v0.1.0-preview.2

This release overhauls tool handling, makes options types fully mutable, adds logging capability, and improves serialization.

Breaking Changes

Refer to the C# SDK Versioning documentation for details on versioning and breaking change policies.

1. Overhaul tool handling #89
   • McpToolAttribute renamed to McpServerToolAttribute; McpToolTypeAttribute renamed to McpServerToolTypeAttribute
   • WithTools() renamed to WithToolsFromAssembly()
   • ListToolsAsync return type changed from IAsyncEnumerable<Tool> to Task<IList<McpClientTool>>
   • CallToolAsync parameter changed from Dictionary<string, object> to IReadOnlyDictionary<string, object?>
2. Make options types fully mutable #107
   • McpClientOptions, Implementation, and all capability types changed from record to class
   • init-only setters changed to set; with expressions on these types will no longer compile
3. Fix enum serialization #61
   • Role, LoggingLevel, and ContextInclusion enums now use JsonStringEnumConverter with [JsonStringEnumMemberName] instead of [JsonPropertyName]
   • This is a serialization format change; any code depending on the previous serialized form needs to be updated
4. List tools from DI once #115
   • ServerInstructions property removed from McpServer
   • McpServerHostedService is no longer public

What's Changed

• Logging Capability #53 by @PederHP (co-authored by @stephentoub)
• Fix enum serialization #61 by @zaevi (co-authored by @eiriktsarpalis)
• Make client config optional to McpClientFactory.CreateAsync #65 by @stephentoub (co-authored by @eiriktsarpalis)
• Fix stdio encoding issue: Enforce explicit UTF-8 for correct Unicode handling #73 by @willibrandon (co-authored by @stephentoub)
• Overhaul tool handling #89 by @stephentoub
• Avoid race starting SseResponseStreamTransport #91 by @halter73
• Adding a base class for request params that exposes the progressToken #99 by @aaronpowell (co-authored by @stephentoub)
• Add [McpServerTool] support for instance methods #100 by @stephentoub
• complete fix for SampleLlmTool discovery #102 by @NeverMorewd (co-authored by @stephentoub)
• Make options types fully mutable #107 by @halter73
• Configurable messages endpoint for SSE transport #109 by @edis-uipath
• Use different logger categories for client and server in McpJsonRpcEndpoint #110 by @halter73
• List tools from DI once #115 by @halter73
• Adding support for returning collections from tools #116 by @aaronpowell

Documentation Updates

• Add nuget badge to README #58 by @stephentoub
• docs: update McpToolAttribute name comment #63 by @WeihanLi
• docs: add McpServerOptionsSetup code comment #77 by @JaneConan
• Update documentation configuration #86 by @localden (co-authored by @eiriktsarpalis)
• Add acknowledgements to README #94 by @mikekistler (co-authored by @stephentoub)
• Add links to API docs from README.md #96 by @eiriktsarpalis
• Add package installation to README #101 by @timheuer
• Samples for quickstart docs #104 by @aaronpowell

Test Improvements

• Run integration test SSE server in process #56 by @halter73
• Remove reflection from Connect test #57 by @jaredpar (co-authored by @stephentoub)
• Fix private reflection #60 by @jaredpar
• Add XunitLoggerProvider #81 by @halter73

Repository Infrastructure Updates

• Adding code coverage to tests in workflow #75 by @aaronpowell (co-authored by @stephentoub @eiriktsarpalis)
• Adding merge files to gitignore #78 by @aaronpowell
• Add gitattributes #98 by @halter73
• Set up package publishing for daily, manual, and release builds #118 by @jeffhandley (co-authored by @Copilot)

Acknowledgements

• @PederHP made their first contribution in #53
• @jaredpar made their first contribution in #57
• @zaevi made their first contribution in #61
• @WeihanLi made their first contribution in #63
• @willibrandon made their first contribution in #73
• @aaronpowell made their first contribution in #75
• @JaneConan made their first contribution in #77
• @localden made their first contribution in #86
• @timheuer made their first contribution in #101
• @NeverMorewd made their first contribution in #102
• @edis-uipath made their first contribution in #109
• @colombod @Meir017 reviewed pull requests

Full Changelog: v0.1.0-preview.1.25171.12...v0.1.0-preview.2