v2.1.0

Highlights

File attachments and Agentic User support

• Receive file attachments in personal scope (#712).
• Resolve Agentic User file content securely through Microsoft Graph /shares (#817).
• Use the clearer IncomingFile.contentUrl API (#773).

Authentication and lifecycle

• Configure and run multiple OAuth flows in one app (#744).
• Prevent duplicate token-exchange sign-in events (#686).
• Handle Teams installation upgrade activities (#788).

State, messaging, and streaming

• Add per-turn conversation and user state (#729).
• Support targeted message updates and personal-chat sends (#739, #795).
• Preserve and update textFormat throughout streamed activities (#762, #784).

Cards and extensibility

• Add the new @microsoft/teams.m365extensions package and sample for Microsoft 365 Agents SDK integration (#725).
• Add setCachePolicy to CardActionType (#574).
• Produce smaller Adaptive Card payloads by omitting schema-default properties (#832).
• Add an HTTP transport seam at the IHttpServerAdapter layer (#720).

Samples and developer experience

• Add an AI file-analysis sample (#727).
• Consolidate message interaction examples (#719).
• Improve HTML Widget rendering and MessageBack scrolling (#715).

Compatibility and migration

• The minimum supported Node.js version is now 22.12.0 (#753).
• IncomingFile.webUrl has been renamed to IncomingFile.contentUrl (#773).
• Attachment.id is deprecated (#708).
• Adaptive Card serialization no longer emits schema-default values; consumers comparing raw payloads may observe smaller output (#832).

Security and reliability

The dependency graph was refreshed to address npm audit findings (#783, #831). The 2.1.0 release validated with zero production audit findings, and all build, lint, and test checks passed.

Full comparison: v2.1.0-preview.3...release/v2.1