​
Presentation Highlights

The following presentation describes the past, present and future iterations of Blockscout along with details about how block imports work both synchronously and asynchronously, and a description of the regular and on-demand fetchers.

Blockscout Indexer Architecture Overview.pdf

1MB pdf

​
Blockscout indexers

See the pdf ⬆️ for more details about the Blockscout indexer. The indexing architecture includes all of the following indexers and fetchers

​
Primary Indexers

Both indexers utilize synchronous and asynchronous operations.
  • Realtime: Imports new block data from the head of the chain.
  • Catchup: Imports data down the chain (starting from the head and moving backwards towards the genesis block)

​
Secondary fetchers

​
Regular

  • Internal transactions
  • Pending transactions
  • Dropped/Replaced transactions
  • Contract bytecodes
  • Block rewards
  • Token catalog
  • Token/coin balances
  • NFT instances
  • Uncles

​
On Demand

  • Coin/token balances update
  • Contract bytecodes fetch/re-check
  • Contract source codes lookup
  • NFT instance metadata re-fetch
  • Token total supply

​
Off-chain integrations

  • Coin / token price, market cap, tvl sources: CMC, Coingecko, Cryptorank, Defillama
  • Smart contract verification: ETH bytecode DB, Sourcify
  • Data enrichment: ENS names, public tags, AI interpreters (own, Noves Fi), sc security scanners (Solidityscan), assets portfolio (Zerion)
  • Chain initialization data import: pre-mined coins, precompiled smart-contracts

​
Chain-specific fetchers

  • There are more than a dozen of chain-specific data fetchers to account for chain differences including arbitrum, optimism, polygon edge, polygon zkevm, zksync etc.

​
Temporary fetchers

  • Used once to resolve possible data inconsistencies.