Microsoft Dynamics GP and Gusto integration

What moves between them

Employee records and payroll allocations flow from Microsoft Dynamics GP into Gusto. New employees created in Dynamics GP are synced to Gusto with their job codes and compensation details mapped from GP cost centers and vendor records. Payroll GL journals generated by Gusto are read and mapped back to Dynamics GP's general ledger, with each line allocated to the corresponding GL account and cost center in GP. Reference data such as locations and earning types are aligned in both directions to ensure payroll processing lands on valid Gusto dimensions.

How ml-connector handles it

ml-connector manages two separate auth bridges: it presents Windows domain credentials to authenticate against Dynamics GP's SBA or SOAP endpoint, and uses OAuth2 client credentials to authenticate against Gusto's REST API. On the Dynamics GP side, it polls for GL journal entries and employee records using ModifiedDate filters, respecting the 2-5 concurrent request limit and 100-200ms delays to avoid overwhelming the on-premises SQL Server. When a Gusto webhook signals a payroll event, ml-connector reads the Gusto payroll run, maps the GL lines to Dynamics GP GL accounts and cost centers, and posts the journal entries into Dynamics GP. Because Dynamics GP allows writes only to unposted (Work) transactions and requires fiscal periods to be open, ml-connector validates the fiscal period status before posting and routes failed entries to the audit log for manual review. Gusto's 200-request-per-minute rate limit is tracked per grant, and ml-connector backs off on 429 responses. Every record carries a full audit trail and can be replayed if a downstream GL posting fails.

A real-world example

A mid-sized professional services firm runs Microsoft Dynamics GP on-premises for GL, AP, and AR, and Gusto in the cloud for payroll and employee management. Before the integration, the accounting team manually exported payroll summaries from Gusto each pay period, entered labor cost allocations into Dynamics GP by hand, and spent hours month-end matching employee headcount in Gusto against GP labor accounts. With Dynamics GP and Gusto connected, new hires and terminations flow automatically from GP to Gusto, and after each payroll run, the labor cost journals post into GP's general ledger allocated by location and job code. Month-end close starts with labor accounts already reconciled, eliminating the manual re-entry step.

What you can do

• •Sync employees and compensation records from Microsoft Dynamics GP to Gusto, mapped to Gusto locations and earning types.
• •Post Gusto payroll GL journals back into Dynamics GP's general ledger, allocated to the correct GL accounts and cost centers.
• •Poll Dynamics GP on a schedule tied to your payroll calendar, respecting Windows auth, fiscal period constraints, and SQL Server performance limits.
• •Authenticate Dynamics GP via Windows Active Directory and Gusto via OAuth2, managing token refresh and credential storage encrypted.
• •Validate fiscal periods, track rate limits on both platforms, and maintain a full audit trail with replay capability for failed GL postings.

Questions

How does ml-connector authenticate to Microsoft Dynamics GP when it requires Windows Active Directory?

ml-connector stores Windows domain credentials encrypted and presents them via Negotiate/Kerberos or NTLM authentication against the Dynamics GP SBA or SOAP endpoint. The customer must create a dedicated Windows domain account with appropriate GP user role and security restrictions, and ml-connector manages that credential securely for every request.

Can payroll data flow both directions between Dynamics GP and Gusto?

No. Employee records and payroll GL journals flow from Dynamics GP into Gusto. Payroll GL documents generated by Gusto flow back into Dynamics GP as general ledger journal entries. Gusto has no native GL accounts or vendor records, so financial data cannot flow back to Gusto from GP.

Why does ml-connector need to validate fiscal periods in Dynamics GP before posting payroll GL entries?

Dynamics GP only allows write operations to unposted (Work) transactions, and the fiscal period must be open in the GP calendar to create new transactions. If the period is closed or locked, the GL posting fails with a validation error. ml-connector checks the fiscal period status before posting and routes failed entries to the audit log so you can review and retry after opening the period.