This paper presents the project Poetriae, focusing on the steps already taken and on the ongoing work, as well as on its methods and future steps. Mainly, Poetriae aims at building a digital library of Medieval and Golden Age Castilian poetry treatises. It will create digital editions for them, by philologically marking up each metrical and poetic concept in an unambiguous way, in order to allow treatises to be retrievable not just by bibliographic metadata, but also by key concepts, such as poetic genre, stanza types, rhyme, etc. The project also intends to enable automatic analysis and visualizations of such data. Design and application of specific vocabularies for poetry and metrics are the basis for the whole project. Metadata standards for thesaurus and markup (XML-TEI) will be applied. This platform will be fed on previous highly recognized critical editions, enriched with metrical concepts from a controlled vocabulary or thesaurus, with categorised and unambiguous metrical concepts. Advantages: data visualisation, same-concept collation across various texts; even metric theory comparison for Medieval and Golden Age poems. We also introduce the first working edition in this series, Arte de poesía castellana by Juan del Encina.