browser-payment-mcp

name	browser-payment-mcp
description	MCP server for browser-based payment portal automation using Playwright. Supports navigating payment sites, filling forms, drafting payments with mandatory HITL approval before execution. Never auto-approves payments. Use when Claude needs to interact with payment portals, banking websites, or any web-based financial operations requiring human oversight.

Browser Payment MCP Server

Overview

This skill provides a FastMCP server that automates browser-based payment portal interactions using Playwright. It enforces strict Human-In-The-Loop (HITL) controls so that no payment is ever executed without explicit human approval.

Prerequisites

• Python 3.10+
• Playwright (pip install playwright) with Chromium browser installed (playwright install chromium)
• FastMCP (pip install fastmcp>=0.1.0)

Install all dependencies:

pip install -r .claude/skills/browser-payment-mcp/assets/requirements.txt
playwright install chromium

HITL Controls

All payment operations follow a strict approval workflow:

1. Draft Phase -- draft_payment fills the payment form in the browser but does NOT click submit. It creates an approval file under demo_vault/Pending_Approval/.
2. Human Review -- A human must review the approval file, verify the details, and move it to demo_vault/Approved/.
3. Execute Phase -- execute_payment checks that a valid, non-expired approval file exists in the Approved folder before clicking submit.

Hard rules (cannot be overridden):

• ALL payments require human approval regardless of amount.
• Payments to new (previously unseen) recipients always require approval.
• Amounts above $100 always require approval (this is every payment by rule above).
• Approval files expire after 24 hours.
• Maximum 3 payments executed per rolling hour.

Security

• No credential storage in vault. Browser sessions use Playwright persistent context so credentials are managed by the browser profile, never written to disk by this skill.
• DRY_RUN mode -- Set PAYMENT_DRY_RUN=true to prevent any real browser interactions. All tools return simulated responses and still create audit logs tagged as dry-run.
• Allowed domains -- Configure PAYMENT_ALLOWED_DOMAINS to restrict which URLs the browser may navigate to.
• Screenshots -- Every significant action captures a screenshot stored in the audit directory for post-hoc review.

Supported Operations

Tool	Description	HITL Required
navigate_to	Navigate to a URL	No
fill_form	Fill a form field by CSS selector	No
click_element	Click an element by CSS selector	No
get_page_content	Extract text content from selector	No
screenshot	Take a named screenshot	No
draft_payment	Fill payment form, create approval file	Creates file
execute_payment	Submit an approved payment	YES
check_balance	Read account balance from portal	No
get_transaction_history	Read recent transactions from portal	No

Configuration

Environment variables (or .env):

Variable	Default	Description
PAYMENT_DRY_RUN	false	Simulate all browser actions
PAYMENT_HEADLESS	true	Run Chromium in headless mode
PAYMENT_SCREENSHOT_DIR	demo_vault/Logs/payments/screenshots	Where screenshots are saved
PAYMENT_MAX_PER_HOUR	3	Max payments per rolling hour
PAYMENT_APPROVAL_EXPIRY_H	24	Hours before approval file expires
PAYMENT_ALLOWED_DOMAINS	*	Comma-separated allowed domains
PAYMENT_VAULT_DIR	demo_vault	Root vault directory
PAYMENT_AUDIT_RETENTION_DAYS	90	Days to retain audit logs

Running the Server

python .claude/skills/browser-payment-mcp/scripts/browser_payment_mcp.py

The server starts on stdio transport by default (suitable for MCP client integration).