FIDEL API

Fidel API is a global card-linking platform that connects Visa, Mastercard and Amex payment cards to web and mobile applications through a single API. Once a cardholder links a card (via Fidel's PCI-compliant Web, iOS, Android or React Native SDKs), Fidel streams enriched, real-time transaction data - authorization, clearing and refund events - from the card networks to the developer's server via signed webhooks. Developers use it to build card-linked loyalty, rewards, cashback and offers programs without handling raw card data or PCI scope. The platform spans Programs, Brands, Locations, Cards, Transactions, Offers and Merchant IDs, operates test and live environments, and is available across the US, UK, Ireland, Canada, Sweden and the UAE (with Japan in beta). Founded in 2018 and headquartered in London, Fidel is backed by Bain Capital Ventures.

FIDEL API publishes 1 API on the APIs.io network. Tagged areas include Company, Fintech, Card Linking, Payments, and Transactions.

The FIDEL API catalog on APIs.io includes 1 event-driven AsyncAPI specification.

FIDEL API’s developer surface includes documentation, API reference, getting-started guide, support, engineering blog, pricing, signup flow, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub
38.6/100 thin Agent 15/100 agent aware Full breakdown ↓
scored 2026-07-20 · rubric v0.4
1 APIs 0 Features
CompanyFintechCard LinkingPaymentsTransactionsWebhooksSDKCard-Linked OffersFinancial Data

API Rating

API Evangelist API Evangelist Rating How this is scored →
scored 2026-07-20 · rubric v0.4
Composite quality — 38.6/100 · thin
Contract Quality 0.0 / 25
Developer Ergonomics 13.0 / 20
Commercial Clarity 10.5 / 20
Operational Transparency 5.8 / 13
Governance 0.0 / 12
Discoverability 9.3 / 10
Agent readiness — 15/100 · agent aware
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 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/fidel-api: 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

Fidel API

Card-linking REST API for linking Visa/Mastercard/Amex cards to programs and receiving real-time transaction events (Programs, Brands, Cards, Transactions, Locations, Offers, We...

Event Specifications

Fidel Api Webhooks

ASYNCAPI

Resources

Get Started 5

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 SignUp
SignUp
 Login
Login
 Sandbox
Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt
LLMsTxt

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Webhooks
Webhooks
 Conventions
Conventions
 Lifecycle
Lifecycle
 Conformance
Conformance
 Components
Components
 DataModel
DataModel

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 Packages
Packages
 SDKs
SDKs

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication
 Compliance
Compliance

Operate 3

Status, limits, changes, and where to get help

Support
Support
 StatusPage
StatusPage
 ChangeLog
ChangeLog

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)

apis.yml Raw ↑ 
aid: fidel-api
name: FIDEL API
description: Fidel API is a global card-linking platform that connects Visa, Mastercard and Amex payment cards to web and
  mobile applications through a single API. Once a cardholder links a card (via Fidel's PCI-compliant Web, iOS, Android or
  React Native SDKs), Fidel streams enriched, real-time transaction data - authorization, clearing and refund events - from
  the card networks to the developer's server via signed webhooks. Developers use it to build card-linked loyalty, rewards,
  cashback and offers programs without handling raw card data or PCI scope. The platform spans Programs, Brands, Locations,
  Cards, Transactions, Offers and Merchant IDs, operates test and live environments, and is available across the US, UK, Ireland,
  Canada, Sweden and the UAE (with Japan in beta). Founded in 2018 and headquartered in London, Fidel is backed by Bain Capital
  Ventures.
url: https://raw.githubusercontent.com/api-evangelist/fidel-api/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- bain-capital-ventures
x-tier: enriched
x-tier-reason: portfolio-lead-enriched
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
image: https://fidelapi.com/fidel_social.png
tags:
- Company
- Fintech
- Card Linking
- Payments
- Transactions
- Webhooks
- SDK
- Card-Linked Offers
- Financial Data
apis:
- name: Fidel API
  description: Card-linking REST API for linking Visa/Mastercard/Amex cards to programs and receiving real-time transaction
    events (Programs, Brands, Cards, Transactions, Locations, Offers, Webhooks, MIDs).
  humanURL: https://docs.fidelapi.com/docs/select
  baseURL: https://api.fidel.uk/v1
  tags:
  - Card Linking
  - Payments
  - Transactions
  properties:
  - type: Documentation
    url: https://docs.fidelapi.com/
  - type: APIReference
    url: https://reference.fidel.uk/
  - type: Authentication
    url: authentication/fidel-api-authentication.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/fidel-api-domain-security.yml
- type: Website
  url: https://fidelapi.com/
- type: DeveloperPortal
  url: https://dashboard.fidel.uk/
- type: Documentation
  url: https://docs.fidelapi.com/
- type: APIReference
  url: https://reference.fidel.uk/
- type: GettingStarted
  url: https://docs.fidelapi.com/docs/select
- type: Support
  url: https://community.fidel.uk/
- type: Blog
  url: https://fidelapi.com/blog/
- type: GitHubOrganization
  url: https://github.com/Enigmatic-Smile
- type: Pricing
  url: https://fidelapi.com/pricing
- type: SignUp
  url: https://dashboard.fidel.uk/sign-up
- type: Login
  url: https://dashboard.fidel.uk/
- type: TermsOfService
  url: https://fidelapi.com/terms
- type: PrivacyPolicy
  url: https://fidelapi.com/privacy
- type: StatusPage
  url: https://status.fidel.uk/
- type: Authentication
  url: authentication/fidel-api-authentication.yml
- type: Packages
  url: packages/fidel-api-packages.yml
- type: SDKs
  url: packages/fidel-api-packages.yml
- type: Sandbox
  url: sandbox/fidel-api-sandbox.yml
- type: Webhooks
  url: asyncapi/fidel-api-webhooks.yml
- type: Conventions
  url: conventions/fidel-api-conventions.yml
- type: Lifecycle
  url: lifecycle/fidel-api-lifecycle.yml
- type: ChangeLog
  url: changelog/fidel-api-changelog.yml
- type: Conformance
  url: conformance/fidel-api-conformance.yml
- type: Compliance
  url: https://docs.fidelapi.com/docs/select
- type: Components
  url: components/fidel-api-components.yml
- type: DataModel
  url: data-model/fidel-api-data-model.yml
- type: LLMsTxt
  url: llms/fidel-api-llms.txt
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence