Token List Bridge Utils is a specialized package designed to enhance an L1 token list by converting it into a comprehensive cross-chain token list, integrating cross-chain mapping data for platforms like Arbitrum, Optimism, and Polygon. By appending an `extensions` field to each token entry, it introduces `bridgeInfo` for relevant Layer 2 networks, ensuring seamless cross-chain operations by filling in token addresses for these environments. Key functionalities include `chainify`, which appends `bridgeInfo` across specified L2 networks, `chainifyTokenList`, which updates a TokenList based on selected chain IDs, and `mergeTokenLists`, facilitating conflict resolution between token lists. Installation and execution are streamlined through yarn or npm, with Mainnet RPC configurations adjustable via an optional `.env` file to ensure compatibility with arbitrum-sdk. Comprehensive testing and build tools are supported to facilitate efficient development workflows.