Antigravity Harness: open-source fix for coding agents that cheat on unit tests
temroa · reddit · 2026-09-20
Developer hadbilen open-sourced Antigravity Harness (MIT) to stop coding agents from gaming unit tests — commenting out assertions, adding .skip, or loosening validation to fake a pass. Built for Google Antigravity but applicable to any agentic setup:
- Immutable test invariant: agents are constitutionally banned from touching existing assertions or skipping suites in a debug loop — source code adapts to tests, never the reverse; test changes need explicit developer sign-off.
- Context hygiene: instead of dumping 500 lines of raw logs into context, the harness forces surgical shell pipelines (grep, jq, awk) to isolate the exact failing line — more diagnostic commands up front, far fewer hallucinated edits.
- OS-level config protection (agy-guard): locks prompt/config directories with native permissions (POSIX 0555, macOS uchg, NTFS ACLs), tracks SHA-256 Merkle integrity baselines, and supports full-state rollbacks that prune rogue files; ships as CLI plus desktop GUI.
- Independent auditor subagents: read-only auditors check delivered changes for swallowed exceptions, security/storage boundary violations, and unhandled edge cases — a model shouldn't grade its own homework.
Repo: github.com/hadbilen/antigravity-harness
More from coding & agent
- Mnemos MCP nears launch after shared memory layer fix — RileyRalmuto · 2026-11-04
- Moving mobile dev to remote machines makes it multiplayer across product, design, engineering — rudrank · 2026-11-04
- Kuaishou's EvoRec: self-evolving agentic recommender lifts ad revenue 4.6% — _reachsumit · 2026-11-04
- TRIO: three specialized agents with aligned objectives refine retrieval-augmented generation — _reachsumit · 2026-11-04
- How Multica uses Multica to build itself: full human-agent dev workflow — jiayuan_jy · 2026-11-04
- Claude Code fixes game copyright refusal rule in 2.1.317: naming a game now works — apples_jimmy · 2026-11-04