Digital innovation is an important change agent in service economy (Barrett et al., 2015). It can be defined as “the carrying out of new combinations of digital and physical components that produce novel outcomes” (Yoo et al., 2010, p.
725). Furthermore, the characteristics of digital technology influence digital ma-teriality and innovation. Digital products and services are malleable and in-complete. Data and its processing capabilities are loosely coupled and can be configured and reconfigured into almost infinite combinations. Self-referential nature enables positive reinforcement and generativity that increase the useful-ness and innovation potential of digital technology. (Yoo et al., 20120).
Information systems (IS) research considers digital innovation, and there-fore digital platform innovation, as a sociotechnical concept (Nambisan et al., 2017). There are several aspects and models that can be used to study, describe,
and explain it. This research utilizes open and distributed innovation models to describe digital platform innovation. In addition, digital innovation and tech-nology are assumed as cross-cutting and ubiquitous themes. Like Nambisan et al. (2017) describe, digital innovation is a complex concept that includes aspects such as digital platforms and artefacts, environments, ecosystems, and relation-ships. It has had a transformational influence on service innovation and value creation.
Open and distributed innovation models can be used to study and de-scribe digital innovation and digital platform innovation (Nambisan et al., 2017;
Chesbrough, 2012; West & Bogers, 2017; Anttiroiko & Valkama, 2013). In the recent decades, innovation has undergone a paradigm shift from closed to open.
Open innovation is based on the inbound and outbound knowledge flows and malleable innovation processes boundaries. Inbound knowledge flows enable technology and knowledge insourcing and utilization of external innovation mechanisms. Outbound knowledge flows provide new paths to market and commercialization opportunities. (Chesbrough, 2003). Together these two types of knowledge flows enable ecosystem interaction and feedback loops that in-crease generativity and innovation (Aitamurto & Lewis, 2012). Boundary cross-ing open innovation targets and utilizes resources, processes, and knowledge that are distributed across the organizational landscape and ecosystems (Nam-bisan et al., 2017; West & Bogers, 2017). The locus of innovation has shifted from centralized organizations to unevenly distributed knowledge. Moreover, the innovation opportunities have become distributed as well. (Lakhani & Panetta, 2007; Sawhney & Prandelli, 2000). Management of open and distributed digital innovation requires new kinds of architectures, knowledge, and resources (Nambisan et al., 2017; Yoo et al., 2010).
Digital platform is a relevant and important topic in IS research and prac-tice (Yoo et al., 2010; de Reuver et al., 2017; Smedlund & Faghankhani, 2015). It can be conceptualized as a sociotechnical system that acts as a foundation for development of processes and digital applications and services. A platform in-cludes a multitude of elements such as digital artifacts, organizational processes, structures, standards, and the surrounding ecosystem. (Anttiroiko & Valkama, 2013; Yoo et al., 2010; de Reuver et al., 2017).
Digital platform innovation is influenced by the characteristics of digital technology and mechanisms of open and distributed innovation. More specifi-cally, digital platform innovation is enabled and accelerated by generativity, positive reinforcements, cumulative and combinatorial innovation, ecosystem interaction, openness, and facilitated collaboration. (Tilson et al., 2010;
Chesbrough 2012; Smedlund & Faghankhani, 2015; Anttiroiko & Valkama, 2013). However, digital platforms include an inherent paradox of control and openness that influences digital platform innovation. The paradox must be con-tinuously managed and balanced to enable generativity and stimulate innova-tion but also maintain stability. (Tilson et al., 2010; de Reuver et al., 2017).
Moreover, digital platform innovation is intertwined with platform business models and platform governance (Parker & Alstyne, 2016; Chesbrough, 2012),
and ecosystems (de Reuver et al., 2017; Han et al., 2017; Smedlund & Fa-ghankhani, 2015).
Platform boundary resource is an emerging concept in digital platform re-search and comprises of software and regulations that facilitate the relation-ships between a platform and its users and developers. Boundary resources are important for platform interaction and innovation. (Ghazawneh & Henfridsson, 2013; de Reuver et al., 2017; Yoo et al., 2010). However, boundary resources need to be tuned and aligned with platform ecosystem needs and platform ob-jectives (Eaton et al., 2015). Application programming interfaces (APIs) are one of the most common platform boundary resources, but also other types of tech-nical and social resources exist (Ghazawneh & Henfridsson, 2013; dal Bianco et al., 2014). Platform boundary resources are utilized to both resource and secure the platform. Resourcing enables generativity, creativity, diversity, and innova-tion. Securing moderates resourcing and provides control points and maintains stability. (Ghazawneh & Henfridsson, 2013; dal Bianco et al., 2014; Eaton et al., 2015; Yoo et al., 2010). Platform boundary resources are also utilized for service specialization (Chesbrough 2012) and service innovation (Barrett et al., 2015).
Application programming interfaces (APIs) are machine-readable soft-ware that provide connectivity and enable interaction with softsoft-ware modules and information systems. Moreover, they enable combinations of different modules, increase interoperability, and provide abstraction for the underlying software and modules. (Wulf & Blohm, 2017). This study focuses especially on web-based APIs that operate on the Internet. Web-based APIs are typically or-ganizational boundary crossing interfaces that enable value creation, combina-torial innovation, integration of resources, access to functionalities, and creation of service configurations (Tan et al., 2016; Huhtamäki et al., 2017; Bonardi et al., 2016; Aitamurto & Lewis, 2012). APIs are often bundled with other types of platform boundary resources to enable and stimulate external innovation mechanism (Yoo et al., 2010; Ghazawneh & Henfridsson, 2013). APIs are also technological building blocks for modern service architectures and applications (Tan et al., 2016; Basole, 2016; Evans & Basole, 2016; Weiss & Gangadharan, 2010). APIs enable and influence platform ecosystem interaction but also re-quire new kinds of management, governance, and innovation strategies (Huhtamäki et al., 2017; Weiss & Gangadharan, 2010; Basole, 2016; Bonardi et al., 2016).
Web-based APIs are enablers and catalysts for digital platform innovation.
Moreover, they are an emerging research topic in platform and service innova-tion research (Basole, 2016; Huhtamäki et al., 2017; Wulf & Blohm, 2017). Study-ing APIs as platform boundary resources provides a fresh sociotechnical lens to study digital platform innovation and digital platforms. APIs interact with and influence platform ecosystems, business models, management, and other as-pects that are related to innovation and should thus be studied from the IS per-spective (Huhtamäki et al., 2017).