/usr/include/bamtools/api/ is in libbamtools-dev 2.4.0+dfsg-3build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/bamtools/api/BamAlgorithms.h
/usr/include/bamtools/api/BamAlignment.h
/usr/include/bamtools/api/BamAux.h
/usr/include/bamtools/api/BamConstants.h
/usr/include/bamtools/api/BamIndex.h
/usr/include/bamtools/api/BamMultiReader.h
/usr/include/bamtools/api/BamReader.h
/usr/include/bamtools/api/BamWriter.h
/usr/include/bamtools/api/IBamIODevice.h
/usr/include/bamtools/api/SamConstants.h
/usr/include/bamtools/api/SamHeader.h
/usr/include/bamtools/api/SamProgram.h
/usr/include/bamtools/api/SamProgramChain.h
/usr/include/bamtools/api/SamReadGroup.h
/usr/include/bamtools/api/SamReadGroupDictionary.h
/usr/include/bamtools/api/SamSequence.h
/usr/include/bamtools/api/SamSequenceDictionary.h
/usr/include/bamtools/api/algorithms/
/usr/include/bamtools/api/algorithms/Sort.h
/usr/include/bamtools/api/api_global.h