The C ABI is a deliberately small, stable surface for FFI and language bindings. The header is capi/include/libkeepass-c.h; it is built by default and can be disabled with -DLIBKEEPASS_BUILD_C_API=OFF.

Handles

kp_keepass owns the key and output-format selection.
kp_database owns an imported or created Database.
Both are opaque; destroy them with kp_keepass_destroy / kp_database_destroy.

Errors

Every fallible function returns a kp_status:

Status	Meaning
`KP_STATUS_OK`	success
`KP_STATUS_INVALID_ARGUMENT`	null/invalid argument
`KP_STATUS_AUTHENTICATION`	wrong password/key
`KP_STATUS_FORMAT`	corrupt or invalid database
`KP_STATUS_IO`	open/read/write failure
`KP_STATUS_UNSUPPORTED`	unsupported format feature
`KP_STATUS_RESOURCE_LIMIT`	parser/decompression budget exceeded
`KP_STATUS_INTERNAL`	allocation or internal error

kp_last_error() returns a thread-local message; returned strings must be released with kp_free_string().

Example

kp_keepass* kp = kp_keepass_create("password", NULL);
kp_database* db = NULL;
 
if (kp_keepass_open(kp, "database.kdbx", &db) != KP_STATUS_OK) {
    fprintf(stderr, "%s\n", kp_last_error());
    return 1;
}
 
char* json = NULL;
kp_database_to_json(db, 0, &json);
puts(json);
 
kp_free_string(json);
kp_database_destroy(db);
kp_keepass_destroy(kp);

Supported operations: open from path/bytes, save, create an empty KDBX 4 database, count entries/groups, JSON/CSV output, exact-title lookup, add an entry to a group and delete an entry by title. Editing operations mutate the in-memory database; call kp_keepass_save afterwards.

Threading

Handles are not safe for concurrent mutation. The error message is thread-local, so separate handles can be used from separate threads. See docs/ownership.md for the object-model rules.