Notes — Wisp Write-ups of the traps hit while building Wisp, a desktop AI agent with a VRM body. Measurements and mistakes, not announcements. https://wisp-gules-mu.vercel.app/blog/ 2026-08-23T00:00:00Z Renga The jitter wasn't in the interpolation. It was in the schedule. https://wisp-gules-mu.vercel.app/blog/jitter-is-a-schedule-bug/ 2026-08-23T00:00:00Z One symptom, three unrelated causes, and the order to check them in. Including a threshold-free test for telling a real kink from a smooth curve. My VRM was rejected at upload and every viewer I own said it was fine https://wisp-gules-mu.vercel.app/blog/accessor-bounds-drift/ 2026-08-22T00:00:00Z The mesh data was correct. The declaration about the mesh data was wrong — and rendering never reads the declaration, so nothing local could see it. I set the font to the largest size and found the same bug eleven times https://wisp-gules-mu.vercel.app/blog/xxxl-broke-japanese-worse/ 2026-08-16T00:00:00Z Reading the code found none of them. Screenshots found all eleven — and Japanese broke worse than English, because Japanese can wrap anywhere. My dev environment was hiding eight production bugs https://wisp-gules-mu.vercel.app/blog/dev-env-hid-eight-bugs/ 2026-08-15T00:00:00Z Every convenience in my development setup was concealing a defect on the other side of it. Counting the conveniences found the bugs faster than looking for the bugs. My evidence pipeline was saving Cloudflare block pages as evidence https://wisp-gules-mu.vercel.app/blog/block-pages-as-evidence/ 2026-08-15T00:00:00Z A third-party wrapper died, and the failure came back as a plausible-looking image with an HTTP 200 attached. What broke, and what I changed. I redacted my username from a screen recording three times and missed it every time https://wisp-gules-mu.vercel.app/blog/mask-screen-recording/ 2026-08-14T00:00:00Z Fixed rectangles cannot hide a dialog that animates in. I tracked the text with an FFT correlation, missed it twice more, and finally scanned the finished file with a machine — which found one more frame nobody was looking at. My approval dialog grew until the buttons went off screen https://wisp-gules-mu.vercel.app/blog/approval-dialog/ 2026-08-14T00:00:00Z Showing the user everything the agent is about to do, and letting them actually choose, are two different properties. I only had the first one, and it took a demo recording to find out. Where to split a sentence for streaming TTS is decided by one number https://wisp-gules-mu.vercel.app/blog/streaming-tts-split-point/ 2026-08-11T00:00:00Z The split point for streaming text-to-speech follows from the real-time factor. I measured that factor on a machine with a full disk, got it 4x wrong, and shipped a constant that was never going to fail loudly enough to notice.