nevermined-payments

# Nevermined Payments Integration

## Overview

Nevermined provides financial rails for AI agents — real-time monetization, access control, and payments. This skill gives you everything needed to:

- Protect API endpoints with the **x402 payment protocol**
- Charge per-request using **credit-based billing**
- Integrate with **Express.js**, **FastAPI**, **Strands agents**, **MCP servers**, or **Google A2A agents**
- Support **subscriber-side** flows (purchase plans, generate tokens, call protected APIs)
- Enable **agent-to-agent** payments via the Google A2A protocol

The x402 protocol uses HTTP 402 responses to advertise payment requirements. Clients acquire an access token and retry the request. The server verifies permissions, executes the workload, then settles (burns credits).

## Quick Start Checklist

1. **Get an API key** at [nevermined.app](https://nevermined.app) → Settings → API Keys
2. **Install the SDK** (`npm install @nevermined-io/payments` or `pip install payments-py`)
3. **Register your agent and plan** (via the App UI or programmatically — see `references/payment-plans.md`)
4. **Add payment protection** to your routes/tools (see framework-specific references below)
5. **Test** — call without token (expect 402), then with token (expect 200)

## Environment Setup

| Variable | Required | Description |
|---|---|---|
| `NVM_API_KEY` | Yes | Your Nevermined API key (get it at [nevermined.app](https://nevermined.app) → Settings → API Keys) |
| `NVM_ENVIRONMENT` | Yes | `sandbox` for testing, `live` for production |
| `NVM_PLAN_ID` | Yes | The plan ID from registration |
| `NVM_AGENT_ID` | Sometimes | Required for MCP servers and plans with multiple agents |
| `BUILDER_ADDRESS` | For registration | Wallet address to receive payments |

### `.env` Template

```bash
# Required
NVM_API_KEY=your-api-key-here
NVM_ENVIRONMENT=sandbox
NVM_PLAN_ID=your-plan-id-here

# Required for MCP servers or multi-agent plans
NVM_AGENT_ID=your-agent-id-here

# Required for reg...