> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oynk.io/llms.txt
> Use this file to discover all available pages before exploring further.

# BNB Smart Chain indexing

> ERC-20 log ingestion, confirmation depth, adaptive ranges, replay, and supported BSC assets.

## Inputs

The BSC indexer scans configured tracked wallets against allowlisted token contracts:

* USDT (`18` decimals, operational USD price `1`)
* USDC (`18` decimals, operational USD price `1`)
* BTCB (`18` decimals, fixed operational USD estimate `25,000`)

Contract addresses are configured in the token service rather than inferred from symbols. RPC access is supplied through `BSC_RPC_URL`.

## Safe range processing

The indexer subtracts `BSC_CONFIRMATION_DEPTH` from the latest block to obtain a safe tip. On a subsequent run it rewinds by `BSC_REORG_REWIND_BLOCKS`, then scans forward. Deterministic transfer identities and upserts make replay safe.

RPC providers frequently limit `eth_getLogs` ranges. Oynk starts with a configured chunk, retries temporary errors, reduces rejected ranges to a minimum, and grows the size after consecutive successes. Delays and jitter reduce burst pressure. Block timestamps are cached within the run.

## Cursor identity

Each cursor includes normalized wallet and contract address. This avoids collisions between assets and prevents a symbol rename from redirecting checkpoint state.

## Operational repair

Use the contract-specific sync script with `--dry-run` before resetting a cursor. A reset replays a bounded target and should be treated as a controlled repair, not routine operation.