Pull processed payroll run data (earnings, deductions, taxes) from the Paychex Flex API to construct general ledger journal entries for posting to an accounting system.

Steps

1. Register in the Paychex Developer Program portal and complete the required partner/client approval process to obtain API credentials.
2. Obtain an OAuth2 access token from the Paychex token endpoint using your client credentials.
3. Query the Payroll resource for the target company to retrieve EmployeePayrollRun objects for the processed run, each containing Earnings (e.g., SALARY, OVERTIME, BONUS, REIMBURSEMENT), Deductions, taxes, and net pay per employee.
4. Map each employee's company/department/location and earning/deduction type to your GL chart of accounts, since the API returns pay data rather than GL-coded entries.
5. Aggregate the mapped line items into journal entries and post them to your accounting system.
6. If instead you want Paychex to post directly into an accounting package, note that Paychex Flex's separate General Ledger Service (GLS) — set up with a Paychex GL specialist and linked via a 'Link and Sync' tool (e.g., to QuickBooks Online) — is a distinct product feature, not part of the public developer API.