better-auth-core

Original：🇺🇸 English

Translated

Better Auth core setup for TypeScript apps. Use when configuring the Better Auth instance, wiring server handlers and client instances, working with sessions, or calling server-side auth APIs.

1installs

Sourcebobmatnyc/claude-mpm-skills

Added on2026-02-04

NPX Install

npx skill4agent add bobmatnyc/claude-mpm-skills better-auth-core

SKILL.md Content

View Translation Comparison →

Better Auth Core (TypeScript)

Goals

Set up a Better Auth instance with environment variables and data layer wiring.
Wire server handlers and a client instance.
Use sessions and server-side API methods safely.
Keep data-layer choices pluggable (drivers or adapters).

Quick start

Install
```
better-auth
```
.
Set
```
BETTER_AUTH_SECRET
```
(32+ chars) and
```
BETTER_AUTH_URL
```
.
Create
```
auth.ts
```
and export
```
auth
```
.
Provide
```
database
```
(driver or adapter) or omit for stateless sessions.
Mount a handler (
```
auth.handler
```
or a framework helper).
Create a client with
```
createAuthClient
```
.

ts

import { betterAuth } from "better-auth";

export const auth = betterAuth({
  database: myDatabaseOrAdapter, // driver or adapter; omit for stateless mode
  emailAndPassword: { enabled: true },
  socialProviders: {
    github: {
      clientId: process.env.GITHUB_CLIENT_ID as string,
      clientSecret: process.env.GITHUB_CLIENT_SECRET as string,
    },
  },
});

Core setup checklist

Export the instance as
```
auth
```
(or default export) so helpers find it.
Keep
```
BETTER_AUTH_URL
```
in sync with the public base URL.
Pass the full base URL to the client if you change the
```
/api/auth
```
base path.
Add database migrations before enabling plugins that require tables.

Server API usage

Call server endpoints via
```
auth.api.*
```
with
```
{ body, headers, query }
```
.
Use
```
asResponse: true
```
if you need a
```
Response
```
object.
Use
```
returnHeaders: true
```
to access
```
Set-Cookie
```
headers.

ts

import { auth } from "./auth";

const session = await auth.api.getSession({
  headers: request.headers,
});

const response = await auth.api.signInEmail({
  body: { email, password },
  asResponse: true,
});

Session access

Client:

authClient.useSession()

or

authClient.getSession()

.

Server:
```
auth.api.getSession({ headers })
```
.

TypeScript tips

Infer types with
```
auth.$Infer
```
and
```
authClient.$Infer
```
.
Use
```
inferAdditionalFields
```
on the client when you extend the user schema.

References

toolchains/platforms/auth/better-auth/better-auth-core/references/setup-database.md

toolchains/platforms/auth/better-auth/better-auth-core/references/client-server.md

toolchains/platforms/auth/better-auth/better-auth-core/references/typescript.md