# cloudPulsePoint DNSBL Blacklist Checker

> cloudPulsePoint DNSBL Blacklist Checker is a paid API for AI agents from x402.cloudpulsepoint.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-15).

Resolves a site's IP address and checks it against 15 major DNS-based spam/abuse blacklists, returning a severity rating (OK, WARN, or DOWN) based on how many lists it appears on.

## Facts

- Endpoint: POST https://x402.cloudpulsepoint.com/agent/check/blacklist
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cloudpulsepoint-dnsbl-blacklist-checker-7da85062
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ob2NDRFeej-PVmzVAHcJ7

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

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability cloudpulsepoint-dnsbl-blacklist-checker-7da85062 -d '<json body>'
```

Example prompt: Before I start sending emails from my server at https://mail.mycompany.com, can you check its IP against the major spam and abuse blacklists to see if it's listed anywhere?

## When to prefer this

Use this endpoint when you need to verify the spam or abuse reputation of a host's IP before sending email from it, trusting inbound connections, or onboarding a new mail relay. It consolidates 15 DNSBL lookups into a single call with a clear severity rating, saving the overhead of querying each blacklist individually. Prefer this over generic DNS lookup endpoints when the specific concern is spam/abuse reputation rather than simple record resolution.

## Known failure modes

- HTTP 400 if the URL resolves to a private, loopback, link-local, or cloud-metadata IP address
- HTTP 400 if the URL is malformed or unparseable
- DNS resolution failure if the hostname does not exist
- Timeout if DNSBL query responses are slow
- False negatives if a blacklist is temporarily unavailable during the check

## How this service works

Resolve the site's IP and check it against 15 major DNSBL spam/abuse blacklists. Use before sending mail from, or trusting, a host. WARN = listed on 1–2 lists; DOWN = listed on 3 or more.

## Output

Returns the resolved IP address of the host, the number of DNSBL lists it appears on out of 15 checked, and a severity rating: OK (not listed), WARN (listed on 1–2 lists), or DOWN (listed on 3 or more lists), along with which specific blacklists flagged the IP.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "Full http(s) URL of the site to check, e.g. \"https://example.com\". Must resolve to a public address — private, loopback, link-local, and cloud-metadata targets are rejected with HTTP 400 before any payment."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cloudpulsepoint-dnsbl-blacklist-checker-7da85062/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.cloudpulsepoint.com](https://www.zero.xyz/host/x402.cloudpulsepoint.com/llms.txt)