NFC Apps overwriting each other?

Hi all, so I have an xNT implant and I wanna use it for sharing my contact to other phones whenever I’m working outside and also to automate the logins in websites and apps. I use NFC Tools Pro for the first task and NFC Scan & Fill for the second one, but apparently if I have my contact info written in the tag I have to format the memory and register the tag in the NFC Scan & Fill app. Basically I can’t get them both to work at the same time. Is it a protocol limitation or can I do something about it without having another implant?

You’ll want to research NDEF messages and records, and how they work. The memory pages of NFC tags are treated like blank sheets of paper that everything must share, with no serious way to define who owns what. The NFC standard defines the NDEF protocol for data storage (on passive tags) and transmission (p2p between two active NFC devices)… and it consists of messages and records within those messages. On an NFC tag the only limit is how much space is available.

Problems come into play when the phone OS, NDEF library in the OS, and apps all do things their own way when it comes to dealing with NDEF messages and records. In the beginning, phones only cared about the first message, and the first record in the first message… any other data was ignored. Now there is expanding support for multiple records within the first message… but other messages are ignored… which is fine, because having one message on a tag that is filled with multiple records achieves the same thing, so no need to bother with multiple messages… having multiple messages is good for large data transmissions using NFC peer to peer (p2p) comms… but anyway… the point is this - most apps use Android’s NDEF library to deal with writing data to the NFC tag… and that library is simple. It takes an existing message on the tag and writes stuff the app sends it to the first record. NFC Tools knows how to write multiple NDEF records into the NDEF message… and some phones (only some) know how to handle multi-record NDEF messages… but other apps just don’t bother… they will tell Android “I want this data written to the tag” and it just stomps all over whatever records are in there already, leaving a single message with a single record. The NFC Scan & Fill app does this, as do probably every single other NFC app you can find that isn’t a “tools” type app.


Thank you for the answer now it’s all clear!