> ## Documentation Index
> Fetch the complete documentation index at: https://docs.truv.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Payroll
> Payroll provider coverage, authentication methods, and Smart Login
Truv connects to 93+ payroll providers covering 220M+ Americans, 96% of the US labor force, including gig income workers. Truv maps over 300,000 employers to payroll providers so users don't need to make that selection.
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## Provider coverage API
Query provider coverage and success rates using the [Data Providers API](/api-reference/data-providers/providers-list). Search for employers and retrieve their mapped payroll provider using the [Companies API](/api-reference/companies/object).
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## Authenticate users
Truv's [Smart Login](/banking/smart-login) presents the best authentication method for each user based on employer, historical success rates, and payroll system compatibility.
| Method | Description |
| --------------------- | ------------------------------------------------------------------------------------------ |
| Native OAuth | In-bridge redirect to payroll provider. Patented solution across the largest integrations. |
| Single Sign-On (SSO) | Employee credentials via 64 SSO system integrations |
| Credential-less Login | One-time passcode via trusted phone or email. Supported by ADP, Paycom. |
| AppClip & Instant App | iOS AppClip and Android Instant App for employers behind VPNs |
| Mapped Payroll | 300,000+ employers mapped to payroll providers automatically |
| Unmapped Payroll | Provider recommendations based on historical data and employer size |
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## Data sources
The `data_source` field on links and providers identifies how data was collected.
| Data source | Description |
| -------------------- | ---------------------------------------------------- |
| `payroll` | Direct API connection to payroll provider |
| `docs` | User-uploaded documents (pay stubs, W-2s, tax forms) |
| `financial_accounts` | Bank account transaction analysis |
| `tax` | Tax return data |
***
## Payroll products
Instant income and employment verification from payroll
Multi-year employment history from payroll systems
Redirect user paychecks to your bank account
Automatic loan repayment from borrower paychecks