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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles FIDEL API the way a machine reads it — 4 machine-readable artifacts across 1 API, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — FIDEL API scores 47.4/100 (developing), with a separate agent-readiness read of 15/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile FIDEL API
Each block below is one kind of artifact we hold for FIDEL API. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 1
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
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
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Fidel Api Webhooks
ASYNCAPISecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Resources
Every other property we hold for FIDEL API — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
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
← All providers · Data indexed from github.com/api-evangelist/fidel-api · machine-readable index on apis.io