# Services from mcp.dropenginehq.com on Zero

> mcp.dropenginehq.com serves 17 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/mcp.dropenginehq.com
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/mcp.dropenginehq.com/health.json

## Services

- [Invoice Preflight](https://www.zero.xyz/c/invoice-preflight-fd88b9ff/llms.txt): $0.065/call via x402. Validates an invoice document against expected amounts, line items, and purchase details, returning a match/discrepancy/needs_review decision with field-level evidence.
- [MCP Server Inspector](https://www.zero.xyz/c/mcp-server-inspector-afa9a977/llms.txt): $0.01/call via x402. Read-only health check and tool-schema inspection for a public MCP (Model Context Protocol) endpoint, returning reachability status, tool count, and schema details without invoking any tools.
- [Strategy Backtest](https://www.zero.xyz/c/strategy-backtest-b91998ad/llms.txt): $0.1/call via x402. Runs a bounded declarative historical spot trading strategy backtest over a specified date range and market, returning performance metrics.
- [Token Security Audit](https://www.zero.xyz/c/token-security-audit-e7c6b457/llms.txt): $0.01/call via x402. Audits an EVM token contract for security risks using GoPlus security intelligence, returning detailed threat signals and risk metadata.
- [Transaction Preflight](https://www.zero.xyz/c/transaction-preflight-c950cd38/llms.txt): $0.02/call via x402. Simulates an unsigned EVM transaction on Base or Base Sepolia before signing, returning gas estimates, revert status, ERC-20 token transfer/approval decoding, and risk signals.
- [URL Safety Gate](https://www.zero.xyz/c/url-safety-gate-b3f2aff9/llms.txt): $0.005/call via x402. Performs a paid preflight risk assessment of a URL by checking syntax, transport security, host/IP reputation, suspicious patterns, and up to five HTTPS redirects — without fetching page content.
- [Prompt-Injection Firewall](https://www.zero.xyz/c/prompt-injection-firewall-fe513e7b/llms.txt): $0.005/call via x402. Scans untrusted text, HTML, email, documents, and tool outputs for prompt injection attacks, credential theft, data exfiltration, and tool manipulation before an AI agent acts on the content.
- [Arbitrage Intelligence](https://www.zero.xyz/c/arbitrage-intelligence-32919868/llms.txt): $0.03/call via x402. Compares public exchange order books (Binance and Coinbase) after fee assumptions to identify net cross-exchange arbitrage spreads for a given crypto asset.
- [Agent Tool Router + Trust Layer](https://www.zero.xyz/c/agent-tool-router-trust-layer-ee5eac45/llms.txt): $0.002/call via x402. Finds, ranks, and recommends machine-payable services for a given agent capability query, applying price, latency, and quality constraints.
- [Change / Diff Check](https://www.zero.xyz/c/change-diff-check-2aaa95ab/llms.txt): $0.001/call via x402. Compares normalized public webpage text against a previously stored SHA-256 hash to detect whether the page content has changed.
- [Fresh Structured Extract](https://www.zero.xyz/c/fresh-structured-extract-bc098964/llms.txt): $0.01/call via x402. Fetches a public webpage and extracts user-defined structured JSON fields from its live content.
- [Trade Execution Quote](https://www.zero.xyz/c/trade-execution-quote-a0004e1d/llms.txt): $0.01/call via x402. Returns an indicative, read-only swap quote for a token pair across multiple chains and DEX venues without executing a trade.
- [Package Safety Gate](https://www.zero.xyz/c/package-safety-gate-f69d5786/llms.txt): $0.005/call via x402. Checks npm package metadata and security risks before installation to help agents safely resolve dependencies.
- [Wallet Risk Check](https://www.zero.xyz/c/wallet-risk-check-7900d538/llms.txt): $0.02/call via x402. Checks a Base blockchain wallet or contract address for counterparty risk signals before an agent sends funds, accepts payments, or grants approvals
- [Whale Intelligence](https://www.zero.xyz/c/whale-intelligence-53631ab2/llms.txt): $0.02/call via x402. Analyzes publicly indexed large DEX trades by asset or wallet address across major blockchains, surfacing whale activity patterns.
- [Live Product Quote](https://www.zero.xyz/c/live-product-quote-6096c53a/llms.txt): $0.01/call via x402. Returns real-time public product price, availability, and shipping cost for a given product URL, variant, quantity, and destination country before purchase.
- [Freshness / Claim Verifier](https://www.zero.xyz/c/freshness-claim-verifier-9831ac8e/llms.txt): $0.02/call via x402. Verifies a factual claim against fresh web evidence within a specified recency window, optionally scoped to preferred domains.

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

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