generated: '2026-07-23'
method: searched
source: https://github.com/americanexpress
description: >-
  First-party client libraries published by American Express for authenticating
  with and consuming APIs on the Amex for Developers portal
  (developer.americanexpress.com). These "client core" libraries implement the
  two-way TLS + HMAC/OAuth request-signing the Amex developer APIs require, so
  they are shared authentication SDKs rather than per-product clients. Only
  genuinely first-party American Express packages are listed.
packages:
  - language: java
    registry: github
    name: amex-api-java-client-core
    url: https://github.com/americanexpress/amex-api-java-client-core
    install: "clone/build: https://github.com/americanexpress/amex-api-java-client-core"
    description: Library for authenticating with APIs published to the Amex for Developers portal (Java).
    official: true
  - language: csharp
    registry: nuget
    name: Amex.Api.Client.Core
    url: https://www.nuget.org/packages/Amex.Api.Client.Core/
    install: dotnet add package Amex.Api.Client.Core
    description: Library for authenticating with APIs published to the Amex for Developers portal (.NET). Authored by American Express Travel Related Services Company, Inc.
    official: true
  - language: csharp
    registry: github
    name: amex-api-dotnet-client-core
    url: https://github.com/americanexpress/amex-api-dotnet-client-core
    install: "clone/build: https://github.com/americanexpress/amex-api-dotnet-client-core"
    description: Source repository for the .NET Amex for Developers authentication client core.
    official: true
  - language: javascript
    registry: github
    name: targeted-offers-client
    url: https://github.com/americanexpress/targeted-offers-client
    install: "clone/build: https://github.com/americanexpress/targeted-offers-client"
    description: SDK for the American Express Targeted Offers (Smart Offer Partnership) API.
    official: true
notes:
  - American Express also publishes many open-source engineering frameworks under
    github.com/americanexpress (One App, Holocron, Iguazu, EarlyBird, Parrot, etc.);
    those are not API client libraries for the developer platform and are excluded here.
  - No first-party client library was found on npm, PyPI, RubyGems, Packagist,
    crates.io, or pkg.go.dev; the Java/JS clients are distributed as source on GitHub
    and the .NET client on NuGet.