes, and source links.

releases
7
breaking
2
security
0
deprecated
2
migrations
2

Get source-linked upgrade notes and occasional sponsor recommendations. No GitHub login required.

what stackpulse tracks

Mastra releases from GitHub

StackPulse watches Mastra release notes and keeps the original source link close to every summary.

upgrade risk

Breaking changes and deprecations

Risky changes are separated from normal feature notes so you can scan upgrade impact before changing production dependencies.

migration notes

Source-backed next steps

Migration steps and recommended actions are only shown when the upstream release notes support them.

# latest_releases

source-backed
@mastra/core@1.46.0highbreakingdeprecationmigrationfeatureJun 24, 2026

June 24, 2026

This release introduces multi-session architecture with isolated session management, HTTP harness operations, and cross-process signal delivery. It also adds deterministic agent experiments and new integrations.

affected

Users of Harness singleton and direct API calls will need to migrate to session-based operations.

action

Update code to use the new session-based APIs for state, events, and run control.

release_signals
-Harness no longer exposes a singleton harness.session; must use harness.createSession()
-Run control moved from Harness to Session (e.g., sendMessage, abort)
-Event subscription moved to session.subscribe()
-Thread lifecycle APIs moved to session.thread
-Model/mode switching moved to session.model.switch() and session.mode.switch()
!Removed deprecated Harness.getState() Harness.setState() compatibility wrappers
!Removed Harness.getObserverModelId, getReflectorModelId, and related methods
!Removed Harness.sendMessage, Harness.sendSignal, and related run-control methods
!Removed Harness.subscribe()
+Multi-session Harness architecture with isolated session management
+HTTP harness operations and remote session control via JS client
+Cross-process signal delivery with distributed leasing
+Deterministic agent experiments with tool mocks and multi-tenant datasets
+New integrations for Next.js, TanStack Start, and Archil filesystem provider
migration_steps5 steps
  1. 01Use harness.createSession() and operate on the returned Session
  2. 02Use session.state.get() session.state.set() instead of Harness state methods
  3. 03Access observational-memory via session.om
  4. 04Run control operations now on Session (e.g., session.sendMessage)
  5. 05Subscribe to events via session.subscribe()
view source on github->
@mastra/core@1.42.0highbreakingfeatureJun 12, 2026

June 12, 2026

This release introduces trusted system actor execution for workflows, tools, and agents, enabling server-side/background work without JWT/human membership requirements. It also adds a new SignalProvider framework for declarative agent signal wiring and makes task tools agent-agnostic with durable thread state storage.

affected

Developers using Harness APIs for question handling and plan approval will need to migrate to the new tool suspension APIs.

action

Update code to use `respondToToolSuspension` and handle `tool_suspended` events instead of deprecated question and plan approval APIs.

release_signals
-Removed `harness.respondToQuestion(...)` → use `harness.respondToToolSuspension(...)`
-Removed `ask_question` event → listen for `tool_suspended` and read `event.suspendPayload`
-Removed Harness question-related APIs/types (`registerQuestion`, `pendingQuestion`, `HarnessQuestion*` types)
-Removed `harness.respondToPlanApproval(...)` and `plan_approval_required/plan_approved` events → resume `submit_plan` via `respondToToolSuspension`
+Trusted system actor execution for workflows, tools, memory, and agents
+SignalProvider framework for declarative agent signal wiring (webhooks/polling/subscriptions)
+Agent-agnostic interactive tools via native tool suspension (ask_user, submit_plan)
+ThreadState storage domain for durable, agent-agnostic task tools
+New infrastructure/storage options: Postgres vNext observability, ClickHouse replication, durable harness sessions
view source on github->