Modern Authentication
for Web3 Applications

Blockchain-based authentication with zero server secrets. Edge-ready, globally distributed.

Sign In With Any Blockchain

Universal authentication for all major blockchains

Ethereum
Solana
Bitcoin Core
Bitcoin SV
Bitcoin Cash
Polygon
Avalanche

How It Works

Two ways to authenticate with blockchain

Choose Your Method
Method 1: Direct Wallet(Limited Features)

Connect Wallet

Use MetaMask or similar

Sign Challenge

Prove ownership

Basic Access

Single device only

Method 2: Import & Encrypt✓ Recommended

Import Keys

Backup file or private key

Encrypted Locally

Set password

Full Access

Multi-device + backup

✓ Cloud backup  ·  ✓ Multi-device sync  ·  ✓ Session timeout control

Why Choose Sigma Auth?

The most secure, open, and cost-effective authentication solution

Universal

Deploy as a standalone service or embed into existing applications. Works with any framework or platform.

Edge Runtime Compatible

Runs on edge runtimes like Cloudflare Workers & Vercel Edge, or traditional servers with Node.js, Bun, and AWS Lambda.

Standards-based

Implements OAuth 2.0 spec and web standards. Any OAuth client can use it.

Customizable

Theme customization via OAuth URL parameters for seamless brand integration.

Edge Runtime Optimized

Near-zero cold starts, global distribution, and automatic scaling at the edge.

Cross Device Restore

Restore your identity across all your devices with just your password.

Backup File Import

Handles all backup file formats. Import your backup file to sign in.

For Developers

Use our public OAuth 2.0 API, or host your own

Quick Start

1

Redirect to authorization endpoint

Point users to /login with your client_id and redirect_uri

2

User completes blockchain authentication

Users sign with blockchain keys or restore from backup, returns authorization code

3

Exchange code for JWT access token

POST to /token endpoint with authorization code

4

Use token for authenticated API calls

Include Bearer token in Authorization header

API Endpoints

OAuth 2.0 Core

GET/login
POST/token
GET/userinfo

Authentication

POST/loginBlockchain
GET/google/callbackGoogle
GET/github/callbackGitHub

Backup & Restore

GET/backup
POST/backup
GET/backup/status
GET/backup/oauth
POST/backup/link-oauth