Nick Liu

Showing "this session is 34% full" requires two numbers. The token count is easy and always right. The window size it divides by is not in the transcript, not in the session state files, not in settings, and not in any hook payload. It exists in exactly one place, and if you cannot read that place you are guessing at the denominator of a number you are about to display as fact. 🧪 Tested with Claude Code 2.1.x · macOS I built a script that reports how full a Claude Code session’s context window is, so a Stream Deck key could draw a ring for it. The token side was straightforward. The denominator turned into the whole project.

An installer writes a script. It stamps that script with `HERDR_INTEGRATION_ID=claude`, an identifier that exists for no reason other than to say "I made this". Then, to decide whether it has already run, it ignores that stamp entirely and compares the rendered command string in a config file. Rewrite the command to an equivalent form and the installer no longer recognises its own work, so it installs a second copy alongside the first. I hit three bugs in three days. They looked unrelated until I wrote them down next to each other: one in someone else’s tool, two in a plugin of mine. They share a shape, and the shape is worth more than any of the three fixes.

`launchctl bootout` exited 0. `launchctl bootstrap`, on the very next line, failed with `Bootstrap failed: 5: Input/output error` because the label was still loaded. Then the bootout finished on its own schedule and the label went away, leaving a machine with no daemon at all and an installer that had just told me it was done. This one is mine: I caused it while fixing something else. 🧪 Tested with launchd · macOS I have written before about launchctl unload returning 0 while the daemon kept running, which turned out to be KeepAlive’s supervisor racing the teardown. This is the sibling. Same API, opposite failure, and where that one was launchd surprising me, this one I built myself.

The daemon reported the tunnel as established. The local socket file was right there on disk with the right permissions. The target sat at `offline` forever. Meanwhile `connect to /home/nick/.config/herdr/sessions/main/herdr.sock port 0 failed` was being written to a stderr stream that nothing in my process ever read, several times a second, for as long as I left it running. Deleting ClaudeDeck · Part 5 of 5 1 2 3 4 5 🧪 Tested with herdr 0.8.0 · macOS HerdDeck drives agents on a second machine. My laptop has the Stream Deck and the daemon; the desktop runs herdr and the agents actually doing work. They are joined by ssh -N -L <local.sock>:<remote.sock> host, a Unix-domain socket forward, and the daemon speaks the same protocol to a forwarded socket as it does to a local one.

A key on my Stream Deck showed an agent with a context window 65% full. The ring around it displayed a little over a third of a circle, which anyone would read as 35%. Not blank, not obviously broken, no missing-data placeholder. Confidently wrong, by exactly the amount that inverts the decision you are making when you look at it. Deleting ClaudeDeck · Part 4 of 5 1 2 3 4 5 🧪 Tested with herdr 0.8.0 · macOS That is the hardware, live against five agents on a remote machine. The top row is one key per agent. The tint is that session’s lifecycle state, and the ring is how full its context window is. Two independent signals, one key.

Each agent key on the Stream Deck draws a ring showing how full that session's context window is. Mine sat at 10% for days. Every session, regardless of activity, regardless of how long the agent had been grinding. I found the bug, fixed it, watched agents start reporting correct percentages every single turn, and the ring still said 10%. That was the good part, because it meant there were two. Deleting ClaudeDeck · Part 3 of 5 1 2 3 4 5 🧪 Tested with Claude Code 2.1.x · macOS Ten percent is a suspicious number. Not zero, which would say “nothing ever arrived”. Not a plausible-looking 37%, which would say “this works and your session is small”. Ten percent is round, and round numbers in a display that should be noisy mean the display is not reading anything.