Formatting Phone Numbers in Genesys Cloud Architect Using Expression Language

StarAdmin · May 8, 2026, 9:00am

Formatting Phone Numbers in Genesys Cloud Architect Using Expression Language

What You Will Build

One sentence: You will create a Genesys Cloud Architect flow that converts a raw E.164 phone number string (e.g., +15551234567) into a standard US formatted string (e.g., (555) 123-4567).
One sentence: This uses the Genesys Cloud Architect Expression Language (EL) built-in functions, specifically substring and concatenation, or the format function if available in your instance version.
One sentence: The programming language covered is Genesys Cloud Expression Language (EL), executed within the Architect UI or via the architect SDK in Python/JavaScript for flow definition.

Prerequisites

OAuth client type and required scopes: You need a Genesys Cloud account with permissions to edit Architect flows. If using the SDK to deploy flows, you need architect:flow:write and architect:flow:view scopes.
SDK version or API version: Genesys Cloud API v2. Architect Expression Language is server-side; no specific SDK version is required for the logic itself, but the tutorial includes Python SDK examples for context.
Language/runtime requirements: None for the EL itself. For SDK examples: Python 3.8+ or Node.js 14+.
Any external dependencies: genesys-cloud-purecloud-sdk (Python) or @genesyscloud/purecloud-platform-client-v2 (Node.js).

Authentication Setup

Genesys Cloud uses OAuth 2.0 for API access. When building flows in the Architect UI, authentication is handled by your browser session. When using the SDK to manage flow definitions, you must authenticate explicitly.

Below is the Python setup for authenticating to the Genesys Cloud API using client credentials. This is required if you are programmatically managing the flow definition.

import os
from purecloudplatformclientv2 import ApiClient, Configuration, ArchitectApi

def get_architect_client():
    """
    Initializes the Genesys Cloud API Client for Architect operations.
    """
    # Load credentials from environment variables
    client_id = os.getenv("GENESYS_CLIENT_ID")
    client_secret = os.getenv("GENESYS_CLIENT_SECRET")
    environment = os.getenv("GENESYS_ENVIRONMENT", "mypurecloud.com")

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

    # Create the API client configuration
    client = ApiClient(
        client_id=client_id,
        client_secret=client_secret,
        environment=environment
    )

    # Return the Architect API instance
    return client

# Example usage
try:
    api_client = get_architect_client()
    print("Authentication successful. Ready to interact with Architect APIs.")
except Exception as e:
    print(f"Authentication failed: {e}")

OAuth Scopes Required:

architect:flow:write: To save or update flows containing the new expression.
architect:flow:view: To read existing flow definitions.

Implementation

Step 1: Understanding the Input Data Structure

In Genesys Cloud, phone numbers typically arrive in E.164 format (e.g., +15551234567) via the contact.phoneNumber attribute. Before formatting, you must ensure the input is a string and contains the expected length.

The standard US E.164 format for a 10-digit local number is +1 followed by 10 digits (11 characters total).

Index 0: +
Index 1: 1 (Country Code)
Indices 2-4: Area Code (XXX)
Indices 5-7: Prefix (XXX)
Indices 8-11: Line Number (XXXX)

We will assume the input variable is ${contact.phoneNumber}.

Step 2: Constructing the Expression Language Logic

Genesys Cloud EL does not have a dedicated formatPhoneNumber function that automatically handles international variations in a single call. However, for US numbers, you can achieve this using substring and string concatenation.

The logic is:

Extract Area Code: substring(phone, 2, 3)
Extract Prefix: substring(phone, 5, 3)
Extract Line Number: substring(phone, 8, 4)
Concatenate with formatting characters: ( + Area + ) + Prefix + - + Line

The Expression:

concat("(", substring(contact.phoneNumber, 2, 3), ") ", substring(contact.phoneNumber, 5, 3), "-", substring(contact.phoneNumber, 8, 4))

Edge Case Handling:
If the phone number might not be in E.164 format or might be missing, you should wrap this in a conditional check to prevent runtime errors.

Safe Expression:

if(
    and(
        notEmpty(contact.phoneNumber),
        length(contact.phoneNumber) == 11,
        startsWith(contact.phoneNumber, "+1")
    ),
    concat("(", substring(contact.phoneNumber, 2, 3), ") ", substring(contact.phoneNumber, 5, 3), "-", substring(contact.phoneNumber, 8, 4)),
    contact.phoneNumber
)

This expression checks:

The number is not empty.
The length is exactly 11 characters (standard US E.164).
It starts with +1.

If all conditions are met, it formats the number. Otherwise, it returns the original value.

Step 3: Implementing in Architect UI

Open Architect in Genesys Cloud.
Create a new flow or edit an existing one.
Add a Set Property node.
In the Property Name field, enter a new variable name, e.g., formattedPhoneNumber.
In the Value field, click the Expression button (usually represented by fx or a lambda symbol).
Paste the Safe Expression from Step 2 into the expression builder.
Validate the expression. The builder will show syntax errors if any function names are misspelled.

Visual Representation in Set Property Node:

Property Name: formattedPhoneNumber
Value: if(and(notEmpty(contact.phoneNumber),length(contact.phoneNumber)==11,startsWith(contact.phoneNumber,"+1")),concat("(",substring(contact.phoneNumber,2,3),") ",substring(contact.phoneNumber,5,3),"-",substring(contact.phoneNumber,8,4)),contact.phoneNumber)

Step 4: Alternative Approach Using Python SDK for Complex Logic

If you require more complex formatting (e.g., handling multiple countries, extensions, or non-standard inputs), EL may become unwieldy. In such cases, you can use a Python Script node in Architect (if licensed) or a Webhook node to call an external service.

Here is an example of a Python script that uses the phonenumbers library to format a number. This script can be embedded in a Genesys Cloud Python Script node.

import phonenumbers
from phonenumbers import NumberParseException

def format_phone_number(raw_number: str) -> str:
    """
    Formats a phone number to US national format.
    Input: E.164 string (e.g., '+15551234567')
    Output: US formatted string (e.g., '(555) 123-4567')
    """
    if not raw_number:
        return ""

    try:
        # Parse the number
        parsed_number = phonenumbers.parse(raw_number, None)

        # Check if the number is valid
        if not phonenumbers.is_valid_number(parsed_number):
            return raw_number

        # Format to national format
        # For US, this results in (XXX) XXX-XXXX
        formatted = phonenumbers.format_number(parsed_number, phonenumbers.PhoneNumberFormat.NATIONAL)
        return formatted

    except NumberParseException as e:
        # Log the error if necessary
        print(f"Phone number parsing error: {e}")
        return raw_number
    except Exception as e:
        print(f"Unexpected error: {e}")
        return raw_number

Note: The phonenumbers library must be installed in the environment where this script runs. In Genesys Cloud Architect Python Script nodes, the standard library is available, but third-party libraries like phonenumbers require specific licensing and environment configuration. If not available, stick to the EL approach or use a Webhook.

Step 5: Deploying the Flow via SDK (Optional)

If you are managing flows as code, you can update the flow definition to include the new Set Property node with the EL expression.

from purecloudplatformclientv2 import Flow, FlowNode, SetPropertyAction

def update_flow_with_formatting(api_client, flow_id, new_node_id="set_formatted_phone"):
    """
    Example skeleton for updating a flow to include the phone formatting node.
    Note: Full flow definition updates are complex and require careful handling of the flow graph.
    """
    # Fetch existing flow
    flows_api = ArchitectApi(api_client)
    flow = flows_api.get_flow(flow_id)

    # Create new Set Property Node
    new_node = FlowNode(
        id=new_node_id,
        type="setProperty",
        actions=[
            SetPropertyAction(
                property_name="formattedPhoneNumber",
                value="if(and(notEmpty(contact.phoneNumber),length(contact.phoneNumber)==11,startsWith(contact.phoneNumber,\"+1\")),concat(\"(\",substring(contact.phoneNumber,2,3),\") \",substring(contact.phoneNumber,5,3),\"-\",substring(contact.phoneNumber,8,4)),contact.phoneNumber)"
            )
        ]
    )

    # Add node to flow definition
    flow.nodes[new_node_id] = new_node

    # Update flow
    # flows_api.put_flow(flow_id, flow)
    print("Flow updated with phone formatting node.")

Complete Working Example

Below is the complete Expression Language string to paste into a Genesys Cloud Architect Set Property node.

Property Name: formattedPhoneNumber

Value (Expression):

if(
    and(
        notEmpty(contact.phoneNumber),
        length(contact.phoneNumber) == 11,
        startsWith(contact.phoneNumber, "+1")
    ),
    concat("(", substring(contact.phoneNumber, 2, 3), ") ", substring(contact.phoneNumber, 5, 3), "-", substring(contact.phoneNumber, 8, 4)),
    contact.phoneNumber
)

Test Scenario:

Input: contact.phoneNumber = +15551234567
Condition Check:
- notEmpty: True
- length == 11: True
- startsWith("+1"): True
Formatting:
- substring(..., 2, 3) → 555
- substring(..., 5, 3) → 123
- substring(..., 8, 4) → 4567
- concat → (555) 123-4567
Output: formattedPhoneNumber = (555) 123-4567

Test Scenario (Invalid Input):

Input: contact.phoneNumber = 5551234567 (Missing +1)
Condition Check:
- startsWith("+1"): False
Output: formattedPhoneNumber = 5551234567 (Original value preserved)

Common Errors & Debugging

Error: `substring` index out of bounds

What causes it: The input phone number is shorter than expected (e.g., 10 digits without country code). The substring function attempts to access indices that do not exist.
How to fix it: Always wrap the substring calls in a length check as shown in the Safe Expression. Ensure the condition length(contact.phoneNumber) == 11 is met before calling substring.

Error: `concat` argument type mismatch

What causes it: One of the arguments passed to concat is not a string (e.g., null or number).
How to fix it: Ensure all inputs are strings. Use toString() if necessary, though substring returns a string. The notEmpty check helps prevent null values.

Error: Expression too long for UI input box

What causes it: The EL expression is verbose.
How to fix it: Use the Expression Builder’s multiline mode or break down the logic into multiple Set Property nodes. For example, first extract area code, then prefix, then line number, and finally concatenate.

Refactored Multi-Step Approach:

Node 1: isUsNumber = and(notEmpty(contact.phoneNumber), length(contact.phoneNumber) == 11, startsWith(contact.phoneNumber, "+1"))
Node 2: areaCode = if(isUsNumber, substring(contact.phoneNumber, 2, 3), "")
Node 3: prefix = if(isUsNumber, substring(contact.phoneNumber, 5, 3), "")
Node 4: lineNumber = if(isUsNumber, substring(contact.phoneNumber, 8, 4), "")
Node 5: formattedPhoneNumber = if(isUsNumber, concat("(", areaCode, ") ", prefix, "-", lineNumber), contact.phoneNumber)

Formatting Phone Numbers in Genesys Cloud Architect Using Expression Language

Formatting Phone Numbers in Genesys Cloud Architect Using Expression Language

What You Will Build

Prerequisites

Authentication Setup

Implementation

Step 1: Understanding the Input Data Structure

Step 2: Constructing the Expression Language Logic

Step 3: Implementing in Architect UI

Step 4: Alternative Approach Using Python SDK for Complex Logic

Step 5: Deploying the Flow via SDK (Optional)

Complete Working Example

Common Errors & Debugging

Error: substring index out of bounds

Error: concat argument type mismatch

Error: Expression too long for UI input box

Official References

Error: `substring` index out of bounds

Error: `concat` argument type mismatch