October Codex Pet FAQ: Your Top 10 Pet Questions

Codex pet questions about upload limits

Every October batch of codex pet questions starts in the same place, which is why this codex pet FAQ opens with uploads. The generator accepts files up to about 12MB. Anything bigger is nearly always a straight export from a phone camera, where one frame can clear 8MB before you touch it. Resizing to roughly 2000 pixels on the long edge drops most files under 2MB, and at pet scale you cannot see the difference.

Format behaves differently from size. WebP, JPG and PNG all upload. AVIF and HEIC come back rejected on some builds, and the failure message does not always say why. When an upload refuses three times, convert the file locally before hunting for anything more exotic.

• Under 12MB uploads without complaint
• Around 2000 pixels on the long edge is the sweet spot
• WebP, JPG and PNG are all accepted
• Reject three times, convert locally and try once more

Pet troubleshooting FAQ: the pet resets after an update

This one dominates the October inbox. A Codex desktop update replaces part of the application directory, and on a minority of installs the pets lookup path moves with it. The folder you built is still on disk. Copy it back into the pets directory, quit the app fully, then open it again.

Where people lose pets for good is keeping the only copy inside that directory. Put the backup somewhere else entirely and an update turns into a two minute fix instead of starting over.

• Your pet folder survives, the lookup path moves
• Copy it back, then quit and relaunch the app
• Keep the backup outside the app directory
• A missing pet rarely means a deleted pet

Reader QA: two monitors, one pet

A reader qa thread that surfaced three separate times this month asked whether each monitor can hold a different pet. It cannot. One companion renders per window, and every window draws whichever companion is active. Move the window and the pet travels with it rather than staying on one screen.

What you can change is placement behaviour. Several builds let you dock the pet to the left or right edge, which matters once your editor window and your terminal sit on different displays. The walkthrough is at /blog/dual-monitor-pet-placement.

• One active companion across every window
• The pet travels with the window you move
• Edge docking depends on the Codex build
• Placement tuning beats adding more pets

Reader QA on pets and the model behind them

Two entries in this month of reader mail ask whether a pet changes how the assistant behaves. It does not. The companion renders beside the conversation and never enters the request path, so token counts and replies stay identical whether the pet is switched on or off.

The follow up asks whether a pet can react to a failing test run. Custom state hooks exist for exactly that, and across two years of reading this inbox I have met maybe three people who wired them up. Most readers pick one pet and leave it alone, which is a reasonable outcome.

• Pets sit beside the model, not inside it
• Token usage does not move when a pet is active
• State hooks exist and stay mostly unused
• One pet you like beats four you forget

Where to read next

Upload limits and file types get the full comparison at /blog/codex-pet-upload-limit. The invisible pet walkthrough lives at /blog/installation-troubleshooting, and everything about what happens to a photo after the render sits at /blog/is-the-pet-generator-private.

The rest of the archive is at /blog. Questions for the November round can go to the same inbox, and yes, the ones that land on the last day of the month do get read.