The same skill lived in two places, and only one copy still had its files
Two scopes held skills with identical names. The SKILL.md files matched down to the sha256, yet one copy was missing the files its own body points to. Here is how I scanned 66 skills and rewrote the detector three times to get from four hits to two real ones.
Handing a long job to another session — and the completion marker for when the notification never arrives
How to use notify_when_idle to hear when another Claude Code session finishes, and a small completion marker that keeps you from waiting forever when the notification is dropped.
Switching to headersHelper in Claude Code broke auth for project-scoped catalogs only
Moving a private plugin catalog to headersHelper worked at user scope and failed under the project directory. The cause was credential non-inheritance. Here are two working helpers, measured execution costs, and what unattended runs need.
Adding ANTHROPIC_DEFAULT_MODEL Changes Nothing While ANTHROPIC_MODEL Is Still Set
ANTHROPIC_DEFAULT_MODEL, added in v2.1.236, is not a replacement for ANTHROPIC_MODEL. Here is how the two differ, plus a Python script that lists every place a model can be pinned.
My read-deny rules never reached inside the folder I had allowed
An audit of how far permissions.deny Read rules actually reach in a working tree where secrets and source code live side by side, with a script you can run today.
Take Inventory of What You Allowed with Don't Ask Again in Claude Code
After clicking Don't ask again a few dozen times, can you still explain what you approved? Here is a script that counts your current rules, plus a way to rebuild permissions from the smallest possible set.
The Biggest Section in Your SKILL.md Is Usually the One to Keep
A skill I run every week cost about 10K tokens just to load. Measuring it section by section showed why the largest block was the one I had to leave in place, and what splitting by reach actually saved.
The listen Stream Kept Reopening Against My Serverless MCP Server
No errors anywhere, yet connections to the MCP server kept piling up overnight. Here is what happens when a fixed platform timeout meets a resubscribe loop, reproduced in a few dozen lines.
Fixing the Code Doesn't Evict a Broken Page From the Edge Cache
I shipped a fix and the broken page kept serving. The problem was not the code but the edge cache, which had stored a broken HTML response because the store decision looked only at the status code. Here is the integrity guard I now run before every cache write, and the thresholds I had to tune in production.
Choosing a WebFetch Cache TTL That Fits the Way You Research
Claude Code lets you tune the WebFetch URL cache TTL. Here is how to see the shape of your own research sessions with a tiny observation server, then trade fetch count against freshness with numbers instead of guesswork.
Now that forking is the default, review agents are the ones I still call by name
Subagent forking became the default, so delegated work now inherits the parent conversation. Work can inherit context. Judgment cannot. Here is how I declare that boundary in the repository and catch it drifting.
A Runaway Build Dies Very Differently Under cgroup Than Under ulimit
Claude Code v2.1.233 added opt-in memory cgroup support for Bash tool commands on Linux. Capping virtual address space with ulimit -v and capping physical memory with a cgroup produce completely different failures — and only one of them lets your Node build start at all.