Sezzle website screenshot

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, Payments, Installments, Fintech, and Merchant Integration.

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 12 more developer resources.

🌐 Visit website 📡 Source on GitHub
37.8/100 thin ▬ flat Agent 24/100 agent aware saas Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0
AccessPaid
1 APIs
Buy Now Pay LaterPaymentsInstallmentsFintechMerchant IntegrationCheckout

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0
Composite quality — 37.8/100 · thin
Contract Quality 10.7 / 19
Developer Ergonomics 4.7 / 15
Access Clarity 5.9 / 15
Operational Transparency 0.5 / 10
Contract Governance 0.9 / 9
Discoverability 5.1 / 8
Regulatory Posture 6.3 / 15
Create-or-Update Ergonomics 0.0 / 10
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 Well-Known Document 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.
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% 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/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. 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. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 8

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

Sezzle API v1

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 ...

Sezzle Bearer Authentication API

The Bearer Authentication API from Sezzle — 1 operation(s) for bearer authentication.

Sezzle Customer API

The Customer API from Sezzle — 4 operation(s) for customer.

Sezzle Order API

The Order API from Sezzle — 7 operation(s) for order.

Sezzle Reports API

The Reports API from Sezzle — 4 operation(s) for reports.

Sezzle Session API

The Session API from Sezzle — 2 operation(s) for session.

Sezzle Token API

The Token API from Sezzle — 2 operation(s) for token.

Sezzle Webhooks API

The Webhooks API from Sezzle — 3 operation(s) for webhooks.

Scroll for all 8

Open Collections 8

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

Sezzle API v2 Bearer Authentication API

OPEN COLLECTION

Sezzle API v2 Bearer Authentication Customer API

OPEN COLLECTION

Sezzle API v2 Bearer Authentication Order API

OPEN COLLECTION

Sezzle API v2 Bearer Authentication Reports API

OPEN COLLECTION

Sezzle API v2 Bearer Authentication Session API

OPEN COLLECTION

Sezzle API v2 Bearer Authentication Token API

OPEN COLLECTION

Sezzle API v2 Bearer Authentication Webhooks API

OPEN COLLECTION

Scroll for all 8

Pricing Plans 1

Published pricing tiers and plan structures.

Plans

2 plans

PLANS

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.

Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Sezzle Context

12 classes · 60 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Sezzle API Rules

5 rules · 4 warnings 1 info

SPECTRAL

JSON Schema 8

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

Address

8 properties

JSON SCHEMA

Customer

8 properties

JSON SCHEMA

Discount

2 properties

JSON SCHEMA

LineItem

4 properties

JSON SCHEMA

Order

9 properties

JSON SCHEMA

Payout

0 properties

JSON SCHEMA

Price

2 properties

JSON SCHEMA

Webhook

2 properties

JSON SCHEMA

Scroll for all 8

Examples 7

Example request and response payloads for these APIs.

Authentication Request

2 fields

EXAMPLE

Authentication Response

3 fields

EXAMPLE

Capture Request

1 fields

EXAMPLE

Refund Request

2 fields

EXAMPLE

Session Request

4 fields

EXAMPLE

Session Response

4 fields

EXAMPLE

Webhook Create Request

2 fields

EXAMPLE

Scroll for all 7

Security Posture 3

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

Sezzle Authentication

apiKey · 1 scheme

SECURITY

Sezzle Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Sezzle Vulnerability Disclosure

security.txt · contact published

SECURITY

Agentic Access 1

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

Sezzle Agentic Access

27 operations · 15 acting

27 operations · 15 acting

AGENTIC

Resources

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
GitHub
 SDKNode
SDKNode
 SDKAndroid
SDKAndroid
 SDKiOS
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

Company 1

The organization behind the API

Website
Website

Other 1

Properties that don't map to a standard resource type

Dashboard
Dashboard

Source (apis.yml)

apis.yml Raw ↑ 
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.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  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
- Payments
- Installments
- Fintech
- Merchant Integration
- Checkout
tags_raw:
- 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: Website
  url: https://www.sezzle.com/
- 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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