Pybliometrics is a Python library that provides programmatic access to Elsevier's bibliographic databases (Scopus, ScienceDirect, and SciVal). It acts as a wrapper around the respective APIs, handling authentication, request throttling, caching, and response parsing. The library is designed for researchers and developers who need to extract bibliometric data for analysis, literature reviews, or academic workflows. The architecture follows a modular design with separate subpackages for each service (Scopus, ScienceDirect, SciVal) and a set of superclasses that encapsulate common functionality such as caching and HTTP request handling. Utility modules provide cross-cutting concerns like configuration management, parameter validation, and safe data extraction from JSON responses. This separation of concerns allows for maintainability and extension. Key features include automatic caching of API responses to reduce redundant requests, support for multiple API views (e.g., FULL, STANDARD) to control the level of detail returned, and the conversion of raw JSON data into structured Python objects (like namedtuples) for ease of use. The library also implements rate limiting and error handling specific to the Elsevier APIs.