> 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. # Get a time-limited recording download URL (legacy) GET https://api.smallest.ai/atoms/v1/conversation/{callId}/recording/download-url **Legacy.** Prefer [`GET /recordings/{callId}`](#get-a-presigned-recording-download-url) for new integrations. It supports both mono and dual channels via `?channel=mono|dual` and uses the same authenticated flow. Returns a presigned S3 URL for the call's mono composite recording. Hand the URL straight to the customer or pull bytes server-side. The presigned URL is time-limited to 15 minutes (same TTL as the new endpoint); do not cache it, request a fresh one each time you need the recording. Returns `404` if the call has no recording (call hasn't started, was cancelled before audio captured, or was deleted by the platform's retention policy). Returns `400 Invalid call ID format` if `callId` does not match the expected pattern. Reference: https://docs.smallest.ai/api-reference/voice-agents/conversations/get-a-time-limited-recording-download-url-legacy ## 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 ### Path parameters - `callId` (string, required) — The `callId` string for the conversation (e.g. `CALL-1778226705739-7e4c17`). This is the `callId` field returned by `GET /conversation`. ## Response ### 200 Successful response — presigned URL ready to fetch. - `status` (boolean, optional) - `data` (ConversationCallIdRecordingDownloadUrlGetResponsesContentApplicationJsonSchemaData, optional) ## Errors ### 400 Bad Request Error Invalid call ID format. - `any` ### 401 Unauthorized Error Unauthorized access - `status` (boolean, optional) - `errors` (list of string, optional) ### 404 Not Found Error No recording found for this call. - `any` ### 500 Internal Server Error Internal server error - `status` (boolean, optional) - `errors` (list of string, optional) ## Types ### ConversationCallIdRecordingDownloadUrlGetResponsesContentApplicationJsonSchemaData - `presignedUrl` (string, optional) — Time-limited HTTPS URL pointing at the recording in S3. The URL expires after a short window; request a fresh one if needed. ## Examples **Response** ```json { "status": true, "data": { "presignedUrl": "string" } } ``` **SDK Code** ```python import requests url = "https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url" headers = {"Authorization": "Bearer "} response = requests.get(url, headers=headers) print(response.json()) ``` ```javascript const url = 'https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url'; const options = {method: 'GET', headers: {Authorization: 'Bearer '}}; 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" "net/http" "io" ) func main() { url := "https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url" req, _ := http.NewRequest("GET", url, nil) req.Header.Add("Authorization", "Bearer ") 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/conversation/CALL-1781127346211-e765f7/recording/download-url") http = Net::HTTP.new(url.host, url.port) http.use_ssl = true request = Net::HTTP::Get.new(url) request["Authorization"] = 'Bearer ' response = http.request(request) puts response.read_body ``` ```java import com.mashape.unirest.http.HttpResponse; import com.mashape.unirest.http.Unirest; HttpResponse response = Unirest.get("https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url") .header("Authorization", "Bearer ") .asString(); ``` ```php request('GET', 'https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url', [ 'headers' => [ 'Authorization' => 'Bearer ', ], ]); echo $response->getBody(); ``` ```csharp using RestSharp; var client = new RestClient("https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url"); var request = new RestRequest(Method.GET); request.AddHeader("Authorization", "Bearer "); IRestResponse response = client.Execute(request); ``` ```swift import Foundation let headers = ["Authorization": "Bearer "] let request = NSMutableURLRequest(url: NSURL(string: "https://api.smallest.ai/atoms/v1/conversation/CALL-1781127346211-e765f7/recording/download-url")! as URL, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10.0) request.httpMethod = "GET" request.allHTTPHeaderFields = headers 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() ```