# TypeScript TAuth SDK

TypeScript SDK for TAuth-based login and transport session bootstrap.

This SDK starts a local HTTP callback server, verifies a challenge, and opens an authenticated TTP transport client per `userId:sessionId`.

## What this SDK does

- Generates and verifies authentication challenges
- Starts callback and auth endpoints (`/callback`, `/auth`)
- Redirects users to your TAuth frontend URL
- Creates and tracks TTP clients in `clientMap`

## Requirements

- A modern version of Bun
- A domain with TXT record support
- App x448 key pair (`privateKey`, `publicKey`) (can be generated)

## Install

```bash
bun add https://git.methanium.net/tensamin/tauth-sdk/archive/0.0.1.tar.gz
```

## Generate an app key pair

Use the built-in helper once and store the keys securely:

```ts
import { generateKeyPair } from "@tensamin/tauth-sdk";

const keys = generateKeyPair();
console.log(keys.private);
console.log(keys.public);
```

## Add the TXT record

Add a TXT record at `tauth.your.domain` with your app public key as the value (base64 format). This is used to verify that your app is authorized for your domain.

## Basic usage

```ts
import z from "zod";
import { TAuthClient } from "@tensamin/tauth-sdk";

const client = new TAuthClient({
  frontendUrl: "http://localhost:3000",
  identifier: "your-app-identifier",
  privateKey: "<APP_PRIVATE_KEY_BASE64>",
  publicKey: "<APP_PUBLIC_KEY_BASE64>",
  redirectUrl: "http://localhost:7878/callback",
  appData: z.object({
    my: z.string(),
    cool: z.string(),
    data: z.string(),
  }),
  httpServer: {
    hostname: "localhost",
    port: 7878,
  },
});
```

## Endpoints exposed by the SDK

- `GET /auth`: Redirects user to TAuth frontend
- `GET /callback`: Handles challenge flow and session bootstrap

These endpoints need to be exposed behind some kind of http proxy to apply ssl