The main scriptures or texts of Shaiva Tantra are known as the Agamas. These texts are considered to be the divine revelations of Lord Shiva himself and are believed to have been passed down through the lineage of gurus and disciples.

The most important and widely studied Agamas in Shaiva Tantra are the 28 Shaiva Siddhanta Agamas, which are divided into four categories: Kamika, Yoga, Charya, and Jnana. These texts cover various aspects of Shaiva philosophy, rituals, and practices, and provide a comprehensive guide for spiritual growth and enlightenment.

The Kamika Agama is considered to be the most important of the 28 Agamas and is believed to contain the essence of all the other Agamas. It focuses on the worship of Lord Shiva and the attainment of liberation through devotion and selfless service.

The Yoga Agama explores the practice of yoga and its role in spiritual development. It includes teachings on various forms of yoga, such as Hatha, Raja, and Kundalini yoga, and emphasizes the importance of physical and mental discipline in achieving oneness with Lord Shiva.

The Charya Agama focuses on the rituals and ceremonies performed in Shaiva temples, including the construction of temples, installation of deities, and various forms of worship. It also includes teachings on the use of mantras, yantras, and other spiritual tools for invoking the presence of Lord Shiva.

The Jnana Agama delves into the philosophical aspects of Shaiva Tantra, exploring the nature of reality, the concept of duality and non-duality, and the path to self-realization. It emphasizes the importance of understanding the true nature of the self and the universe in order to attain enlightenment.

Apart from the 28 Shaiva Siddhanta Agamas, there are also other important texts in Shaiva Tantra, such as the Rudrayamala Tantra, the Vijnana Bhairava Tantra, and the Shiva Sutras. These texts provide further insights into the teachings and practices of Shaiva Tantra and are widely studied by practitioners.

In conclusion, the Agamas are the main scriptures or texts of Shaiva Tantra, providing a comprehensive guide for spiritual growth and enlightenment through devotion, yoga, rituals, and philosophical understanding. They are considered sacred and are revered by practitioners as the divine revelations of Lord Shiva himself.