# OnPay

**Canonical:** https://apis.io/providers/onpay/  
**Website:** https://onpay.com/  
**APIs profiled:** 6

OnPay is an Atlanta, Georgia based provider of full-service online payroll, HR, and employee benefits software for small and mid-size US businesses, founded in 2011 and funded by Carrick Capital Partners. The platform runs payroll and direct deposit, files federal, state, and local payroll taxes, and handles onboarding, PTO, org charts, health insurance, 401(k), and workers' compensation. For developers, OnPay publishes a partner-only REST API (v2) documented on a public ReadMe hub, covering employees, employee deductions, wages, leave, tax fields, bank accounts, terminations and rehires, company worksites, locations, departments and positions, pay schedules, and payroll reporting. Access is limited to approved partners, authorized with OAuth 2.0 authorization-code grants against app.onpay.com and role-scoped bearer tokens.

## Kin Score — 44.7 / 100 (developing)

Scored 2026-08-17 under rubric 0.11.0. Trend: flat (+0.0 from 44.7).

| Facet | Score |
|---|---|
| Discoverability | 92.6 |
| Contract Quality | 44.0 |
| Governance | 11.5 |
| Operational Transparency | 10.5 |
| Developer Ergonomics | 56.0 |
| Commercial Clarity | 52.6 |

## Agent readiness — 42.1 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| MCP Server | derived |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | verified |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | yes |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## APIs (6)

- **OnPay Company API** — The Company API from OnPay — 17 operation(s) for company.
- **OnPay Deductions API** — The Deductions API from OnPay — 7 operation(s) for deductions.
- **OnPay Employees API** — The Employees API from OnPay — 14 operation(s) for employees.
- **OnPay Pay Runs API** — The Pay-runs API from OnPay — 2 operation(s) for pay-runs.
- **OnPay Reports API** — The Reports API from OnPay — 2 operation(s) for reports.
- **OnPay User API** — The User API from OnPay — 1 operation(s) for user.

## MCP servers (1)

- **onpay-mcp.yml**

## Agentic access (1)

- **Onpay Agentic Access** — 58 operations · 28 acting

## Security (3)

- **Onpay Authentication** — apiKey/oauth2 · 2 schemes
- **Onpay Domain Security** — TLSv1.3 · HSTS · DMARC
- **Onpay Vulnerability Disclosure** — Hackerone · contact published

## Tags

payroll, human-resources, employee-benefits, payroll-tax, small-business, workforce-management, fintech, hr-tech, time-and-attendance, retirement-401k

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/onpay/). Scores are computed from the provider's own public artifacts under a published rubric.