Blockin Overview

Blockin is a universal, multi-chain sign-in interface for Web 3.0. Here, you will find all the documentation about how it works, how to use it, and how to contribute!

What is Blockin?

Blockin is a free-to-use, decentralized, universal sign-in standard for all of Web 3.0 that can support signing in with all blockchains! Check out the demo site! Or, see it in action at

Current Supported Chains: Ethereum, BitBadges, Algorand, Polygon, Avalanche, Binance Smart Chain, Cosmos, Solana

What Does Blockin Provide?

Blockin provides all the tools for users to connect and authenticate with your application from any blockchain (see Supported Chains), including fine-grained access control through blockchain token / asset verification!

Example Use Case

Netflix could use Blockin to allow any user (with a valid key pair on any blockchain) to sign-in to their site. Users who sign-in and own the "family plan" asset on their respective chain will be granted "family plan" access, and users who own the "standard plan" asset will be granted "standard plan" access. All will result in the same sign-in access because Netflix is not a chain-specific app.

Problems that Blockin Solves

The problems that Blockin is trying to solve are that existing Web 3.0 sign-in solutions are pretty limited, as explained below.

Problem 1: All users of an application are not going to be on a single blockchain. Everyone will have their own preferred blockchain. However, existing sign-in interfaces (like Sign-In with Ethereum) are limited to a single blockchain at a time. Blockin is able to support all blockchains at once!

Problem 2: Existing sign-in interfaces don't natively support web3 technologies like signing-in with NFTs or other digital assets. Blockin makes this super easy!

Problem 3: Other blockchain sign-in products and services cost money, use centralized servers, are not open source, and are not too customizable. Blockin changes all this!

How Is Blockin Different from Competitors?

Blockin is very different from all its competitors for a few reasons!

1) Open Source Ecosystem - Blockin is community based and fully open-sourced! The community is encouraged to create and share new implementations for different blockchains. Eventually, the ecosystem will have a large amount of implementation options built by both the Blockin team and its community which can be chosen from (see Supported Chains).

2) Decentralized - Blockin has no centralized servers. All sign-in logic is hosted and executed by your project's backend directly. You make all API requests directly. You verify signatures directly. You shouldn't need to rely on a centralized service to do this for you.

3) Free - Blockin will always be free! Other competitors charge subscriptions and fees to use their products. Blockin is open-source and free-to-use code!

4) Customizable - You make all the design choices. Want to use this decentralized API instead of that centralized one? Want to support these blockchains but not that one? Want to use your own node instead of an API? Easy, no problem. Other competitors are very rigid and don't allow for such customization.

5) Future-Proof - Blockin is built in a way that it can easily support any new blockchain!

Demo Site -

Official Source Code (Core Library, Starter Templates, Chain Driver Implementations, etc) -

Whitepaper -

Gitcoin -

Discord -

Project Board -

Want to use Blockin in your project?

pageGetting Started

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