What Are AI Agents? A Complete Guide
An AI agent is a language model placed inside a loop with tools and a stopping rule. How that loop works, where it breaks, and when not to build one.
A. Rahman10 min read
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Long-form technical writing on agent architecture, applied AI engineering, developer tooling and the security surface that comes with all of it.
12 articles9 sections
Rule-based automation fails on inputs it was not written for. Agents fail unpredictably. A structured comparison of where each belongs, and how to combine them.
Build a tool-calling agent as a Next.js route handler: typed tool definitions, a bounded loop, a streamed step log, and a client leaf that renders progress.
RAG solves a knowledge problem; agents solve an action problem. Where each architecture belongs, how they combine, and why their failure modes barely overlap.
MCP replaces N times M model-to-system adapters with one server many clients can use. What the protocol standardises, and what it deliberately leaves to you.
A criteria-first assessment of AI coding tools by category — completion, repo chat, agentic editors and review bots — with a harness for testing them yourself.
A comparison of what actually differs between the two API surfaces — system prompts, tool schemas, structured output, state and streaming — and how to choose.
When a change can be drafted by a process that runs your tests, the constraint moves from writing code to reviewing it. What that shift breaks and rewards.
The layers between a working AI demo and a system people depend on: call boundaries, budgets, tenant isolation, evaluation, observability, degradation.
Agentic systems are limited less by model capability than by compounding reliability, context economics, machine identity and interoperability. What each gates.
Prompt injection cannot be fixed by wording: instructions and data share one channel. The controls that work are architectural — scoping, provenance, approval.
How to stream model output into a React app without turning the page into a client bundle: Suspense boundaries, a tiny leaf, cancellation and stable layout.