# Cardstream

**Canonical:** https://apis.io/providers/cardstream/  
**Website:** https://cardstream.com/  
**APIs profiled:** 4

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.

## Kin Score — 50.9 / 100 (developing)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 50.9).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 45.1 |
| Governance | 18.2 |
| Contract Governance | 18.2 |
| Operational Transparency | 42.1 |
| Developer Ergonomics | 71.4 |
| Commercial Clarity | 25.0 |
| Access Clarity | 25.0 |

Regulatory layer — **Payments**: 62.5 (matched via tags).

## Agent readiness — 36.3 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | documented |
| Error Semantics | documented |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | yes |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## APIs (4)

- **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...

## Security (2)

- **Cardstream Authentication** — merchantID/password/message-signing/ip-allowlist · 4 schemes
- **Cardstream Domain Security** — TLSv1.3 · HSTS · DMARC

## Tags

Payments, United Kingdom, Payment Gateway, Payment Processing, White Label, Card Payments, Acquiring, Hosted Payment Pages, Tokenization, 3D Secure, Alternative Payment Methods, Subscription

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/cardstream/). Scores are computed from the provider's own public artifacts under a published rubric.