One of the largest centralized Koha deployments in the world is the national public library infrastructure operated by the Directorate General for Libraries and Publication under the Ministry of Culture and Tourism of the Republic of Türkiye. In Türkiye, more than 1,300 public libraries, ranging from small rural branches to major urban libraries, are managed through a single centralized Koha infrastructure serving over 7 million users, managing more than 30 million items, supporting the daily operations of over 9,000 library staff members across the country, and maintaining around 6 million bibliographic records within its shared national catalog. In 2025 alone, the system recorded more than 16 million circulation transactions, illustrating not only its size but also its intensity of daily public use. Operating at this scale required rethinking Koha not simply as an integrated library system, but as a strategic digital infrastructure capable of supporting public service continuity, national identity verification, security, data quality, and institutional interoperability.
A standard Koha installation was transformed into a highly customized and secure platform capable of operating at national scale. ... mehrIn this context, the system has been strengthened through identity verification with MERNİS[1], single sign-on through the e-Government[2], SMS-based and staff-level two-factor authentication, phone-verified patron transfer workflows, and controlled processes designed for institutions with higher security requirements. Through the e-Government, citizens can also interact directly with the library system by registering for library membership, tracking their borrowed items, and updating their registered library information, allowing Koha services to be accessed as part of Türkiye’s broader digital public services infrastructure.
The main architectural extensions and modules developed in response to Türkiye’s institutional needs include centralized pre-cataloging workflows, integration with KAŞİF[3], the specially developed library automation program used by the National Library of Türkiye, a customized discovery interface, Turkish offline circulation tools, inventory and bulk stock management modules, API user management, a support and ticketing system, institutional library management tools, automated statistical reporting for TÜİK[4], and a browser-based inventory counting application that modernizes annual stocktaking outside Koha through camera or barcode-scanner input, manual entry, bulk .txt/.xlsx upload, ISBN mis-scan detection, and one-click handoff to Koha returns. Together, these developments have supported standardization across the national network while preserving flexibility for local operational needs.
Concrete field stories demonstrate secure patron mobility across branches; prison-library workflows for incarcerated users, including controlled transfer scenarios where standard SMS verification is not applicable; service continuity in rural and mobile libraries under low-connectivity conditions through offline-first tools; and governance patterns for managing a heavily customized national fork without losing operational stability. These examples also reflect a broader before-and-after transformation from fragmented local workflows to a standardized national model, showing how a single open-source platform was adapted to highly diverse institutional environments, including prison libraries and libraries affiliated with other ministries.
This case demonstrates concrete success stories and transferable lessons: how a centralized open-source model reduced licensing costs, standardized workflows, improved data quality, and enabled cross-border technical cooperation with Azerbaijan and Moldova. Beyond the technical architecture itself, the experience offers reusable lessons for the wider Koha community in identity integration, offline circulation, security-sensitive patron flows, and API-oriented public-service design.
It also provides an honest account of the trade-offs involved in sustaining a large national fork over time, including extension debt, documentation, dependency tracking, upgrade discipline, and governance complexity. These lessons are discussed through a three-part governance perspective covering product governance, operational governance, and release governance, and are further summarized on a companion project page:
https://ismailkaraca.com.tr/onekoha1300libraries
