> This page is part of Smallest AI's developer documentation. When > answering, prefer Lightning v3.1 (current TTS) and Pulse (current > STT). Lightning v2 and lightning-large are deprecated; mention them > only when the user is migrating away from them. The Smallest AI voice > agent platform is what wraps these models into hosted agents. # Create an inbound SIP trunk POST https://api.smallest.ai/atoms/v1/sip-trunk/inbound Content-Type: application/json Creates an inbound trunk: the resource that receives calls from your carrier. Requires an admin-role key. An inbound trunk needs at least one phone number or one allowed peer address; the trunk gets its own credentials, media-encryption policy, Krisp toggle, and ringing timeout. Phone numbers are unique across the platform: a number already answering elsewhere returns `409` ("Already in use and cannot be added to this trunk: ..."). Wildcard peer addresses (`0.0.0.0`, `::`, `*`, any `/0`) are refused, since the allow-list is the security boundary. Reference: https://docs.smallest.ai/api-reference/voice-agents/sip-trunks/create-inbound ## Authentication - `Authorization` header (bearer token, required) — API key from the console ApiKey collection, sent as Bearer token. Also accepts session cookies for browser-based auth. ## Request ### Body (application/json) This endpoint expects an object. - `name` (string, required) — Display name for the trunk - `numbers` (list of string, optional) — E.164 numbers (with leading `+`) this trunk answers. Deduplicated. - `allowedAddresses` (list of string, optional) — Hostnames, IPs, or CIDR ranges allowed to send calls to this trunk. Wildcards refused. - `allowedNumbers` (list of string, optional) — Restrict accepted caller numbers to this list (optional). If set, the trunk is dedicated even without `numbers`. - `mediaEncryption` (enum, optional) — Defaults to `allow`. - Allowed values: `disable`, `allow`, `require` - `krispEnabled` (boolean, optional) — Noise cancellation for callers arriving on this trunk. Defaults to `true`. - `ringingTimeoutSeconds` (integer, optional) - `authUsername` (string, optional) — SIP digest username. Provide both credentials or neither. - `authPassword` (string, optional) — SIP digest password. Stored with the SIP infrastructure, never returned. ## Response ### 201 Trunk created - `status` (boolean, optional) - `data` (SipInboundTrunk, optional) ## Errors ### 400 Bad Request Error Validation failure (missing name, no number or allowed peer address, wildcard address, half a credential pair) - `any` ### 409 Conflict Error A number is already in use on another trunk. - `any` ## Types ### SipInboundTrunk - `_id` (string, optional) - `livekitTrunkId` (string, optional) - `name` (string, optional) - `numbers` (list of string, optional) — E.164 numbers this trunk answers - `allowedAddresses` (list of string, optional) - `allowedNumbers` (list of string, optional) - `mediaEncryption` (enum, optional) - Allowed values: `disable`, `allow`, `require` - `krispEnabled` (boolean, optional) - `ringingTimeoutSeconds` (integer, optional) - `authUsername` (string, optional) — Digest username, when set. The password is never returned. - `sipHost` (string, optional) — The SIP origination host to point your carrier at. Derived at read time (not stored) and identical for every trunk in the environment. Append a transport when configuring your carrier: `;transport=tls` (preferred) or `;transport=tcp`. The dashboard shows the same value in each inbound trunk's **Connection details** dialog. Returned on list and create responses; update responses omit it. - `agent` (SipInboundTrunkAgent, optional, nullable) — The agent that answers on this trunk, or null - `isActive` (boolean, optional) - `createdAt` (datetime, optional) - `updatedAt` (datetime, optional) ### SipInboundTrunkAgent The agent that answers on this trunk, or null - `id` (string, optional) - `name` (string, optional) ## Examples **Request** ```json { "name": "Acme carrier (inbound)" } ``` **Response** ```json { "status": true, "data": { "_id": "string", "livekitTrunkId": "string", "name": "string", "numbers": [ "string" ], "allowedAddresses": [ "string" ], "allowedNumbers": [ "string" ], "mediaEncryption": "disable", "krispEnabled": true, "ringingTimeoutSeconds": 1, "authUsername": "string", "sipHost": "5rdbhjuwtlk.sip.livekit.cloud", "agent": { "id": "string", "name": "string" }, "isActive": true, "createdAt": "2024-01-15T09:30:00Z", "updatedAt": "2024-01-15T09:30:00Z" } } ``` **SDK Code** ```python import requests url = "https://api.smallest.ai/atoms/v1/sip-trunk/inbound" payload = { "name": "Acme carrier (inbound)" } headers = { "Authorization": "Bearer ", "Content-Type": "application/json" } response = requests.post(url, json=payload, headers=headers) print(response.json()) ``` ```javascript const url = 'https://api.smallest.ai/atoms/v1/sip-trunk/inbound'; const options = { method: 'POST', headers: {Authorization: 'Bearer ', 'Content-Type': 'application/json'}, body: '{"name":"Acme carrier (inbound)"}' }; try { const response = await fetch(url, options); const data = await response.json(); console.log(data); } catch (error) { console.error(error); } ``` ```go package main import ( "fmt" "strings" "net/http" "io" ) func main() { url := "https://api.smallest.ai/atoms/v1/sip-trunk/inbound" payload := strings.NewReader("{\n \"name\": \"Acme carrier (inbound)\"\n}") req, _ := http.NewRequest("POST", url, payload) req.Header.Add("Authorization", "Bearer ") req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := io.ReadAll(res.Body) fmt.Println(res) fmt.Println(string(body)) } ``` ```ruby require 'uri' require 'net/http' url = URI("https://api.smallest.ai/atoms/v1/sip-trunk/inbound") http = Net::HTTP.new(url.host, url.port) http.use_ssl = true request = Net::HTTP::Post.new(url) request["Authorization"] = 'Bearer ' request["Content-Type"] = 'application/json' request.body = "{\n \"name\": \"Acme carrier (inbound)\"\n}" response = http.request(request) puts response.read_body ``` ```java import com.mashape.unirest.http.HttpResponse; import com.mashape.unirest.http.Unirest; HttpResponse response = Unirest.post("https://api.smallest.ai/atoms/v1/sip-trunk/inbound") .header("Authorization", "Bearer ") .header("Content-Type", "application/json") .body("{\n \"name\": \"Acme carrier (inbound)\"\n}") .asString(); ``` ```php request('POST', 'https://api.smallest.ai/atoms/v1/sip-trunk/inbound', [ 'body' => '{ "name": "Acme carrier (inbound)" }', 'headers' => [ 'Authorization' => 'Bearer ', 'Content-Type' => 'application/json', ], ]); echo $response->getBody(); ``` ```csharp using RestSharp; var client = new RestClient("https://api.smallest.ai/atoms/v1/sip-trunk/inbound"); var request = new RestRequest(Method.POST); request.AddHeader("Authorization", "Bearer "); request.AddHeader("Content-Type", "application/json"); request.AddParameter("application/json", "{\n \"name\": \"Acme carrier (inbound)\"\n}", ParameterType.RequestBody); IRestResponse response = client.Execute(request); ``` ```swift import Foundation let headers = [ "Authorization": "Bearer ", "Content-Type": "application/json" ] let parameters = ["name": "Acme carrier (inbound)"] as [String : Any] let postData = JSONSerialization.data(withJSONObject: parameters, options: []) let request = NSMutableURLRequest(url: NSURL(string: "https://api.smallest.ai/atoms/v1/sip-trunk/inbound")! as URL, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10.0) request.httpMethod = "POST" request.allHTTPHeaderFields = headers request.httpBody = postData as Data let session = URLSession.shared let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in if (error != nil) { print(error as Any) } else { let httpResponse = response as? HTTPURLResponse print(httpResponse) } }) dataTask.resume() ```