# SpendPreflight (remote · api.spendpreflight.com)

Operated by SpendPreflight: free x402 Lint risk scores, paid Listing Guard and seller monitoring.

- Trust score: 74/100 (medium)
- Change this week: +1
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-24

## Components

- remote · `api.spendpreflight.com`: 74/100 (this document), [markdown](https://verifymcp.io/servers/spendpreflight-spendpreflight/api.md), [page](https://verifymcp.io/servers/spendpreflight-spendpreflight/api)

## Channel facts

- Endpoint: `https://api.spendpreflight.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.2.0-metadata.1`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-24.

- **Endpoint Security**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS check failed: the endpoint is reachable over plaintext HTTP.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 78/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1853 tokens (~142/item across 13 items; 10 tools + 3 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 57/100
  - Stability observed for 17 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 82/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 37% of tool parameters carry a description.
  - Structured output schemas are declared (40% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 10 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 12 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the SpendPreflight MCP server?

SpendPreflight is a hosted endpoint at https://api.spendpreflight.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http spendpreflight-spendpreflight 'https://api.spendpreflight.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "spendpreflight-spendpreflight": {
      "url": "https://api.spendpreflight.com/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "spendpreflight-spendpreflight": {
      "type": "http",
      "url": "https://api.spendpreflight.com/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.spendpreflight-spendpreflight]
url = "https://api.spendpreflight.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "spendpreflight-spendpreflight": {
      "type": "remote",
      "url": "https://api.spendpreflight.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add spendpreflight-spendpreflight --url 'https://api.spendpreflight.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  spendpreflight-spendpreflight:
    url: "https://api.spendpreflight.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "spendpreflight-spendpreflight": {
      "Transport": "http",
      "Url": "https://api.spendpreflight.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add spendpreflight-spendpreflight -t streamable-http -u 'https://api.spendpreflight.com/mcp'
```

### Other

```json
{
  "mcpServers": {
    "spendpreflight-spendpreflight": {
      "type": "http",
      "url": "https://api.spendpreflight.com/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-24 (score 74, 0)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “check_listing” rewrote its description, which is the text the model reads
- [security] Tool “lint_endpoint” rewrote its description, which is the text the model reads
- [security] Tool “listing_guard” rewrote its description, which is the text the model reads
- [security] Tool “check_token” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 1590 → 1853
- [functional] New tool “check_listing”
- [cosmetic] Tool “check_listing” changed its title: Bazaar Listing Guard → Listing Guard compatibility alias

### 2026-10-23 (score 74, −1)

- [functional regression] Tool coverage: 92% → 39%
- [functional regression] Schema quality: 1112 → 1590
- [functional regression] Tool coverage: 80% → 44%
- [functional] Schema quality: excellent → good
- [functional] New tool “check_token”
- [functional] New tool “find_rv_stations”
- [functional] New tool “listing_guard”
- [functional] New tool “size_solar”

### 2026-10-21 (score 75, +1)

No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-19 (score 74, 0)

- [functional regression] Tool coverage: 100% → 80%
- [functional regression] Tool coverage: 100% → 92%
- [functional] New tool “lint_endpoint”

### 2026-10-18 (score 74, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-16 (score 73, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-15 (score 72, 0)

- [security] Tool “check_payee” rewrote its description, which is the text the model reads
- [security] Tool “get_service_info” rewrote its description, which is the text the model reads
- [security] Tool “preflight_payment” rewrote its description, which is the text the model reads

### 2026-10-14 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (10)

### `listing_guard` (~109 tokens)

Bazaar Listing Guard

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.

Input parameters:

- `method` (string, required)
- `url` (string, required)

### `check_listing` (~139 tokens)

Listing Guard compatibility alias

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.

Input parameters:

- `method` (string, required)
- `url` (string, required)

### `find_rv_stations` (~114 tokens)

FillPoint archived station proximity

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.

Input parameters:

- `latitude` (number, required)
- `limit` (integer)
- `longitude` (number, required)
- `radius_km` (number)
- `service` (string)

### `size_solar` (~117 tokens)

Wattpath solar energy-balance estimate

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.

Input parameters:

- `battery` (object)
- `inverter_efficiency` (number)
- `loads` (array, required)
- `panel_watts` (number)
- `peak_sun_hours` (number, required)
- `pv_loss_fraction` (number, required)

### `check_token` (~164 tokens)

Base token / contract safety signals

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.

Input parameters:

- `address` (string, required)
- `chain` (string)
- `tier` (string)

### `lint_endpoint` (~130 tokens)

Free x402 Lint

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.

Input parameters:

- `url` (string, required)

### `check_payee` (~198 tokens)

Check payee before paying

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).

Input parameters:

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

Output parameters:

- `data_as_of` (string): Timestamp of the sanctions data used
- `disclaimer` (string)
- `domain`: Domain age/DNS signals, or null if no domain given
- `flags` (array): e.g. sanctioned_address, sanctioned_name_exact, sanctioned_name_possible, new_domain, domain_no_dns
- `risk` (string): Overall payee risk
- `sanctions` (object): OFAC SDN matches

### `preflight_payment` (~307 tokens)

Preflight a payment (allow / hold / block)

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).

Input parameters:

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

Output parameters:

- `chosen_option`: The cheapest acceptable payment option
- `decision` (string): Pay on allow, ask a human on hold, never pay on block
- `index_evidence` (object)
- `options_evaluated` (integer)
- `payee`: Payee screening details
- `reasons` (array): Every rule that fired, prefixed with its decision
- `receipt` (object): Signed decision; keep privately for audit

### `check_endpoint` (~195 tokens)

Read an x402 endpoint's observed health

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.

Input parameters:

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

Output parameters:

- `assessment` (object)
- `category` (string)
- `components` (object)
- `data_as_of` (string)
- `disclaimer` (string)
- `history` (array)
- `method` (string)
- `methodology` (string)
- `observed_at` (string|null)
- `operator` (string)
- `score`
- `sources` (array)
- `url` (string)

### `get_service_info` (~104 tokens)

SpendPreflight: pricing, defaults, how to pay

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.

Output parameters:

- `client_guard` (string)
- `default_rules` (object)
- `disclaimer` (string)
- `example_call` (object)
- `example_note` (string)
- `free_trial_per_day` (number)
- `guarantees` (array)
- `guidance_version` (string)
- `http_api` (object)
- `payment` (object)
- `pricing` (object)
- `site` (string)
- `trust` (object)
- `when_to_use` (string)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/spendpreflight-spendpreflight/api#diagnostics

## Score history

- 2026-10-24: 74
- 2026-10-23: 74
- 2026-10-22: 75
- 2026-10-21: 75
- 2026-10-20: 74
- 2026-10-19: 74
- 2026-10-18: 74
- 2026-10-17: 73
- 2026-10-16: 73
- 2026-10-15: 72
- 2026-10-14: 72
- 2026-10-13: 71
- 2026-10-12: 71
- 2026-10-11: 70
- 2026-10-10: 70
- 2026-10-07: 69

## Common questions

### What is the SpendPreflight MCP server?

SpendPreflight is an MCP server listed in the public MCP registry as io.github.spendpreflight/spendpreflight. Operated by SpendPreflight: free x402 Lint risk scores, paid Listing Guard and seller monitoring. This page covers its hosted endpoint (https://api.spendpreflight.com/mcp).

### Is the SpendPreflight MCP server safe to use?

SpendPreflight scores 74 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the SpendPreflight MCP server expose?

SpendPreflight exposes 10 tools: listing_guard, check_listing, find_rv_stations, size_solar, check_token, and 5 more. Their descriptions and schemas cost roughly 1,577 tokens of context every time the server is loaded.

### Does the SpendPreflight MCP server require authentication?

No. We connected to SpendPreflight without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the SpendPreflight MCP server still maintained?

SpendPreflight is still listed as active in the MCP registry. We last reached this channel on 24 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://api.spendpreflight.com/mcp
- Website: https://spendpreflight.com/
- Changelog RSS feed: https://verifymcp.io/servers/spendpreflight-spendpreflight/api.xml
- Changelog JSON feed: https://verifymcp.io/servers/spendpreflight-spendpreflight/api.json
- HTML version of this page: https://verifymcp.io/servers/spendpreflight-spendpreflight/api