Cardstream
Cardstream is an independent United Kingdom payment gateway providing a white-label payment platform that banks, PSPs, ISOs, acquirers and software companies resell under their own brand. It connects merchants to card schemes (Visa, Mastercard), digital wallets and 150+ Alternative Payment Methods from a single integration, with PCI DSS Level 1 processing, tokenisation, recurring billing, 3-D Secure 2 authentication, risk and fraud checking, and dynamic currency conversion. Its developer surface is a mature form-post gateway API exposed through three integration methods — Hosted (Hosted Payment Pages and Hosted Payment Fields), Direct (server-to-server), and Batch — documented in a public GitBook integration guide and supported by SDKs for PHP, Java, Node.js, Go, Ruby, C#, iOS and Android plus e-commerce modules. Requests are HTTP POST with application/x-www-form-urlencoded fields authenticated by merchantID plus optional password, HMAC message signing and IP allow-listing; the gateway does not publish a downloadable OpenAPI/Swagger definition or a JSON/REST surface.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles Cardstream the way a machine reads it — 7 machine-readable artifacts across 4 APIs, 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 — Cardstream scores 43.2/100 (thin), with a separate agent-readiness read of 32/100 (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 Cardstream
Each block below is one kind of artifact we hold for Cardstream. 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 4
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.
Cardstream Gateway - Hosted Integration
Hosted Payment Pages (HPP) integration. The merchant's browser POSTs a URL-encoded request to the Gateway, which collects and processes the cardholder's payment details on a Car...
Cardstream Gateway - Direct Integration
Server-to-server integration. The merchant collects payment details on its own secure server and sends a URL-encoded HTTP POST directly to the Gateway for processing, supporting...
Cardstream Gateway - Batch Integration
An enhancement to the Direct Integration that submits multiple transactions in a single multipart/mixed HTTP POST. The Gateway queues the transactions and returns a batch refere...
Cardstream Hosted Payment Fields
A client-side library where only the individual input fields that collect sensitive cardholder data are hosted by the Gateway while the rest of the payment form is served by the...
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.
Cardstream 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 Cardstream — 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 4
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 7
Pagination, idempotency, versioning, errors, and events
Scroll within the panel for all 7 ·
Build 4
SDKs, sample code, and the tooling you integrate with
Access & Security 4
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 1
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/cardstream · machine-readable index on apis.io