Onsi

Onsi is a global technology provider and UK/EU insurance intermediary that delivers flexible, shift-linked worker benefits — on-demand ("Embedded") pay, insurance cover, and a rewards marketplace — to employers and their frontline workers. Its Partner (BMO) API lets benefit-program partners manage members (invite, read, update, replace, and offboard individually, in batches, or via full-list CSV jobs), read tiers and earned-wage balances, run on-demand pay withdrawals through a two-step intent/complete flow, and reconcile pay cycles and deductions with payroll. Authentication is an x-api-key header; requests support idempotency (x-idempotency-key, 7-day retention) and skip/take offset pagination, with a consistent code/message error envelope.

Onsi publishes 2 APIs on the APIs.io network: members API and pay API. Tagged areas include Company, Benefits, Earned Wage Access, On-Demand Pay, and Payroll.

Onsi’s developer surface includes documentation, API reference, getting-started guide, support, engineering blog, changelog, authentication, and 18 more developer resources.

42.7/100 thin ▬ flat Agent 81/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5
AccessSelf serve
2 APIs 1 MCP Servers
CompanyBenefitsEarned Wage AccessOn-Demand PayPayrollFintechInsuranceWorkforceHRHealth

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 42.7/100 · thin
Contract Quality 10.3 / 25
Developer Ergonomics 14.8 / 20
Commercial Clarity 4.2 / 20
Operational Transparency 2.1 / 13
Governance 0.0 / 12
Discoverability 9.3 / 10
Agent readiness — 81/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
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/onsi: 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 2

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

Onsi members API

The members API from Onsi — 7 operation(s) for members.

Onsi pay API

The pay API from Onsi — 9 operation(s) for pay.

MCP Servers 1

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

onsi-mcp.yml

MCP SERVER

Rate Limits 1

Documented rate limits and quota policies.

Onsi Rate Limits

0 limits

RATE LIMITS

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Onsi Authentication

apiKey · 1 scheme

SECURITY

Onsi Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Onsi Agentic Access

20 operations · 10 acting

20 operations · 10 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Access & Security 2

Authentication, authorization, and security posture

Operate 4

Status, limits, changes, and where to get help

Commercial 2

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

Source (apis.yml)

apis.yml Raw ↑
aid: onsi
name: Onsi
description: Onsi is a global technology provider and UK/EU insurance intermediary that delivers flexible, shift-linked worker
  benefits — on-demand ("Embedded") pay, insurance cover, and a rewards marketplace — to employers and their frontline workers.
  Its Partner (BMO) API lets benefit-program partners manage members (invite, read, update, replace, and offboard individually,
  in batches, or via full-list CSV jobs), read tiers and earned-wage balances, run on-demand pay withdrawals through a two-step
  intent/complete flow, and reconcile pay cycles and deductions with payroll. Authentication is an x-api-key header; requests
  support idempotency (x-idempotency-key, 7-day retention) and skip/take offset pagination, with a consistent code/message
  error envelope.
url: https://raw.githubusercontent.com/api-evangelist/onsi/refs/heads/main/apis.yml
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://framerusercontent.com/assets/Kgx16PhdTJfIAzqiv0XeASdgeZU.jpg
x-type: company
x-source: vc-portfolio
x-backed-by:
- prosus-ventures
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Benefits
- Earned Wage Access
- On-Demand Pay
- Payroll
- Fintech
- Insurance
- Workforce
- HR
- Health
apis:
- aid: onsi:onsi-members-api
  name: Onsi members API
  description: The members API from Onsi — 7 operation(s) for members.
  humanURL: https://docs.onsi.com
  baseURL: https://api.onsi.com
  tags:
  - members
  properties:
  - type: OpenAPI
    url: openapi/onsi-members-api-openapi.yml
  - type: Documentation
    url: https://docs.onsi.com
  - type: APIReference
    url: https://docs.onsi.com/api-reference/introduction
- aid: onsi:onsi-pay-api
  name: Onsi pay API
  description: The pay API from Onsi — 9 operation(s) for pay.
  humanURL: https://docs.onsi.com
  baseURL: https://api.onsi.com
  tags:
  - pay
  properties:
  - type: OpenAPI
    url: openapi/onsi-pay-api-openapi.yml
  - type: Documentation
    url: https://docs.onsi.com
  - type: APIReference
    url: https://docs.onsi.com/api-reference/introduction
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://onsi.com
- type: DeveloperPortal
  url: https://docs.onsi.com
- type: Documentation
  url: https://docs.onsi.com
- type: APIReference
  url: https://docs.onsi.com/api-reference/introduction
- type: GettingStarted
  url: https://docs.onsi.com/docs/member-management/get-started
- type: Support
  url: https://onsi.com/contact
- type: Blog
  url: https://onsi.com/blog
- type: PrivacyPolicy
  url: https://pages.onsi.com/onsi-global-privacy-policy
- type: TermsOfService
  url: https://pages.onsi.com/onsi-terms-of-use-uk-and-row
- type: ChangeLog
  url: https://docs.onsi.com/docs/changelog
- type: ChangeLog
  url: changelog/onsi-changelog.yml
- type: LLMsTxt
  url: llms/onsi-llms.txt
- type: Authentication
  url: authentication/onsi-authentication.yml
- type: Conventions
  url: conventions/onsi-conventions.yml
- type: Idempotency
  url: conventions/onsi-conventions.yml
- type: ErrorCatalog
  url: errors/onsi-error-codes.yml
- type: RateLimits
  url: rate-limits/onsi-rate-limits.yml
- type: Lifecycle
  url: lifecycle/onsi-lifecycle.yml
- type: Conformance
  url: conformance/onsi-conformance.yml
- type: DataModel
  url: data-model/onsi-data-model.yml
- type: Sandbox
  url: sandbox/onsi-sandbox.yml
- type: MCPServer
  url: mcp/onsi-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: DomainSecurity
  url: security/onsi-domain-security.yml
- type: AgenticAccess
  url: agentic-access/onsi-agentic-access.yml
x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 20
  pass: local-v1