Zilch

Zilch is a London-headquartered "buy now, pay later" and ad-subsidised payments network founded in 2018, and one of the United Kingdom's most prominent BNPL brands. Rather than integrating at each retailer's checkout, Zilch is deliberately merchant-agnostic: consumers apply in the Zilch mobile app, receive a virtual (and physical) Mastercard, and can Pay-in-3, pay over six weeks, or Pay-now-and-earn-cashback anywhere Mastercard is accepted, online or in-store, through Apple Pay and Google Pay wallets. Because Zilch reaches merchants over the open Mastercard card rails and relies on partners such as Mastercard for card issuing and Checkout.com as its payments processor, it does not operate a public merchant-integration or developer platform the way a PSP or open-banking provider does. As of this review Zilch publishes no developer portal, no API reference, and no downloadable OpenAPI/Swagger specification; its public surface is a consumer marketing site, a help centre, and a customer sign-up/login app. This profile therefore records Zilch's verified public web properties honestly and carries no API entries, because none are publicly documented.

Zilch is profiled on the APIs.io network. Tagged areas include Payments, United Kingdom, Buy Now Pay Later, Consumer Credit, and Digital Wallet.

Zilch’s developer surface includes engineering blog, product news, signup flow, and 13 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

17.3/100 emerging ▬ flat Agent 0/100 human only Front door AI 1/6 silent Heartbeat 52/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

0 APIs

Payments United Kingdom Buy Now Pay Later Consumer Credit Digital Wallet Cards Mastercard Fintech

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 17.3/100 · emerging

Contract Quality 0.0 / 21

Developer Ergonomics 1.2 / 17

Access Clarity 7.2 / 17

Operational Transparency 1.2 / 11

Contract Governance 0.0 / 10

Discoverability 4.8 / 9

Regulatory Posture 3.3 / 15

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

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

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 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.

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/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes

13 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Developer Ergonomics scores 7.1 — up to +18.6 composite points
Contract Governance scores 0.0 — up to +12.0 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/zilch/apis.yml: open an issue on github.com/api-evangelist/zilch to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Consumer Lending Licensing (UK, US, Canada credit licence registers)	regulated	19.2 (thin)	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Security Posture 2

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

Zilch Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Zilch Vulnerability Disclosure

security.txt · contact published

SECURITY

Resources

Get Started 2

Portal, sign-up, and the first successful call

SignUp

SignUp

Login

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

WellKnown

WellKnown

LLMsTxt

LLMsTxt

Access & Security 5

Authentication, authorization, and security posture

Compliance

Compliance

SecurityTxt

SecurityTxt

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

Security

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

HelpCenter

HelpCenter

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 3

The organization behind the API

Website

Website

Blog

Blog

News

News

Other 1

Properties that don't map to a standard resource type

Merchants

Merchants

Source (apis.yml)

aid: zilch
url: https://raw.githubusercontent.com/api-evangelist/zilch/refs/heads/main/apis.yml
name: Zilch
kind: company
description: 'Zilch is a London-headquartered "buy now, pay later" and ad-subsidised payments network founded in 2018, and
  one of the United Kingdom''s most prominent BNPL brands. Rather than integrating at each retailer''s checkout, Zilch is
  deliberately merchant-agnostic: consumers apply in the Zilch mobile app, receive a virtual (and physical) Mastercard, and
  can Pay-in-3, pay over six weeks, or Pay-now-and-earn-cashback anywhere Mastercard is accepted, online or in-store, through
  Apple Pay and Google Pay wallets. Because Zilch reaches merchants over the open Mastercard card rails and relies on partners
  such as Mastercard for card issuing and Checkout.com as its payments processor, it does not operate a public merchant-integration
  or developer platform the way a PSP or open-banking provider does. As of this review Zilch publishes no developer portal,
  no API reference, and no downloadable OpenAPI/Swagger specification; its public surface is a consumer marketing site, a
  help centre, and a customer sign-up/login app. This profile therefore records Zilch''s verified public web properties honestly
  and carries no API entries, because none are publicly documented.'
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:
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Payments
- United Kingdom
- Buy Now Pay Later
- Consumer Credit
- Digital Wallet
- Cards
- Mastercard
- Fintech
tags_raw:
- Payments
- United Kingdom
- BNPL
- Buy Now Pay Later
- Consumer Credit
- Digital Wallet
- Card
- Mastercard
- Fintech
created: '2026-07-24'
modified: '2026-07-24T18:00:00Z'
specificationVersion: '0.23'
apis: []
common:
- type: Website
  url: https://www.zilch.com/uk/
- type: HelpCenter
  url: https://help.zilch.com/en/
- type: Blog
  url: https://www.zilch.com/uk/thegreen/
- type: News
  url: https://www.zilch.com/corporate/news/
- type: Merchants
  url: https://www.zilch.com/uk/retailers/
- type: SignUp
  url: https://customers.payzilch.com/apply/
- type: Login
  url: https://customers.payzilch.com/login/
- type: Compliance
  url: https://www.zilch.com/uk/compliance/
- type: TermsOfService
  url: https://www.zilch.com/uk/terms-of-service/
- type: PrivacyPolicy
  url: https://www.zilch.com/uk/privacy-notice/
- type: SecurityTxt
  url: well-known/zilch-security.txt
- type: WellKnown
  url: well-known/zilch-well-known.yml
- type: VulnerabilityDisclosure
  url: security/zilch-vulnerability-disclosure.yml
- type: Security
  url: https://www.zilch.com/.well-known/security.txt
- type: DomainSecurity
  url: security/zilch-domain-security.yml
- type: LLMsTxt
  url: llms/zilch-llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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