Author-created digital agents and content corpora for electronic documents are described. A content corpora service can include application programming interfaces such as for adding content to a corpus, attaching a corpus to a document, retrieving corpora associated with an author, and searching content of a corpus. An author-created digital agent can receive a request from a consumer of a document, determine corpora associated with the document, formulate a query based on the request, and search content associated with the corpora associated with the document.