# SYNTHORA DNS HTTPS/SVCB Record Resolver (DoH)

> SYNTHORA DNS HTTPS/SVCB Record Resolver (DoH) is a paid API for AI agents from doh-https-svcb-record.hergertsynthora.com, paid per call via x402, $0.0015/call, status unknown (last checked 2026-09-13).

Resolves HTTPS/SVCB DNS records (type 65) for a domain via Google DoH JSON, returning ALPN protocols, IPv4/IPv6 hints, and ECH config

## Facts

- Endpoint: POST https://doh-https-svcb-record.hergertsynthora.com/service
- Price: $0.0015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-dns-https-svcb-record-resolver-doh-cee50092
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dLW7NaknswRP-0MVDBjUf

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 synthora-dns-https-svcb-record-resolver-doh-cee50092 -d '<json body>'
```

Example prompt: Look up the HTTPS/SVCB DNS records for cloudflare.com and tell me whether it supports HTTP/3 and ECH, and what IPv4 and IPv6 hints it advertises.

## When to prefer this

Use this endpoint when an agent needs to determine HTTP/3 (QUIC) or ECH support for a domain before establishing a connection, or when building connection-optimizing logic that reads ALPN and IP hint data from DNS. Prefer this over generic DNS resolvers when you specifically need type-65 HTTPS/SVCB records rather than A, AAAA, or MX records. It is ideal for TLS fingerprinting, pre-connection protocol negotiation, and infrastructure analysis workflows.

## Known failure modes

- Domain does not have HTTPS/SVCB records — returns empty records array
- Invalid or malformed domain name causes query failure
- Upstream Google DoH service is unreachable or rate-limits the request
- Non-existent domain returns NXDOMAIN with no records
- Network timeout from the resolver service

## How this service works

Returns HTTPS (type 65 / SVCB) records exposing ALPN protocols (h3, h2), IPv4/IPv6 hints and ECH config for a host via Google DoH JSON. A2A use: connection-optimizing and TLS-fingerprinting agents detect HTTP/3 support and encrypted-client-hello readiness before dialing. First 3 calls FREE per wallet — send header X-WALLET: 0x<addr>. No charge on upstream failure.

## Output

Returns a JSON object with ok:true, the queried domain, an array of HTTPS/SVCB DNS records each containing TTL, record name, type (65), and a value string showing priority, ALPN protocols (e.g. h3,h2), IPv4 hints, IPv6 hints, and ECH config, plus provenance metadata pointing to Google DoH.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domain": {
   "type": "string",
   "description": "domain"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "doh-https-svcb-record",
  "result": {
   "domain": "cloudflare.com",
   "records": [
    {
     "ttl": 300,
     "name": "cloudflare.com.",
     "type": 65,
     "value": "1 . alpn=h3,h2 ipv4hint=104.16.132.229,104.16.133.229 ipv6hint=2606:4700::6810:84e5,2606:4700::6810:85e5"
    }
   ]
  },
  "provenance": {
   "url": "https://dns.google/resolve",
   "source": "DNS HTTPS/SVCB Record Resolver (DoH)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-dns-https-svcb-record-resolver-doh-cee50092/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from doh-https-svcb-record.hergertsynthora.com](https://www.zero.xyz/host/doh-https-svcb-record.hergertsynthora.com/llms.txt)