# MQTT SRV Record Lookup via Cloudflare DoH

> MQTT SRV Record Lookup via Cloudflare DoH is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Resolves _mqtt._tcp.<domain> SRV DNS records to discover the host, port, priority, and weight of a domain's MQTT broker service.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/srv/mqtt-tcp?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mqtt-srv-record-lookup-via-cloudflare-doh-7d3fdd6e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cO3rfnvgWEgfOt9qnybp-

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 mqtt-srv-record-lookup-via-cloudflare-doh-7d3fdd6e
```

Example prompt: Look up the MQTT SRV DNS record for example.com so I can find out which host and port the MQTT broker is running on.

## When to prefer this

Use this endpoint when you need to programmatically discover a domain's MQTT broker connection details (host and port) via standard DNS SRV service discovery, rather than hardcoding broker addresses. Ideal for IoT agents, automation workflows, or dynamic client configuration that must respect published DNS service records. Prefer this over generic DNS lookup tools when the specific service type is MQTT over TCP.

## Known failure modes

- No SRV record found for domain — MQTT service not advertised in DNS
- Domain does not exist or NXDOMAIN response
- Cloudflare DoH upstream timeout or unavailability
- Malformed domain input causing DNS query failure
- Domain exists but has no _mqtt._tcp SRV records configured

## How this service works

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

## Output

Returns SRV DNS record data for _mqtt._tcp.<domain> including one or more records each containing: priority (integer), weight (integer), port (integer), and target hostname. Sourced from Cloudflare DoH for reliability and speed.

## 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/mqtt-srv-record-lookup-via-cloudflare-doh-7d3fdd6e/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)