Sezzle

Sezzle is a buy-now-pay-later platform that enables merchants to offer installment payment options at checkout. Its REST APIs support merchant checkout integration, order management, shopper authentication, customer tokenization, and payment installment processing — allowing shoppers to split purchases into four interest-free payments over six weeks.

Sezzle publishes 7 APIs on the APIs.io network, including Bearer Authentication API, Customer API, Order API, and 4 more. Tagged areas include Buy Now Pay Later, BNPL, Payments, Installments, and Fintech.

The Sezzle catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Sezzle’s developer surface includes authentication, developer portal, GitHub presence, pricing, terms of service, privacy policy, and 11 more developer resources.

🌐 Visit website 📡 Source on GitHub

37.1/100 thin ▬ flat Agent 24/100 agent aware Full breakdown ↓
scored 2026-08-25 · rubric v0.14.0

AccessPaidSelf serve

8 APIs

Buy Now Pay Later BNPL Payments Installments FintechMerchant IntegrationCheckout

Kin Score

Kin Score How this is scored →
scored 2026-08-25 · rubric v0.14.0

Composite quality — 37.1/100 · thin

Contract Quality 12.1 / 21

Developer Ergonomics 3.6 / 17

Access Clarity 6.7 / 17

Operational Transparency 0.6 / 11

Contract Governance 1.0 / 10

Discoverability 6.3 / 9

Regulatory Posture 6.3 / 15

Agent readiness — 24/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Surface 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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/sezzle: 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 8

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

Rate Limits 1

Documented rate limits and quota policies.

Rate Limits

0 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

JSON Schema 8

Standalone JSON Schema definitions for this provider's data models.

Scroll for all 8

Examples 7

Example request and response payloads for these APIs.

Scroll for all 7

Get Started 1

Portal, sign-up, and the first successful call

Portal

Portal

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 7

SDKs, sample code, and the tooling you integrate with

GitHub

SDKNode

SDKAndroid

SDKiOS

IntegrationMagento2

IntegrationMagento2

IntegrationWooCommerce

IntegrationWooCommerce

IntegrationShopify

IntegrationShopify

Scroll for all 7

Access & Security 3

Authentication, authorization, and security posture

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

MerchantSupport

MerchantSupport

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

Terms

Terms

Privacy

Privacy

Other 1

Properties that don't map to a standard resource type

Dashboard

Dashboard

Source (apis.yml)

name: Sezzle
description: Sezzle is a buy-now-pay-later platform that enables merchants to offer installment payment options at checkout.
  Its REST APIs support merchant checkout integration, order management, shopper authentication, customer tokenization, and
  payment installment processing — allowing shoppers to split purchases into four interest-free payments over six weeks.
accessModel:
  pricing: paid
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Paid · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/sezzle.png
url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/apis.yml
version: '0.19'
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
tags:
- Buy Now Pay Later
- BNPL
- Payments
- Installments
- Fintech
- Merchant Integration
- Checkout
apis:
- name: Sezzle API v1
  description: The legacy Sezzle v1 API for merchants. Supports checkout creation and order completion via redirect-based
    flow. Deprecated in favor of v2; existing integrations are encouraged to migrate to v2.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://docs.sezzle.com/docs/api/v1/v1
  baseURL: https://gateway.sezzle.com/v1
  tags:
  - Payments
  - Checkout
  - Legacy
  properties:
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/v1/v1
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v1
  contact:
  - FN: Sezzle Merchant Support
    url: https://merchant-help.sezzle.com
    email: ''
- aid: sezzle:sezzle-bearer-authentication-api
  name: Sezzle Bearer Authentication API
  description: The Bearer Authentication API from Sezzle — 1 operation(s) for bearer authentication.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Bearer Authentication
  properties:
  - type: OpenAPI
    url: openapi/sezzle-bearer-authentication-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
- aid: sezzle:sezzle-customer-api
  name: Sezzle Customer API
  description: The Customer API from Sezzle — 4 operation(s) for customer.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Customers
  tags_raw:
  - Customer
  properties:
  - type: OpenAPI
    url: openapi/sezzle-customer-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
- aid: sezzle:sezzle-order-api
  name: Sezzle Order API
  description: The Order API from Sezzle — 7 operation(s) for order.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Order
  properties:
  - type: OpenAPI
    url: openapi/sezzle-order-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
- aid: sezzle:sezzle-reports-api
  name: Sezzle Reports API
  description: The Reports API from Sezzle — 4 operation(s) for reports.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Reports
  properties:
  - type: OpenAPI
    url: openapi/sezzle-reports-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
- aid: sezzle:sezzle-session-api
  name: Sezzle Session API
  description: The Session API from Sezzle — 2 operation(s) for session.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Session
  properties:
  - type: OpenAPI
    url: openapi/sezzle-session-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
- aid: sezzle:sezzle-token-api
  name: Sezzle Token API
  description: The Token API from Sezzle — 2 operation(s) for token.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Token
  properties:
  - type: OpenAPI
    url: openapi/sezzle-token-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
- aid: sezzle:sezzle-webhooks-api
  name: Sezzle Webhooks API
  description: The Webhooks API from Sezzle — 3 operation(s) for webhooks.
  humanURL: https://docs.sezzle.com/docs/api/intro
  baseURL: https://gateway.sezzle.com/v2
  tags:
  - Webhook
  tags_raw:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/sezzle-webhooks-api-openapi.yml
  - type: Documentation
    url: https://docs.sezzle.com/docs/api/intro
  - type: Sandbox
    url: https://sandbox.gateway.sezzle.com/v2
  - type: Authentication
    url: https://docs.sezzle.com/docs/api/intro
  - type: Plans
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/plans/plans.yml
  - type: RateLimits
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/rate-limits/rate-limits.yml
  - type: FinOps
    url: https://raw.githubusercontent.com/api-evangelist/sezzle/refs/heads/main/finops/finops.yml
common:
- type: AgenticAccess
  url: agentic-access/sezzle-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/sezzle-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/sezzle-domain-security.yml
- type: Authentication
  url: authentication/sezzle-authentication.yml
- type: Portal
  url: https://docs.sezzle.com/
- type: Dashboard
  url: https://dashboard.sezzle.com/merchant
- type: MerchantSupport
  url: https://merchant-help.sezzle.com
- type: GitHub
  url: https://github.com/sezzle
- type: SDKNode
  url: https://github.com/sezzle/sezzle-node
- type: SDKAndroid
  url: https://github.com/sezzle/sezzle-merchant-sdk-android
- type: SDKiOS
  url: https://github.com/sezzle/sezzle-merchant-sdk-ios
- type: IntegrationMagento2
  url: https://github.com/sezzle/sezzle-magento2
- type: IntegrationWooCommerce
  url: https://docs.sezzle.com/
- type: IntegrationShopify
  url: https://apps.shopify.com/sezzle-payments
- type: Pricing
  url: https://sezzle.com/pricing
- type: Terms
  url: https://sezzle.com/terms-of-service
- type: Privacy
  url: https://sezzle.com/privacy-policy
maintainers:
- FN: API Evangelist
  url: https://apievangelist.com
  email: kin@apievangelist.com

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