# esyURL Custom Domain Registration

> esyURL Custom Domain Registration is a paid API for AI agents from esyurl.fyi, paid per call via x402, $5/call, status unknown (last checked 2026-10-10).

Registers a custom domain (e.g. go.acme.com) with esyURL so it can be used for branded short links, returning DNS records required to validate ownership and provision a certificate.

## Facts

- Endpoint: PUT https://esyurl.fyi/v1/domain?utm_source=zero.xyz
- Price: $5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/esyurl-custom-domain-registration-19c3f5d7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MD1DZWdO_T9QSaLU_oNTd

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 esyurl-custom-domain-registration-19c3f5d7 -d '<json body>'
```

Example prompt: Register go.acme.com as a custom domain on esyURL so I can use it for branded short links — give me the DNS records I need to add to verify it.

## When to prefer this

Use this endpoint when you need to attach a user-controlled domain (e.g. go.company.com) to esyURL for branded short links and QR codes. It is the first step in the custom domain setup flow; prefer it over generic domain registration APIs because it integrates directly with esyURL's link routing, certificate provisioning, and analytics pipeline.

## Known failure modes

- Domain already registered to another account — conflict error
- Invalid domain format — validation error on input
- DNS records not yet created — domain stays in pending_validation state
- Payment failure — x402 payment required before processing
- Domain not publicly resolvable — may cause certificate provisioning issues

## How this service works

esyURL: short links, QR codes, redirect rules, custom domains and visit analytics, managed by your AI agent over MCP or REST. Since 2007.

## Output

Returns the domain name, a status of 'pending_validation', and an array of DNS records (name, type, value, purpose) that must be created at the DNS registrar to prove ownership and provision a TLS certificate. Also includes a human-readable instruction string explaining the next step (GET /v1/domain to advance setup).

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "description": "A domain you control, e.g. go.acme.com"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "PUT"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "bodyType": {
     "enum": [
      "json"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "domain": "go.example.com",
  "status": "pending_validation",
  "dnsRecords": [
   {
    "done": false,
    "name": "_acme-challenge.go.example.com",
    "type": "TXT",
    "value": "...",
    "purpose": "certificate_validation"
   }
  ],
  "instructions": "Create the DNS records listed, then GET /v1/domain to move the setup forward."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/esyurl-custom-domain-registration-19c3f5d7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from esyurl.fyi](https://www.zero.xyz/host/esyurl.fyi/llms.txt)