Sebastian Cochinescu
Developer of agentmarkup
Builder of developer tools for machine-readable websites. Developer of agentmarkup. Founder of Anima Felix.
About
Sebastian is a product builder and developer with over 25 years in technology. He created agentmarkup to solve a problem he encountered on his own projects: making websites machine-readable for LLMs and AI agents required juggling separate tools for llms.txt, JSON-LD, robots.txt, markdown mirrors, headers, and validation. agentmarkup combines that build-time surface into one toolkit for Vite, Astro, and Next.js.
He is also the founder of Anima Felix, an anxiety support app that uses agentmarkup in production.
Articles
We ran 500 of America's biggest companies through an AI-crawler audit
We fetched 500 corporate homepages the way ChatGPT, Claude, and Perplexity do. Most serve readable HTML, but 46% have no usable structured data, 86% have no llms.txt, and seven serve crawlers a blank page. Built for Google, not yet for AI agents.
July 2, 2026 · 4 min readSee your website the way AI crawlers do
Use @agentmarkup/audit to fetch any live URL as GPTBot, ClaudeBot, PerplexityBot, and other AI crawlers, diff each response against a browser, and catch machine-readability issues in CI.
July 2, 2026 · 6 min readHow to add llms.txt, JSON-LD, and AI crawler controls to Nuxt
Use @agentmarkup/nuxt to generate llms.txt, inject JSON-LD, create markdown mirrors, and manage AI crawler rules from prerendered Nuxt output.
June 21, 2026 · 7 min readRun agentmarkup on any static site with the CLI
Use @agentmarkup/cli to run llms.txt, JSON-LD, markdown mirrors, and AI crawler controls over any built static output, with a CI check command.
June 21, 2026 · 6 min readHow to add llms.txt, JSON-LD, and AI crawler controls to Next.js
Use @agentmarkup/next to generate llms.txt, inject JSON-LD, manage AI crawler rules, and understand the dynamic SSR boundary in Next.js.
March 23, 2026 · 8 min readWhen markdown mirrors help, and when they do not
A practical guide to when generated markdown mirrors add signal, when HTML is already enough, and how to avoid unnecessary downsides.
March 20, 2026 · 7 min readIs your website ready for AI? Free LLM discoverability checker
Audit your website for llms.txt, JSON-LD, robots.txt, markdown mirrors, and sitemap. Free tool for e-commerce and brand websites.
March 20, 2026 · 8 min readBuild-time markdown mirrors for agent readability: Cloudflare comparison
Build-time markdown generation for AI readability, including when it helps and how it compares to Cloudflare runtime extraction.
March 20, 2026 · 7 min readHow to make your brand appear in AI conversations
Organization schema, llms.txt, and FAQ markup make your brand visible in ChatGPT, Claude, and Perplexity answers.
March 20, 2026 · 7 min readWhy LLM-optimized e-commerce websites sell more
Product JSON-LD, llms.txt, and AI crawler access make your store visible in AI product recommendations.
March 20, 2026 · 8 min readEvery AI crawler indexing your website in 2026
Complete list: GPTBot, ClaudeBot, PerplexityBot, Google-Extended, CCBot, and more. What each does and how to control access.
March 20, 2026 · 8 min readJSON-LD structured data: the complete guide for web developers
Schema types, JSON-LD vs microdata, common mistakes, and build-time validation.
March 20, 2026 · 10 min readWhat is GEO? Generative Engine Optimization explained for developers
What is real, what is hype, and what you can do today to make your site citeable by AI.
March 20, 2026 · 7 min readWhy llms.txt matters: making your website discoverable by AI
LLMs answer questions by synthesizing web content. llms.txt gives them a structured overview of your site.
March 20, 2026 · 6 min read