Add Spraay crypto payments agent example

Summary

This PR adds a Spraay Crypto Payments Agent example that demonstrates how to build an AI agent capable of executing cryptocurrency payments across 13 blockchains using the x402 protocol.

What It Does

The example provides 8 custom tools that connect to the Spraay x402 gateway (gateway.spraay.app), enabling any NeMo Agent Toolkit agent to:

• Query tools (free): check gateway health, list routes/pricing, list supported chains, check wallet balances, get token prices
• Action tools (paid via x402 USDC micropayment): batch-send tokens to multiple recipients, create milestone-based escrow contracts, discover robots/IoT devices via the Robot Task Protocol (RTP)

Why This Matters for Agent Toolkit Users

Agents that take action in the real world need to pay for things. The x402 protocol makes payments native to HTTP — agents pay per API request with USDC, no wallet UX required. This example shows how to integrate a payment layer into any NeMo Agent Toolkit workflow.

What's Included

examples/spraay_crypto_payments/
├── README.md                                    # Full documentation
├── pyproject.toml                               # Dependencies
├── configs/
│   └── config.yml                               # Workflow config (ReAct + 8 tools)
└── src/spraay_crypto_payments/
    ├── __init__.py                              # Tool registration
    └── spraay_tools.py                          # 8 async tools (httpx-based)

Quick Start

export NVIDIA_API_KEY=<your-key>
nat run --config_file configs/config.yml --input "What chains does Spraay support?"

Supported Chains

Base · Ethereum · Arbitrum · Polygon · BNB · Avalanche · Solana · Bitcoin · Stacks · Unichain · Plasma · BOB · Bittensor

Related

• Spraay OpenShell Sandbox — also submitted as a community sandbox
• Spraay MCP Server — 60+ tools on Smithery
• x402 Protocol