Sage 50 and Gusto integration

What moves between them

The main flow runs from Gusto into Sage 50. After each payroll run in Gusto, ml-connector reads Gusto's payroll records and earnings data, then posts the labor cost journals into Sage 50's general ledger, mapped to the correct GL accounts and cost codes that already exist in Sage 50. Employee records flow the same direction: new hires, terminations, and status changes in Gusto are synced to Sage 50 so that headcount and employee data stay in agreement. The sync runs on a schedule tied to your payroll calendar or in response to Gusto webhook events for payroll changes. Because Gusto is cloud-based with webhooks and Sage 50 is desktop-based with polling only, ml-connector receives Gusto payroll notifications and translates them into scheduled polls of Sage 50 via the local SDK.

How ml-connector handles it

ml-connector stores both credential sets encrypted: Gusto OAuth2 credentials (client ID, client secret, and refresh token) are refreshed on a 90-minute schedule before expiry, and Sage 50 credentials (username, password, and full Windows path to the company folder) are sent only to the Windows process running the local SDK. When a Gusto payroll event arrives via webhook, ml-connector verifies the signature using HMAC-SHA256 and the subscription verification token, then schedules a poll of Sage 50 to read the payroll GL postings that need to be created. GL postings are constructed from Gusto earnings and compensations data, matched to Sage 50 GL accounts and cost codes by employee job code or location, and written as General Journal entries in Sage 50. Employee data flows from Gusto (hire date, name, job title, location) to Sage 50's Employee entity. Because Gusto rate limits at 200 requests per minute and Sage 50 is polling only, ml-connector throttles requests to both systems and backs off on 429 responses. Every record carries a full audit trail, and the system tracks which payroll run corresponds to which GL postings so they can be reversed and replayed if needed.

A real-world example

A small accounting firm manages Sage 50 for its client's general ledger and tax filings, while the client uses Gusto for payroll processing across three locations. Previously, after each payroll run the firm manually exported the labor totals from Gusto, looked up the correct GL accounts in Sage 50 by location and department code, and entered the journal entries by hand. This was error-prone and time-consuming during month-end close. Now, with Sage 50 and Gusto connected, each payroll run's GL data flows automatically into Sage 50 with the correct accounts already matched, and employee hire and termination data stays in sync. The firm no longer spends time on payroll data re-entry, and the general ledger reconciles faster.

What you can do

• •Post Gusto payroll GL postings into Sage 50's general ledger after each pay run, allocated to the correct GL accounts and cost codes.
• •Keep Sage 50 employee records in sync with Gusto hires, terminations, and status changes.
• •Authenticate Gusto via OAuth2 and Sage 50 via local Windows SDK credentials, managing token refresh and credential expiry.
• •Receive Gusto payroll webhook notifications and translate them into Sage 50 local SDK polls to keep polling and webhooks in sync.
• •Track each payroll posting through the audit trail so GL entries can be reversed and replayed if a downstream sync fails.

Questions

Does ml-connector handle Sage 50's requirement for a Windows machine with the SDK installed?

Yes. ml-connector runs a Windows process with direct access to the Sage 50 company data files and the local SDK. The Sage 50 credentials (username, password, and full path to the company folder) are stored encrypted and used only by that Windows process. The integration user must not be logged into Sage 50 interactively while ml-connector is polling, as Sage 50 requires exclusive access.

Which direction does data move between Sage 50 and Gusto?

The main flow is Gusto into Sage 50. Payroll GL postings and employee records move from Gusto into Sage 50. Gusto provides no GL accounts or accounting dimensions of its own, so ml-connector maps Gusto earnings and employee attributes to existing Sage 50 GL accounts and cost codes based on job codes or locations that you configure.

How does ml-connector handle Gusto's 2-hour token expiry and Sage 50's lack of webhooks?

ml-connector refreshes the Gusto OAuth2 token on a 90-minute schedule before expiry, so the token is always fresh when a payroll event arrives. Gusto sends payroll webhook notifications when a payroll is created or processed; ml-connector receives those webhooks, verifies the signature, and then polls Sage 50 via the local SDK to read and post the GL entries, bridging Gusto's webhook model with Sage 50's polling-only approach.