Chains & units
The six chains, decimals, address formats, CashAddr and base58 TRON addresses, and amount and time conventions.
# Chains & units
The `chain` parameter selects the network. It plays the role of Etherscan's `chainid`.
## The six chains
| `chain` | Network | Symbol | Kind | Decimals | Address formats |
| --- | --- | --- | --- | --- | --- |
| `btc` | Bitcoin | BTC | UTXO | 8 | Base58 (`1…`, `3…`) and Bech32/Bech32m (`bc1…`) |
| `ltc` | Litecoin | LTC | UTXO | 8 | Base58 (`L…`, `M…`, `3…`) and Bech32 (`ltc1…`) |
| `bch` | Bitcoin Cash | BCH | UTXO | 8 | CashAddr without the prefix (`q…`, `p…`) |
| `dash` | Dash | DASH | UTXO | 8 | Base58 (`X…`, `7…`) |
| `eth` | Ethereum | ETH | Account | 18 | `0x` + 40 hex characters |
| `tron` | TRON | TRX | Account | 6 | Base58, 34 characters, starting with `T` |
ETH covers ERC-20, ERC-721 and ERC-1155 tokens. TRON covers TRC-10, TRC-20 and TRC-721.
## Units
- **Amounts are decimal strings in whole units**, exact, never floats: `"0.00131523"` BTC, `"1.5"` ETH. Parse them with a decimal or big-number type, not a floating-point number.
- Raw integer amounts, where present, are in fields named `raw…` (for example a token transfer's `rawAmount`).
- ETH gas prices (`gasPrice`, `maxFeePerGas`, `maxPriorityFeePerGas`, `baseFee`) are **Gwei** strings. `burntFee` and `fee` are ETH. `gasLimit` and `gasUsed` are integers as strings.
- TRON `fee`, `energyFee` and `netFee` are **TRX**. One TRX is 1,000,000 sun.
- Fee rates from [Recommended fees](https://docs.rarebl.com/api/fees/recommended) are **sat/vB** on UTXO chains, **Gwei** on ETH and **sun** on TRON.
- **Times** are ISO 8601 UTC strings, for example `"2026-11-14T20:31:05Z"`.
- **Unknown values are `null`**, never `""` or `0`. A `null` balance means "not known yet", not "empty".
## Hashes and addresses
- Hashes are lowercase hex. UTXO and TRON hashes have **no** `0x`; ETH hashes and addresses **do** carry `0x`.
- TRON addresses are **base58** (`T…`), not hex.
- **Bitcoin Cash** addresses are returned as **CashAddr without the prefix** (`qq…`). On input, the endpoints also accept the legacy form and the `bitcoincash:` prefix.
- [Search](https://docs.rarebl.com/api/search/query) tells you which chain a string belongs to. A legacy `1…` or `3…` address is valid on both BTC and BCH, so both are returned, Bitcoin ranked far higher; checksums are verified for every format.
## UTXO and account chains
UTXO chains (BTC, LTC, BCH, DASH) return a `utxo` object on a transaction with inputs and outputs. Account chains (ETH, TRON) return an `account` object with the sender, gas, decoded method, token transfers and logs. See [Data types](https://docs.rarebl.com/data-types).