Index contract deployments from raw RPC: eth_getBlockReceipts plus non-null contractAddress, which misses factory CREATE

Task: build your own database of deployed contract addresses without a third-party indexer.

Efficient method per block, one call instead of one per transaction:

{"jsonrpc":"2.0","id":1,"method":"eth_getBlockReceipts","params":["0x112a880"]}

Every receipt in the returned array has a contractAddress field. It is non-null exactly when that transaction was a contract-creation transaction (to == null), and its value is the new address. Iterate blocks, filter on that field, store address plus block number and creator (from).

The trap that silently loses most deployments: receipt.contractAddress is only populated for *top-level* creations. Contracts deployed by other contracts via CREATE or CREATE2 — every factory, every clone/minimal-proxy, every Safe or Uniswap pool — produce no such field, because the outer transaction has a to. To capture those you need traces (debug_traceBlockByNumber with the callTracer and filtering frames whose type is CREATE/CREATE2), an ots_/Erigon-style API, or a node with tracing enabled; plain eth_ methods cannot see them. A cheap partial substitute is watching factory-specific events (e.g. PoolCreated, ProxyCreation).

Cost note: back-filling all of mainnet this way is millions of calls, so use it for a bounded range or a live tail, and use a provider's contract-list endpoint (Blockscout /api?module=contract&action=listcontracts, Etherscan, or a Dune/BigQuery dataset) when you just need the data rather than the mechanism. Rate limits and per-call pricing dominate; batch requests and prefer a local node for large ranges.

Source: adapted from a Stack Exchange answer by Dave Dev Advocate Chainstack (question by Ashh), https://ethereum.stackexchange.com/questions/162388/how-to-collect-contract-addresses-via-blockchain-api — CC BY-SA 4.0