v0.3.0-preview.4

What's Changed

• Respect HandleResponse() and SkipHandler() calls in OnResourceMetadataRequest by @halter73 in #607
• UnreferenceDisposable made slimmer by @Scooletz in #627
• IdleTracking uses lists instead of SortedSet by @Scooletz in #629
• Fix ResourceLinkBlock deserialization by adding missing "name" case by @Copilot in #645
• Add an in-memory transport sample by @stephentoub in #664
• Remove 'Sse' from AspNetCoreSseServer sample name by @halter73 in #665
• Fix NotSupportedException when returning IEnumerable by @Copilot in #675
• Enhance HTTP and MCP session logging by @theojiang25 in #608
• Remove special-casing of string enumerables in McpServerTool by @stephentoub in #699
• Prune idle sessions before starting new ones by @halter73 in #701
• Add framework for conceptual docs by @mikekistler in #708

New Contributors

• @Scooletz made their first contribution in #627
• @Copilot made their first contribution in #645
• @theojiang25 made their first contribution in #608

Full Changelog: v0.3.0-preview.3...v0.3.0-preview.4

v0.3.0-preview.3

What's Changed

• Enable netfx testing. by @eiriktsarpalis in #588
• fix: Prevent crash when Options.ResourceMetadata is null but handled by event by @DavidParks8 in #603
• Update to M.E.AI 9.7.0 by @stephentoub in #602
• Ensure IsExternalInit is type forwarded on NET builds by @stephentoub in #619
• Flow ExecutionContext with JsonRpcMessage by @halter73 in #616
• Update MEAI version and add regression test for #601. by @eiriktsarpalis in #628

New Contributors

• @DavidParks8 made their first contribution in #603

Full Changelog: v0.3.0-preview.2...v0.3.0-preview.3

v0.3.0-preview.2

What's Changed

• Authorization Support (Using ASP.NET Core Native AuthN/AuthZ Integration) by @localden in #377
• Fix URI template derivation and lookup by @eiriktsarpalis in #530
• Implement ReturnJsonSchema in McpClientTool. by @S-Luiten in #538
• Document default value for UseStructuredContent. by @S-Luiten in #539
• Fix deserialization of PrimitiveSchemaDefinition by @stephentoub in #537
• Update README.md to fix the server sample build issue. by @Anduin2017 in #546
• Styling: remove a few redundant parens from object initializer expressions. by @eiriktsarpalis in #548
• Delete unused method and linker suppression by @stephentoub in #567
• Enable injecting IMcpServer and friends into ctors by @stephentoub in #570
• Removed space by @rokenbuzz in #563
• Make CallToolResult.IsError optional by @stephentoub in #573
• Fix relative path resolution in sample app. by @eiriktsarpalis in #572
• Add CallToolResult.ToChatMessage extension method by @stephentoub in #575
• Change default name casing of McpServerXx.Create tools/prompts by @stephentoub in #568
• Fixed StreamableHttpClientSessionTransport.cs for netstandard by @lucapivato in #582

New Contributors

• @S-Luiten made their first contribution in #538
• @Anduin2017 made their first contribution in #546
• @rokenbuzz made their first contribution in #563
• @lucapivato made their first contribution in #582

Full Changelog: v0.3.0-preview.1...v0.3.0-preview.2

v0.3.0-preview.1

What's Changed

• Remove incorrect acknowledgement from README of new Core package by @halter73 in #482
• Add context to complete requests by @stephentoub in #488
• Add structured output/output schema support for server-side tools. by @eiriktsarpalis in #480
• Pass session id's to MCP endpoints. by @eiriktsarpalis in #466
• Make enums serialize as strings if using the reflection-based serializer. by @eiriktsarpalis in #473
• Update Microsoft.Extensions.AI version & expose JSON configuration on McpServerResourceCreateOptions by @sbomer in #511
• Update content according to latest spec by @stephentoub in #513
• Fix visibility of polyfill by @stephentoub in #523
• Add a callback for receiving stderr output by @stephentoub in #525
• Send MCP-Protocol-Version header in Streamable HTTP client transport by @halter73 in #500
• Send DELETE request when closing a Streamable HTTP session on the client by @halter73 in #501
• Fix QuickstartClient path by @stephentoub in #528
• Add 2025-06-18 as supported version by @stephentoub in #529
• Bump version number to 0.3.0 by @eiriktsarpalis in #534

New Contributors

• @sbomer made their first contribution in #511

Full Changelog: v0.2.0-preview.3...v0.3.0-preview.1

v0.2.0-preview.3

What's Changed

• Bump version to 0.2.0-preview.3 by @jeffhandley in #465
• Add elicitation capability by @stephentoub in #467
• Convert records to classes by @eiriktsarpalis in #470
• Convert solution to slnx by @eiriktsarpalis in #472
• Update dependency versions by @stephentoub in #474
• Add ModelContextProtocol.Core package by @halter73 in #428
• Improve protocol version handling by @stephentoub in #468
• Don't conflate request and response IDs in Streamable HTTP transports by @halter73 in #475

Full Changelog: v0.2.0-preview.2...v0.2.0-preview.3

v0.2.0-preview.2

What's Changed

• Bump version to 0.2.0-preview.2 by @jeffhandley in #424
• Serilog AOT has been fixed as of 4.3.0 by @agocke in #434
• Allow more accept headers by @halter73 in #429
• Update README.md by @Gavinluo in #437
• SSE client transport: tolerate return of RPC responses in POST requests. by @eiriktsarpalis in #445
• Log tool invocation errors by @kooshi in #447
• Automatically fall back from Streamable HTTP to SSE on the client by default by @halter73 in #456
• Set CreateNoWindow=true in RunProcessAndWaitForExit by @stephentoub in #462
• Update documentation of McpJsonUtilities.DefaultOptions. by @eiriktsarpalis in #463

New Contributors

• @Gavinluo made their first contribution in #437
• @kooshi made their first contribution in #447

Full Changelog: 0.2.0-preview.1...v0.2.0-preview.2

0.2.0-preview.1

What's Changed

• Bump version to 0.2.0-preview.1 by @jeffhandley in #417
• Update to stable M.E.AI :) by @stephentoub in #421
• Fix NRT annotation on StdioClientTransportOptions.EnvironmentVariables by @stephentoub in #419
• Remove internal GetBase64Data helper by @stephentoub in #422

Full Changelog: v0.1.0-preview.14...0.2.0-preview.1

v0.1.0-preview.14

What's Changed

• Make small corrections to release process docs by @jeffhandley in #402
• Bump next version to preview.14 by @jeffhandley in #403
• Update M.E.AI.Abstractions to 9.5.0-preview.1.25262.9 by @stephentoub in #412
• Add stateless Streamable HTTP support by @halter73 in #392
• Fix McpServerResource registration by @stephentoub in #411
• Improve exception diagnostics for stdio client by @stephentoub in #376
• Clean up namespaces by @stephentoub in #410

Full Changelog: v0.1.0-preview.13...v0.1.0-preview.14

v0.1.0-preview.13

What's Changed

• Set IsError on CallToolResponse to true when result is ErrorContent by @Astaggrock in #394
• Add McpServer/ClientResource{Template} and friends by @stephentoub in #391
• Use WithResources in EverythingServer sample by @stephentoub in #400
• Update to latest M.E.AI version by @stephentoub in #401

New Contributors

• @Astaggrock made their first contribution in #394

Full Changelog: v0.1.0-preview.12...v0.1.0-preview.13

v0.1.0-preview.12

What's Changed

• Add SchemaCreateOptions in McpServerToolCreateOptions/McpServerPromptCreateOptions by @1357310795 in #354
• Adapt GetAlerts endpoint to use the latest weather API spec by @vladnega in #363
• Add static resources to EverythingServer sample by @mikekistler in #361
• Backfills trace injection test and migrates from request.params to request.params._meta by @codefromthecrypt in #360
• Fix typo in McpSession.cs by @stephentoub in #371
• Add a McpClientTool.CallAsync helper by @stephentoub in #367
• Add client-side Streamable HTTP transport support by @halter73 in #356
• Update System and M.E.AI dependencies by @stephentoub in #374
• Remove batching support from StreamableHttpServerTransport by @halter73 in #372

New Contributors

• @1357310795 made their first contribution in #354
• @vladnega made their first contribution in #363
• @codefromthecrypt made their first contribution in #360

Full Changelog: v0.1.0-preview.11...v0.1.0-preview.12