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2026-04-13 dotnet-11 ef-core

EF Core 11 Adds Native SQL Server Vector Search with DiskANN Indexes

EF Core 11 Preview 2 supports SQL Server 2025 VECTOR_SEARCH() and DiskANN vector indexes directly from LINQ. Here is how to set up the index, run approximate queries, and what changes from the EF Core 10 VectorDistance approach.

2026-04-08 csharp dotnet

C# 15 Union Types Are Here: Type Unions Ship in .NET 11 Preview 2

C# 15 introduces the union keyword for type unions with exhaustive pattern matching and implicit conversions. Available now in .NET 11 Preview 2.

2026-04-06 dotnet-11 csharp

.NET 11 Runtime Async Replaces State Machines with Cleaner Stack Traces

Runtime Async in .NET 11 moves async/await handling from compiler-generated state machines into the runtime itself, producing readable stack traces, correct breakpoints, and fewer heap allocations.

2026-07-27 cursor ai-agents developer-tools

Cursor Router Makes Auto a Per-Request Model Decision

Cursor Router shipped on July 22, 2026. Auto now classifies every request and routes it to a different model, and the Cost, Balance, and Intelligence modes change both the quality you get and how you are billed.

2026-07-27 csharp dotnet dotnet-11

How to diagnose a managed memory leak with dotnet-gcdump and dotnet-dump

A complete workflow for finding a managed memory leak in .NET 11: confirm growth with dotnet-counters, take two gcdumps and diff them, then collect a dump and use dumpheap, gcroot, and objsize in dotnet-dump analyze to find what is still holding the reference.

2026-07-27 dotnet dotnet-11 csharp

How to publish a .NET 11 app as a container image with dotnet publish /t:PublishContainer

A complete guide to building container images from a .NET 11 app with no Dockerfile: the PublishContainer target, ContainerRepository and ContainerImageTags, base image selection through ContainerBaseImage and ContainerFamily, pushing to a registry and how authentication resolves, multi-arch OCI image indexes, the non-root default user, entrypoint control, tarball output for scanners, and the cases where you still need a Dockerfile.

2026-07-27 csharp dotnet dotnet-11

How to serialize a polymorphic type hierarchy with JsonDerivedType in System.Text.Json

A complete guide to polymorphic JSON in .NET 11: JsonDerivedType and JsonPolymorphic, why the declared type decides everything, the $type ordering rule, every exception the feature throws, the contract model for types you do not own, and what ASP.NET Core emits in OpenAPI.

2026-07-27 claude-code ai-agents subagents

How to Stream Nested Subagent Output From a Headless Claude Code Run

By default a headless Claude Code run emits only tool_use and tool_result blocks from its subagents, so the delegated reasoning is invisible. Pass --forward-subagent-text (Claude Code 2.1.211+) to get subagent text and thinking in the stream-json output, and demultiplex it by parent_tool_use_id.

2026-07-26 claude-code ai-agents subagents

Claude Code 2.1.219 Reopens Nested Subagents, Three Layers Deep

Version 2.1.219 raises the default subagent spawn depth from 1 to 3, adds a workflowSizeGuideline settings key, and ships a fail-closed sandbox network allowlist.

2026-07-26 aspire dotnet aspnetcore

How to add Aspire to an existing ASP.NET Core solution without restructuring it

Add Aspire 13.4 to a brownfield ASP.NET Core solution by adding two new projects and three lines per service: aspire init, AppHost wiring with AddProject and WithReference, keeping your existing launchSettings.json and connection strings, and the resilience, health-endpoint, and proxy gotchas that bite on day one.

2026-07-26 ai-agents claude-code cursor

How to Lock Down a Coding Agent's Network Egress With a Strict Host Allowlist

Claude Code, Cursor, and the GitHub Copilot coding agent all ship host allowlists for outbound traffic, and all three default to something looser than you want. The exact settings keys, a policy you can copy, and the four surfaces the allowlist does not cover.

2026-07-26 csharp dotnet dotnet-11

How to test time-dependent code with TimeProvider and FakeTimeProvider in .NET 11

Replace DateTime.UtcNow, Stopwatch, and Task.Delay with System.TimeProvider so tests can control the clock: DI registration, FakeTimeProvider.Advance and SetUtcNow, testing timeouts and PeriodicTimer-based BackgroundServices, plus the Advance-continuation and xUnit v2 gotchas.

2026-07-26 csharp dotnet dotnet-11

How to write integration tests with WebApplicationFactory<T> in ASP.NET Core 11

A complete guide to WebApplicationFactory<TEntryPoint> in ASP.NET Core 11: making the Program entry point reachable, ConfigureTestServices vs ConfigureWebHost, replacing the EF Core registration through IDbContextOptionsConfiguration, the new ConfigureHostApplicationBuilder hook in .NET 11 preview 6, faking authentication, WebApplicationFactoryClientOptions, and UseKestrel when you need a real port.

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