SKILL Installation Guide

Install the CardZero payment SKILL on your Agent platform. Once installed, your Agent can create wallets, make payments, and check balances.

OpenClaw

OpenClaw is currently the primary supported platform. The SKILL is defined as a SKILL.md file that gives your Agent instructions on how to use the CardZero API.

Step 1: Add the SKILL.md

Add the CardZero SKILL.md to your OpenClaw agent's skills directory. The SKILL file contains:

API base URL and authentication instructions
Wallet creation and lifecycle management
Payment execution (direct and x402)
Balance checking and transaction history
Error handling and user communication guidelines

Step 2: Configure the API Key

After you claim the wallet (see Getting Started), you receive an Agent Configuration with an API Key and wallet ID. Add these to your Agent's environment or configuration:

# Agent Configuration from CardZero Dashboard
CARDZERO_API_KEY=czapi_prefix_secret
CARDZERO_WALLET_ID=wallet_abc123
CARDZERO_API_URL=https://api.cardzero.ai

Step 3: Test the Integration

Ask your Agent to check its wallet balance. If configured correctly, it should respond with the current USDC balance:

Example conversation

You: "Check your CardZero wallet balance."

Agent: "My CardZero wallet has 25.00 USDC available."

What the SKILL Teaches Your Agent

Once installed, your Agent understands:

Wallet Creation

When it needs payment capability for the first time, the Agent calls POST /v1/wallets and tells the user (owner) the claim key and wallet address.

Direct Payments

The Agent makes USDC payments to specific addresses using POST /v1/payments. It checks balance first and respects spending rules.

x402 Payments

When encountering a 402 Payment Required response, the Agent automatically processes the payment using the x402 endpoint.

Error Handling

The Agent communicates balance issues, frozen wallets, and limit exceeded errors to the user in plain language, with suggested actions.

Other Platforms

Integration files for additional platforms are available in the plugins/ directory of the CardZero repository:

Claude Code

CLAUDE.md configuration snippet

Available

ChatGPT Custom Actions

OpenAPI spec for GPT plugin system

Available

Cursor / Windsurf

Rules file integration

Available

In the meantime, the CardZero REST API works with any platform that can make HTTP requests. See the API Reference for endpoint details.

Next Steps

Getting Started -- complete the 5-step setup API Reference -- full endpoint documentation