Transcribing Genesys Cloud Conversation Media Streams via Conversations API with Python SDK

Transcribing Genesys Cloud Conversation Media Streams via Conversations API with Python SDK

What You Will Build

  • A Python service that submits transcription jobs for Genesys Cloud conversation recordings, validates media constraints, triggers ASR processing with speaker diarization, and synchronizes results with external NLP pipelines via webhooks.
  • This uses the Genesys Cloud Conversations Transcripts API (/api/v2/conversations/{conversationId}/transcripts) and the official Python SDK.
  • The implementation is written in Python 3.10+ using purecloudplatformclientv2, httpx, fastapi, and pydantic.

Prerequisites

  • OAuth 2.0 Client Credentials flow with scopes: conversation:transcript:write, conversation:read, recording:read
  • Genesys Cloud Python SDK (purecloudplatformclientv2 >= 130.0.0)
  • Python 3.10+ runtime
  • External dependencies: httpx, pydantic, fastapi, uvicorn, structlog

Authentication Setup

Genesys Cloud uses OAuth 2.0 Client Credentials for server-to-server API access. You must cache the access token and refresh it before expiration. The following example demonstrates token retrieval with httpx and SDK initialization.

import httpx
import time
from typing import Optional
from purecloudplatformclientv2 import PlatformClient

class GenesysAuth:
    def __init__(self, environment: str, client_id: str, client_secret: str):
        self.base_url = f"https://{environment}.mypurecloud.com"
        self.token_endpoint = f"{self.base_url}/oauth/token"
        self.client_id = client_id
        self.client_secret = client_secret
        self._token: Optional[str] = None
        self._expires_at: float = 0.0

    def _fetch_token(self) -> dict:
        payload = {
            "grant_type": "client_credentials",
            "client_id": self.client_id,
            "client_secret": self.client_secret,
            "scope": "conversation:transcript:write conversation:read recording:read"
        }
        with httpx.Client() as client:
            response = client.post(self.token_endpoint, data=payload)
            response.raise_for_status()
            return response.json()

    def get_access_token(self) -> str:
        if self._token and time.time() < self._expires_at - 60:
            return self._token

        data = self._fetch_token()
        self._token = data["access_token"]
        self._expires_at = time.time() + data["expires_in"]
        return self._token

    def create_platform_client(self) -> PlatformClient:
        client = PlatformClient()
        client.set_access_token(self.get_access_token())
        client.set_base_url(self.base_url)
        return client

Implementation

Step 1: Media Constraint Validation and Format Verification

Before submitting a transcription job, you must validate the recording against Genesys Cloud media engine constraints. The platform rejects files exceeding four hours (14400 seconds), unsupported codecs, or invalid audio configurations. This step fetches recording metadata and validates sample rate, channel interleaving, and duration.

import logging
from typing import Dict, Any
from pydantic import BaseModel, ValidationError

logger = logging.getLogger(__name__)

class MediaConstraints(BaseModel):
    max_duration_seconds: int = 14400
    supported_formats: list[str] = ["wav", "mp3", "ogg", "flac"]
    min_sample_rate: int = 8000
    max_sample_rate: int = 48000
    supported_channels: list[int] = [1, 2]

def validate_recording_metadata(recording_id: str, media_id: str, client: PlatformClient) -> Dict[str, Any]:
    """Fetches recording details and validates against media engine constraints."""
    try:
        recordings_api = client.recordings_api
        recording = recordings_api.get_recording(recording_id)
    except Exception as e:
        raise RuntimeError(f"Failed to fetch recording {recording_id}: {str(e)}")

    constraints = MediaConstraints()
    
    # Duration validation
    if recording.media_duration_seconds > constraints.max_duration_seconds:
        raise ValueError(f"Recording exceeds maximum duration limit of {constraints.max_duration_seconds} seconds")

    # Format validation
    file_ext = recording.media_url.rsplit(".", 1)[-1].lower()
    if file_ext not in constraints.supported_formats:
        raise ValueError(f"Unsupported audio format: {file_ext}. Supported: {constraints.supported_formats}")

    # Sample rate and channel verification
    # Genesys Cloud recording object does not expose raw sample rate directly in the base model.
    # We simulate metadata extraction from the media manifest or assume standard telephony/conference specs.
    # In production, download a header snippet or use the /api/v2/recordings/{id}/media endpoint.
    assumed_sample_rate = 16000  # Standard ASR input
    assumed_channels = 1         # Mono is optimal for ASR; stereo requires interleaving verification
    
    if not (constraints.min_sample_rate <= assumed_sample_rate <= constraints.max_sample_rate):
        raise ValueError(f"Invalid sample rate: {assumed_sample_rate} Hz")
        
    if assumed_channels not in constraints.supported_channels:
        raise ValueError(f"Invalid channel configuration: {assumed_channels}")

    logger.info("Media validation passed for recording %s", recording_id)
    return {
        "media_id": media_id,
        "duration_seconds": recording.media_duration_seconds,
        "format": file_ext,
        "sample_rate": assumed_sample_rate,
        "channels": assumed_channels
    }

Step 2: Payload Construction and Atomic POST with ASR Model Selection

The transcript request requires a TranscriptRequest payload. You must specify the media ID, language code, speaker diarization directive, and ASR model. Genesys Cloud supports automatic ASR model selection when asr_model is omitted or set to auto. The following code constructs the payload and executes an atomic POST with retry logic for 429 rate limits.

import time
from purecloudplatformclientv2 import TranscriptRequest, ApiException

def submit_transcription_job(
    conversation_id: str,
    media_id: str,
    language_code: str = "en-US",
    enable_diarization: bool = True,
    asr_model: str = "auto",
    callback_url: str = "",
    client: PlatformClient = None
) -> dict:
    """Submits a transcription job with exponential backoff for rate limits."""
    transcripts_api = client.transcripts_api
    
    # Construct the transcript request payload
    request_body = TranscriptRequest(
        media_id=media_id,
        language_code=language_code,
        speaker_diarization=enable_diarization,
        asr_model=asr_model,
        callback_url=callback_url if callback_url else None
    )

    max_retries = 3
    base_delay = 2.0
    
    for attempt in range(max_retries):
        try:
            response = transcripts_api.post_conversation_transcripts(
                conversation_id=conversation_id,
                body=request_body
            )
            logger.info("Transcription job submitted successfully. Status: %s", response.status)
            return response.to_dict()
        except ApiException as e:
            if e.status == 429:
                wait_time = base_delay * (2 ** attempt)
                logger.warning("Rate limited (429). Retrying in %s seconds...", wait_time)
                time.sleep(wait_time)
                continue
            elif e.status in [400, 401, 403]:
                logger.error("Fatal API error %s: %s", e.status, e.body)
                raise
            else:
                logger.error("Unexpected error %s: %s", e.status, e.body)
                raise
    raise RuntimeError("Max retries exceeded for transcription job submission")

Step 3: Webhook Synchronization and External NLP Pipeline Alignment

Genesys Cloud pushes transcription events to the callback_url specified in the request. You must expose an endpoint to receive these events, extract the transcript data, and forward it to your external NLP pipeline. The following FastAPI route handles webhook synchronization, latency tracking, and audit logging.

from fastapi import FastAPI, Request
import asyncio
from datetime import datetime, timezone

app = FastAPI()

async def forward_to_nlp_pipeline(transcript_data: dict) -> None:
    """Simulates forwarding transcript data to an external NLP service."""
    logger.info("Forwarding transcript to NLP pipeline...")
    # In production, use httpx.AsyncClient to POST to your NLP endpoint
    await asyncio.sleep(0.1)  # Simulate network latency

@app.post("/webhooks/genesys/transcripts")
async def handle_transcript_webhook(request: Request):
    payload = await request.json()
    
    # Extract core transcript metadata
    conversation_id = payload.get("conversationId")
    transcript_id = payload.get("id")
    status = payload.get("status")
    created_at = payload.get("createdTime")
    completed_at = payload.get("updatedTime")
    
    if status != "completed":
        logger.info("Transcript %s status: %s. Ignoring.", transcript_id, status)
        return {"status": "accepted"}

    # Calculate processing latency
    if created_at and completed_at:
        start = datetime.fromisoformat(created_at.replace("Z", "+00:00"))
        end = datetime.fromisoformat(completed_at.replace("Z", "+00:00"))
        latency_seconds = (end - start).total_seconds()
    else:
        latency_seconds = 0.0

    # Extract word count for WER tracking baseline
    utterances = payload.get("utterances", [])
    total_words = sum(len(u.get("text", "").split()) for u in utterances)
    
    # Generate audit log entry
    audit_entry = {
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "conversation_id": conversation_id,
        "transcript_id": transcript_id,
        "status": status,
        "latency_seconds": latency_seconds,
        "total_words": total_words,
        "speaker_count": len(set(u.get("speaker", "unknown") for u in utterances))
    }
    logger.info("AUDIT: %s", audit_entry)

    # Synchronize with external NLP pipeline
    await forward_to_nlp_pipeline(payload)
    
    # Calculate placeholder WER metric (requires reference text in production)
    # WER = (Substitutions + Deletions + Insertions) / Total Reference Words
    # We log the metric structure for compliance tracking
    wer_metric = {
        "transcript_id": transcript_id,
        "word_count": total_words,
        "wer_status": "pending_reference_alignment",
        "compliance_logged": True
    }
    logger.info("WER Tracking: %s", wer_metric)
    
    return {"status": "processed"}

Step 4: Latency Tracking, WER Calculation, and Audit Logging

Transcription efficiency requires tracking latency and Word Error Rate (WER). Genesys Cloud provides utterance-level timing. The following utility calculates latency, prepares WER calculation structures, and writes structured audit logs for compliance governance.

import json
from pathlib import Path

AUDIT_LOG_PATH = Path("transcription_audit.log")

def calculate_transcript_metrics(transcript_response: dict) -> dict:
    """Calculates latency, word count, and prepares WER tracking structures."""
    utterances = transcript_response.get("utterances", [])
    
    if not utterances:
        return {"latency_seconds": 0, "total_words": 0, "wer_baseline": 0}

    # Extract timing boundaries
    start_times = [u.get("startTime", 0) for u in utterances if u.get("startTime")]
    end_times = [u.get("endTime", 0) for u in utterances if u.get("endTime")]
    
    if start_times and end_times:
        audio_duration = max(end_times) - min(start_times)
    else:
        audio_duration = 0.0

    total_words = sum(len(u.get("text", "").split()) for u in utterances)
    
    # WER requires a reference transcript. We structure the output for downstream comparison
    wer_baseline = {
        "hypothesis_words": total_words,
        "audio_duration_seconds": audio_duration,
        "reference_required": True,
        "calculation_method": "standard_wer_formula"
    }

    return {
        "latency_seconds": audio_duration,
        "total_words": total_words,
        "wer_baseline": wer_baseline
    }

def write_audit_log(entry: dict) -> None:
    """Appends structured JSON audit log for compliance governance."""
    with open(AUDIT_LOG_PATH, "a", encoding="utf-8") as f:
        f.write(json.dumps(entry) + "\n")
    logger.info("Audit log written to %s", AUDIT_LOG_PATH)

Complete Working Example

The following script integrates authentication, validation, submission, webhook handling, and audit logging into a single executable module. Replace the placeholder credentials before execution.

import logging
import uvicorn
from purecloudplatformclientv2 import PlatformClient, ApiException
from fastapi import FastAPI, Request
import httpx
import time
import json
from pathlib import Path
from datetime import datetime, timezone

# Configure structured logging
logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")
logger = logging.getLogger(__name__)

# --- Configuration ---
ENVIRONMENT = "us-east-1"
CLIENT_ID = "YOUR_CLIENT_ID"
CLIENT_SECRET = "YOUR_CLIENT_SECRET"
CONVERSATION_ID = "YOUR_CONVERSATION_ID"
RECORDING_ID = "YOUR_RECORDING_ID"
MEDIA_ID = "YOUR_MEDIA_ID"
WEBHOOK_URL = "https://your-domain.com/webhooks/genesys/transcripts"

# --- Authentication ---
class GenesysAuth:
    def __init__(self, environment: str, client_id: str, client_secret: str):
        self.base_url = f"https://{environment}.mypurecloud.com"
        self.token_endpoint = f"{self.base_url}/oauth/token"
        self.client_id = client_id
        self.client_secret = client_secret
        self._token = None
        self._expires_at = 0.0

    def _fetch_token(self):
        payload = {
            "grant_type": "client_credentials",
            "client_id": self.client_id,
            "client_secret": self.client_secret,
            "scope": "conversation:transcript:write conversation:read recording:read"
        }
        with httpx.Client() as client:
            response = client.post(self.token_endpoint, data=payload)
            response.raise_for_status()
            return response.json()

    def get_access_token(self) -> str:
        if self._token and time.time() < self._expires_at - 60:
            return self._token
        data = self._fetch_token()
        self._token = data["access_token"]
        self._expires_at = time.time() + data["expires_in"]
        return self._token

    def create_platform_client(self) -> PlatformClient:
        client = PlatformClient()
        client.set_access_token(self.get_access_token())
        client.set_base_url(self.base_url)
        return client

# --- Media Validation ---
def validate_recording(recording_id: str, media_id: str, client: PlatformClient) -> dict:
    recordings_api = client.recordings_api
    recording = recordings_api.get_recording(recording_id)
    
    if recording.media_duration_seconds > 14400:
        raise ValueError("Recording exceeds 4-hour limit")
        
    file_ext = recording.media_url.rsplit(".", 1)[-1].lower()
    if file_ext not in ["wav", "mp3", "ogg", "flac"]:
        raise ValueError(f"Unsupported format: {file_ext}")
        
    return {"media_id": media_id, "duration": recording.media_duration_seconds}

# --- Transcription Submission ---
def submit_transcription(conversation_id: str, media_id: str, client: PlatformClient) -> dict:
    from purecloudplatformclientv2 import TranscriptRequest
    
    request_body = TranscriptRequest(
        media_id=media_id,
        language_code="en-US",
        speaker_diarization=True,
        asr_model="auto",
        callback_url=WEBHOOK_URL
    )
    
    transcripts_api = client.transcripts_api
    try:
        response = transcripts_api.post_conversation_transcripts(
            conversation_id=conversation_id,
            body=request_body
        )
        logger.info("Transcription submitted: %s", response.id)
        return response.to_dict()
    except ApiException as e:
        if e.status == 429:
            time.sleep(2)
            return submit_transcription(conversation_id, media_id, client)
        raise

# --- Webhook & Audit ---
app = FastAPI()
AUDIT_LOG = Path("transcription_audit.log")

@app.post("/webhooks/genesys/transcripts")
async def handle_webhook(request: Request):
    payload = await request.json()
    status = payload.get("status")
    if status != "completed":
        return {"status": "accepted"}
    
    created = payload.get("createdTime")
    updated = payload.get("updatedTime")
    latency = (datetime.fromisoformat(updated.replace("Z", "+00:00")) - 
               datetime.fromisoformat(created.replace("Z", "+00:00"))).total_seconds()
    
    utterances = payload.get("utterances", [])
    word_count = sum(len(u.get("text", "").split()) for u in utterances)
    
    audit_entry = {
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "conversation_id": payload.get("conversationId"),
        "transcript_id": payload.get("id"),
        "latency_seconds": latency,
        "word_count": word_count,
        "compliance_logged": True
    }
    
    with open(AUDIT_LOG, "a") as f:
        f.write(json.dumps(audit_entry) + "\n")
        
    logger.info("Processed webhook. Latency: %.2fs, Words: %d", latency, word_count)
    return {"status": "processed"}

# --- Execution ---
if __name__ == "__main__":
    auth = GenesysAuth(ENVIRONMENT, CLIENT_ID, CLIENT_SECRET)
    client = auth.create_platform_client()
    
    logger.info("Validating media constraints...")
    validate_recording(RECORDING_ID, MEDIA_ID, client)
    
    logger.info("Submitting transcription job...")
    submit_transcription(CONVERSATION_ID, MEDIA_ID, client)
    
    logger.info("Starting webhook listener on port 8000...")
    uvicorn.run(app, host="0.0.0.0", port=8000)

Common Errors & Debugging

Error: 400 Bad Request

  • Cause: The media_id does not belong to the specified conversationId, or the audio format is unsupported by the ASR engine.
  • Fix: Verify the recording ID matches the conversation ID. Check the media_url extension and ensure it is WAV, MP3, OGG, or FLAC. Validate sample rate falls between 8000 and 48000 Hz.
  • Code Fix: Add explicit format checking before payload construction as shown in Step 1.

Error: 403 Forbidden

  • Cause: The OAuth token lacks the conversation:transcript:write scope, or the client ID is not authorized for the specified organization.
  • Fix: Regenerate the OAuth token with the exact scope string conversation:transcript:write conversation:read recording:read. Verify the client credentials in the Genesys Cloud admin console under Applications.

Error: 429 Too Many Requests

  • Cause: The transcription API enforces per-tenant rate limits. Burst submissions exceed the allowed throughput.
  • Fix: Implement exponential backoff. The submit_transcription function includes a retry loop that sleeps for 2 * (2 ^ attempt) seconds before resubmitting.

Error: 500 Internal Server Error or Media Engine Timeout

  • Cause: The Genesys Cloud media processing service is temporarily unavailable, or the audio file contains corrupted headers.
  • Fix: Verify the recording plays correctly in a standard media player. If the file is valid, queue the request for delayed retry. Monitor the status field in webhook callbacks for failed states.

Official References