@ercref/erc8117

TypeScript implementation of ERC-8117 — a compressed display format for Ethereum addresses with leading zeros.

What is ERC-8117?

Ethereum vanity addresses with many leading zeros (e.g. 0x00000000219ab540356cBB839Cbe05303d7705Fa) are hard to read. ERC-8117 defines a compact notation that replaces consecutive leading zero nibbles with a subscript count:

| Full Address | ERC-8117 (Unicode) | ERC-8117 (ASCII) | |---|---|---| | 0x00000000219ab540... | 0x0₈219ab540... | 0x0(8)219ab540... | | 0x0000000071727De2... | 0x0₇71727De2... | 0x0(7)71727De2... |

Compression only triggers when there are 4 or more consecutive leading zero nibbles after the 0x prefix.

Install

npm install @ercref/erc8117
# or
bun add @ercref/erc8117

Usage

import { compressAddressERC8117 } from '@ercref/erc8117';

// Unicode mode (default) — uses subscript digits
compressAddressERC8117('0x00000000219ab540356cBB839Cbe05303d7705Fa');
// → '0x0₈219ab540356cBB839Cbe05303d7705Fa'

// ASCII mode — uses parentheses
compressAddressERC8117('0x00000000219ab540356cBB839Cbe05303d7705Fa', 'ascii');
// → '0x0(8)219ab540356cBB839Cbe05303d7705Fa'

// Truncated display
compressAddressERC8117('0x00000000219ab540356cBB839Cbe05303d7705Fa', 'unicode', true);
// → '0x0₈219a...05Fa'

Helper utilities

import { toSubscript, SUBSCRIPTS } from '@ercref/erc8117';

toSubscript(42);  // → '₄₂'
SUBSCRIPTS['7'];  // → '₇'

API

compressAddressERC8117(address, mode?, truncate?)

Compress an Ethereum address using ERC-8117 notation.

| Parameter | Type | Default | Description | |-----------|------|---------|-------------| | address | string | — | Ethereum address (with or without 0x prefix) | | mode | 'unicode' \| 'ascii' | 'unicode' | 'unicode' uses subscript digits (0₇), 'ascii' uses parentheses (0(7)) | | truncate | boolean | false | Truncate the suffix with ellipsis for compact display |

Returns the compressed address string.

toSubscript(num)

Convert a number to its Unicode subscript representation.

SUBSCRIPTS

Record mapping digit characters ('0'–'9') to their Unicode subscript equivalents ('₀'–'₉').

License

MIT