mongoose/docs/c-api/mbuf.h/intro.md

title	symbol_kind	decl_name	items
Memory Buffers	intro	mbuf.h	type name file mbuf_init.md type name file mbuf_free.md type name file mbuf_append.md type name file mbuf_insert.md type name file mbuf_remove.md type name file mbuf_resize.md type name file mbuf_trim.md type name file struct_mbuf.md

Mbufs are mutable/growing memory buffers, like C++ strings. Mbuf can append data to the end of a buffer, or insert data into arbitrary position in the middle of a buffer. The buffer grows automatically when needed.