x402: arhitektura in praktična uporaba strojnih plačil z uporabo HTTP 402

Authors

Martin Ferenec
University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics
https://orcid.org/0009-0006-7848-5716
Adnan Bratanović
University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics
https://orcid.org/0009-0002-6850-585X
Teo Lah
University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics
Muhamed Turkanović
University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics
https://orcid.org/0000-0002-5079-5468

Synopsis

The article presents the x402 protocol, an open standard for machine-based online payments, which, after three decades of non-use, implements the HTTP 402 status code as an actual payment mechanism for the first time. The current state of data access charging is described, as well as the obstacles such as dependency on intermediaries, high costs of microtransactions, and the absence of a built-in payment mechanism that led to the creation of the protocol. The x402 architecture (client, source server, wallet, payment schemes, payment broker), operation, and comparison of versions v1 and v2 are presented in more detail. This is followed by a comparison with the alternative Machine Payments Protocol (MPP) with a recommendation on when to choose which one. The article ends with a presentation of the use of x402 in reference implementations of artificial intelligence agents and in data spaces, using the example of the DSX Engine connector in the DADS data space (DIH AGRIFOOD Data Space).

Author Biographies

Martin Ferenec, University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics

Maribor, Slovenia. E-mail: martin.ferenec@um.si

Adnan Bratanović, University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics

Maribor, Slovenia. E-mail: adnan.bratanovic@student.um.si

Teo Lah, University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics

Maribor, Slovenia. E-mail: teo.lah@student.um.si

Muhamed Turkanović, University of Maribor, Faculty of Electrical Engineering, Computer Science and Informatics

Maribor, Slovenia. E-mail: muhamed.turkanovic@um.si

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Published

September 1, 2026

How to Cite

Ferenec, M., Bratanović, A., Lah, T., & Turkanović, M. (2026). x402: arhitektura in praktična uporaba strojnih plačil z uporabo HTTP 402. In L. Pavlič, T. Beranič, & M. Heričko (Eds.), & (Ed.), OTS 2026 Sodobne informacijske tehnologije in storitve: Zbornik 29. konference (Vols. 29, pp. 25-44). University of Maribor Press. https://doi.org/10.18690/um.feri.7.2026.3