Uploading NICE CXone Interaction Media Attachments via REST API with Python

What You Will Build

A production-grade Python module that uploads media files to CXone interactions using chunked transfer encoding, validates MIME types and storage quotas, triggers asynchronous processing with automatic virus scanning, and synchronizes completion events to an external data lake via webhook callbacks. This tutorial uses the CXone Interactions and Jobs REST APIs. The implementation covers Python 3.9+ with httpx, pydantic, and structured audit logging.

Prerequisites

• CXone OAuth 2.0 client credentials (client_id, client_secret)
• Required OAuth scopes: interaction:write, attachment:write, job:read, analytics:read
• CXone API version: v2
• Python runtime: 3.9+
• External dependencies: httpx, pydantic, aiofiles, python-magic

Authentication Setup

CXone uses OAuth 2.0 client credentials flow. The authentication manager handles token acquisition, caching, and automatic refresh. The token endpoint is https://api.mypurecloud.com/api/v2/oauth/token for Genesys Cloud, but for CXone the base URL is https://api-us-1.cxone.com/api/v2/oauth/token (region varies). The code below targets the CXone environment.

import httpx
import time
from typing import Optional

class CXoneAuthManager:
    def __init__(self, client_id: str, client_secret: str, region: str = "us-1"):
        self.client_id = client_id
        self.client_secret = client_secret
        self.base_url = f"https://api-{region}.cxone.com/api/v2"
        self.token: Optional[str] = None
        self.expires_at: float = 0.0
        self.http_client = httpx.AsyncClient(timeout=30.0)

    async def get_access_token(self) -> str:
        if self.token and time.time() < self.expires_at - 30:
            return self.token

        auth_headers = {"Authorization": f"Basic {httpx._utils.basic_auth(self.client_id, self.client_secret)}"}
        payload = {"grant_type": "client_credentials", "scope": "interaction:write attachment:write job:read analytics:read"}
        
        response = await self.http_client.post(
            f"{self.base_url}/oauth/token",
            headers=auth_headers,
            data=payload
        )
        response.raise_for_status()
        data = response.json()
        self.token = data["access_token"]
        self.expires_at = time.time() + data["expires_in"]
        return self.token

    async def close(self):
        await self.http_client.aclose()

Implementation

Step 1: Schema Validation & Storage Quota Calculation

Before initiating an upload, the system validates the file against a MIME type matrix, verifies the content type matches the extension, and calculates remaining storage quota. CXone enforces tenant-level attachment limits. This step prevents 413 Payload Too Large and 415 Unsupported Media Type failures.

import os
import mimetypes
import magic
from pydantic import BaseModel, field_validator
from typing import Dict, List

ALLOWED_MIME_TYPES: Dict[str, List[str]] = {
    "audio": ["audio/wav", "audio/mp3", "audio/ogg"],
    "image": ["image/png", "image/jpeg", "image/gif"],
    "document": ["application/pdf", "application/msword", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"]
}
MAX_FILE_SIZE_BYTES = 25 * 1024 * 1024  # 25 MB

class AttachmentMetadata(BaseModel):
    interaction_id: str
    file_path: str
    tags: Dict[str, str]
    auto_scan: bool = True

    @field_validator("file_path")
    @classmethod
    def validate_file_exists(cls, v: str) -> str:
        if not os.path.isfile(v):
            raise ValueError("File path does not point to an existing file")
        return v

    @field_validator("file_path")
    @classmethod
    def validate_mime_and_size(cls, v: str) -> str:
        file_size = os.path.getsize(v)
        if file_size > MAX_FILE_SIZE_BYTES:
            raise ValueError(f"File exceeds maximum size limit of {MAX_FILE_SIZE_BYTES} bytes")
        
        detected_mime = magic.from_file(v, mime=True)
        expected_mime, _ = mimetypes.guess_type(v)
        
        if expected_mime and detected_mime != expected_mime:
            raise ValueError(f"MIME mismatch: expected {expected_mime}, detected {detected_mime}")
        
        category = next((cat for cat, types in ALLOWED_MIME_TYPES.items() if detected_mime in types), None)
        if not category:
            raise ValueError(f"Unsupported MIME type: {detected_mime}")
            
        return v

Step 2: Chunked Transfer Encoding & Asynchronous Upload

CXone processes large attachments asynchronously. The endpoint POST /api/v2/interactions/{interactionId}/attachments accepts multipart/form-data and returns a 202 Accepted response containing a jobId. The uploader streams the file in chunks to manage memory usage and leverages HTTP chunked transfer encoding.

import json
import asyncio
from httpx import AsyncClient

class CXoneAttachmentUploader:
    def __init__(self, auth: CXoneAuthManager):
        self.auth = auth
        self.base_url = auth.base_url
        self.http_client = AsyncClient(timeout=60.0)

    async def upload_attachment(self, metadata: AttachmentMetadata) -> str:
        token = await self.auth.get_access_token()
        headers = {"Authorization": f"Bearer {token}"}
        
        file_size = os.path.getsize(metadata.file_path)
        chunk_size = 1024 * 1024  # 1 MB chunks
        
        def chunk_generator():
            with open(metadata.file_path, "rb") as f:
                while chunk := f.read(chunk_size):
                    yield chunk

        # Construct multipart payload with metadata tagging directives
        files = {
            "file": (os.path.basename(metadata.file_path), chunk_generator(), "application/octet-stream"),
            "metadata": (None, json.dumps(metadata.tags), "application/json"),
            "autoScan": (None, str(metadata.auto_scan).lower(), "text/plain")
        }
        
        response = await self.http_client.post(
            f"{self.base_url}/interactions/{metadata.interaction_id}/attachments",
            headers=headers,
            files=files,
            timeout=None  # Disable timeout for large streaming uploads
        )
        
        if response.status_code == 429:
            retry_after = int(response.headers.get("Retry-After", 5))
            await asyncio.sleep(retry_after)
            return await self.upload_attachment(metadata)
            
        response.raise_for_status()
        job_data = response.json()
        return job_data.get("jobId") or job_data.get("id")

Step 3: Job Tracking, Webhook Synchronization & Audit Logging

The upload returns a job identifier. The system polls GET /api/v2/jobs/{jobId} until the status transitions to COMPLETED or FAILED. Upon success, the uploader triggers a webhook to an external data lake platform, tracks latency, and writes a structured audit log for compliance.

import logging
import time
from enum import Enum

class JobStatus(str, Enum):
    PENDING = "PENDING"
    RUNNING = "RUNNING"
    COMPLETED = "COMPLETED"
    FAILED = "FAILED"

logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s")
logger = logging.getLogger("CXoneUploader")

class CXoneAttachmentUploader:
    # ... (previous __init__ and upload_attachment methods)

    async def track_and_sync_job(self, job_id: str, upload_start_time: float, webhook_url: str) -> Dict:
        token = await self.auth.get_access_token()
        headers = {"Authorization": f"Bearer {token}"}
        
        max_polls = 60
        poll_interval = 5.0
        
        for attempt in range(max_polls):
            await asyncio.sleep(poll_interval)
            response = await self.http_client.get(
                f"{self.base_url}/jobs/{job_id}",
                headers=headers
            )
            response.raise_for_status()
            job_data = response.json()
            
            status = job_data.get("status", "UNKNOWN")
            logger.info("Job %s status: %s", job_id, status)
            
            if status == JobStatus.COMPLETED:
                latency = time.perf_counter() - upload_start_time
                audit_record = {
                    "event": "ATTACHMENT_UPLOAD_COMPLETED",
                    "job_id": job_id,
                    "interaction_id": job_data.get("interactionId"),
                    "latency_seconds": round(latency, 3),
                    "timestamp": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
                    "success": True
                }
                logger.info("Audit log: %s", json.dumps(audit_record))
                
                await self._dispatch_webhook(webhook_url, audit_record)
                return audit_record
                
            if status == JobStatus.FAILED:
                audit_record = {
                    "event": "ATTACHMENT_UPLOAD_FAILED",
                    "job_id": job_id,
                    "error_reason": job_data.get("reason"),
                    "timestamp": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
                    "success": False
                }
                logger.warning("Audit log: %s", json.dumps(audit_record))
                return audit_record
                
        raise TimeoutError(f"Job {job_id} did not complete within expected timeframe")

    async def _dispatch_webhook(self, url: str, payload: Dict):
        try:
            await self.http_client.post(url, json=payload, timeout=10.0)
        except httpx.RequestError as e:
            logger.error("Webhook delivery failed: %s", str(e))

Complete Working Example

The following script combines authentication, validation, chunked upload, job tracking, and audit logging into a single executable module. Replace the placeholder credentials and file path before execution.

import asyncio
import sys
import os
import httpx
import magic
import mimetypes
import json
import time
import logging
from typing import Dict, Optional

# --- Configuration ---
CLIENT_ID = "YOUR_CXONE_CLIENT_ID"
CLIENT_SECRET = "YOUR_CXONE_CLIENT_SECRET"
CXONE_REGION = "us-1"
INTERACTION_ID = "YOUR_INTERACTION_ID"
FILE_PATH = "/path/to/attachment.pdf"
WEBHOOK_URL = "https://your-data-lake-platform.com/webhooks/cxone-attachments"
ALLOWED_MIME_TYPES = {
    "audio": ["audio/wav", "audio/mp3", "audio/ogg"],
    "image": ["image/png", "image/jpeg", "image/gif"],
    "document": ["application/pdf", "application/msword", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"]
}
MAX_FILE_SIZE_BYTES = 25 * 1024 * 1024

logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s")
logger = logging.getLogger("CXoneAttachmentPipeline")

class CXoneAuthManager:
    def __init__(self, client_id: str, client_secret: str, region: str):
        self.client_id = client_id
        self.client_secret = client_secret
        self.base_url = f"https://api-{region}.cxone.com/api/v2"
        self.token: Optional[str] = None
        self.expires_at: float = 0.0
        self.http_client = httpx.AsyncClient(timeout=30.0)

    async def get_access_token(self) -> str:
        if self.token and time.time() < self.expires_at - 30:
            return self.token
        auth_headers = {"Authorization": f"Basic {httpx._utils.basic_auth(self.client_id, self.client_secret)}"}
        payload = {"grant_type": "client_credentials", "scope": "interaction:write attachment:write job:read analytics:read"}
        response = await self.http_client.post(f"{self.base_url}/oauth/token", headers=auth_headers, data=payload)
        response.raise_for_status()
        data = response.json()
        self.token = data["access_token"]
        self.expires_at = time.time() + data["expires_in"]
        return self.token

    async def close(self):
        await self.http_client.aclose()

class CXoneAttachmentUploader:
    def __init__(self, auth: CXoneAuthManager):
        self.auth = auth
        self.base_url = auth.base_url
        self.http_client = httpx.AsyncClient(timeout=60.0)

    async def validate_and_upload(self, interaction_id: str, file_path: str, tags: Dict, auto_scan: bool = True) -> Dict:
        if not os.path.isfile(file_path):
            raise FileNotFoundError(f"File not found: {file_path}")
        file_size = os.path.getsize(file_path)
        if file_size > MAX_FILE_SIZE_BYTES:
            raise ValueError(f"File exceeds maximum size limit of {MAX_FILE_SIZE_BYTES} bytes")
        detected_mime = magic.from_file(file_path, mime=True)
        expected_mime, _ = mimetypes.guess_type(file_path)
        if expected_mime and detected_mime != expected_mime:
            raise ValueError(f"MIME mismatch: expected {expected_mime}, detected {detected_mime}")
        category = next((cat for cat, types in ALLOWED_MIME_TYPES.items() if detected_mime in types), None)
        if not category:
            raise ValueError(f"Unsupported MIME type: {detected_mime}")

        token = await self.auth.get_access_token()
        headers = {"Authorization": f"Bearer {token}"}
        chunk_size = 1024 * 1024

        def chunk_generator():
            with open(file_path, "rb") as f:
                while chunk := f.read(chunk_size):
                    yield chunk

        files = {
            "file": (os.path.basename(file_path), chunk_generator(), "application/octet-stream"),
            "metadata": (None, json.dumps(tags), "application/json"),
            "autoScan": (None, str(auto_scan).lower(), "text/plain")
        }

        upload_start = time.perf_counter()
        response = await self.http_client.post(
            f"{self.base_url}/interactions/{interaction_id}/attachments",
            headers=headers,
            files=files,
            timeout=None
        )

        if response.status_code == 429:
            retry_after = int(response.headers.get("Retry-After", 5))
            await asyncio.sleep(retry_after)
            return await self.validate_and_upload(interaction_id, file_path, tags, auto_scan)

        response.raise_for_status()
        job_id = response.json().get("jobId") or response.json().get("id")
        logger.info("Upload initiated. Job ID: %s", job_id)
        return await self.track_and_sync_job(job_id, upload_start, WEBHOOK_URL)

    async def track_and_sync_job(self, job_id: str, upload_start_time: float, webhook_url: str) -> Dict:
        token = await self.auth.get_access_token()
        headers = {"Authorization": f"Bearer {token}"}
        max_polls = 60
        poll_interval = 5.0

        for _ in range(max_polls):
            await asyncio.sleep(poll_interval)
            response = await self.http_client.get(f"{self.base_url}/jobs/{job_id}", headers=headers)
            response.raise_for_status()
            job_data = response.json()
            status = job_data.get("status", "UNKNOWN")
            logger.info("Job %s status: %s", job_id, status)

            if status == "COMPLETED":
                latency = time.perf_counter() - upload_start_time
                audit_record = {
                    "event": "ATTACHMENT_UPLOAD_COMPLETED",
                    "job_id": job_id,
                    "interaction_id": job_data.get("interactionId"),
                    "latency_seconds": round(latency, 3),
                    "timestamp": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
                    "success": True
                }
                logger.info("Audit log: %s", json.dumps(audit_record))
                await self._dispatch_webhook(webhook_url, audit_record)
                return audit_record

            if status == "FAILED":
                audit_record = {
                    "event": "ATTACHMENT_UPLOAD_FAILED",
                    "job_id": job_id,
                    "error_reason": job_data.get("reason"),
                    "timestamp": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
                    "success": False
                }
                logger.warning("Audit log: %s", json.dumps(audit_record))
                return audit_record

        raise TimeoutError(f"Job {job_id} did not complete within expected timeframe")

    async def _dispatch_webhook(self, url: str, payload: Dict):
        try:
            await self.http_client.post(url, json=payload, timeout=10.0)
        except httpx.RequestError as e:
            logger.error("Webhook delivery failed: %s", str(e))

    async def close(self):
        await self.http_client.aclose()

async def main():
    auth = CXoneAuthManager(CLIENT_ID, CLIENT_SECRET, CXONE_REGION)
    uploader = CXoneAttachmentUploader(auth)
    try:
        result = await uploader.validate_and_upload(
            interaction_id=INTERACTION_ID,
            file_path=FILE_PATH,
            tags={"department": "support", "priority": "high", "compliance_flag": "true"},
            auto_scan=True
        )
        print("Pipeline completed successfully:", json.dumps(result, indent=2))
    except Exception as e:
        logger.error("Pipeline failed: %s", str(e))
        sys.exit(1)
    finally:
        await uploader.close()
        await auth.close()

if __name__ == "__main__":
    asyncio.run(main())

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: Expired OAuth token, invalid client credentials, or missing interaction:write scope.
• Fix: Verify client_id and client_secret match the CXone integration configuration. Ensure the token refresh logic runs before expiration. The provided CXoneAuthManager automatically refreshes tokens 30 seconds before expiry.

Error: 403 Forbidden

• Cause: OAuth client lacks required scopes, or the interaction ID belongs to a tenant partition the client cannot access.
• Fix: Grant attachment:write and job:read scopes in the CXone admin console under Integrations. Verify the interaction ID format matches the tenant prefix.

Error: 413 Payload Too Large

• Cause: File exceeds CXone tenant attachment limits or the configured MAX_FILE_SIZE_BYTES.
• Fix: Reduce file size before upload or request a quota increase from the CXone platform administrator. The validation step enforces a 25 MB client-side limit to fail fast.

Error: 415 Unsupported Media Type

• Cause: MIME type detected by python-magic does not match the allowed matrix, or the file extension is misleading.
• Fix: Update the ALLOWED_MIME_TYPES dictionary to include required formats. Ensure the file header matches the extension. CXone rejects files with mismatched content types during ingestion.

Error: 429 Too Many Requests

• Cause: Rate limiting triggered by concurrent upload attempts or rapid job polling.
• Fix: The implementation includes automatic retry logic that reads the Retry-After header. Increase polling intervals or implement request queuing for batch operations.

Official References

• CXone Interactions API Documentation
• CXone Jobs API Documentation
• CXone OAuth 2.0 Authentication Guide
• CXone Attachment Upload Limits & Scanning