Reverse DNS

Request a reverse DNS (PTR) name for one of your server's IP addresses, and see the requests that are still open. Requesting needs manage; reading needs read.

Request a reverse DNS name

POST /servers/{id}/rdns asks for ip to resolve to hostname. Needs an Idempotency-Key. The change is not made during your request: it is queued and applied shortly after, the same way as a request made in the client area.

curl -sS -X POST https://api.redswitches.com/v1/servers/srv_123/rdns \
  -H "Authorization: Bearer $REDSWITCHES_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"ip":"203.0.113.10","hostname":"mail.example.com"}'

const req = await rs.rdns.set("srv_123", { ip: "203.0.113.10", hostname: "mail.example.com" });

req = client.rdns.set("srv_123", ip="203.0.113.10", hostname="mail.example.com")

req, err := client.RDNS.Set(ctx, "srv_123", &redswitches.RDNSRequest{IP: "203.0.113.10", Hostname: "mail.example.com"})

{
  "server_id": "srv_123",
  "ip": "203.0.113.10",
  "hostname": "mail.example.com",
  "state": "pending",
  "already_requested": false
}

The answer is 202 Accepted. already_requested is true when the same name was already waiting for that IP; nothing new is queued then.

Rules:

• One open request per IP address.
• At most 20 requests per server per day. Over that: 429 action_limit with details.limit and details.per: "server_day".
• The server must be active: otherwise 409 server_not_active.
• The IP must be on the server: otherwise 422 ip_not_on_server.
• hostname "" clears the PTR record.

Changes carried out as actions

On some servers the change is carried out as an action, and clearing a name (hostname "") always is. The answer is then a 202 with an action id to follow with GET /actions/{id}:

{
  "id": "act_42",
  "server_id": "srv_123",
  "ip": "203.0.113.10",
  "hostname": "mail.example.com",
  "state": "queued",
  "already_requested": false,
  "poll_after": 10
}

For those changes: the same IP with another hostname while a change is still open answers 409 server_busy; the same hostname again returns the open action with already_requested: true. Other servers keep the pending answer above. Use the id field to tell the two answers apart: only the action answer has one.

List open requests

GET /servers/{id}/rdns returns this server's requests made by your account that are pending or applied.

curl -sS https://api.redswitches.com/v1/servers/srv_123/rdns \
  -H "Authorization: Bearer $REDSWITCHES_API_KEY"

const { data } = await rs.rdns.list("srv_123");

requests = client.rdns.list("srv_123").data

list, err := client.RDNS.List(ctx, "srv_123")

{
  "server_id": "srv_123",
  "data": [
    {
      "ip": "203.0.113.10",
      "hostname": "mail.example.com",
      "state": "pending",
      "requested": "2026-11-15T09:30:00Z",
      "action_id": null
    }
  ]
}

Changes carried out as actions appear too (the newest 20); their state is that action's state: queued, running, done, failed or unknown. The list holds the job's requests first (oldest first), then the action changes (newest first): to find the newest entry for an IP, sort by requested.