To retrieve all fields from a given record type, you need to add the parameter detail=full.
The default level of detail is detail=summary, which contains only the most important fields.
Detail=full is a way to output all fields. However, you usually don't need all fields in the output. This way, your program will load a lot of data, of which you will actually use only some. But the fields your program will process are already known in advance. So there is no reason to use detail=full.
💡 The right question should be: how do I get all the fields I need in the output? The answer is to use the detail=custom:… parameter, in which you can list the fields that ABRA Flexi should return.
Using detail=custom can also speed up ABRA Flexi's response time. This is because objects you don't specify won't be loaded from the database, which eliminates many SQL queries. In addition to speeding up responses from ABRA Flexi, this also reduces the memory demands of your program, since it won't be necessary to hold such large responses from ABRA Flexi in memory.
How to find out which fields a record type provides
The simplest and clearest option is to use /properties (e.g. https://demo.flexibee.eu/c/demo/faktura-vydana/properties).
This output tells you what values individual fields can take. For linked objects, you'll find out which record type they reference, and, last but not least, whether the field will be considered during XML import.
Details are described in the detail levels documentation.
Example
https://demo.flexibee.eu/c/demo/faktura-vydana.xml – detail=summary
https://demo.flexibee.eu/c/demo/faktura-vydana.xml?detail=full – detail=full
https://demo.flexibee.eu/c/demo/faktura-vydana.xml?detail=custom:id,typDokl,nazFirmy,sumCelkem,zbyvaUhradit – detail=custom, který vrací jen potřebná pole