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

# Overview

> Block-level balances of assets on EVM-compatible blockchains.

We support balances for the following asset types:

| Asset Type | Description                                                                                                 |
| ---------- | ----------------------------------------------------------------------------------------------------------- |
| Fungible   | Fungible assets models contains erc20 tokens and native (gas) token.                                        |
| Native     | Native tokens are the gas tokens of the blockchain, such as ETH, BNB, POL, AVAX, etc.                       |
| ERC20      | ERC20 tokens are the tokens that follow the ERC20 standard, such as USDC, USDT, etc.                        |
| ERC721     | ERC721 tokens are the tokens that follow the ERC721 standard, such as Pudgy Penguins, etc.                  |
| ERC1155    | ERC1155 tokens are the tokens that follow the ERC1155 standard, such as OpenSea Collection StoreFront, etc. |

### Balance Tracking Methodology

| Asset Type                      | Methodology                                                                                                                                                                                                                                          |
| ------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Fungible (ERC20 & Native)       | We detect balance-changing events (transfers, mints, burns) and fetch balance at each relevant block height directly from the blockchain and index it into the balances table.                                                                       |
| Non-Fungible (ERC721 & ERC1155) | We track transfers through standard events: ERC721: Transfer() events and ERC1155: TransferSingle() and TransferBatch() events. From there, we build credit-debit tables to calculate cumulative ownership, accounting for multiple token transfers. |

### Precision Handling

To maintain numerical precision, especially for tokens with large supplies or many decimal places:

1. Raw balances are stored as VARCHAR to preserve exact values.
2. Normalized balances are calculated using high-precision arithmetic with custom Snowflake UDFs.
3. Both raw and human-readable balances are provided.

This approach ensures:

* No loss of precision from floating-point arithmetic.
* Accurate balance tracking over time.
* Reliable historical data for analysis.