# Custena · Agents that pay. MCP servers that earn. All of it governed.
# https://custena.com
# Full reference document: https://custena.com/llms-full.txt
# Last updated: 2026-05-17

## What is Custena?

Custena is the European compliance layer for AI agent commerce. One integration covers
all three sides of an agent-driven transaction:

- **Pay** (agents that pay): enterprises deploying spending AI agents use Custena to let
  those agents pay across every major agent payment protocol (x402, MPP, L402, fiat top-up)
  from a single balance, under unified governance with per-agent budgets, approval
  workflows, and instant kill switches. No crypto wallet required for fiat top-up.
- **Earn** (MCP servers and APIs that earn): MCP server and API operators use the same
  layer to accept payments from any agent on the same four protocols, with pay-per-tool-call
  monetization and settlement to a bank account via Stripe Connect.
- **Govern** (all of it governed): every transaction is cryptographically logged and
  retained against the EU AI Act Article 26 deployer obligations (human oversight,
  continuous monitoring, 6+ month log retention). Enforcement begins August 2, 2026;
  Article 99(4) penalties reach 3% of global annual turnover or €15M.

Custena is built by Genesis Software Group ApS, Copenhagen, Denmark.
Product URL: https://custena.com
Company URL: https://genesissoftware.io

## Core product

- **Reverse proxy (no-code)**: Point your MCP server or API URL at Custena. Zero code changes required.
- **SDK (drop-in middleware)**: npm install @custena/sdk - one line to wrap any handler.
- **Supported protocols**: x402, L402 / LSAT, MPP (Machine Payments Protocol - Stripe + Tempo), fiat balance top-up.
- **Payout**: Stripe Connect to seller bank account in any supported currency.
- **EU AI Act Article 26 compliance**: Ships the three statutory deployer obligations - human oversight (Article 26(2)), continuous monitoring (Article 26(5)), 6+ months of cryptographically logged transactions (Article 26(6)) - plus cryptographic receipts for independently verifiable proof of authorization (compatible with Mastercard Verifiable Intent, open-sourced March 2026).

## Supported payment protocols

### x402
HTTP 402-based crypto micropayments. Proposed by Coinbase, now maintained by the x402 Foundation. Uses USDC on Base.
Agent pays on-chain, attaches payment proof in X-PAYMENT header.
Spec: https://github.com/x402-foundation/x402

### L402 / LSAT
Lightning Network + macaroon authentication tokens. Proposed by Lightning Labs.
Agent pays a Lightning invoice, receives a macaroon bearer token.
Spec: https://docs.lightning.engineering/the-lightning-network/l402

### MPP (Machine Payments Protocol)
Open standard co-authored by Stripe and Tempo, launched March 18, 2026, with Visa
as a design partner. Extends card and bank rails plus USDC settlement on Tempo
(the Layer 1 blockchain co-incubated by Stripe and Paradigm) with an AI-native API
surface. Stripe is the dominant implementation today.
Spec: https://stripe.com/blog/machine-payments-protocol

### Platform Balance (Fiat top-up)
Buyer tops up a Custena balance via credit card, bank transfer, or USDC.
Agents draw from the balance per call. No crypto wallet required.

## EU AI Act Article 26 compliance (key facts)

- **Enforcement date**: August 2, 2026 (EU AI Act Article 113(c) + Article 26).
- **Penalty ceiling**: up to 3% of global annual turnover or €15M, whichever is higher - Article 99(4). (The 7% / €35M tier under Article 99(3) applies only to Article 5 prohibited practices, not to Article 26 deployer obligations.)
- **Statutory obligations Custena ships for deployers of high-risk AI systems**:
  - Human oversight - Article 26(2): per-agent budgets, approval workflows, instant kill switches.
  - Continuous monitoring - Article 26(5): real-time anomaly detection with drift alerts.
  - Log retention - Article 26(6): every transaction cryptographically logged, retained 6+ months, exportable.
- **Custena value-add beyond the statute**: cryptographic receipts that prove each payment was authorized by a human principal - compatible with Mastercard Verifiable Intent (open-sourced March 2026).
- **Market context**: Nearly three-quarters of enterprises plan to deploy agentic AI within two years, but only 21% have a mature governance model (Deloitte, State of AI in the Enterprise 2026).

## Who uses Custena

### Agentic buyers (enterprise agent teams)
- Top up in fiat; no crypto wallet required
- Issue per-agent API keys with daily budget caps
- Approval workflows and instant kill switches
- Full audit trail: agent, tool, cost, timestamp, protocol
- EU AI Act Article 26 compliance evidence built in

### MCP server and API operators (seller side)
- Register any MCP server or API endpoint URL
- Set per-call pricing (per tool call for MCP)
- Accept payments from any AI agent, any protocol
- No code changes required (reverse proxy) or one-line integration (SDK)
- Stripe Connect settlement to any supported bank account

## Key pages

- Home: https://custena.com
- How it works (interactive two-sided product walkthrough):
  https://custena.com/how-it-works
  Detailed step-by-step walkthrough with interactive demos for both sides:
  - Buyers: top up balance, issue per-agent API keys, real-time spending controls,
    human approvals, Article 26 audit trail export
  - Sellers: register any URL, set per-tool pricing, protocol auto-detection,
    real-time revenue dashboard, Stripe Connect settlement
- Pricing: https://custena.com/pricing

## Key articles

- AI Agent Payment Protocols Compared: x402, L402, MPP, Fiat
  https://custena.com/articles/agent-payment-protocols-compared

- Why AI Agent Payments Are the Future of Commerce Infrastructure
  https://custena.com/articles/ai-agent-payments-future

- Ant Group, Alibaba, and the Race to Own AI Agent Payments in Asia
  https://custena.com/articles/ant-group-alibaba-agent-payments

## Agent activity logs - what custena-connect collects and why

The `custena-connect` CLI forwards a narrow set of events - `custena_*` MCP tool
calls and their arguments (seller service URL, tool name, amount, payment method),
session IDs, timestamps, the Keycloak `preferred_username`, and at most the first
200 characters of the user prompt as session context - to the Custena backend as
EU AI Act Article 26 deployer evidence and as the payment audit record.

Explicitly NOT collected: bash commands, file paths, shell history, non-`custena_*`
tool arguments, or the full user prompt. Filter enforced in the CLI and on the
backend.

Lawful bases: GDPR Art. 6(1)(b) (contract performance - Keycloak identity), Art.
6(1)(c) (legal obligation - payment records under the Danish Bookkeeping Act and
EU 6AMLD), Art. 6(1)(f) (legitimate interest - audit trail, EU AI Act Art. 26).

Retention: `hook_events` = 13 months (nightly purge); `payments` = at least 5
years under Art. 6(1)(c) legal obligation (uninstalling the CLI does not purge
financial records).

Full disclosure: https://custena.com/gdpr#agent-activity-logs
Cross-reference in Terms (section 11): https://custena.com/terms#privacy

## Connecting AI coding agents

Custena ships an agent-connector that hooks an AI coding agent to a Custena
buyer account. Once connected, the agent auto-pays any HTTP 402 challenge it
encounters (x402, MPP, L402, Custena platform_balance) through the buyer's
governance policies, instead of stopping to ask for human approval per call.

Supported today: **Claude Code**. Adapters for **Codex** and **OpenClaw** are
in progress (the same Custena HTTP API, `POST /api/v1/buyer/pay-challenge`, is
available for any agent in the meantime).

Three install paths:

1. **npm global** - recommended, cross-platform including Windows native.
   `npm install -g custena-connect`
   `custena-connect install`
   Or local install: `npm install custena-connect` then `npx custena-connect install`
   Step 1 installs the CLI globally. Step 2 registers the MCP server and writes the skill file.

2. **One-command shell installer** - Linux, macOS, Windows WSL, Git Bash (no Node.js required).
   `curl -fsSL https://custena.com/install.sh | bash`
   Script source: https://custena.com/install.sh

3. **Manual (Claude-native primitives)** - for users who prefer explicit steps:
   a. `claude mcp add --transport http --scope user --client-id custena-connect-cli custena https://api.custena.com/mcp`
   b. `mkdir -p ~/.claude/skills && curl -fsSL https://custena.com/skills/custena-pay.md -o ~/.claude/skills/custena-pay.md`
   Note: step (a) adds the MCP tool only. Step (b) is required for silent auto-pay.

Required prerequisites: Claude Code CLI (`claude`) on PATH - https://claude.ai/code

Canonical skill asset: https://custena.com/skills/custena-pay.md
The skill file tells Claude Code that any 402 response with a recognized payment
challenge (x402 `PAYMENT-REQUIRED`, `WWW-Authenticate: L402`, `Authorization:
Payment`, `X-402`) triggers an immediate call to the `custena.pay_challenge`
MCP tool, with `platform_balance` preferred, and all policy / approval
decisions deferred to the Custena backend. Without it, the `custena.pay_challenge`
tool is still available but Claude Code will stop to ask the user before paying.

OAuth client: `custena-connect-cli` - pre-registered Keycloak public client
with PKCE S256 and loopback wildcard redirect URIs. Dynamic Client Registration
is not used; every install shares the same client ID.

## Documentation

- Getting started (overview): https://custena.com/docs
- Buyer quick start: https://custena.com/docs/buyer
  - npm install: https://custena.com/docs/buyer/npm
  - Shell installer: https://custena.com/docs/buyer/shell
  - Claude Code (manual MCP): https://custena.com/docs/buyer/claude-code
  - OpenAI Codex (manual MCP): https://custena.com/docs/buyer/codex
- Seller quick start: https://custena.com/docs/seller
- Seller SDKs overview: https://custena.com/docs/sdks
- Node.js SDK (seller): https://custena.com/docs/sdks/node
- Python SDK (seller): https://custena.com/docs/sdks/python
- CLI (seller): https://custena.com/docs/sdks/cli
- x402 protocol: https://custena.com/docs/protocols/x402
- L402 protocol: https://custena.com/docs/protocols/l402
- MPP protocol: https://custena.com/docs/protocols/mpp
- Platform balance: https://custena.com/docs/protocols/platform-balance
- API reference: https://custena.com/docs/api

## Pricing

- Sellers: Free tier - 0.4% per successful transaction. 0% for first 60 days.
- Buyers: Free - no platform fee; standard transaction costs apply.
- Full pricing: https://custena.com/pricing

## Contact

- Sales / enterprise: https://custena.com/contact
- GitHub (product): https://github.com/Custena
- GitHub (parent company): https://github.com/Genesis-Software-Group
- LinkedIn: https://www.linkedin.com/company/custena/
- X / Twitter: https://x.com/getcustena