Measure retrieval misses separately from model failures

Give retrieval its own outcome and telemetry so missing or irrelevant context is not diagnosed as a model problem.

July 26, 2026 · 2 min · Lukas Walter

Keep RAG citations tied to retrieved chunks

Citations should point back to the retrieved evidence, not to sources the model guessed after answering.

July 8, 2026 · 2 min · Lukas Walter

Keep vector search filters separate from semantic ranking

Use filters for eligibility and ranking for relevance instead of blending both concerns.

July 5, 2026 · 2 min · Lukas Walter

Agent Framework RAG for Agents: Giving Your Agent the Right Context

How to connect Microsoft Agent Framework agents to private application knowledge without stuffing full documents into the prompt.

June 10, 2026 · 10 min · Lukas Walter

RAG with EF Core and pgvector

How to build RAG retrieval in .NET by storing embeddings in PostgreSQL with pgvector and querying them through EF Core.

May 2, 2026 · 6 min · Lukas Walter

Controlling Token Growth with Chat Reducers

How to control token growth in Microsoft Agent Framework with message-count and summarizing chat reducers, including setup, tradeoffs, and when each approach fits.

April 28, 2026 · 6 min · Lukas Walter

Context Compression in .NET

Reduce token cost and latency in .NET by compressing RAG context with a cheap summarizer model or an IChatClient middleware pipeline.

April 1, 2026 · 2 min · Lukas Walter

Indirect Prompt Injection Is a Trust Boundary Problem

Indirect prompt injection is a trust-boundary failure; treat retrieved content as untrusted data, isolate it from instructions, and validate actions before execution.

March 23, 2026 · 7 min · Lukas Walter

Stop RAG Hallucinations with the Short-Circuit Pattern

How to reduce RAG hallucinations by short-circuiting generation when retrieval returns weak evidence, with a simple C# threshold check.

March 22, 2026 · 2 min · Lukas Walter

RAG Is a Data Problem Before It’s a Prompt Problem

Why stale documents, weak chunking, and thin metadata usually break RAG before prompt tuning does.

March 9, 2026 · 6 min · Lukas Walter