EasySize

EasySize is an AI-powered size-recommendation platform for fashion e-commerce, marketed as "Fit Quiz." It helps clothing, footwear, sportswear, and swimwear retailers reduce returns and increase conversion by giving shoppers a personalized size recommendation without asking them for body measurements. EasySize ships as a native Shopify app and as a JavaScript library ("web app") that merchants embed on non-Shopify storefronts; the library is configured with a merchant-specific shop_id and product context and renders an in-page Fit Quiz widget. Merchants wire order-tracking and return-tracking events back to EasySize so the recommendation algorithm can learn, and can capture emails and drive personalized flows through a Klaviyo integration. EasySize supports 11+ languages with auto-detection, multiple size formats (UK/EU/US/international/custom), unisex and gender-aware logic, and additional fit/width/length recommendations. The company was a portfolio company of 500 Global.

EasySize publishes 1 API on the APIs.io network. Tagged areas include Company, Fashion, E-Commerce, Size Recommendation, and FIT.

EasySize’s developer surface includes documentation, getting-started guide, support, engineering blog, pricing, signup flow, and 10 more developer resources.

🌐 Visit website 📡 Source on GitHub

27.6/100 thin ▬ flat Agent 0/100 human only saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

1 APIs

Company Fashion E-CommerceSize RecommendationFIT Retail Shopify Personalization Widget JavaScript

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 27.6/100 · thin

Contract Quality 0.0 / 25

Developer Ergonomics 9.0 / 20

Access Clarity 8.9 / 20

Operational Transparency 2.1 / 13

Contract Governance 0.0 / 12

Discoverability 7.6 / 10

Agent readiness — 0/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 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

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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APIs 1

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

EasySize Fit Quiz JavaScript Library

Client-side JavaScript library that embeds the EasySize "Fit Quiz" size-recommendation widget on a merchant storefront. Loaded via a script tag from the EasySize web app CDN, it...

Security Posture 1

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

Easysize Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Lifecycle

Lifecycle

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

HelpCenter

HelpCenter

Support

Support

StatusPage

StatusPage

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

Source (apis.yml)

aid: easysize
name: EasySize
description: EasySize is an AI-powered size-recommendation platform for fashion e-commerce, marketed as "Fit Quiz." It helps
  clothing, footwear, sportswear, and swimwear retailers reduce returns and increase conversion by giving shoppers a personalized
  size recommendation without asking them for body measurements. EasySize ships as a native Shopify app and as a JavaScript
  library ("web app") that merchants embed on non-Shopify storefronts; the library is configured with a merchant-specific
  shop_id and product context and renders an in-page Fit Quiz widget. Merchants wire order-tracking and return-tracking events
  back to EasySize so the recommendation algorithm can learn, and can capture emails and drive personalized flows through
  a Klaviyo integration. EasySize supports 11+ languages with auto-detection, multiple size formats (UK/EU/US/international/custom),
  unisex and gender-aware logic, and additional fit/width/length recommendations. The company was a portfolio company of 500
  Global.
url: https://raw.githubusercontent.com/api-evangelist/easysize/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- 500-global
x-tier: stub
x-tier-reason: portfolio-lead
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-18'
image: https://cdn.prod.website-files.com/61fd2ddef6278cfc29072ae9/61fd48610cc67c01afaecfd3_easysize-logo.svg
tags:
- Company
- Fashion
- E-Commerce
- Size Recommendation
- FIT
- Retail
- Shopify
- Personalization
- Widget
- JavaScript
tags_raw:
- Company
- Fashion
- E-Commerce
- Size Recommendation
- Fit
- Retail
- Shopify
- Personalization
- Widget
- JavaScript
apis:
- name: EasySize Fit Quiz JavaScript Library
  description: Client-side JavaScript library that embeds the EasySize "Fit Quiz" size-recommendation widget on a merchant
    storefront. Loaded via a script tag from the EasySize web app CDN, it exposes a global EasySize object configured with
    a merchant shop_id plus product context, and provides hooks for size selection, order tracking, and return tracking.
  humanURL: https://developers.easysize.me
  baseURL: https://webapp.easysize.me
  tags:
  - Size Recommendation
  - JavaScript
  - Widget
  properties:
  - type: Documentation
    url: https://developers.easysize.me
  - type: GettingStarted
    url: https://developers.easysize.me/easysize_library/
  - type: Packages
    url: packages/easysize-packages.yml
  - type: SDKs
    url: packages/easysize-packages.yml
  - type: Components
    url: components/easysize-components.yml
  - type: Conventions
    url: conventions/easysize-conventions.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://easysize.me
- type: DeveloperPortal
  url: https://developers.easysize.me
- type: Documentation
  url: https://developers.easysize.me
- type: GettingStarted
  url: https://developers.easysize.me/easysize_library/
- type: HelpCenter
  url: https://help.easysize.me
- type: Support
  url: https://help.easysize.me
- type: Blog
  url: https://www.easysize.me/blog
- type: Pricing
  url: https://www.easysize.me/pricing
- type: TermsOfService
  url: https://www.easysize.me/terms-of-service
- type: PrivacyPolicy
  url: https://www.easysize.me/privacy-policy
- type: SignUp
  url: https://apps.shopify.com/fit-quiz
- type: StatusPage
  url: https://easysize.statuspage.io
- type: Lifecycle
  url: lifecycle/easysize-lifecycle.yml
- type: LLMsTxt
  url: llms/easysize-llms.txt
- type: WellKnown
  url: well-known/easysize-well-known.yml
- type: DomainSecurity
  url: security/easysize-domain-security.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

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