payrail402

Cross-rail spend tracking for AI agents — Visa IC, Mastercard Agent Pay, Stripe ACP, x402, and ACH in one dashboard.

Track every financial transaction your AI agent makes — across any payment rail — in one place.

PayRail402 is the control plane for AI agent transactions. When your agent makes a purchase, payment, or financial operation on Visa Intelligent Commerce, Mastercard Agent Pay, Stripe ACP, x402 (USDC on-chain), or ACH, this skill reports it to your PayRail402 dashboard for budget enforcement, anomaly detection, and cross-rail reconciliation.

Setup

1. Go to payrail402.com and create a free account
2. Add an agent in the dashboard — you'll receive a webhook token
3. Configure your environment:

Option A — Webhook auth (simplest, one agent):

PAYRAIL402_WEBHOOK_TOKEN=your-webhook-token

Option B — API key auth (multi-agent setups):

PAYRAIL402_API_KEY=pr4_your-key
PAYRAIL402_AGENT_ID=your-agent-id

You only need one auth method. Webhook auth is recommended for single-agent use.

Tools

payrail402_track

Track a financial transaction after any purchase, payment, or financial operation.

Required inputs:

• amount — Transaction amount (positive number, USD)
• description — What the agent did (max 500 chars)

Optional inputs:

• merchant — Merchant or service name (e.g., "OpenAI", "AWS")
• category — One of: shopping, finance, devops, research, travel, api, other
• rail — Payment rail: visa_ic, mc_agent, stripe_acp, x402, ach, manual
• mandate — Authorization or mandate reference
• proofHash — On-chain transaction hash (for x402 payments)

When to use: Call this immediately after your agent completes any financial transaction. This feeds the PayRail402 dashboard with real-time spend data and triggers budget rule evaluation.

payrail402_register

Self-register this agent with PayRail402 to get tracking credentials.

Required inputs:

• name — Agent name (max 100 chars)
• contactEmail — Developer/owner email for notifications and dashboard claiming

Optional inputs:

• description — What this agent does
• type — Agent type: shopping, finance, devops, research, travel, api, general
• callbackUrl — Webhook URL for receiving alerts and budget violation events

When to use: Call this once when the agent first starts and has no existing credentials. The response includes an API key (shown once — save it) and a webhook token.

payrail402_status

Check this agent's current status, claim state, and configuration on PayRail402.

Required inputs:

• agentAccountId — Agent account ID from registration

When to use: Call this to verify the agent is still active, check its registration tier, or confirm it has been claimed by a dashboard user.

Supported Payment Rails

Rail ID	Name	Description
visa_ic	Visa Intelligent Commerce	Visa's AI agent payment protocol
mc_agent	Mastercard Agent Pay	Mastercard's autonomous agent payment rail
stripe_acp	Stripe Agent Credit Platform	Stripe's agent-to-agent payment system
x402	x402 Protocol	USDC on-chain payments via HTTP 402
ach	ACH	Traditional ACH bank transfers
manual	Manual	Manual or unclassified transactions

What Happens After Tracking

When you call payrail402_track, the PayRail402 backend:

1. Records the transaction with full metadata
2. Updates agent spend stats (total spent, transaction count)
3. Evaluates budget rules (per-transaction max, daily/weekly/monthly limits)
4. Runs anomaly detection (flags transactions 3x above agent average)
5. Sends alerts to the dashboard (and optionally via email) on violations

Permission Justification

This skill requires three environment variables. Here is exactly what each one is used for and why it is necessary:

PAYRAIL402_WEBHOOK_TOKEN (primary credential)

• Used by: payrail402_track tool
• How: Embedded in the API URL path (/api/ingest/webhook/{token}) to authenticate transaction submissions
• Why: Each agent has a unique webhook token that links transactions to the correct agent in the dashboard. Without it, the skill cannot submit transactions.
• Security: Sent as a URL path segment over HTTPS only. Never included in query strings, headers, or request bodies.

PAYRAIL402_API_KEY

• Used by: payrail402_track (alternative auth path) and payrail402_status tool
• How: Sent via x-agent-key or x-api-key HTTP header over HTTPS
• Why: Required for checking agent status and for multi-agent setups where one API key manages multiple agents. Not needed if you only use webhook auth for tracking.
• Security: Transmitted only in HTTP headers over HTTPS. Format: pr4_ prefix + base64url secret. Stored as SHA-256 hash on the server.

PAYRAIL402_AGENT_ID

• Used by: payrail402_track (with API key auth) and payrail402_status tool
• How: Included in the API URL path (/api/v1/agents/{agentId}) and request body
• Why: Identifies which agent account to operate on when using API key auth. Not needed for webhook auth (the webhook token already identifies the agent).
• Security: Not a secret — it is a public CUID identifier. Included in URL paths only.

Security

This skill is designed to be transparent and minimal:

• Single endpoint: All network requests go to https://payrail402-production-2a69.up.railway.app over HTTPS only
• No filesystem access: The skill does not read, write, or modify any files
• No shell commands: The skill does not execute any system commands
• No other network calls: The skill makes no requests to any other domain or service
• Zero dependencies: The entire implementation is a single JavaScript file with no external packages
• Credential handling: API keys and webhook tokens are sent via HTTP headers or URL path segments — never in query strings, never logged, never stored locally

You can inspect the full implementation in openclaw-skill.js — it is 184 lines of plain JavaScript.

Troubleshooting

Error	Cause	Fix
No credentials configured. Set webhookToken or apiKey in skill config.	Neither PAYRAIL402_WEBHOOK_TOKEN nor PAYRAIL402_API_KEY is set	Set at least one credential — see Setup above
amount must be a positive number	The amount input is missing, zero, or negative	Pass a positive number for the transaction amount
apiKey is required in skill config to check status	Called payrail402_status without PAYRAIL402_API_KEY	Set PAYRAIL402_API_KEY — status checks require API key auth
HTTP 429 (Too Many Requests)	Rate limit exceeded	Webhook: max 60 requests/minute. Register: max 10/hour. Wait and retry.
HTTP 403 (Forbidden)	Agent is paused or stopped in the dashboard	Resume the agent in your PayRail402 dashboard
HTTP 400 (Bad Request)	Invalid input (missing required field or bad format)	Check that amount and description are provided and valid
Network error / timeout	Cannot reach PayRail402 API	Check internet connectivity. The API is at payrail402-production-2a69.up.railway.app

Links

• Dashboard: payrail402.com
• SDK: npm install @payrail402/sdk
• Agent Card: payrail402.com/.well-known/agent-card.json
• Full API Docs: payrail402.com/llms-full.txt