ARSIA Protocol

EU regulatory compliance as a protocol primitive for AI agents.

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AI agents are being deployed across finance, agriculture, healthcare, and government — negotiating contracts, processing claims, and making decisions that affect real people. But no existing agent protocol handles EU regulatory compliance at the wire level.

ARSIA Protocol embeds compliance into the message envelope — the same way TLS moved encryption to the transport layer. Every message carries identity, audit obligations, data residency, human oversight mode, and regulatory basis as first-class fields. The protocol sits above MCP and A2A as a compliance layer — it doesn't replace them, it makes them audit-ready.

{
  "v": "1.0",
  "from": "agent:acme.risk-assessor",
  "to": "agent:acme.compliance-checker",
  "intent": "request",
  "compliance": {
    "profile": "MIFID-II",
    "retention_days": 1827,
    "data_residency": "EU",
    "human_oversight": "required_before_execution",
    "audit_required": true,
    "pii_involved": true,
    "legal_basis": "contract"
  },
  "security": {
    "alg": "EdDSA",
    "kid": "agent:acme.risk-assessor#key-1",
    "sig": "..."
  }
}

Specifications

The protocol follows a 5+1 architecture: one foundational spec — Core — and five domain primitives that spell the name.

Spec	Domain	Description
ARSIA-Core	Foundation	Message envelope, EdDSA signing, discovery, authorization, compliance field, transport
ARSIA-Actions	Actions	Capabilities, human oversight, explainability, action registry
ARSIA-Routing	Routing	Message routing, broker topology, data residency enforcement
ARSIA-State	State	State lifecycle, GDPR obligations, compliance profiles, audit trail
ARSIA-Identity	Identity	Agent identity, certificates, trust levels, 6-phase onboarding
ARSIA-Assets	Assets	Transaction validation, escrow, MiFID II / DORA / PSD2 controls

Compliance Profiles

Seven normative profiles map EU regulation directly to protocol fields:

Profile	Regulation	Retention	Human Oversight	Audit
GDPR-STANDARD	GDPR Art. 5, 6	Per operator	Not required	Optional
EU-AI-ACT-HIGH-RISK	EU AI Act Art. 13, 14, 17, 26	180 days	Required before execution	Required
EU-AI-ACT-LIMITED-RISK	EU AI Act Art. 50	90 days	Not required	Required
MIFID-II	MiFID II Art. 16(7), DORA, PSD2	1827 days (5 years)	Required before execution	Required
PAC-AGRICULTURE	CAP Reg. 2021/2116	1096 days (3 years)	Required post-execution	Required
DSA-VLOP	DSA Art. 15, 34, 37, 40, 42	730 days (2 years)	Required within 24h	Required
DORA	DORA Art. 5, 17, 19, 28	1827 days (5 years)	Required within 24h	Required

Source: arsia-compliance-profiles.json — defined normatively in ARSIA-State §6.

Schemas & Test Vectors

The protocol is fully machine-verifiable. 31 JSON Schemas (Draft 2020-12) validate every structure defined in the specs. 613 test vectors (514 valid, 99 invalid, 73 runtime-only) provide cross-implementation validation with real Ed25519, ES256, and RS256 cryptography. 9 test keypairs are published in keypairs.json.

See schemas/ and test-vectors/ for details.

• docs/FAQ.md — Frequently Asked Questions: design rationale and decision explanations

Ecosystem

ARSIA Protocol is not a competitor to MCP or A2A — it's a complement.

┌─────────────────────────────────────────────────┐
│  Your Application                               │
├─────────────────────────────────────────────────┤
│  ARSIA Protocol — compliance, identity, audit   │
├─────────────────────────────────────────────────┤
│  A2A — agent-to-agent communication             │
├─────────────────────────────────────────────────┤
│  MCP — tool & data access                       │
├─────────────────────────────────────────────────┤
│  Infrastructure — LLMs, cloud, databases        │
└─────────────────────────────────────────────────┘

Contributing

The specification is in draft. We welcome contributions — see CONTRIBUTING.md for guidelines and CLA.md for the Contributor License Agreement. Feedback via GitHub Issues.

License

The ARSIA Protocol specification (specs, schemas, compliance profiles, RTMs, and test vectors) is licensed under CC BY-SA 4.0 — this specification may be freely implemented by anyone, with attribution. Implementing this specification in software does not create a derivative work; you may license your implementation under any terms.

Reference implementation code, scripts, and CI workflows are licensed under BSL 1.1, converting to Apache 2.0 after four years.

See LICENSE-SPEC.md and LICENSE-CODE.md for details.

Patent Notice

Certain methods described in Arsia Labs (Arsia Tecnologia Unipessoal Lda) product implementations are subject to pending patent applications. The specification license (CC BY-SA 4.0) does not grant patent rights. See LICENSE-SPEC.md for details.

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ARSIA Protocol (arsiaprotocol.org) | by Arsia Labs