How Gem Wallet Uses the Blockscout API Across 12 EVM Chains

TL;DR: Gem Wallet, an open-source mobile wallet trusted by more than 1 million users, uses the Blockscout API v2 to pull transaction history, token transfers and balances across 12 EVM networks.

"We chose Blockscout because it is open, supports a large number of EVM chains, and aligns well with Gem Wallet's principles."

Gem Wallet team

Gem Wallet is a self-custodial wallet for iOS and Android that supports more than 100 blockchain networks. It is fully open source and ships with no analytics and no advertising tracking.

For EVM chains, Gem Wallet runs a unified indexing layer, and Blockscout is an integral part of it. Every time a user opens a wallet on Ethereum, Base, Gnosis or Robinhood Chain, Blockscout data can be accessed to show transactions, holdings and more.

Why Blockscout

Gem Wallet's lead developer, Tim, gave three reasons.

• Open codebase. It matches how Gem Wallet itself is built.
• Broad EVM coverage. One integration reaches a long list of chains.
• A consistent API. Gem Wallet can add a network without maintaining separate indexing infrastructure for transaction history, token transfers and token balances on that chain.

The third point is the most important, providing a seamless developer and user experience across networks. With one consistent API, adding an EVM network is a simple plug-and-play process.

How the integration works

Gem Wallet uses Blockscout API v2 endpoints to access and populate user data including:

1. Address transaction history
2. Token-transfer data
3. Token balances (ERC-20), plus NFT data on Arc
4. Multi-chain asset discovery and activity display

Blockscout is integrated across 12 EVM networks in the current codebase: Ethereum, Polygon, Arbitrum, Optimism, Base, Gnosis, Celo, World Chain, Ink, Unichain, Robinhood Chain and Arc.

The provider architecture supports automatic fallback, so the wallet keeps a consistent experience across different networks even when one data source is inaccessible for some reason.

Because Gem Wallet is open source, you can read the integration yourself:

• Blockscout client
• EVM indexer integration
• Source repository

Under the hood

Gem Wallet is written in Rust and routes EVM address lookups through an ordered list of providers per chain. If one fails, the next answers. On Ink, Robinhood Chain and Arc, Blockscout is the first provider. On other chains it sits alongside other providers.

Calls go to a single base URL with the chain ID in the path (/{chain_id}/api/v2/addresses/...) and one API key. The wallet requests transactions and token transfers separately, caps pages at 50, then merges and deduplicates by hash, newest first. Blockscout supplies the list of hashes, and details are fetched afterwards. On Arc, Gem Wallet also uses Blockscout for NFTs, following its pagination for ERC-721 and ERC-1155 until the requested limit is hit.

Privacy first

Gem Wallet does not track active-wallet numbers. The app uses no analytics and no advertising tracking, which is part of its privacy-first approach. Learn more about Gem Wallet security.

Gem Wallet is an independent project and is not affiliated with Blockscout. Blockscout does not specifically endorse it. Nothing in this post is financial advice.

Gem Wallet is an independent project and is not affiliated with Blockscout. Blockscout does not specifically endorse it. Nothing in this post is financial advice.