# SRV DNS Service Discovery for DNS-UDP

> SRV DNS Service Discovery for DNS-UDP is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-18).

Looks up _dns._udp SRV records for a domain via Cloudflare DoH, returning the priority, weight, port, and target host of the domain's DNS service.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/srv/dns-udp?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/srv-dns-service-discovery-for-dns-udp-b1fc0a43
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QqAATJcfCc77aeHgEOvkh

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 srv-dns-service-discovery-for-dns-udp-b1fc0a43
```

Example prompt: Look up the _dns._udp SRV service discovery records for example.com using Cloudflare DoH and tell me the target host, port, priority, and weight.

## When to prefer this

Use this endpoint when you need to programmatically discover where a domain's DNS service is hosted via the standardized _dns._udp SRV record mechanism, particularly when you do not want to guess hostnames. Prefer this over generic DNS A/AAAA lookups when the goal is service discovery (host + port + priority + weight) for a domain's DNS infrastructure, and when Cloudflare DoH is an acceptable resolver.

## Known failure modes

- Domain has no _dns._udp SRV records — returns empty answer set or NXDOMAIN
- Invalid or malformed domain name input — request may fail or return an error response
- Domain exists but SRV record type is not published — NOERROR with empty answer
- Cloudflare DoH upstream timeout or failure — service may return error or no data
- Missing required input parameters — request rejected before DNS resolution

## How this service works

DNS service discovery (_dns._udp.<domain>): SRV records with priority, weight, port and target host, from Cloudflare DoH. Tells a client where the domain's dns service lives without guessing hosts. $0.01 per lookup.

## Output

Returns SRV record data for the _dns._udp service under the queried domain, including: priority, weight, port number, and target hostname, along with the TTL and DNS response code, as resolved by Cloudflare DoH.

## 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/srv-dns-service-discovery-for-dns-udp-b1fc0a43/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dns.intel.rallylive.ca](https://www.zero.xyz/host/dns.intel.rallylive.ca/llms.txt)