SpendPreflight

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Operated by SpendPreflight: sanctions screening and allow/hold/block preflight for x402 payments.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "SpendPreflight": {
      "url": "https://api.spendpreflight.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (10)

• listing_guard read-only

  Bazaar Listing Guard: CDP technical validation plus a bounded heuristic metadata screen for agent-directed instructions, embedded URLs, tool calls, invisible Unicode, long fields and prices above 100x a fresh Scout category median. Returns riskScore, flagged spans and rewrite suggestions. Not Coinbase policy certification or guaranteed detection. Public HTTPS only; no target payment or request bodies stored. Price $0.05 USDC on Base; shared trial may apply.

  Parameters:

  • url (required) — string
  • method (required) — string

  Hints: read-only yes · destructive not declared · idempotent not declared · open-world yes

• check_listing read-only

  Compatibility alias of listing_guard for existing clients. Prefer listing_guard for a new detailed metadata check; these are the same operation, not two independent checks. Bazaar Listing Guard: CDP technical validation plus a bounded heuristic metadata screen for agent-directed instructions, embedded URLs, tool calls, invisible Unicode, long fields and prices above 100x a fresh Scout category median. Returns riskScore, flagged spans and rewrite suggestions. Not Coinbase policy certification or guaranteed detection. Public HTTPS only; no target payment or request bodies stored. Price $0.05 USDC on Base; shared trial may apply.

  Parameters:

  • url (required) — string
  • method (required) — string

  Hints: read-only yes · destructive not declared · idempotent not declared · open-world yes

• find_rv_stations read-only

  Nearest RV dump/water stations from FillPoint RV's dated September 17, 2026 ODbL snapshot. $0.01 for bounded straight-line proximity calculation, not live access, potable-water assurance or road routing. Snapshot age and unknown current conditions are explicit. Full underlying projection is free under ODbL.

  Parameters:

  • latitude (required) — number
  • longitude (required) — number
  • limit — integer
  • service — string
  • radius_km — number

  Hints: read-only yes · destructive not declared · idempotent not declared · open-world no

• size_solar read-only

  Off-grid PV energy-balance estimate based on Wattpath by Nomad Energy Club. Supply daily loads, peak sun hours, PV losses, and optional battery assumptions. No location/weather lookup, electrical design, surge or installation certification. $0.02 per calculation; no stored inputs.

  Parameters:

  • loads (required) — array
  • peak_sun_hours (required) — number
  • pv_loss_fraction (required) — number
  • battery — object
  • panel_watts — number
  • inverter_efficiency — number

  Hints: read-only yes · destructive not declared · idempotent not declared · open-world no

• check_token read-only

  Base contract safety signals from bounded public-chain reads and OFAC. Basic: deployed bytecode and SDN match. Deep adds standard owner(), paused(), totalSupply(), decimals() and ERC-1967 storage observations, exact ERC-1167 minimal-proxy target detection, a Sourcify runtime-verification claim matched to current bytecode, and direct-deployment age when independently supported by the creation receipt. Honeypot/sellability, liquidity locks, holder concentration and scam lists are NOT assessed. Missing data is unknown; never a safe-to-buy verdict. Informational, not financial advice. Basic $0.02; deep $0.05. Shared trial first.

  Parameters:

  • address (required) — string
  • tier — string
  • chain — string

  Hints: read-only yes · destructive no · idempotent no · open-world yes

• lint_endpoint

  Free x402 Lint by SpendPreflight. Checks a public HTTPS endpoint with an unpaid GET: v1/v2 challenge shape, payTo/asset/network syntax, price, Bazaar metadata and browser CORS headers. Returns a heuristic Listing Guard riskScore (0–100 or unknown), fixes and a public seven-day report link. Positive scores include optional paid Listing Guard and monitoring links; no paid call is made. Scores are not safety or Bazaar acceptance guarantees. No payment or credentials; GET cannot validate a POST-only endpoint or paid delivery. Do not submit private URLs.

  Parameters:

  • url (required) — string

  Hints: read-only no · destructive no · idempotent no · open-world yes

• check_payee read-only

  Payee risk check. Screens a payee wallet address and name against the OFAC SDN sanctions list and checks the merchant domain's registration age and DNS. Returns risk low|medium|high|unknown with flags such as sanctioned_address, sanctioned_name_possible, new_domain. Call this before a USDC payment when you only have a payee name, wallet or domain. Provide at least one of domain, address, or name; inputs may be combined, and domain accepts a hostname or URL. For an x402 challenge or cart and an allow/hold/block spending-rule decision, use preflight_payment instead. Price $0.01 per call (free trial first).

  Parameters:

  • name — string — Merchant or payee legal name
  • domain — string — Merchant domain or URL, e.g. shop.example.com
  • address — string — Payee wallet address (EVM 0x…, BTC, etc.)

  Hints: read-only yes · destructive not declared · idempotent yes · open-world yes

• preflight_payment read-only

  Call this before any x402/USDC payment to evaluate the actual challenge or cart before signing. Spend preflight for AI agents. Send the x402 PaymentRequired body (v1 or v2) you received, or a cart, plus optional rules (per-payment max, hold threshold, daily cap, allowlists, new-domain days, endpoint category price multiple, liveness and payTo changes). Returns allow|hold|block with reasons, the cheapest acceptable payment option, and a receipt id. Read-only: never signs, settles, or holds funds. Use before every payment. It includes payee screening in its spending-rule decision. For standalone wallet, name, or domain screening without a payment, use check_payee instead. Each repeat call creates a new receipt and may consume another trial or paid call. Price $0.02 per call (free trial first).

  Parameters:

  • cart — object — Use instead of challenge for agent checkout / card payments
  • rules — object — Spending rules; all optional. See get_service_info for defaults.
  • challenge — object — The x402 PaymentRequired body (v1 or v2) your agent received with HTTP 402
  • resource_url — string — URL that returned the 402, if not inside the challenge
  • resource_method — string — Advertised method for an indexed URL with multiple methods
  • spent_today_usd — number — What this agent already spent today, for the daily cap

  Hints: read-only yes · destructive not declared · idempotent no · open-world yes

• check_endpoint read-only

  Cached x402 endpoint observations, operated by SpendPreflight. Returns a transparent score (or unknown), its components and seven-day unpaid probe history for an already publicly listed URL. Never fetches the caller's URL or pays the endpoint. Unlisted, unavailable or stale data is not charged. This is not a paid-delivery or compliance guarantee. Provide the exact resource URL; add method when the URL has multiple advertised methods. Use for endpoint history and price context before paying. Use check_payee for wallet/name screening or preflight_payment for an allow/hold/block decision. Price $0.005 per cached lookup (shared free trial first). An unknown score means missing evidence; repeated paid calls may incur another charge.

  Parameters:

  • url (required) — string — Exact public HTTP(S) URL already listed by Bazaar or x402scan
  • method — string — Advertised method such as GET or POST; required if the URL is ambiguous

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• get_service_info read-only

  Free, read-only service reference. Use when you need prices, default spending rules, payment setup, trial allowance, or a ready-to-use example call. If you already have a payment challenge or cart, call preflight_payment directly; this reference call is optional. Takes no arguments and performs no payee screening or payment decision. Use check_payee for standalone payee risk; use preflight_payment for an x402 challenge or cart and an allow/hold/block decision.

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

Publisher website

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.