Context
The Antigravity harness imposes a strict combined limit of 24,000 bytes (24KB) for injected turn-based memory files. Our current core substrate (AGENTS.md + ANTIGRAVITY_RULES.md + GEMINI.md) significantly exceeds this limit, resulting in AGENTS.md being silently truncated and ANTIGRAVITY_RULES.md being dropped entirely. This blinds the agent to critical downstream rules (e.g., Escalation Ladder, Edge Cases, Session Sunset).
The Problem
Substrate bloat in our core files is causing systemic "Helpful Assistant" regression drift. We have reached the physical cap of the prompt injection mechanism.
The Architectural Reality
AGENTS.md is currently ~27.6KB..agents/ANTIGRAVITY_RULES.md is ~3.7KB.- Total combined loaded payload exceeds the Antigravity 24KB limit.
- We must architecturally adapt our substrate to survive this limit using Progressive Disclosure (Map vs. World Atlas).
The Fix (Option D from Discussion #11410)
- Canonical Map: Keep
AGENTS.md as the cross-harness constitution, but reduce it below the verified 24KB combined ceiling by migrating workflow skill tables to atlas triggers.
- Antigravity Boot Capsule: Maintain an Antigravity-specific survival rule capsule (
ANTIGRAVITY_RULES.md), keeping the combined size under 24KB.
- Atlas Triggers: Move detailed rationale and edge cases into
.agents/skills/ payloads loaded purely on trigger.
- Mechanical Guard: Implement a CI gate to prevent future substrate bloat from exceeding the 24KB combined limit.
Discussion Criteria Mapping
- Discussion #11410 AC0 -> Epic AC0 (Raw payload capture)
- Discussion #11410 AC1 -> Epic AC1 (Budget table)
- Discussion #11410 AC2 -> Epic AC2 (No duplicate-body rule)
- Discussion #11410 AC3 -> Epic AC3 (Mechanical guard)
- Discussion #11410 AC4 -> Epic AC4 (Cross-harness non-regression)
Acceptance Criteria
Out of Scope
- Modifying the underlying Antigravity IDE harness configuration or node modules.
- Refactoring non-agent workflows or standard UI/Engine components.
Avoided Traps
- Rejected Option A (Collapsing Files): We explicitly rejected collapsing
GEMINI.md, AGENTS.md, and ANTIGRAVITY_RULES.md into a single root file. Doing so would flatten cross-harness ownership boundaries and make the canonical AGENTS.md substrate Antigravity-specific.
Related
- Resolves/Graduated from: Discussion #11410
Origin Session ID: 188acb85-b41e-435c-94ee-0cc9944d4c97
Context The Antigravity harness imposes a strict combined limit of 24,000 bytes (24KB) for injected turn-based memory files. Our current core substrate (
AGENTS.md+ANTIGRAVITY_RULES.md+GEMINI.md) significantly exceeds this limit, resulting inAGENTS.mdbeing silently truncated andANTIGRAVITY_RULES.mdbeing dropped entirely. This blinds the agent to critical downstream rules (e.g., Escalation Ladder, Edge Cases, Session Sunset).The Problem Substrate bloat in our core files is causing systemic "Helpful Assistant" regression drift. We have reached the physical cap of the prompt injection mechanism.
The Architectural Reality
AGENTS.mdis currently ~27.6KB..agents/ANTIGRAVITY_RULES.mdis ~3.7KB.The Fix (Option D from Discussion #11410)
AGENTS.mdas the cross-harness constitution, but reduce it below the verified 24KB combined ceiling by migrating workflow skill tables to atlas triggers.ANTIGRAVITY_RULES.md), keeping the combined size under 24KB..agents/skills/payloads loaded purely on trigger.Discussion Criteria Mapping
Acceptance Criteria
check-substrate-size.mjsor similar) is implemented and fails CI if the combined injected payload exceeds the verified 24KB byte budget.Out of Scope
Avoided Traps
GEMINI.md,AGENTS.md, andANTIGRAVITY_RULES.mdinto a single root file. Doing so would flatten cross-harness ownership boundaries and make the canonicalAGENTS.mdsubstrate Antigravity-specific.Related
Origin Session ID:
188acb85-b41e-435c-94ee-0cc9944d4c97