Environment for all captures
- Linux x86_64, packaged T3 Code desktop 0.1.8, Electron 44.10.1.
- Built independently from base and head with vp run dist:desktop:artifact --platform linux --target dir --arch x64.
- Run under headless-desktop on Xvfb 1920x1080; captured Electron window 1100x780 at 410,150; light theme.
- Fresh isolated HOME and T3CODE_HOME for each run; T3CODE_DEV_SEED=0; no copied database, no providers, no projects.
- Disposable SSH account evidence31396 at 127.0.0.1:22396; synthetic UTS hostname mirror-target.
- SSH key authentication through a dedicated ssh-agent; target host key trusted through a temporary system SSH known-hosts file.
- OUTPUT firewall rule for only the disposable account rejects outbound TCP 443; HTTP mirror at 127.0.0.1:18396 remains reachable.
- Mirror serves unmodified official v0.1.8 SHA256SUMS and t3-0.1.8-linux-x64.tar.gz.
- Archive SHA256: b9c49dc00c23fbbc5961bdaff2d88e556d96c8dbd638c4501e2937c70650a9e5.
- Every side starts with no remote runtime or remote server. Runs are sequential; successful runtime state is moved aside before the next run.
- inherited: T3CODE_RELEASE_BASE_URL=http://127.0.0.1:18396 is in the Electron launch environment.
- profile: T3CODE_RELEASE_BASE_URL is absent from the Electron launch environment and exported only from the fresh HOME's .bash_profile; SHELL=/bin/bash.
- Recording starts after onboarding, at Settings > Environments. No private data is seeded.
- Endpoint stills require two byte-identical screenshots 500 ms apart. Videos show the actual desktop interaction.

Driver usage
HOME=<fresh-home> SSH_AUTH_SOCK=<dedicated-agent-socket> headless-desktop node desktop-driver.cjs <checkout> <packaged-executable> <output-root> inherited
Replace inherited with profile for the login-shell-only case. Run sides sequentially and stop/reset the remote server/runtime before each.

Fixture preparation
ssh-fixture.sh <scratch-root> prepares the account, keys, port and account-scoped HTTPS rejection. It requires passwordless sudo. Run it in a disposable environment; stop its sshd, remove the exact firewall rule and delete its account afterward.
Trust the generated known_hosts entry. Serve the two official release files from mirror/v0.1.8 with python3 -m http.server 18396 --bind 127.0.0.1 --directory <mirror-root>.
The mirror origin intentionally uses loopback because the isolated SSH host is another account on the same disposable Linux system; the real SSH transport, runtime downloader, checksum verification, extraction, server launch, tunnel and desktop connection all execute unchanged.

AI-assisted; verified with the tests and tools listed above.