Supply system (200, 500, 600), comprising: - a first entity (204, 304, 504, 604.1) connectable to at least one physical supply channel network (202, 302, 502, 602), - at least one further entity (206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2) connectable to the physical supply channel network (202, 302, 502, 602), - at least one peer-to-peer network (222, 522, 622) configured to provide a peer-to-peer application (224, 424) - wherein the further entity (206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2) comprises at least one communication device (220.2) connectable to the peer-to-peer network (222, 522, 622), - wherein the first entity (204, 304, 504, 604.1) comprises at least one further communication device (220.1, 320) connectable to the peer-to-peer network (222, 522, 622), and - wherein at least one of the communication devices (220.1, 220.2, 320) is configured to cause at least a generation of a supply medium transaction agreement, comprising a supply medium quantity to be exchanged, about the physical exchange of a supply medium between the first entity (204, 304, 504, 604.1) and the further entity (206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2) by means of the peer-to-peer application (224, 424) by sending a message, comprising instructions for generating the supply medium transaction agreement, - wherein at least one of said communication devices (220.1, 220.2, 320) is configured, based on a supply medium plan created for the entity (204, 304, 504, 604.1, 206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672) comprising said communication device, to generate at least one request message, comprising a supply medium quantity specification, a time period and/or at least one transaction criterion, and/or at least one acceptance message, comprising a supply medium quantity specification, a time period and/or at least one transaction criterion, and - at least one meter device, configured to detect the supply medium quantity transmitted via a port (208, 308) of an entity (204, 304, 504, 604.1, 206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672. 2) with the physical supply channel network (202, 302, 502, 602), wherein a comparison of the detected supply medium quantity with the supply medium quantity defined in the supply medium transaction agreement is carried out, and - wherein the communication device (220.1, 220.2, 320) is configured, upon detection of a deviation by the entity (204, 304, 504, 604.1, 206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2), to cause a generation of a further supply medium transaction agreement on the detected deviation with a further entity. - a first entity (204, 304, 504, 604.1) connectable to at least one physical supply channel network (202, 302, 502, 602), - at least one further entity (206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2) connectable to the physical supply channel network (202, 302, 502, 602), - at least one peer-to-peer network (222, 522, 622) configured to provide a peer-to-peer application (224, 424) - wherein the further entity (206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2) comprises at least one communication device (220.2) connectable to the peer-to-peer network (222, 522, 622), - wherein the first entity (204, 304, 504, 604.1) comprises at least one further communication device (220.1, 320) connectable to the peer-to-peer network (222, 522, 622), and - wherein at least one of the communication devices (220.1, 220.2, 320) is configured to cause at least a generation of a supply medium transaction agreement, comprising a supply medium quantity to be exchanged, about the physical exchange of a supply medium between the first entity (204, 304, 504, 604.1) and the further entity (206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2) by means of the peer-to-peer application (224, 424) by sending a message, comprising instructions for generating the supply medium transaction agreement, - wherein at least one of said communication devices (220.1, 220.2, 320) is configured, based on a supply medium plan created for the entity (204, 304, 504, 604.1, 206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672) comprising said communication device, to generate at least one request message, comprising a supply medium quantity specification, a time period and/or at least one transaction criterion, and/or at least one acceptance message, comprising a supply medium quantity specification, a time period and/or at least one transaction criterion, and - at least one meter device, configured to detect the supply medium quantity transmitted via a port (208, 308) of an entity (204, 304, 504, 604.1, 206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672. 2) with the physical supply channel network (202, 302, 502, 602), wherein a comparison of the detected supply medium quantity with the supply medium quantity defined in the supply medium transaction agreement is carried out, and - wherein the communication device (220.1, 220.2, 320) is configured, upon detection of a deviation by the entity (204, 304, 504, 604.1, 206, 506, 564, 566, 568, 570, 572, 606.2, 664.1, 666.1, 668.2, 670.2, 672.2), to cause a generation of a further supply medium transaction agreement on the detected deviation with a further entity.