Installation

Server-Side

Install the Express middleware and server packages:

pnpm add @stripe402/express @stripe402/server

This also installs @stripe402/core as a transitive dependency.

Peer Dependencies

The following peer dependencies must be installed separately based on your setup:

Peer Dependency	Required By	Required?	Notes
express >= 4.0.0	@stripe402/express	Yes	Tested with Express 5.1
stripe >= 17.7.0	@stripe402/server	Yes	Stripe Node.js SDK
ioredis >= 5.0.0	@stripe402/server	If using RedisStore	Redis client
pg >= 8.0.0	@stripe402/server	If using PostgresStore	PostgreSQL client

Install peer dependencies for your chosen store:

# With Redis (recommended)
pnpm add express stripe ioredis

# With PostgreSQL
pnpm add express stripe pg

Client-Side

Choose one client package based on your HTTP library:

Axios

pnpm add @stripe402/client-axios axios

Peer dependency: axios >= 1.0.0

Fetch (native)

pnpm add @stripe402/client-fetch

No peer dependencies — uses the native fetch API (available in Node.js 18+).

Core Only

If you're building a custom integration (e.g., a middleware for a different framework), install the core package directly:

pnpm add @stripe402/core

This gives you access to all protocol types, header encoding/decoding, HMAC identity derivation, and error types — with zero external dependencies.