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, why static clues cannot predict the worst of them, and a capability-probe preflight for unattended Claude Code runs.
The 400-Character Preview That Was Still Holding On to a Megabyte
Truncating tool output in your own MCP server does not free the original. Node's sliced strings keep the parent alive. Here is the measured 13-character boundary, which flattening tricks actually work, and a heap-snapshot audit script that counts the retained parents for you.
You Added a Second Working Root — Now Ask How Far Your Ignore Rules and Deny Patterns Actually Reach
Adding a working root mid-session does not carry your ignore rules or deny patterns with it. Measured evidence from git check-ignore and a three-way matcher comparison, plus the scope-delta audit script I now run from the DirectoryAdded hook.
The MCP Server Connects Fine and Still Hands Back Zero Tools — Catching Silent Capability Drift with a Tool Manifest Diff
A missing credential does not break the MCP handshake. initialize succeeds, tools/list succeeds, and the array comes back empty. Here is the measured behaviour, and a preflight that locks the expected tool surface and fails closed before the agent ever starts.