ETAS & API Guide

Connect your platform to Newline’s payment APIs and complete the supporting data integration required for your Embedded Transaction Account Solution (ETAS) program.

How ETAS uses Newline APIs

ETAS enables business payments through a Fifth Third Bank-owned custodial account held for the benefit of your end users. You maintain your own ledger to track customer balances and transaction activity.

Your implementation includes two technical workstreams, typically completed in parallel:

Integration	Purpose	Your responsibilities
API integration	Initiate, manage, and monitor payment activity through Newline services.	Configure authentication, implement approved payment workflows, handle responses, and monitor transaction status.
Batch File integration	Submit business and transaction data to Newline DataMart for reporting, reconciliation, and monitoring.	Configure SFTP, generate required files, validate submissions, and review processing results.

API integration does not replace the required Batch File integration. Both workstreams must be tested before production approval.

See the ETAS Quick Start Onboarding Guide for the overall implementation process.

Prerequisites

Execute the required agreements and initiate ETAS onboarding.
Identify your business, technical, and support contacts.
Confirm the payment rails approved for your program.
Determine how your platform will maintain customer balances and transaction records.
Obtain API credentials, Sandbox access information, and endpoint details from your implementation team.
Review your organization’s credential-management, access-control, and data-handling requirements.
Assign resources to complete both API and Batch File integration.

1. Configure API authentication

ETAS uses the existing Newline authentication framework. Use the Authentication Guide for token generation, request headers, token expiration, and environment-specific connection details.

Your integration must support:

Credential configuration and protected storage
Access token generation
Token renewal
Authorization validation
Error handling for expired or invalid credentials

Before implementing payment workflows, verify that you can:

Authenticate successfully.
Retrieve an access token.
Connect to the Sandbox endpoints provided during onboarding.
Receive authorized responses.
Handle authentication failures and token expiration.

Use the Newline API Reference for endpoint-specific request and response requirements.

2. Implement approved payment workflows

Implement only the payment rails enabled for your ETAS program. ETAS supports ACH, domestic wire transfers, book transfers, and sending and receiving Instant Payments through The Clearing House RTP® Network.

Payment rail	Documented ETAS capabilities	Implementation checks
ACH	Inbound and outbound ACH, standard ACH, and Same Day ACH where enabled	Validate request structures, inbound and outbound scenarios, and transaction status responses.
Domestic wire transfers	Domestic wire payment activity	Validate payment requests, response handling, and status monitoring.
Book transfers	Movement of funds between Fifth Third accounts	Validate transfer processing, balance movement, and transaction status reporting.
Instant Payments (RTP)	Sending and receiving RTP payments where enabled for your program	Validate outbound requests, received transaction visibility, status monitoring, and ledger records for both directions. Confirm the receiving configuration with your implementation team.

Review the corresponding payment guides:

For RTP sending, use Initiate a Transfer and review the source-account funding and receiving-bank eligibility requirements in the Instant Payments guide. For VRN-based receipt, follow Receive RTP Payments with Virtual Reference Numbers for rail-access and registration requirements.

For each enabled rail:

Review the applicable API request requirements.
Map your source data to the documented request fields.
Submit test payment instructions.
Review the API response and transaction information.
Verify the resulting activity against your expected test outcome.

Do not assume that a capability available elsewhere on the Newline platform is enabled for your ETAS program. Confirm program-specific access with your implementation team.

3. Handle responses and monitor payment activity

Use API responses and transaction information to monitor processing outcomes and keep your ledger records aligned with payment activity.

Test your application’s handling of:

Successful requests
Validation failures
Authentication failures
Connectivity interruptions
Processing failures
Timeout events
Transaction status updates and lifecycle events

Validate request fields and accepted values against the applicable API reference. The ETAS overview guides do not define separate ETAS-specific request schemas.

If a transaction remains pending:

Monitor its status.
Verify processing completion.
Review reporting outputs.
Contact your implementation or support team if its status remains unchanged.

See ETAS Troubleshooting for investigation steps.

4. Complete the DataMart integration

Configure the Batch File integration alongside your API implementation. This integration sends your business and transaction records to Newline DataMart through Secure File Transfer Protocol (SFTP).

ETAS requires two primary data files:

File	Content	Purpose
Business File	Business information for participants in your ETAS program	Supports customer identification, reporting, operational oversight, and monitoring.
Transaction File	Transaction-level activity associated with your ETAS program	Supports reporting, reconciliation, and payment monitoring.

Complete the following steps:

Obtain SFTP connection details and configure access to the designated directories.
Verify upload and response-file download capabilities.
Map your business and transaction source data to the approved file layouts.
Validate required fields, formatting, record completeness, and duplicate handling.
Submit test files through the approved SFTP channel.
Review processing results and correct validation failures.
Confirm production delivery schedules with your implementation team.

Use the Batch File Integration Guide for the submission workflow and the ETAS File Specs for field-level requirements.

These files provide data to DataMart; they are not a replacement for API payment instructions. If RTP is enabled, include reportable sent and received RTP activity and validate the applicable network-reference fields against the ETAS File Specs.

5. Reconcile payment activity and ledger records

Your organization remains responsible for maintaining customer balances and transaction history. Reconcile those records against payment-processing information, submitted files, and DataMart outputs.

Verify that:

Ledger balances agree with expected results.
Transaction totals balance correctly.
Business counts match your source systems.
API responses align with expected payment outcomes.
DataMart outputs align with submitted files.
Reporting outputs accurately reflect the activity being tested.

Perform reconciliation according to your internal processes and program requirements. Typical activities include daily transaction balancing, exception review, and variance investigation.

If results do not reconcile:

Review source transactions and ledger activity.
Compare submitted file contents with the source records.
Review processing results and exception reports.
Investigate missing records, duplicates, timing differences, and processing exceptions.
Escalate unresolved differences to your implementation or support team.

6. Complete testing and production approval

Complete testing across both integrations before requesting production approval.

Test area	Required validation
API connectivity	Credentials, authentication, endpoint access, and request/response handling work as expected.
Payment workflows	Each enabled rail handles successful payments, validation failures, errors, and status changes. For RTP, validate both sending and receiving, including VRN registration and receipt if your implementation uses VRNs.
File connectivity	SFTP access, directory access, uploads, and downloads work as expected.
File processing	Required files pass validation, processing results are reviewed, and response-file handling is tested.
Reconciliation	Ledger balances, payment activity, submitted data, and reporting outputs align with expected results.
User Acceptance Testing (UAT)	Business requirements are met and operational procedures are ready for production.

Before go-live:

Validate authentication and protect production credentials.
Implement access controls and monitoring.
Complete payment and file-processing tests.
Resolve reconciliation discrepancies.
Document balancing, exception-handling, and support procedures.
Identify escalation contacts.
Confirm production connectivity and file schedules.
Obtain production deployment approval.

Support and troubleshooting

Contact your assigned implementation or support team when:

Authentication or connectivity failures prevent testing.
API responses differ from documented or expected behavior.
Payment activity remains unresolved.
Files fail validation or cannot be processed.
Reconciliation differences remain unresolved.
Production configuration or delivery schedules need clarification.

Provide the environment, issue date and time, relevant transaction or business identifiers, file names, error messages, and steps to reproduce the issue. Share diagnostic information through approved channels and follow your organization’s data-handling policies.