diff --git a/changelog.md b/changelog.md
index 4325390b..120940e2 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,16 +1,33 @@
-# Microsoft 365 Agents SDK for Python - Release Notes v1.5.0 (Unreleased)
+# Microsoft 365 Agents SDK for Python - Release Notes v1.5.0
-**Release Date:** Unreleased
+**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.
+- **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)
+
+## New Models & APIs
+
+- **`StreamInfo` Compatibility**: Added serialization and deserialization behavior compatible with the .NET SDK for reliable cross-SDK streaming round trips (#561)
+
+## Bug Fixes
+
+- **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)
## Developer Experience
-- **Authentication Configuration Validation**: Added validation for certificate, federated credential, and workload identity authentication settings
-- **Configuration Loading**: Expanded `load_configuration_from_env` to accept any mapping type
+- **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)
+
+## Documentation
+
+- **Release Notes Formatting**: Standardized release-note heading formatting (#557)
---
diff --git a/libraries/microsoft-agents-activity/readme.md b/libraries/microsoft-agents-activity/readme.md
index 8e98c8b6..479d2841 100644
--- a/libraries/microsoft-agents-activity/readme.md
+++ b/libraries/microsoft-agents-activity/readme.md
@@ -15,6 +15,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-authentication-entra-auth-sidecar/readme.md b/libraries/microsoft-agents-authentication-entra-auth-sidecar/readme.md
index 2166666f..a9c7f4bb 100644
--- a/libraries/microsoft-agents-authentication-entra-auth-sidecar/readme.md
+++ b/libraries/microsoft-agents-authentication-entra-auth-sidecar/readme.md
@@ -15,6 +15,15 @@ handles secrets, certificates, or keys.
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-authentication-msal/readme.md b/libraries/microsoft-agents-authentication-msal/readme.md
index 2caaba14..0b182f86 100644
--- a/libraries/microsoft-agents-authentication-msal/readme.md
+++ b/libraries/microsoft-agents-authentication-msal/readme.md
@@ -15,6 +15,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-copilotstudio-client/readme.md b/libraries/microsoft-agents-copilotstudio-client/readme.md
index b08d192c..5acc6aff 100644
--- a/libraries/microsoft-agents-copilotstudio-client/readme.md
+++ b/libraries/microsoft-agents-copilotstudio-client/readme.md
@@ -16,6 +16,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-aiohttp/readme.md b/libraries/microsoft-agents-hosting-aiohttp/readme.md
index 0ac97622..29dedf86 100644
--- a/libraries/microsoft-agents-hosting-aiohttp/readme.md
+++ b/libraries/microsoft-agents-hosting-aiohttp/readme.md
@@ -17,6 +17,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-core/readme.md b/libraries/microsoft-agents-hosting-core/readme.md
index 31d43620..d506501e 100644
--- a/libraries/microsoft-agents-hosting-core/readme.md
+++ b/libraries/microsoft-agents-hosting-core/readme.md
@@ -16,6 +16,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-dialogs/readme.md b/libraries/microsoft-agents-hosting-dialogs/readme.md
index aca26a9b..1a8c2308 100644
--- a/libraries/microsoft-agents-hosting-dialogs/readme.md
+++ b/libraries/microsoft-agents-hosting-dialogs/readme.md
@@ -18,6 +18,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-fastapi/readme.md b/libraries/microsoft-agents-hosting-fastapi/readme.md
index 0295b7a3..c6e9e070 100644
--- a/libraries/microsoft-agents-hosting-fastapi/readme.md
+++ b/libraries/microsoft-agents-hosting-fastapi/readme.md
@@ -9,6 +9,15 @@ This library provides FastAPI integration for Microsoft Agents, enabling you to
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-msteams/readme.md b/libraries/microsoft-agents-hosting-msteams/readme.md
index 2e20c397..aa4a95e3 100644
--- a/libraries/microsoft-agents-hosting-msteams/readme.md
+++ b/libraries/microsoft-agents-hosting-msteams/readme.md
@@ -18,6 +18,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** — a compre
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-slack/readme.md b/libraries/microsoft-agents-hosting-slack/readme.md
index f5c0b816..8b2446a1 100644
--- a/libraries/microsoft-agents-hosting-slack/readme.md
+++ b/libraries/microsoft-agents-hosting-slack/readme.md
@@ -13,6 +13,15 @@ Integration library for building Slack agents using the Microsoft 365 Agents SDK
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-hosting-teams/readme.md b/libraries/microsoft-agents-hosting-teams/readme.md
index 496dedcc..a1ae4da0 100644
--- a/libraries/microsoft-agents-hosting-teams/readme.md
+++ b/libraries/microsoft-agents-hosting-teams/readme.md
@@ -18,6 +18,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-storage-blob/readme.md b/libraries/microsoft-agents-storage-blob/readme.md
index 03456f7e..bce07ff8 100644
--- a/libraries/microsoft-agents-storage-blob/readme.md
+++ b/libraries/microsoft-agents-storage-blob/readme.md
@@ -16,6 +16,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-storage-cosmos/readme.md b/libraries/microsoft-agents-storage-cosmos/readme.md
index fa2ca021..c6f7f26b 100644
--- a/libraries/microsoft-agents-storage-cosmos/readme.md
+++ b/libraries/microsoft-agents-storage-cosmos/readme.md
@@ -16,6 +16,15 @@ This library is part of the **Microsoft 365 Agents SDK for Python** - a comprehe
Date |
Release Notes |
+
+ | 1.5.0 |
+ 2026-08-26 |
+
+
+ 1.5.0 Release Notes
+
+ |
+
| 1.4.0 |
2026-08-18 |
diff --git a/libraries/microsoft-agents-testing/readme.md b/libraries/microsoft-agents-testing/readme.md
index 228983ed..02234c34 100644
--- a/libraries/microsoft-agents-testing/readme.md
+++ b/libraries/microsoft-agents-testing/readme.md
@@ -7,6 +7,25 @@ provides an in-memory channel adapter, fluent conversation assertions, and a
mock user-token client so agent behavior can be tested without a live channel
or token service.
+## Release Notes
+
+
+
## Features
- **`TestAdapter`** runs activities through the normal middleware and agent
diff --git a/versioning/TARGET-VERSION b/versioning/TARGET-VERSION
index 9dffe118..49df1202 100644
--- a/versioning/TARGET-VERSION
+++ b/versioning/TARGET-VERSION
@@ -1 +1 @@
-1.5.0.
+1.6.0.