Every decision the fleet has ever made is filed here.800+ architecture decision records. This is the law library.
When someone asks "why does it work this way?" — the answer is an ARB.
An ARB is like a court ruling: it has a number, a date, a problem statement, the options considered,
and the decision made with rationale. Once filed, it's immutable — you can
deprecate it by filing a new ARB that supersedes it, but you can't delete the history.
Categories: infra, security, data, model-routing, proof, fleet-ops, adelic, SOSTLE, bonixer.
Every red line in AGENTS.md has an ARB behind it.
▸ ELEMENT CARDS — ARB Category Breakdown
CAT-1
187
INFRA · FLEET-OPS
Silo, SSH, networking
ARB-INFRA-001 → 187
Port assignments, SSH rules, mDNS, WSL networking, portproxy configs. The physical layer decisions.
CAT-2
134
SECURITY · SOSTLE
Auth, secrets, gates
ARB-SEC-001 → 134
SOSTLE L0-L7 gate rules, MeVault invariants, token policy, PEMLAAM blocks. No secret without an ARB.
CAT-3
98
MODEL ROUTING
LLM chain decisions
ARB-MODEL-001 → 98
Provider fallback chains, model tiers, cost caps, local-first rules. Never change routing without ARB.
CAT-4
112
PROOF · JOFFE-MATH
Theorem, sorry, lean4
ARB-PROOF-001 → 112
When sorry is allowed, proof standards, sorry-to-theorem ratio targets. The ξ < 0.01 rule has an ARB.