OnPay

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.

OnPay publishes 6 APIs on the APIs.io network, including Company API, Deductions API, Employees API, and 3 more. Tagged areas include payroll, human-resources, employee-benefits, payroll-tax, and small-business.

OnPay’s developer surface includes documentation, API reference, getting-started guide, support, engineering blog, pricing, signup flow, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub

44.7/100 developing ▬ flat Agent 42/100 agent ready Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0

6 APIs 1 MCP Servers

payrollhuman-resourcesemployee-benefitspayroll-taxsmall-businessworkforce-managementfintechhr-techtime-and-attendanceretirement-401k

Kin Score

Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0

Composite quality — 44.7/100 · developing

Contract Quality 11.0 / 25

Developer Ergonomics 11.2 / 20

Commercial Clarity 10.5 / 20

Operational Transparency 1.4 / 13

Governance 1.4 / 12

Discoverability 9.3 / 10

Agent readiness — 42/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/onpay: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

Individual APIs this provider publishes, each with its own machine-readable definition.

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Scopes 1

OAuth scopes governing access to this provider's APIs.

Onpay Scopes

6 scopes · authorizationCode

6 scopes

SCOPES

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Login

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer

AgenticAccess

LLMsTxt

AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

Conformance

DataModel

Access & Security 6

Authentication, authorization, and security posture

DomainSecurity

Security

Compliance

Authentication

OAuthScopes

VulnerabilityDisclosure

VulnerabilityDisclosure

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: onpay
name: OnPay
description: 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.
image: https://onpay.com/wp-content/uploads/2017/08/d9fo84j1zi.jpg
url: https://raw.githubusercontent.com/api-evangelist/onpay/refs/heads/main/apis.yml
x-type: company
x-source: harvest:secondary-market
specificationVersion: '0.21'
created: '2026-08-04'
modified: '2026-08-04'
tags:
- payroll
- human-resources
- employee-benefits
- payroll-tax
- small-business
- workforce-management
- fintech
- hr-tech
- time-and-attendance
- retirement-401k
apis:
- aid: onpay:onpay-company-api
  name: OnPay Company API
  description: The Company API from OnPay — 17 operation(s) for company.
  humanURL: https://onpay.readme.io/reference/authorization
  baseURL: https://api.onpay.com/v2
  tags:
  - Company
  properties:
  - type: OpenAPI
    url: openapi/onpay-company-api-openapi.yml
  - type: Documentation
    url: https://onpay.readme.io/
  - type: APIReference
    url: https://onpay.readme.io/reference/authorization
  - type: Authentication
    url: authentication/onpay-authentication.yml
  - type: OAuthScopes
    url: scopes/onpay-scopes.yml
  - type: ErrorCatalog
    url: errors/onpay-problem-types.yml
  - type: Conventions
    url: conventions/onpay-conventions.yml
  - type: DataModel
    url: data-model/onpay-data-model.yml
  - type: LLMsTxt
    url: https://onpay.readme.io/llms.txt
- aid: onpay:onpay-deductions-api
  name: OnPay Deductions API
  description: The Deductions API from OnPay — 7 operation(s) for deductions.
  humanURL: https://onpay.readme.io/reference/authorization
  baseURL: https://api.onpay.com/v2
  tags:
  - Deductions
  properties:
  - type: OpenAPI
    url: openapi/onpay-deductions-api-openapi.yml
  - type: Documentation
    url: https://onpay.readme.io/
  - type: APIReference
    url: https://onpay.readme.io/reference/authorization
  - type: Authentication
    url: authentication/onpay-authentication.yml
  - type: OAuthScopes
    url: scopes/onpay-scopes.yml
  - type: ErrorCatalog
    url: errors/onpay-problem-types.yml
  - type: Conventions
    url: conventions/onpay-conventions.yml
  - type: DataModel
    url: data-model/onpay-data-model.yml
  - type: LLMsTxt
    url: https://onpay.readme.io/llms.txt
- aid: onpay:onpay-employees-api
  name: OnPay Employees API
  description: The Employees API from OnPay — 14 operation(s) for employees.
  humanURL: https://onpay.readme.io/reference/authorization
  baseURL: https://api.onpay.com/v2
  tags:
  - Employees
  properties:
  - type: OpenAPI
    url: openapi/onpay-employees-api-openapi.yml
  - type: Documentation
    url: https://onpay.readme.io/
  - type: APIReference
    url: https://onpay.readme.io/reference/authorization
  - type: Authentication
    url: authentication/onpay-authentication.yml
  - type: OAuthScopes
    url: scopes/onpay-scopes.yml
  - type: ErrorCatalog
    url: errors/onpay-problem-types.yml
  - type: Conventions
    url: conventions/onpay-conventions.yml
  - type: DataModel
    url: data-model/onpay-data-model.yml
  - type: LLMsTxt
    url: https://onpay.readme.io/llms.txt
- aid: onpay:onpay-pay-runs-api
  name: OnPay Pay Runs API
  description: The Pay-runs API from OnPay — 2 operation(s) for pay-runs.
  humanURL: https://onpay.readme.io/reference/authorization
  baseURL: https://api.onpay.com/v2
  tags:
  - Pay-runs
  properties:
  - type: OpenAPI
    url: openapi/onpay-pay-runs-api-openapi.yml
  - type: Documentation
    url: https://onpay.readme.io/
  - type: APIReference
    url: https://onpay.readme.io/reference/authorization
  - type: Authentication
    url: authentication/onpay-authentication.yml
  - type: OAuthScopes
    url: scopes/onpay-scopes.yml
  - type: ErrorCatalog
    url: errors/onpay-problem-types.yml
  - type: Conventions
    url: conventions/onpay-conventions.yml
  - type: DataModel
    url: data-model/onpay-data-model.yml
  - type: LLMsTxt
    url: https://onpay.readme.io/llms.txt
- aid: onpay:onpay-reports-api
  name: OnPay Reports API
  description: The Reports API from OnPay — 2 operation(s) for reports.
  humanURL: https://onpay.readme.io/reference/authorization
  baseURL: https://api.onpay.com/v2
  tags:
  - Reports
  properties:
  - type: OpenAPI
    url: openapi/onpay-reports-api-openapi.yml
  - type: Documentation
    url: https://onpay.readme.io/
  - type: APIReference
    url: https://onpay.readme.io/reference/authorization
  - type: Authentication
    url: authentication/onpay-authentication.yml
  - type: OAuthScopes
    url: scopes/onpay-scopes.yml
  - type: ErrorCatalog
    url: errors/onpay-problem-types.yml
  - type: Conventions
    url: conventions/onpay-conventions.yml
  - type: DataModel
    url: data-model/onpay-data-model.yml
  - type: LLMsTxt
    url: https://onpay.readme.io/llms.txt
- aid: onpay:onpay-user-api
  name: OnPay User API
  description: The User API from OnPay — 1 operation(s) for user.
  humanURL: https://onpay.readme.io/reference/authorization
  baseURL: https://api.onpay.com/v2
  tags:
  - User
  properties:
  - type: OpenAPI
    url: openapi/onpay-user-api-openapi.yml
  - type: Documentation
    url: https://onpay.readme.io/
  - type: APIReference
    url: https://onpay.readme.io/reference/authorization
  - type: Authentication
    url: authentication/onpay-authentication.yml
  - type: OAuthScopes
    url: scopes/onpay-scopes.yml
  - type: ErrorCatalog
    url: errors/onpay-problem-types.yml
  - type: Conventions
    url: conventions/onpay-conventions.yml
  - type: DataModel
    url: data-model/onpay-data-model.yml
  - type: LLMsTxt
    url: https://onpay.readme.io/llms.txt
common:
- type: MCPServer
  url: mcp/onpay-mcp.yml
- type: Overlay
  url: overlays/onpay-api-overlay.yaml
- type: DomainSecurity
  url: security/onpay-domain-security.yml
- type: AgenticAccess
  url: agentic-access/onpay-agentic-access.yml
- type: Website
  url: https://onpay.com/
- type: DeveloperPortal
  url: https://onpay.readme.io/
- type: Documentation
  url: https://onpay.readme.io/
- type: APIReference
  url: https://onpay.readme.io/reference/authorization
- type: GettingStarted
  url: https://onpay.readme.io/docs/getting-started
- type: Support
  url: https://help.onpay.com/hc/en-us
- type: Blog
  url: https://onpay.com/insights/
- type: Pricing
  url: https://onpay.com/payroll/software/costs-pricing/
- type: SignUp
  url: https://onpay.com/get-started/
- type: Login
  url: https://app.onpay.com/app/login
- type: TermsOfService
  url: https://onpay.com/terms-of-service/
- type: PrivacyPolicy
  url: https://onpay.com/privacy/
- type: Security
  url: https://onpay.com/security/
- type: Compliance
  url: https://onpay.com/security/
- type: Integrations
  url: https://onpay.com/app-directory/
- type: LLMsTxt
  url: llms/onpay-llms.txt
- type: Authentication
  url: authentication/onpay-authentication.yml
- type: OAuthScopes
  url: scopes/onpay-scopes.yml
- type: Conventions
  url: conventions/onpay-conventions.yml
- type: ErrorCatalog
  url: errors/onpay-problem-types.yml
- type: Lifecycle
  url: lifecycle/onpay-lifecycle.yml
- type: Conformance
  url: conformance/onpay-conformance.yml
- type: DataModel
  url: data-model/onpay-data-model.yml
- type: VulnerabilityDisclosure
  url: security/onpay-vulnerability-disclosure.yml
- type: AgentSkill
  url: skills/_index.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-08-04'
  status: enriched
  artifacts_added: 20
  pass: local-v1

OnPay

Kin Score

APIs 6

OnPay Company API

OnPay Deductions API

OnPay Employees API

OnPay Pay Runs API

OnPay Reports API

OnPay User API

Open Collections 7

API Collection