> For the complete documentation index, see [llms.txt](https://docs.seismic.systems/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.seismic.systems/clients/python/abis/src20-abi.md).

# SRC20\_ABI

ABI for the `ISRC20` interface — Seismic's privacy-preserving ERC20 standard. Token amounts use shielded types (`suint256`) and `balanceOf()` takes no arguments (uses `msg.sender` internally).

```python
from seismic_web3 import SRC20_ABI

SRC20_ABI: list[dict[str, Any]]
```

## Functions

| Function       | Parameters                                         | Returns   | Mutability   | Description                       |
| -------------- | -------------------------------------------------- | --------- | ------------ | --------------------------------- |
| `name()`       | —                                                  | `string`  | `view`       | Token name                        |
| `symbol()`     | —                                                  | `string`  | `view`       | Token symbol                      |
| `decimals()`   | —                                                  | `uint8`   | `view`       | Token decimals                    |
| `balanceOf()`  | —                                                  | `uint256` | `view`       | Caller's balance (no address arg) |
| `approve`      | `spender: address`, `amount: suint256`             | `bool`    | `nonpayable` | Approve shielded amount           |
| `transfer`     | `to: address`, `amount: suint256`                  | `bool`    | `nonpayable` | Transfer shielded amount          |
| `transferFrom` | `from: address`, `to: address`, `amount: suint256` | `bool`    | `nonpayable` | Transfer from approved account    |

## Events

| Event      | Indexed Parameters                                              | Data                     |
| ---------- | --------------------------------------------------------------- | ------------------------ |
| `Transfer` | `from: address`, `to: address`, `encryptKeyHash: bytes32`       | `encryptedAmount: bytes` |
| `Approval` | `owner: address`, `spender: address`, `encryptKeyHash: bytes32` | `encryptedAmount: bytes` |

## balanceOf — SRC20 vs ERC20

Standard ERC20:

```solidity
function balanceOf(address account) external view returns (uint256);
```

SRC20:

```solidity
function balanceOf() external view returns (uint256);
```

In SRC20, `balanceOf()` always returns the **caller's** balance. Use `.read` (a signed read that proves identity), not `.tread`.

## Example

```python
import os
from eth_abi import decode
from seismic_web3 import PrivateKey, SEISMIC_TESTNET, SRC20_ABI

pk = PrivateKey.from_hex_str(os.environ["PRIVATE_KEY"])
w3 = SEISMIC_TESTNET.wallet_client(pk)

token = w3.seismic.contract("0xYourTokenAddress", SRC20_ABI)

# Transparent metadata (no auth needed)
name = decode(["string"], bytes(token.tread.name()))[0]
symbol = decode(["string"], bytes(token.tread.symbol()))[0]

# Shielded balance (signed read)
balance = decode(["uint256"], bytes(token.read.balanceOf()))[0]

# Shielded transfer
tx_hash = token.write.transfer("0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266", 100)
w3.eth.wait_for_transaction_receipt(tx_hash)
```

## See Also

* [SRC20](/clients/python/src20.md) — Token usage guide
* [Event Watching](/clients/python/src20/event-watching.md) — Decrypt Transfer/Approval events
* [ShieldedContract](/clients/python/contract/shielded-contract.md) — `.read`, `.write`, `.tread` namespaces


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