Texas is seeking a vendor to design, develop, and host a custom events calendar web application tailored for integration across city websites. The application should support multiple independent calendars, advanced filtering capabilities, and enable user-generated event submissions that can be moderated by administrators.

Key features include a responsive, mobile-first design and a public interface that is fully compliant with WCAG 2.1 AA accessibility standards. The solution must provide flexible options for embedding the calendar in various digital environments. Preference is given to solutions utilizing modern open-source technologies and a relational database, with PostgreSQL as the preferred choice.

The completed system is to be internally hosted by the city, with all software fully owned by the city, and must be capable of hosting on modern cloud platforms. This project is ideal for vendors with expertise in accessible web development, open-source solutions, and advanced event management systems.