# DropEngine paid MCP services

> Independent pay-per-call tools for autonomous agents. Select and pay for only the tool needed for each call.

## Connect
- MCP Streamable HTTP: https://mcp.dropenginehq.com/api/paid-mcp
- Agent services MCP (discovery/router): https://mcp.dropenginehq.com/api/agent-services
- Machine-readable agent catalog: https://mcp.dropenginehq.com/api/tools
- Deterministic natural-language intent search: POST https://mcp.dropenginehq.com/api/discover with {"query":"..."}
- HTTP resource catalog and live payment schemas: https://mcp.dropenginehq.com/openapi.json
- Human quickstart: https://mcp.dropenginehq.com/docs#connect
- x402 payment: Base mainnet USDC; read each tool's current 402 offer before paying.

## Services
### Invoice Preflight — invoice_preflight_quote
- Use: Checks invoice fields and calculations against expected purchase details, then returns evidence and a clear review signal.
- Limits and provider notes: For UBL XML invoices or complete PDF/image invoices. OCR tiers check the full document up to the selected page limit.
- Input: Document type, optional file size and PDF page count
- Price: Free per call
- Details: https://mcp.dropenginehq.com/services/invoice-preflight-quote

### Invoice Preflight — invoice_preflight
- Use: Checks invoice fields and calculations against expected purchase details, then returns evidence and a clear review signal.
- Limits and provider notes: For UBL XML invoices or complete PDF/image invoices. OCR tiers check the full document up to the selected page limit.
- Input: UBL XML or PDF/image up to 3 pages
- Price: $0.065 USDC per call
- Details: https://mcp.dropenginehq.com/services/invoice-preflight

### Invoice Preflight — invoice_preflight_10_pages
- Use: Checks invoice fields and calculations against expected purchase details, then returns evidence and a clear review signal.
- Limits and provider notes: For UBL XML invoices or complete PDF/image invoices. OCR tiers check the full document up to the selected page limit.
- Input: PDF/image up to 10 pages
- Price: $0.13 USDC per call
- Details: https://mcp.dropenginehq.com/services/invoice-preflight-10-pages

### Invoice Preflight — invoice_preflight_50_pages
- Use: Checks invoice fields and calculations against expected purchase details, then returns evidence and a clear review signal.
- Limits and provider notes: For UBL XML invoices or complete PDF/image invoices. OCR tiers check the full document up to the selected page limit.
- Input: PDF/image up to 50 pages
- Price: $0.475 USDC per call
- Details: https://mcp.dropenginehq.com/services/invoice-preflight-50-pages

### MCP Server Inspector — mcp_server_inspect
- Use: Checks whether a public MCP endpoint responds and summarizes its advertised tools, input schemas, and basic risk flags.
- Limits and provider notes: Read-only inspection: it does not run the target server's tools and does not use Mistral or OCR.
- Input: Public, unauthenticated MCP endpoint over HTTPS
- Price: $0.01 USDC per call
- Details: https://mcp.dropenginehq.com/services/mcp-server-inspect
- HTTP: POST https://mcp.dropenginehq.com/api/mcp-server-inspect

### Agent Preflight · URL Safety Gate — check_url
- Use: Checks an unknown URL before an agent opens or relies on it, returning a structured allow, caution, or block signal.
- Limits and provider notes: Uses deterministic URL, host/IP, pattern, and HTTPS redirect checks. It never loads page content or uses an LLM. Without an optional threat-intelligence key, results are marked heuristic-only and degraded.
- Input: One HTTP or HTTPS URL, up to 4096 characters
- Price: $0.005 USDC per call
- Details: https://mcp.dropenginehq.com/services/check-url
- HTTP: POST https://mcp.dropenginehq.com/api/check-url

### Prompt-Injection Firewall — scan_content
- Use: Scans untrusted content before an agent adds it to context, follows its instructions, or acts on it.
- Limits and provider notes: Deterministic local analysis returns a structured risk report and sanitized plain text where possible; it does not call an LLM or store raw content.
- Input: Text, HTML, email, document text, API response, or tool output up to 100,000 characters by default
- Price: $0.005 USDC per call
- Details: https://mcp.dropenginehq.com/services/scan-content
- HTTP: POST https://mcp.dropenginehq.com/api/scan-content

### Transaction Preflight — simulate_transaction
- Use: Simulates an unsigned Base transaction before signing and returns gas estimates, decoded top-level calls, approval warnings, and a machine-readable risk signal.
- Limits and provider notes: Read-only RPC simulation only. It never signs, holds keys, or broadcasts; internal token state changes are not exposed by standard RPC and are not claimed as decoded movements.
- Input: Unsigned Base or Base Sepolia transaction fields (from, to, value in wei, calldata)
- Price: $0.02 USDC per call
- Details: https://mcp.dropenginehq.com/services/simulate-transaction
- HTTP: POST https://mcp.dropenginehq.com/api/simulate-transaction

### Wallet Risk Check — check_wallet
- Use: Checks a Base wallet or contract as a counterparty before an agent sends funds, accepts payment, grants approval, or interacts with it.
- Limits and provider notes: Reads basic on-chain metadata and, on Base mainnet, queries GoPlus Address Security for public reputation flags. Unsupported categories remain unknown; only the checked public address is sent to the provider.
- Input: Base or Base Sepolia chain and one public EVM address
- Price: $0.02 USDC per call
- Details: https://mcp.dropenginehq.com/services/check-wallet
- HTTP: POST https://mcp.dropenginehq.com/api/check-wallet

### Wallet Risk Check — token_security_audit
- Use: Checks a Base wallet or contract as a counterparty before an agent sends funds, accepts payment, grants approval, or interacts with it.
- Limits and provider notes: Reads basic on-chain metadata and, on Base mainnet, queries GoPlus Address Security for public reputation flags. Unsupported categories remain unknown; only the checked public address is sent to the provider.
- Input: Supported EVM chain and public token contract address
- Price: $0.01 USDC per call
- Details: https://mcp.dropenginehq.com/services/token-security-audit
- HTTP: POST https://mcp.dropenginehq.com/api/token-security-audit

### Package Safety Gate — check_package
- Use: Checks an npm dependency version for known vulnerabilities, malware advisories, typosquatting, and risky install scripts before installation.
- Limits and provider notes: Reads public npm metadata and OSV vulnerability advisories. Package scripts and source code are analyzed as text only and are never executed; direct dependency trees and maintainer history are not recursively assessed in this MVP.
- Input: npm package name and optional exact semantic version
- Price: $0.005 USDC per call
- Details: https://mcp.dropenginehq.com/services/check-package
- HTTP: POST https://mcp.dropenginehq.com/api/check-package

### Agent Tool Router + Trust Layer — route_tool
- Use: Finds and ranks machine-payable MCP tools and x402 endpoints by capability, price, observed performance, trust, and agent constraints.
- Limits and provider notes: Returns a recommendation only; it never calls or pays the selected provider. External Bazaar discovery is optional and configured separately; local results have cold-start confidence.
- Input: Capability, optional query, price/latency/reliability constraints and routing preference
- Price: $0.002 USDC per call
- Details: https://mcp.dropenginehq.com/services/route-tool
- HTTP: POST https://mcp.dropenginehq.com/api/route-tool

### Live Product Quote — get_live_quote
- Use: Retrieves current structured product price and availability before an agent buys.
- Limits and provider notes: Uses public HTTPS pages and static JSON-LD/product metadata only. Shipping and tax remain unknown unless page data explicitly provides them.
- Input: Public HTTPS product page, optional quantity and variant
- Price: $0.01 USDC per call
- Details: https://mcp.dropenginehq.com/services/get-live-quote
- HTTP: POST https://mcp.dropenginehq.com/api/get-live-quote

### Fresh Structured Extract — extract_structured
- Use: Turns public webpage data into schema-shaped JSON with field provenance and explicit missing values.
- Limits and provider notes: Static JSON-LD, metadata, and visible text only; no browser JavaScript or LLM. Arbitrary private-network URLs are blocked.
- Input: Public HTTPS page and optional simple field schema
- Price: $0.01 USDC per call
- Details: https://mcp.dropenginehq.com/services/extract-structured
- HTTP: POST https://mcp.dropenginehq.com/api/extract-structured

### Change / Diff Check — check_change
- Use: Compares a page's normalized text with a previous hash and returns a compact diff when a prior snapshot is available.
- Limits and provider notes: Stateless hash comparison with short-lived in-memory snapshots. Authenticated pages are not supported.
- Input: Public HTTPS page and prior SHA-256 hash
- Price: $0.001 USDC per call
- Details: https://mcp.dropenginehq.com/services/check-change
- HTTP: POST https://mcp.dropenginehq.com/api/check-change

### Freshness / Claim Verifier — verify_claim
- Use: Checks a factual claim against fresh web search evidence and reports support, conflict, staleness, or insufficient evidence.
- Limits and provider notes: Requires Tavily Search API key for evidence retrieval. If it is not configured, the tool returns a provider-unavailable error before requesting payment. No model knowledge is used as evidence.
- Input: Factual claim, freshness window, optional preferred domains
- Price: $0.02 USDC per call
- Details: https://mcp.dropenginehq.com/services/verify-claim
- HTTP: POST https://mcp.dropenginehq.com/api/verify-claim

### Trade Execution Quote — estimate_trade_execution
- Use: Estimates a swap output and route using a configured aggregator quote before an agent trades.
- Limits and provider notes: Read-only quote only. Solana uses Jupiter and EVM chains use 0x when their API keys are configured. This is not an execution guarantee; gas USD and account-specific fees may be unknown.
- Input: Chain, token addresses or supported Solana symbols, amount and token decimals
- Price: $0.01 USDC per call
- Details: https://mcp.dropenginehq.com/services/estimate-trade-execution
- HTTP: POST https://mcp.dropenginehq.com/api/estimate-trade-execution

### Whale Intelligence — analyze_whale_activity
- Use: Summarizes large indexed DEX trades around a token and marks size-based wallet labels as heuristic.
- Limits and provider notes: Asset mode uses GeckoTerminal public pool/trade data; it is not a chain-wide transfer feed. Wallet mode uses Helius on Solana or Etherscan API V2 for supported EVM chains when configured; it reports recent indexed transactions only, not a complete portfolio valuation.
- Input: Token address and chain, or wallet address and chain
- Price: $0.02 USDC per call
- Details: https://mcp.dropenginehq.com/services/analyze-whale-activity
- HTTP: POST https://mcp.dropenginehq.com/api/analyze-whale-activity

### Arbitrage Intelligence — scan_arbitrage
- Use: Compares Binance and Coinbase order books at a requested trade size after configurable taker-fee assumptions.
- Limits and provider notes: Public order-book snapshots only. It excludes deposits, withdrawals, inventory rebalancing, and guaranteed execution; stale or incomplete books are rejected.
- Input: Asset, quote asset, trade size and optional per-venue taker fees
- Price: $0.03 USDC per call
- Details: https://mcp.dropenginehq.com/services/scan-arbitrage
- HTTP: POST https://mcp.dropenginehq.com/api/scan-arbitrage

### Strategy Backtest — backtest_strategy
- Use: Backtests built-in long-only spot strategies against public Binance candles with next-candle execution.
- Limits and provider notes: No user code is executed. Includes configurable fees/slippage and bounded historical data; results are historical simulations, not predictions.
- Input: Binance market, timeframe, date range, capital and declarative strategy parameters
- Price: $0.10 USDC per call
- Details: https://mcp.dropenginehq.com/services/backtest-strategy
- HTTP: POST https://mcp.dropenginehq.com/api/backtest-strategy

## Agent guidance
- Discover tools with MCP tools/list before calling them.
- A missing provider or incomplete coverage is not a clean/safe verdict; read the structured result and follow your own policy.
- Crypto quote, simulation, wallet and token tools are read-only; they do not sign or broadcast transactions.
- Verify the live payment network, USDC asset, recipient and amount from the x402 challenge before signing.