Uploading calls

Uploads are multipart/form-data to a project:

curl -X POST "$BASE/v1/projects/$PROJECT_ID/calls/upload" \
  -H "X-API-Key: $AFTERTALK_KEY" \
  -F "file=@call.wav"

The response is 202 Accepted with a job id — processing happens in the background. See getting results.

Supported audio

An unsupported format or an oversized file returns 400. Send the right Content-Type for the part — that's what the check uses, not the file extension.

Mapping speakers to roles

For stereo recordings where each channel is one party, pass channel_roles as a JSON object mapping channel index to a role. The transcript then attributes each segment to a named role instead of "Speaker 1":

curl -X POST "$BASE/v1/projects/$PROJECT_ID/calls/upload" \
  -H "X-API-Key: $AFTERTALK_KEY" \
  -F "file=@call.wav" \
  -F 'channel_roles={"0":"agent","1":"customer"}'

To reuse the same mapping across a project, configure a speaker preset and skip the parameter.

Duplicate uploads

Uploads are de-duplicated per project by the audio's content hash. Re-sending bytes that already exist in the project returns 409 Conflict with the id of the original job:

{
  "existingJobId": "8f14e45f-ea0f-4e21-9c1a-2b3c4d5e6f70",
  "existingFilename": "call.wav",
  "code": "DUPLICATE_FILE"
}

This makes retries safe: if a request times out and you send it again, you get a 409 pointing at the job that already exists instead of a second charge. Treat 409 as success and continue with existingJobId:

const res = await fetch(uploadUrl, { method: 'POST', headers, body: form });

if (res.status === 409) {
  const { existingJobId } = await res.json();
  return existingJobId; // already uploaded — carry on
}
const { jobId } = await res.json();
return jobId;

A previously failed upload doesn't block a retry — you can re-send the same audio after a failure. To upload identical audio deliberately, add force=true, which skips the duplicate check and creates a separate call.

Insufficient balance

If the organization has no audio allowance left, the upload is rejected with 402 Payment Required before the file is stored. See rate limits and billing.