https://move-book.com/programmability/sui-framework#implicit-imports

Here are two official references that clearly document the auto-imported Move modules in a Sui development environment:

📘 1. The Move Book — "Importing Modules"

This section explains that starting with Sui CLI v1.45, packages like MoveStdlib, Sui, System, Bridge, and Deepbook are automatically included—so modules like std::option, sui::object, sui::object::UID, and others are available without needing to add them in Move.toml (move-book.com).

📘 2. Sui Framework — Core Modules Reference

In the Sui Move References section, you’ll find a list of core modules such as sui::object, sui::object::ID, sui::object::UID, sui::tx_context, and sui::transfer. These appear under “Implicit Imports,” confirming they are available by default (move-book.com).

🔗 Direct Links:

• 📄 Move Book — Importing Modules (auto-imports)
• 📄 Move Book — Sui Framework: Implicit Imports

These are your authoritative resources confirming which std:: and sui:: modules you can use without explicit imports.