🆘 Need help with Better Auth + Express + MongoDB (Session always null)
Hey everyone 
I'm using Better Auth with Express, TypeScript, and MongoDB.
I've set up authentication as per the docs — login works fine and I can see the session being created in my database.
However, when I call auth.api.getSession, it always returns null.
auth.ts
What’s happening
/auth/login works fine.
I get this response also sessioncreated :
I'm using Better Auth with Express, TypeScript, and MongoDB.
I've set up authentication as per the docs — login works fine and I can see the session being created in my database.
However, when I call auth.api.getSession, it always returns null.
auth.ts
import { betterAuth } from "better-auth";
import { MongoClient } from "mongodb";
import { databaseConfig } from "../config/db.config.js";
import { mongodbAdapter } from "better-auth/adapters/mongodb";
const mongoClient = new MongoClient(databaseConfig.uri);
const db = mongoClient.db();
export const auth = betterAuth({
user: {
additionalFields: {
isActive: { type: "boolean", defaultValue: false },
firstName: { type: "string", required: true },
lastName: { type: "string", required: true },
mobileNumber: { type: "string", required: true },
role: {
type: "string",
required: true,
references: { model: "roles", field: "_id" },
},
team: {
type: "string",
required: false,
references: { model: "teams", field: "_id" },
},
},
},
emailAndPassword: { enabled: true },
advanced: {
useSecureCookies: false,
defaultCookieAttributes: {
httpOnly: true,
sameSite: "None",
secure: false,
maxAge: 1000000,
},
},
session: {
expiresIn: 60 * 60 * 24 * 7,
cookieCache: { enabled: true, maxAge: 5 * 60 },
},
database: mongodbAdapter(db, { client: mongoClient }),
}); What’s happening/auth/login works fine.
I get this response also sessioncreated :
{
"message": "Login successful",
"data": {
"redirect": true,
"token": "RY7qleTD0SwUNggG9bBzp17hfMblIAs7",
"url": "https://google.com",
"user": {
"id": "68f5ef166e37cd53cc1724be",
"email": "john@gmail.com",
"name": "John Doe",
"emailVerified": false,
"createdAt": "2025-10-20T08:13:10.192Z",
"updatedAt": "2025-10-20T08:13:10.192Z"
}
}
}