Formatting Phone Numbers in Genesys Cloud Architect with Expression Language

How-To-Articles
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Formatting Phone Numbers in Genesys Cloud Architect with Expression Language

What You Will Build

  • A working Genesys Cloud Architect flow that converts an E.164 formatted phone number (e.g., +14155552671) into a standard North American display format (e.g., (415) 555-2671).
  • This implementation uses the Genesys Cloud Architect Expression Language (EL) within a Set Data block.
  • The primary logic is covered in Genesys Cloud EL, with a supporting Python example demonstrating how to validate the input format via API before processing.

Prerequisites

  • Access: Genesys Cloud Organization Admin or Architect permissions.
  • API Access: A Service Account or OAuth 2.0 Client Credentials flow setup for the Python validation example.
  • Required Scopes:
    • analytics:query (for validating data sources if needed)
    • flow:read (for inspecting flow structures)
    • telephony:call (if integrating with call flows)
  • Dependencies:
    • Python 3.8+
    • genesys-cloud-purecloud-platform-client SDK (latest stable version)
    • requests library

Authentication Setup

Before manipulating data in Architect, you must ensure your integration has the correct context. While the EL expression runs server-side within the Genesys Cloud environment, any external validation or data enrichment requires OAuth 2.0 Client Credentials.

Here is the Python setup for authenticating and retrieving a token. This token is not used directly in the Architect EL expression but is required if you are pushing data into Genesys via API or pulling reference data.

import os
from purecloud_platform_client import PlatformClient, Configuration
import purecloud_platform_client.rest as rest

# Configuration
client_id = os.environ.get("GENESYS_CLIENT_ID")
client_secret = os.environ.get("GENESYS_CLIENT_SECRET")

if not client_id or not client_secret:
    raise ValueError("GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET must be set.")

# Initialize Platform Client
config = Configuration()
config.client_id = client_id
config.client_secret = client_secret

client = PlatformClient(config)

# This client instance is ready for API calls.
# In Architect EL, no auth code is needed as the flow runs with the organization's context.
print("Auth setup complete. Token will be managed automatically by the SDK.")

Implementation

Step 1: Understanding the Input Format and EL Functions

The input is an E.164 string: +1XXXXXXXXXX.
The target output is: (XXX) XXX-XXXX.

Genesys Cloud Architect Expression Language provides several string manipulation functions:

  • substring(str, start, end): Extracts a portion of the string.
  • concat(str1, str2, ...): Joins strings together.
  • replace(str, old, new): Replaces occurrences of a substring.

We assume the input variable is named phoneNumber. In a real flow, this might come from {{ trigger.event.call.to }} or a Set Data block.

Critical Note on Indexing:
EL string indexing is 0-based.

  • Index 0: +
  • Index 1: 1 (Country Code)
  • Index 2: First digit of Area Code
  • Index 3: Second digit of Area Code
  • Index 4: Third digit of Area Code
  • Index 5: First digit of Exchange
  • Index 6: Second digit of Exchange
  • Index 7: Third digit of Exchange
  • Index 8: First digit of Subscriber Number
  • Index 9: Second digit of Subscriber Number
  • Index 10: Third digit of Subscriber Number
  • Index 11: Fourth digit of Subscriber Number

Step 2: Constructing the EL Expression

We will build the expression step-by-step.

  1. Extract Area Code (Indices 2-5):
    {{ substring(phoneNumber, 2, 5) }} returns 415 from +1415....

  2. Extract Exchange (Indices 5-8):
    {{ substring(phoneNumber, 5, 8) }} returns 555.

  3. Extract Subscriber Number (Indices 8-12):
    {{ substring(phoneNumber, 8, 12) }} returns 2671.

  4. Concatenate with Formatting:
    We need to add parentheses, spaces, and a hyphen.

    The final expression is:

    {{ concat("(", substring(phoneNumber, 2, 5), ") ", substring(phoneNumber, 5, 8), "-", substring(phoneNumber, 8, 12)) }}

Step 3: Handling Edge Cases and Validation

The above expression assumes a perfect 11-character string starting with +1. If the input is malformed (e.g., missing country code, international number with different length), the expression will fail or produce garbage.

In Architect, you should validate the length and prefix before formatting.

Validation Logic:

  1. Check if the string starts with +1.
  2. Check if the length is exactly 11.

If these conditions are not met, you can fallback to the original number or a default value.

Conditional EL Expression:

{{ if startsWith(phoneNumber, "+1") and length(phoneNumber) == 11 then concat("(", substring(phoneNumber, 2, 5), ") ", substring(phoneNumber, 5, 8), "-", substring(phoneNumber, 8, 12)) else phoneNumber }}

This ensures that non-North American numbers or malformed data pass through unchanged.

Step 4: Implementing in Architect (Set Data Block)

  1. Open your Flow in Genesys Cloud Architect.
  2. Drag a Set Data block onto the canvas.
  3. In the Data section, add a new variable.
    • Name: formattedPhoneNumber
    • Type: String
    • Value: Paste the EL expression from Step 3.
  4. Connect the previous block to this Set Data block.

Complete Working Example

Below is a Python script that simulates the validation logic you might run in a pre-processing step or via a custom integration, followed by the exact EL expression to paste into Architect.

Python Validation Helper (Pre-Processing)

This script demonstrates how to validate the input format using Python logic, which mirrors the validation you should consider in your flow design. While Architect EL is limited, you can use this logic in a Genesys Cloud Action or external API if complex validation is needed.

def format_phone_number_e164_to_nanp(phone_number: str) -> str:
    """
    Formats an E.164 North American phone number to (XXX) XXX-XXXX.
    
    Args:
        phone_number (str): The input phone number in E.164 format (e.g., +14155552671).
        
    Returns:
        str: The formatted phone number or the original if validation fails.
    """
    # Validation: Must start with +1 and be 11 characters long
    if not phone_number.startswith("+1") or len(phone_number) != 11:
        return phone_number
    
    # Extract parts
    area_code = phone_number[2:5]
    exchange = phone_number[5:8]
    subscriber = phone_number[8:12]
    
    # Format
    formatted = f"({area_code}) {exchange}-{subscriber}"
    return formatted

# Test Cases
test_numbers = [
    "+14155552671",  # Valid
    "+442071234567", # International (UK) - Should pass through
    "4155552671",    # Missing +1 - Should pass through
    "+1415555",      # Too short - Should pass through
]

for num in test_numbers:
    result = format_phone_number_e164_to_nanp(num)
    print(f"Input: {num:15} -> Output: {result}")

Expected Output:

Input: +14155552671  -> Output: (415) 555-2671
Input: +442071234567 -> Output: +442071234567
Input: 4155552671    -> Output: 4155552671
Input: +1415555      -> Output: +1415555

Architect EL Expression (Final Copy-Paste)

Copy this exact expression into your Set Data block value field. Replace phoneNumber with your actual variable name (e.g., {{ trigger.event.call.to }}).

{{ if startsWith(phoneNumber, "+1") and length(phoneNumber) == 11 then concat("(", substring(phoneNumber, 2, 5), ") ", substring(phoneNumber, 5, 8), "-", substring(phoneNumber, 8, 12)) else phoneNumber }}

Common Errors & Debugging

Error: Invalid Index or Empty String

Cause: The input variable is null, empty, or shorter than 11 characters. The substring function will throw an error or return empty strings if indices are out of bounds.

Fix: Always wrap the formatting logic in a length check. The conditional expression in Step 3 prevents this.

Code Example (Debugging):
Add a Log block before the Set Data block to inspect the raw value.

{{ phoneNumber }}

If the log shows null or +1, the subsequent formatting will fail.

Error: Non-North American Numbers

Cause: The input is a valid E.164 number but not from the US/Canada (e.g., +44...). The startsWith("+1") check fails, and the else branch returns the original number.

Fix: This is expected behavior. If you need to format international numbers, you must implement separate logic for each country code, as there is no universal formatting standard in EL. For now, the else phoneNumber clause ensures data integrity by preserving the original E.164 format.

Error: Variable Name Mismatch

Cause: Using phoneNumber in the EL expression but the variable in the flow is named callerPhoneNumber.

Fix: Ensure the variable name in the EL expression matches the variable defined in the Set Data block or trigger exactly. Genesys Cloud EL is case-sensitive.

Code Example (Correct Reference):
If your trigger is a call event, the variable is likely:

{{ trigger.event.call.to }}

Or if you set it in a previous block:

{{ setPhoneNumber.value }}

Official References