Microsoft 365 Agents SDK for Python - Release Notes v1.5.0

Release Date: 2026-08-26
Previous Version: 1.4.0 (Released 2026-08-18)

Major Features & Enhancements

Testing Package: Added the new microsoft-agents-testing package with an in-memory TestAdapter, fluent TestFlow conversation assertions, and MockUserTokenClient support for testing OAuth and token-exchange flows without external services (#503)
Outbound Host Validation: Added the shared OutboundHostValidator with configurable host-suffix allowlists and default Microsoft service hosts, and integrated it with the aiohttp and FastAPI adapters to help prevent SSRF attacks (#543)
Proactive Trace Linking: Added OpenTelemetry span links that preserve trace correlation across stored proactive conversations and later continue, create-conversation, and send-activity operations (#534)

StreamInfo Compatibility: Added serialization and deserialization behavior compatible with the .NET SDK for reliable cross-SDK streaming round trips (#561)

Streaming Reliability: Improved streaming timeout handling and keep-alive behavior to prevent premature timeout failures (#560)
Expect Replies Handling: Moved expect-replies response handling into the adapter layer, fixing typing-indicator behavior and response aggregation (#556)

Authentication Configuration Validation: Added validation for certificate, federated credential, and workload identity authentication settings (#551)
Configuration Loading: Expanded load_configuration_from_env to accept any mapping type (#552)
Zero-Code OpenTelemetry Sample: Added a sample that uses the OpenTelemetry Python distro, environment-based auto-instrumentation, OTLP export to the Aspire Dashboard, and a custom sampler that drops typing-indicator spans without configuring telemetry in application code (#503)
GitHub Actions Security: Pinned GitHub Actions to full-length commit SHAs and updated action dependencies (#546, #548, #553)