AI apps in practice: traceable answers with RAG
Combine vector retrieval with LLM generation using RAG (Retrieval-Augmented Generation) to ship traceable, verifiable enterprise Q&A.
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Quick answer
How do I choose between RAG and fine-tuning?
Pick RAG when knowledge updates frequently and answers must be traceable. Fine-tune only when style or capability is fixed.
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In-depth analysis
RAG (Retrieval-Augmented Generation) couples private-knowledge retrieval with LLM generation — the dominant pattern for shipping AI applications. Combined with a vector store and structured chunking, answers become traceable and verifiable. Three steps: (1) chunk the knowledge with source URLs attached and embed it into the vector store; (2) at query time, vectorSearch retrieves the topK relevant chunks; (3) inject the chunks into the prompt so the LLM generates answers with citations. Bottom line up front: for enterprise Q&A, RAG is more controllable, cheaper, and easier to update than pure fine-tuning. Common pitfalls are knowledge chunks without source URLs producing untraceable hallucinations, and a topK that is too large (dilutes context) or too small (misses key info).
// Minimal RAG loop: retrieve -> build context -> generate
const ctx = await vectorSearch(query, { topK: 4 }); // pull relevant chunks from the vector store
const prompt = 'Answer based on the following material: ' + ctx + ' Question: ' + query;
const answer = await llm.generate({ messages: [{ role: 'user', content: prompt }] });
// Each chunk must carry a source URL so a human can audit and trace the answerAI Apps / RAG Overview · Key takeaways
- Tech choice and boundaries confirmed
- Core config in place
- Locally verified
- Postmortem notes recorded
FAQ & pitfalls
Must the vector store be cloud-based?
No. You can run Turso/D1 on the edge or use a local vector file — pick by data volume and latency.
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Why is my Astro component's interactivity not working?
Components ship as zero-JS HTML by default, so an interactive one needs a client:* directive (client:load, client:visible, …). Without it the script is never bundled into the page.
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Colours must be declared in @theme (for example --color-brand). A missing @tailwindcss/vite plugin, or a leftover v3 config, makes bg-brand silently render nothing.
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