# IP Listed on Lashback DNSBL

> IP Listed on Lashback DNSBL is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Checks whether an IPv4 address is listed on the Lashback Unsubscribe Blacklist (ubl.unsubscore.com) via a DNSBL lookup using Cloudflare DoH, returning listed status, return codes, and reason text.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/ip/blacklist/lashback?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ip-listed-on-lashback-dnsbl-cae4720f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5il4YewRWgd3H09x6s-SB

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 ip-listed-on-lashback-dnsbl-cae4720f
```

Example prompt: Can you check if the IP address 203.0.113.42 is listed on the Lashback unsubscribe blacklist (ubl.unsubscore.com)?

## When to prefer this

Choose this endpoint when you need a fast, precise, single-list check specifically against the Lashback Unsubscribe Blacklist (ubl.unsubscore.com). It is ideal for email deliverability pipelines, spam filtering decisions, and reputation audits where Lashback listing status is specifically relevant. Prefer this over generic multi-list checkers when you need authoritative reason codes from Lashback specifically.

## Known failure modes

- Invalid or non-routable IPv4 address returns an error
- DNS resolution failure via Cloudflare DoH returns an error
- IPv6 addresses are not supported
- Network timeout from Cloudflare DoH results in an error response
- IP not listed returns listed=false with no reason text

## How this service works

Is this IPv4 address listed on lashback (ubl.unsubscore.com)? Performs the DNSBL query (reversed octets under ubl.unsubscore.com, via Cloudflare DoH) and returns listed yes/no with the return codes and, where the list publishes one, the reason text. One list, one precise answer. $0.01 per lookup.

## Output

Returns a yes/no listing status for the queried IPv4 address on the Lashback UBL DNSBL, along with the raw DNSBL return codes and, where published by the list, a human-readable reason text explaining why the IP was listed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ip-listed-on-lashback-dnsbl-cae4720f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ip.intel.rallylive.ca](https://www.zero.xyz/host/ip.intel.rallylive.ca/llms.txt)