microsoft/Agents-for-net v1.6.150

v1.6 SDK Release

Repository: microsoft/Agents-for-net

Tag: v1.6.150

Published: 2026-06-18T20:32:25Z

Prerelease: no

Release notes:

What's Changed

New Features

Slack Extension (Microsoft.Agents.Extensions.Slack)

New first-class Slack channel extension, enabling agents to communicate directly with Slack without requiring Azure Bot Service as an intermediary:

• `SlackAgentExtension`: Extension class with routing helpers (OnSlackMessage, OnSlackEvent*) for handling Slack-specific events and messages.
• `SlackStream`: Streaming support for Slack, allowing agents to stream responses back to Slack channels.
• `SlackApi`: Low-level Slack API client for direct Slack Web API calls.
• `SlackChannelData`: Strongly-typed channel data model with Payload support for action events.
• `MapSlackEndpoints`: ASP.NET Core endpoint routing for Slack event subscriptions and interactions.
• `SlackExtensionAttribute`: Source-generated attribute for declarative Slack event routing.
• Includes a full SlackAgent sample demonstrating streaming, event handling, and action payloads.

Named Pipe Transport (Microsoft.Agents.Hosting.DirectLine.NamedPipes)

New Named Pipe transport layer for high-performance local inter-process agent communication:

• `NamedPipeProtocol`: Binary protocol with chunked transfer, payload size limits, and content-type negotiation.
• `NamedPipeTransport`: Reliable duplex transport with disconnect handling and error recovery.
• `NamedPipeMessageHandler`: Activity message handler with streaming attachment support.
• `NamedPipeHostedService`: IHostedService implementation for ASP.NET Core integration.
• Enforces payload size limits and handles large object heap (LOH) pressure via 64 KB chunked trailing-byte drain.
• Idempotent DisposeAsync to prevent ObjectDisposedException on double-dispose.
• Comprehensive test coverage for chunking, content type handling, end flag semantics, boundary conditions, and streaming behavior.

Declarative Route Attributes (AgentApplicationAttributes)

New attribute-based routing model for agent handlers, complementing the existing fluent API:

• `AgentExtensionAttribute`: Base attribute for agent extension registration with source-generated routing via AgentExtensionSourceGenerator.
• Route builder base classes: ConversationUpdateRouteBuilderBase, EventRouteBuilderBase, FeedbackRouteBuilderBase, HandoffRouteBuilderBase, MessageRouteBuilderBase, TypeRouteBuilderBase — enabling extensible, attribute-driven route registration.
• `IRouteAttribute`: Public interface for custom route attributes.
• Full test coverage for attribute-based routing.

Agentic Header Propagation

• `AgenticHeaderProvider` / `IHeaderValueProvider`: New infrastructure for propagating agentic context headers across agent-to-agent calls.
• Enables forwarding of correlation and orchestration headers through the call chain.
• Integrated in the AgentAI sample.

OAuth Sign-In Cancellation

• `TeamsSignInInProgressMessage`: New message shown to Teams users when a sign-in flow is already in progress.
• Added cancel options allowing users to abort an in-progress OAuth flow.

Authentication: IdentityProxyManager Auth Type

• New AuthTypes.IdentityProxyManager replaces the UserManagedIdentity + EnableContainerIMDS combination with a single, clearer auth type for container identity proxy scenarios.

Authentication: Azure Region Support

• `AzureRegion` handling added to MsalAuth, enabling region-aware token acquisition for improved latency and resilience.

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Improvements

ServiceUrl Validation

• Added optional Activity.ServiceUrl check against the serviceurl claim in authentication for defense-in-depth validation.
• Graceful handling of invalid ServiceUrl format instead of throwing unhandled exceptions.
• Removed unnecessary DeliveryMode guard in ValidateServiceUrl.

AgentState Thread Safety

• Switched AgentState to lock-based concurrency to preserve serialization order and prevent crashes under streaming workloads.
• Added argument validation and comprehensive locking across AgentState operations.
• New AgentStateThreadSafetyTests and AgentStateValidationTests test suites.

Serialization / JSON

• `DictionaryOfObjectConverter`: Fixed round-trip for primitive arrays in IDictionary — complex types are excluded from primitive array promotion to preserve existing shape for callers expecting IList.
• `DictionaryOfObjectConverter`: Fixed crash on 2D arrays in IDictionary.
• Added comprehensive DictionaryOfObjectConverter unit tests.

Proactive Messaging Instrumentation

• New OpenTelemetry scopes for proactive operations: ContinueConversation, CreateConversation, DeleteConversation, GetConversation, SendActivity, StoreConversation.
• Proactive services are now registered on the TurnContext in Proactive.OnTurnAsync.

Route Builders

• Refactored core route builders (ConversationUpdateRouteBuilder, EventRouteBuilder) to use base classes, enabling future extensibility.
• Added protected constructors to route builder base classes for subclassing.
• Fixed ChannelId wildcard to include subchannel matching.

Logging

• `CloudAdapterLog`: New structured log class for CloudAdapter operations.
• Changed LogNoRouteMatched from Information to Debug level to reduce log noise.
• Surface OAuthHandlers delegate errors in route JSON output for easier diagnostics.
• Added BeginScope to CloudAdapter and HostedActivityService for structured log correlation.

Connector

• `ConversationsRestClient`: Sanitize truncated agents-channel conversation IDs (#840).
• `GetConversationReference`: Added parameterless overload.
• Wrapping the returned task for DeleteConversation.
• Null or whitespace check for audience when creating ConnectorClient.

Startup

• AgentApplication now defaults to MemoryStorage if no IStorage is registered, eliminating the most common startup misconfiguration.
• HttpClientFactory added to AgentApplicationOptions.

OAuth Flow

• Changed OAuth flow to not rely on exceptions for control flow, improving performance and debuggability.
• Added OAuthFlowResult type for structured flow outcomes.

TypingWorker

• Fixed race condition in TypingWorker under...