Code-first guides for developers — the agent loop, MCP, frameworks, and the four ways to build. Working code in every post, no hype.
New here? Start with these
01 · Not sure which way to build?
The right approach isn't about what sounds most sophisticated. It's about where ownership should sit: who builds, who runs, who decides. Answer three questions and Agentailor stitches a recommendation across the four ways to build.
Find your path02 · Ready to read? Start with the complete guide
An eval harness is four components: the case, the runner, the capture, and the graders. A guide to what each one has to do for an AI agent, built around two real harnesses, so you can decide whether to build one, adopt a framework, or combine both.
03 · Know what you want? Browse by topic
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Anthropic deleted over 80% of Claude Code system prompt for Claude 5 with no measurable loss on their coding evals. The instructions did not become wrong. The model outgrew needing them. Here is the maintenance pass that finds which of yours have expired, and why you need evals before you delete a single line.
Agent Plugins is an open standard for packaging Agent Skills and MCP servers into one portable folder any client can load. What plugin.json and mcp.json actually define, which clients support it, and whether to package one yet.
Write AI agent evals that catch what you missed: source cases from production traces, spot tests that pass for the wrong reason, and know when to overrule an LLM judge.
Use with AI
Reading through ChatGPT, Claude, or your own agent? Every post is machine-readable via llms.txt, a full-text dump, and a Markdown twin for every URL. Hand it a prompt and let it reason over everything at once.
I'm new to building AI agents. Fetch https://blog.agentailor.com/llms-full.txt — the full text of the Agentailor blog — and design me a structured 4-week curriculum from its articles, fundamentals to production.
Ask Agentailor
Skip the search. Ask Agentailor anything about building AI agents — frameworks, MCP, coding agents, or which path fits — and get a direct answer, grounded in every post on this site.
$ ask agentailor "which way should I build my agent?"
→ answers grounded in every post here.
→ no hunting through the archive.