Once I passed a dozen MCP servers, I stopped trusting the startup list
Only some of the servers that say connection failed at startup are ones you can actually fix. Here is a probe that separates no-response, launch failure, and protocol rejection, measured across a 14-server fleet where sequential 22.03s became parallel 5.09s, and where trimming the deadline quietly turned healthy servers into failures.
Half of My Scheduled Runs Vanished Without a Single Error
A batch job set to run twice a day was only firing once. No errors, no failure alerts. Here is how to expand your own schedule, count expected runs, and reconcile them against execution records to catch silent misses.
Read the Catalog Your CLI Already Ships Before Bulk-Replacing Model IDs
A newer generation makes older model IDs look stale. Here is how to pull the catalog embedded in your installed binary, sort every reference into matched, date-mismatched, and malformed, and stop the replacement that would break working IDs.
Curating the /model picker with modelPicker, and what replacing the lineup hides
Claude Code v2.1.242 added modelPicker, which lets you write the /model lineup yourself. Here is how appending differs from replacing, why project settings are ignored, and where it quietly narrows what availableModels allows.
One Space in a Folder Name Turned 80 Checks Into Zero
An inspection loop reported 80 files checked and 0 readable. The files were fine. Here is how word splitting turns path fragments into real directories, measured side by side, plus the count assertion I now put in front of every delete-heavy batch.
I counted the keys in my connected folder: filenames found 5 of the 18
A record of counting what lives inside a connected folder, once by filename and once by file contents. Filenames returned 24 hits of which only 5 were real, while a content scan returned 18 of which 13 left no trace in their names. Includes a scanner that never prints a secret, its real output, and the rules I adopted afterwards.
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.
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.
Tracking Multi-Step Work in Claude Code Now That the Todo Tools Are Off by Default
Since Claude Code v2.1.233, TodoWrite and the Task tools are left out on the newer models. Here are the three branches to check before you set the opt-in variable, the PostToolUse ledger I put in their place, and the measured point where that ledger quietly corrupts under parallel agents.
Tightening Filesystem Isolation Separately from the Network — Collect the Paths, Then Squeeze the Write Surface
Claude Code v2.1.216 lets you control filesystem isolation independently from network isolation. Before tightening anything, I traced what a real job actually touches, split reads from writes, and measured how stable the path set is across repeated runs. The numbers changed how I wrote the allowlist.
Existence Checks Pass, Writes Fail — Probing Capabilities Before an Unattended Run
A directory existing and a directory being writable are two different facts. Measured results from five broken-environment cases, and a capability-probe preflight for unattended Claude Code runs.