The runtime API documentation is available in a machine-readable JSON format. It allows for the creation of developer tools that provide code completion and related functionality. This page documents the structure of this format.
The current api_version
that these docs reflect is 6
, which was introduced with Factorio 2.0.5
. See Changelog.
Some notes that apply to the format in general:
null
, it is omitted from the JSON instead.order
property of its members.All text can contain Markdown-type links. There are two broad categories for these: hyperlinks that link to any external website, and internal links that refer to another part of this documentation. All of them will have a title that should be displayed as the link's text.
https://
, and are followed by the URL. Example: [Factorio](https://factorio.com)
.runtime:
or prototype:
, indicating the stage that is linked to. The two stages are separate namespaces, as there would be naming conflicts otherwise. So this first part indicates whether to look for the API member among classes, events, etc., or among prototypes and types.LuaGuiElement
or on_player_created
for runtime:
, and RecipePrototype
or EnergySource
for prototype:
.runtime:
, and 'prototypes', 'types' for prototype:
.::<name>
, where name is the name of a class method or attribute, or a prototype/type property. It is invalid for any other member type.Examples:
[LuaGuiElement](runtime:LuaGuiElement)
links to the LuaGuiElement
class.[results](prototype:RecipePrototype::results)
links to the results
property of the RecipePrototype
prototype.[concepts](runtime:concepts)
links to the Concepts overview page.The format has some top level members indicating the context of the format. These are:
application
:: string: The application this documentation is for. Will always be "factorio"
.application_version
:: string: The version of the game that this documentation is for. An example would be "1.1.35"
.api_version
:: number: The version of the machine-readable format itself. It is incremented every time the format changes. The version this documentation reflects is stated at the top.stage
:: string: Indicates the stage this documentation is for. Will always be "runtime"
(as opposed to "prototype"
; see the Data Lifecycle for more detail).Then, there are several top level members that contain the API documentation itself, organized by their various types. These are:
classes
:: array[Class]: The list of classes (LuaObjects) the API provides. Equivalent to the classes page.events
:: array[Event]: The list of events that the API provides. Equivalent to the events page.concepts
:: array[Concept]: The list of concepts of various types that the API uses. Equivalent to the concepts page.defines
:: array[Define]: The list of defines that the game uses. Equivalent to the defines page.global_objects
:: array[Parameter]: The list of objects that the game provides as global variables to serve as entry points to the API. Uses the same format as parameters, but are never optional.global_functions
:: array[Method]: The list of functions that the game provides as global variables to provide some specific functionality.Several API members follow a common format for their basic fields. This is indicated by inherits from BasicMember
in their title. It includes the following fields:
name
:: string: The name of the member.order
:: number: The order of the member as shown in the HTML.description
:: string: The text description of the member. Can be ''
, but never null
.lists
:: array[string] (optional): A list of Markdown lists to provide additional information. Usually contained in a spoiler tag.examples
:: array[string] (optional): A list of code-only examples about the member.images
:: array[Image] (optional): A list of illustrative images shown next to the member.visibility
:: array[string] (optional): The list of game expansions needed to use this class. If not present, no restrictions apply. Possible values: "space_age"
.parent
:: string (optional): The name of the class that this class inherits from.abstract
:: boolean: Whether the class is never itself instantiated, only inherited from.methods
:: array[Method]: The methods that are part of the class.attributes
:: array[Attribute]: The attributes that are part of the class.operators
:: array[Operator
]: A list of operators on the class. They are called call
, index
, or length
and have the format of either a Method or an Attribute.data
:: array[Parameter]: The event-specific information that is provided.filter
:: string (optional): The name of the filter concept that applies to this event.type
:: Type: The type of the concept. Either a proper Type, or the string "builtin"
, indicating a fundamental type like string
or number
.Defines can be recursive in nature, meaning one Define can have multiple sub-Defines that have the same structure. These are singled out as subkeys
instead of values
.
values
:: array[DefineValue] (optional): The members of the define.subkeys
:: array[Define] (optional): A list of sub-defines.Several data structures are used in different parts of the format, which is why they are documented separately to avoid repetition.
A type field can be a string, in which case that string is the simple type. Otherwise, a type is a table:
complex_type
:: string: A string denoting the kind of complex type.Depending on complex_type
, there are additional members:
type
:union
:array
:value
:: Type: The type of the elements of the array.dictionary
or LuaCustomTable
:table
:parameters
:: array[Parameter]: The parameters present in the table.variant_parameter_groups
:: array[ParameterGroup] (optional): The optional parameters that depend on one of the main parameters.variant_parameter_description
:: string (optional): The text description of the optional parameter groups.tuple
:values
:: array[Type]: The types of the members of this tuple in order.function
:parameters
:: array[Type]: The types of the function arguments.literal
:LuaLazyLoadedValue
:value
:: Type: The type of the LuaLazyLoadedValue.LuaStruct
:attributes
:: array[Attribute]: A list of attributes with the same properties as class attributes.name
:: string: The name of the parameter.order
:: number: The order of the member as shown in the HTML.description
:: string: The text description of the parameter.type
:: Type: The type of the parameter.optional
:: boolean: Whether the type is optional or not.name
:: string: The name of the parameter group.order
:: number: The order of the member as shown in the HTML.description
:: string: The text description of the parameter group.parameters
:: array[Parameter]: The parameters that the group adds.visibility
:: array[string] (optional): The list of game expansions needed to use this method. If not present, no restrictions apply. Possible values: "space_age"
.raises
:: array[EventRaised] (optional): A list of events that this method might raise when called.subclasses
:: array[string] (optional): A list of strings specifying the sub-type (of the class) that the method applies to.parameters
:: array[Parameter]: The parameters of the method. How to interpret them depends on the format
member.variant_parameter_groups
:: array[ParameterGroup] (optional): The optional parameters that depend on one of the main parameters. Only applies if takes_table
is true
.variant_parameter_description
:: string (optional): The text description of the optional parameter groups.variadic_parameter
:: VariadicParameter (optional): The variadic parameter of the method, if it accepts any.format
:: MethodFormat: Details on how the method's arguments are defined.return_values
:: array[Parameter]: The return values of this method, which can contain zero, one, or multiple values. Note that these have the same structure as parameters, but do not specify a name.type
:: Type (optional): The type of the variadic arguments of the method, if it accepts any.description
:: string (optional): The description of the variadic arguments of the method, if it accepts any.takes_table
:: boolean: Whether the method takes a single table with named parameters or a sequence of unnamed parameters.table_optional
:: boolean (optional): If takes_table
is true
, whether that whole table is optional or not.visibility
:: array[string] (optional): The list of game expansions needed to use this attribute. If not present, no restrictions apply. Possible values: "space_age"
.raises
:: array[EventRaised] (optional): A list of events that this attribute might raise when written to.subclasses
:: array[string] (optional): A list of strings specifying the sub-type (of the class) that the attribute applies to.read_type
:: Type (optional): The type of the attribute when it's read from. Only present if this attribute can be read from.write_type
:: Type (optional): The type of the attribute when it's written to. Only present if this attribute can be written to.optional
:: boolean: Whether the attribute is optional or not.name
:: string: The name of the event being raised.order
:: number: The order of the member as shown in the HTML.description
:: string: The text description of the raised event.timeframe
:: string: The timeframe during which the event is raised. One of "instantly", "current_tick", or "future_tick".optional
:: boolean: Whether the event is always raised, or only dependant on a certain condition.name
:: string: The name of the define value.order
:: number: The order of the member as shown in the HTML.description
:: string: The text description of the define value.filename
:: string: The name of the image file to display. These files are placed into the /static/images/
directory.caption
:: string (optional): The explanatory text to show attached to the image.string
A string, which can be an identifier for something, or a description-like text formatted in Markdown.
number
A number, which could either be an integer or a floating point number, as JSON doesn't distinguish between those two.
boolean
A boolean value, which is either true
or false
.
Changes for version 6, introduced with Factorio 2.0.5:
type
, read
, and write
fields on attributes with the read_type
and write_type
fieldsChanges for version 5, introduced with Factorio 1.1.108:
filter
field to eventsvisibility
field to classes, methods and attributes. Unused before Factorio 2.0.notes
and adding lists
and images
tuple
complex type to be an array of types in ordervariadic_type
and variadic_description
fields on methods into a single variadic_parameter
fieldtakes_table
and table_is_optional
fields on methods into a single format
fieldtable_is_optional
fields on MethodFormat to table_optional
base_classes
field on classes to parent
, changing it to a single stringbuiltin_types
top-level member, merging its members as type "builtin"
into concepts
insteadChanges for version 4, introduced with Factorio 1.1.89:
runtime:
or prototype:
)struct
concept type to LuaStruct
Changes for version 3, introduced with Factorio 1.1.62:
abstract
field to classesoptional
field to attributestype
, literal
, tuple
and struct
typesglobal_functions
top level membervariant
type to union
category
field on concepts with the type
fieldChanges for version 2, introduced with Factorio 1.1.54:
raises
field to methods and attributesreturn_type
and return_description
fields on methods with the return_values
-arraysee_also
field from classes, events, concepts, methods and attributesChanges for version 1, introduced with Factorio 1.1.35: