feat: add spraay crypto payments agent example

[plagtech]

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

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[willkill07]

This example doesn't run. The code is invalid.

All examples should show sample runs with expected output.

[plagtech]

This example doesn't run. The code is invalid.

All examples should show sample runs with expected output.

Thanks for the review — I've rewritten the example to use the proper @register_function / FunctionBaseConfig / FunctionInfo pattern and added expected output to the README.

[willkill07]

@plagtech DCO check has failed. Please ensure all commits are signed-off

[plagtech]

Thanks for the review. I've rewritten the example using the proper @register_function / FunctionBaseConfig / FunctionInfo pattern and added expected output to the README. DCO sign-off is now fixed as well.

[willkill07]

/ok to test 0fdfc7b

[plagtech]

Hi @willkill07 — just checking in on this. I believe the requested changes from the initial review have been addressed in the rewrite (proper @register_function / FunctionBaseConfig pattern, DCO sign-off, copyright headers). Is there anything else needed on my end?
Also worth noting — Spraay's x402 payment integration was recently merged into Google ADK, so this example connects to the same gateway already available in Google's agent framework.

[plagtech]

Hi @willkill07 — friendly bump on this. CI was triggered on the rewrite back in April, wondering if there's any remaining feedback. Happy to make adjustments if needed

[willkill07]

/ok to test 0a3e359

[willkill07]

I looked through this again and believe that logic consolidation should occur. Prefer a function group over individual functions so they all share the same HTTP client.

Also, please address CI failures. If we can avoid hyper-specific language, we should.

[plagtech]

Done — converted to a single @register_function_group with shared HTTP client. Config now references spraay as a group. Also renamed module to nat_spraay_crypto_payments per contributor guidelines.