FIDEL API website screenshot

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 Transaction.

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.

33.3/100 thin ▬ flat Agent 20/100 agent aware saas Full breakdown ↓
scored 2026-08-30 · rubric v0.17.2
AccessSelf serve
1 APIs
CompanyFintechCard LinkingPaymentsTransactionWebhookSDKCard-Linked OffersFinancial Data

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-30 · rubric v0.17.2
Composite quality — 33.3/100 · thin
Contract Quality 9.1 / 21
Developer Ergonomics 5.5 / 17
Access Clarity 0.0 / 17
Operational Transparency 4.7 / 11
Contract Governance 1.9 / 10
Discoverability 6.5 / 9
Regulatory Posture 5.9 / 15
Agent readiness — 20/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
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
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/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 1

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

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 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Security Posture 2

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

Fidel Api Authentication

apiKey · 1 scheme

SECURITY

Fidel Api Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Get Started 5

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Build 3

SDKs, sample code, and the tooling you integrate with

Access & Security 3

Authentication, authorization, and security posture

Operate 3

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

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
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: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-19'
image: https://fidelapi.com/fidel_social.png
tags:
- Company
- Fintech
- Card Linking
- Payments
- Transaction
- Webhook
- SDK
- Card-Linked Offers
- Financial Data
tags_raw:
- 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
  - Transaction
  tags_raw:
  - 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

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this
  • find_providersBrowse and filter every provider in the catalog.
  • get_provider_artifactsEvery artifact this provider publishes, grouped by type.
  • get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
  • get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
  • get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
  • get_provider_ratingPRO — composite, band, trend and facet scores.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This provider
curl "https://apis.io/api/v1/providers/fidel-api"
All providers
curl "https://apis.io/api/v1/providers?limit=25"
Every operation they expose
curl "https://apis.io/api/v1/providers/fidel-api/operations?limit=25"
How their score was established
curl "https://apis.io/api/v1/providers/fidel-api/evidence"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no email required.

A second provider on the same verified email joins the account you already have.