Your Unique Visitor Count Has a One-Month Shelf Life
Umami is MIT-licensed, so the identification path is readable. Where, who and when turn out to be a CDN header, a hash that expires on the 1st, and a bucket quantized to the clock hour.
Notes on AI, web, and the systems underneath
Deep dives on AI, web engineering and the infrastructure underneath — written for people who have to run the thing in production. Diagrams and measured numbers over adjectives.
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All 8 posts →Your Browser Agent Is Not Bound by the Same-Origin Policy
The web's oldest isolation guarantee is a string comparison. Put an agent inside the browser and it becomes a model's ability to resist a prompt injection.
Your Agent Re-Sends the Whole Conversation Every Turn
A multi-turn agent replays its entire history on every request. Caching, context editing and compaction each attack a different part of that bill — and one of them, at its defaults, made it worse.
Why increase() Returns 27.5
Prometheus reports fractional counts for counters that only ever increment by one. The reason is a specific extrapolation rule, and knowing it tells you exactly when the number can be trusted.
Hermes Agent's Learning Loop Is a Counter, a Critic and a Garbage Collector
Hermes Agent says it improves its own skills. In the source, that loop is a tool-call counter, a forked LLM review told to be active, and a curator that archives what nobody uses.
Googlebot Is Not Your Browser
Rendering is a separate, queued, stateless stage between crawling and indexing. Almost everything confusing about JavaScript and search comes from ignoring that.