Angad's enduring contribution was to fix the founder's teaching in a durable form. He is associated with the Gurmukhi script, "from the Guru's mouth", which he shaped from the merchant Landa and Sharada writing systems of the Punjab into a standardised alphabet fit for scripture. Whether he invented it or, as scholars more cautiously hold, adapted and popularised an existing hand, it became the script in which the Sikh scriptures would be written, and it gave the community a written vehicle independent of Sanskrit and Persian.
He also gathered and preserved Nanak's hymns and is credited with commissioning early accounts of Nanak's life, the seed of the janamsakhi tradition. Like every Guru after Nanak, he composed his own verse under the shared signature "Nanak," and sixty-two of his saloks were later included in the Guru Granth Sahib, underscoring the continuity of a single voice across the succession.
Around Khadur he expanded the langar, the free communal kitchen, run, the scripture records by name, by his wife Mata Khivi, one of the few women named in it, and encouraged the education of children and physical fitness through wrestling grounds. Under him a movement began to acquire institutions.