AI agents are crossing organizational boundaries. They call tools in partner domains, delegate tasks to external services, and operate in chains where no single actor sees the full picture.
COA-MAS v1 solved the intra-domain governance problem — a four-layer architecture, the Action Claim contract, and the AASG enforcement boundary that ensures zero cognitive load at runtime. If you haven't read it, the paper is at .
The Four Federation Modes
The Pattern Selection Protocol routes each cross-domain interaction to the appropriate mode based on trust distance, acceptable latency, and cognitive burden tolerance.
Mode 0 — Intra-Domain (COA-MAS V1)
Same domain. Deterministic, microsecond latency, zero external dependencies. The foundation everything else builds on.
Mode 1 — Sovereign Visa
Domain A submits the Action Intent to Domain B's authorization endpoint. Domain B's GOV-RISK evaluates it using its own Executable Culture — full sovereignty, no calibration across semantic spaces. GOV-RISK-B issues a standard COA-MAS v1 Action Claim with DPoP binding. AASG-B validates a locally-trusted signature at runtime. Zero cognitive load.
Mode 2 — Ambassador
Domain B doesn't expose tools to foreign agents at all. It exposes an agent communication interface. Domain A's intent becomes the opening message of an A2A conversation. Domain B's Ambassador agent formulates its own plan, submits it to GOV-RISK-B via Mode 0, and executes locally. Maximum isolation. Non-deterministic latency.
Mode 3 — Clearinghouse
A neutral Domain C — a regulated hub both domains trust — evaluates the intent and issues a universally-accepted Action Claim. Appropriate for regulated industries (Open Finance, healthcare prior authorization). Opt-in only: it trades polycentric sovereignty for operational simplicity.
Future Mode 4 — ZK-Policy
The CAGA-compliant target. Domain A generates a zero-knowledge proof of correct policy execution without revealing internal data. Domain B verifies mathematically. Not implementable in production today due to ZKML hardware constraints — but the meta-framework is explicitly designed to incorporate it as Mode 4 when viable, without requiring changes to the Action Intent schema or SPIFFE infrastructure.
The Pattern Selection Protocol
Domains don't negotiate a single mode — they negotiate a Federation Policy that maps operation families and resource classes to modes:
{
"mode_by_operation": {
"read": { "mode": 1, "ttl_seconds": 1800, "single_use": false },
"delete": { "mode": 1, "ttl_seconds": 120, "single_use": true },
"configure": { "mode": 2 }
},
"mode_by_resource_class": {
"pii": { "mode": 2 },
"regulated": { "mode": 3 }
}
}
The same pair of domains can use Mode 1 for routine reads and Mode 2 for infrastructure operations — without renegotiating the peering relationship.
Positioning Against CAGA
Meyman [SSRN 6299461] formalizes the Cross-Agent Governance Alignment (CAGA) problem and identifies zero-knowledge proofs as the theoretically correct solution. COA-MAS v2 is the operationally deployable answer while ZKML hardware matures — trading full policy confidentiality for sub-millisecond runtime enforcement, zero integration cost for Domain B, and compatibility with stochastic LLM-based GOV-RISKs.
The relationship is complementary. CAGA defines what a correct solution must prove. COA-MAS v2 defines how production systems navigate the space between the theoretically ideal and the operationally deployable.
What's Published
📄 Working Paper v0.3
🔧 Action Intent Schema v1.0.0
📚 COA-MAS v1 (foundation)
doi.org/10.5281/zenodo.19057202
If you're building cross-domain multi-agent systems and the governance layer is an afterthought, the meta-framework and the schema are open access. Feedback, critique, and stress-testing welcome.
SOCIAL SHARE CARD GENERATOR