Reproducing the localharness input-detection patch

The Antigravity SDK (google-antigravity, Apache-2.0) ships a Go localharness binary. Input detection in run_command_handler.go names models/gemini-2.5-flash-lite, which Google has withdrawn for new users. Python LocalAgentConfig has no public INPUT_DETECTION model type.

strings notes (installed wheel)

Hits in google/antigravity/bin/localharness:

• Literal gemini-2.5-flash-lite (21 bytes, once)
• error during input detection model call: %v
• Enum MODEL_GOOGLE_GEMINI_2_5_FLASH_LITE
• No env var such as INPUT_DETECTION_MODEL

Resolution order (_get_default_binary_path_external):

1. ANTIGRAVITY_HARNESS_PATH
2. wheel google/antigravity/bin/localharness
3. importlib.resources
4. PATH

Runtime copy-patch (A0b)

gemini-flash-lite-latest is 24 bytes and will not fit. agyloop replaces the 21-byte withdrawn id with gemini-3.5-flash-lite (same length; the live id behind the low-preset alias) in a copy under ~/.cache/agyloop/localharness (or AGYLOOP_HARNESS_CACHE). The stock site-packages file is left alone unless later layers run.

# Disable the copy; use the SDK binary as shipped
export ANTIGRAVITY_HARNESS_PATH=/path/to/venv/lib/python3.12/site-packages/google/antigravity/bin/localharness

If upstream publishes Go source

The Python SDK is Apache-2.0. If Google publishes run_command_handler.go, change the hardcoded id to gemini-flash-lite-latest (or INPUT_DETECTION_MODEL), rebuild for the host OS, keep NOTICE/LICENSE attribution, and point ANTIGRAVITY_HARNESS_PATH at the rebuild.

Site-packages overwrite

Last filesystem resort. Backup is localharness.agyloop-bak next to the original. Restore:

agyloop doctor repair-harness

AGYLOOP_NO_SITE_PACKAGES_PATCH=1 skips this layer.

Localhost rewrite proxy

Only if the binary still calls the withdrawn id. Loopback only. Rewrite only that model id. No API-key logging. No system CA unless AGYLOOP_INSTALL_REWRITE_CA=1. Disable with AGYLOOP_GEMINI_REWRITE_PROXY=0.