POST /api/v2/recording-sessions/{sessionId}/start returns 400 Bad Request

NICE CXone API & Integrations
1

What is the reason the Genesys Cloud Recording API rejects my start command with a 400 error when the session ID is clearly valid and active?

I am attempting to programmatically control call recordings via the REST API. I retrieve the session ID from the conversation webhook payload. The session status is active. I then attempt to trigger the recording.

Endpoint: POST /api/v2/recording-sessions/{sessionId}/start

Payload:

{
 "recordedUserIds": [
 "{userId1}",
 "{userId2}"
 ]
}

The response is consistently a 400 Bad Request with message: “Session is not in a state that allows starting recording.”

I have verified the following:

  • The OAuth token includes the recording:modify scope. The same token successfully lists recording sessions via GET.
  • The session ID corresponds to a live call. I waited 5 seconds after the conversation-started event before sending the request to ensure backend initialization.

I suspect a race condition or a specific status requirement I am missing. The documentation implies active is sufficient. Is there a hidden state check?

2

Have you tried validating the payload structure against the RecordingSessionStartRequest schema? I ran into this same 400 error while setting up a local mock server for my Docker Compose integration tests. The API is strict about the recordingType field, and omitting it or using an invalid enum value triggers the bad request response immediately.

Here is how I structure the call in my Node.js test harness using PureCloudPlatformClientV2:

const recordingApi = new PureCloudPlatformClientV2.RecordingApi();

const startRequest = new PureCloudPlatformClientV2.RecordingSessionStartRequest({
 recordingType: 'call', // Must be 'call', 'screen', or 'co-browse'
 recordingFormat: 'wav' // Optional, but good to specify
});

try {
 const response = await recordingApi.postRecordingSessionStart(sessionId, {
 body: startRequest
 });
 console.log('Recording started:', response);
} catch (error) {
 console.error('Failed to start recording:', error.response?.data || error.message);
}

Key things to check in your setup:

  • Payload Validation: Ensure you are sending a JSON body with recordingType. Sending an empty body {} or null causes a 400.
  • Session State: The session must be in active state. If the call ended before the API call completed, the status might have changed to completed. Add a retry mechanism or check the status first via GET /api/v2/recording-sessions/{sessionId}.
  • Permissions: Your OAuth token needs the recording:session:write scope. I usually verify this in my Terraform genesyscloud_oauth_client configuration to ensure the client has the correct permissions.
  • Content-Type: Explicitly set Content-Type: application/json in your headers. Some HTTP clients default to x-www-form-urlencoded, which the Genesys API rejects for this endpoint.

In my local Docker environment, I mock the Genesys API to return a 202 Accepted with a valid recording ID once the payload matches. This helps isolate whether the issue is network-related or payload-related. Check your request logs to see exactly which field the API is complaining about.

3

the suggestion above regarding recordingType is correct, but the 400 error often persists if the sessionUri or mediaTypes are not explicitly defined in the payload. the RecordingSessionStartRequest schema requires precise alignment with the active conversation’s media capabilities. if you omit mediaTypes, the API cannot determine which tracks to record, resulting in validation failure.

here is the exact JSON payload structure that works with the PureCloudPlatformClientV2 SDK. ensure you map the mediaTypes to the actual conversation channels (e.g., audio, screen, chat).

{
 "recordingType": "call",
 "mediaTypes": ["audio"],
 "sessionUri": "https://api.mypurecloud.com/api/v2/conversations/{conversationId}"
}

in my reporting pipelines, I also enforce the recordingSession scope. without it, the token lacks permission to mutate the recording state, which sometimes returns a misleading 400 instead of a 403. check your OAuth token scopes.

if you are using the Node.js SDK, the method call looks like this:

const RecordingApi = PureCloudPlatformClientV2.RecordingApi;
const recordingApi = new RecordingApi();

const startRequest = {
 recordingType: "call",
 mediaTypes: ["audio"],
 sessionUri: conversationUri
};

recordingApi.postRecordingSessionsSessionIdStart(sessionId, startRequest)
 .then((data) => console.log("Recording started:", data))
 .catch((error) => console.error("API Error:", error.response.data));

verify that the sessionUri matches the conversation ID exactly. mismatched URIs cause the server to reject the request because it cannot locate the active session context. also, ensure the recording session is not already in a recording state. attempting to start an already recording session returns 400. check the current status via GET /api/v2/recording-sessions/{sessionId} before posting the start command.