EU AI ACT ARTICLE 50 ENFORCEMENT: AUGUST 2, 2026 MANDATORY AI CONTENT MARKING — FINES UP TO €15M / 3% GLOBAL TURNOVER CODE OF PRACTICE REQUIRES MULTI-LAYER COMPLIANCE — SINGLE-LAYER SOLUTIONS DO NOT QUALIFY EU AI ACT ARTICLE 50 ENFORCEMENT: AUGUST 2, 2026 MANDATORY AI CONTENT MARKING — FINES UP TO €15M / 3% GLOBAL TURNOVER CODE OF PRACTICE REQUIRES MULTI-LAYER COMPLIANCE — SINGLE-LAYER SOLUTIONS DO NOT QUALIFY
Architecture

The AI Act 50
4-layer stack

A complete technical reference for the AI Act 50 certification protocol. Each layer maps to a specific requirement in the EU AI Office Code of Practice. Built on C2PA 2.1.

View on GitHub →EU AI Act context
System Overview

How the four layers
work together.

Every AI Act 50 certification applies all four layers in a single API call. Each layer is independently verifiable. No layer depends on trusting AI Act 50 as an operator.

AI System Claude, GPT, any model output POST /v1/certify AI Act 50 API Certificate ID + verify_url + tx_hash response Regulator / Auditor independent verification L1 Invisible Watermark Statistical signal L2 C2PA Credential C2PA 2.1 standard L3 Blockchain Log SHA-256 → blockchain BASE L4 Detection API GET /v1/verify — public x402 Autonomous Agent Flow Agent → POST /certify → HTTP 402 → USDC (Base L2) → Certified <4s · No API key · Wallet = identity
Layer reference

Technical specification
per layer.

Every layer maps to a specific requirement in the EU AI Office Code of Practice. The first three exist in other tools. Only AI Act 50 connects all four.

L1
Invisible Watermark
What: Statistically undetectable signal embedded in content at generation time. Frequency-domain encoding compatible with text, image, and audio.

Why: Survives compression, cropping, and reformatting. Detectable without the original. Required for Art. 50 marking. Insufficient alone — provides no identity, provenance, or immutability.
L2
C2PA 2.1 Credential
What: Full C2PA 2.1 Content Credential. Includes: AI system ID, model version, timestamp, deployer identity, content classification, campaign metadata.

Why: Industry standard by Adobe, Google, Microsoft, Sony. AI Act 50 extends C2PA for autonomous agents using wallet-based identity — no X.509 required.
L3
Blockchain Log
What: SHA-256 hash anchored on blockchain BASE (Ethereum L2). Returns transaction hash and block timestamp.

Why: Immutable, tamper-proof, independently verifiable. Regulators verify on-chain without trusting AI Act 50. Zero-trust by design.
L4
Public Detection API
What: GET /v1/verify/{id} — public endpoint, no API key, no account. Returns: all four layer results, C2PA credential, blockchain anchor, full compliance report in <2s.

Why: Any regulator, auditor, or end user verifies independently. Satisfies zero-trust verification in the Code of Practice. Cannot be blocked by the operator.
API Reference

Three endpoints.
Full compliance.

POST /v1/certify
# Certify AI output — all 4 layers in one call
cert = client.certify(
    content=ai_output,
    content_type="text/html",
    ai_system="claude-sonnet-4-5",
    classification="fully_ai_generated",
    metadata={"deployer": "agency", "client": "Corp"}
)
# Returns: cert.verify_url · cert.tx_hash · cert.c2pa_manifest
GET /v1/verify/{id} — public, no auth
# Any regulator, auditor, or client — no API key needed
GET https://api.vottun.com/v1/verify/0x7f3a...
# Returns: 4-layer compliance report · C2PA credential · blockchain proof
Autonomous Agent Mode

Built for agents that run
without humans in the loop.

AI Act 50 is the only certification protocol designed natively for autonomous AI agents. Using the x402 protocol and the MCP Server, any agent can certify its output without an API key, without pre-registration, and without human approval — the wallet is the identity.

MCP Server

Native MCP integration for AI agents

The AI Act 50 MCP Server exposes certification as a tool that any MCP-compatible agent — Claude, GPT, or custom models — can call directly. The agent calls certify() as part of its workflow, just like any other tool.

x402 Protocol

Machine-to-machine HTTP payment

The x402 protocol (Cloudflare + Coinbase) enables agents to pay for certification autonomously. The agent receives an HTTP 402 response with USDC payment instructions, pays from its Base L2 wallet, and retries — all in under 4 seconds, with no human involved.

Wallet = Identity

No X.509. No pre-registration.

The agent's Base L2 wallet address is its cryptographic identity. No certificate authority, no account creation, no API key. Any agent with a wallet can certify any output — immediately, at any scale.

x402 + MCP Autonomous Certification Flow AI Agent Claude / GPT / custom + MCP Client MCP Server AI Act 50 tools certify() · verify() certify(content) HTTP 402 + payment info Agent Wallet Base L2 · 0x... Wallet = Identity pay USDC x402 Endpoint POST /v1/certify payment verified USDC · ~2s on-chain retry with payment proof 4-Layer Certification Watermark · C2PA · Blockchain · API anchored on blockchain BASE certify Certificate verify_url · tx_hash · c2pa_manifest <4s total 01 02 03 04
Get started

Full stack.
One API call.

Open source SDK. 20-minute integration. Free on testnet.

View on GitHub →Start free