# Overview of public API¶

The main package of aiida-core is called aiida, which contains various sub-packages that we refer to as “second-level packages”. These second level packages can have further nested hierarchies. Certain resources within these packages, for example modules, classes, functions and variables, are intended for internal use, whereas others are meant to be used by users of the aiida-core package. To make it easier for users to locate these resources that are intended for external use, as well as to distinguish them from internal resources that are not supposed to be used, they are exposed directly on the second-level package. This means that any resource that can be directly imported from a second-level package, is intended for external use. Below we provide a list of the resources per second-level package that are exposed in this way. If a module is mentioned, then all the resources defined in its __all__ are included

## aiida.cmdline¶

params.arguments
params.options
params.types
utils.decorators
utils.echo


## aiida.common¶

datastructures
exceptions
extendeddicts
log


## aiida.engine¶

processes.process.Process
processes.process.ProcessState
processes.workchains.ToContext
processes.workchains.assign_
processes.workchains.append_
processes.workchains.WorkChain
processes.workchains.while_
processes.workchains.return_
processes.workchains.if_
processes.calcjobs.CalcJob
processes.functions.calcfunction
processes.functions.workfunction
processes.exit_code.ExitCode
launch.run
launch.run_get_node
launch.run_get_pid
launch.submit


## aiida.orm¶

Node
Data
ProcessNode
CalcFunctionNode
CalcJobNode
WorkFunctionNode
WorkChainNode
ArrayData
BandsData
KpointsData
ProjectionData
TrajectoryData
XyData
Bool
Float
Int
Str
List
ParameterData
CifData
Code
FolderData
OrbitalData
RemoteData
SinglefileData
StructureData
UpfData
Comment
Computer
Group
Log
QueryBuilder
User
to_aiida_type


## aiida.parsers¶

Parser


## aiida.plugins¶

entry_point
CalculationFactory
DataFactory
DbImporterFactory
ParserFactory
SchedulerFactory
TransportFactory
WorkflowFactory


## aiida.scheduler¶

Scheduler


## aiida.tools¶

CalculationTools
get_kpoints_path
get_explicit_kpoints_path
structure_to_spglib_tuple
spglib_tuple_to_structure
DbImporter


## aiida.transport¶

Transport