parameters

parameters

MCP tools for Houdini parameter operations.

Exposes 10 tools covering parameter get/set, expressions, channel references, locking, schema inspection, and spare parameter creation.

Functions:

Name	Description
create_spare_parameter	Add a spare parameter to a node.
create_spare_parameters	Batch-create multiple spare parameters in one call, optionally in a folder tab.
get_expression	Get the expression on a parameter.
get_parameter	Get the value and metadata of a parameter.
get_parameter_schema	Get the template schema for parameter(s) on a node.
get_parameters	Read many parameter values at once, matched by name or label substring.
link_parameters	Create a channel reference from one parameter to another.
lock_parameter	Lock or unlock a parameter.
revert_parameter	Revert a parameter to its default value.
set_expression	Set an expression on a parameter.
set_parameter	Set a parameter value.
set_parameters	Batch-set multiple parameters on a node.

Functions:

create_spare_parameter async

create_spare_parameter(
    ctx: Context,
    node_path: str,
    parm_name: str,
    parm_type: str,
    label: str,
    default_value: Value | None = None,
    min_val: float | None = None,
    max_val: float | None = None,
) -> dict

Add a spare parameter to a node.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Internal parameter name.	required
parm_type	str	"float", "int", "string", "toggle", or "menu".	required
label	str	UI label.	required
default_value	Value | None	Default value.	None
min_val	float | None	Minimum value (float/int only).	None
max_val	float | None	Maximum value (float/int only).	None

create_spare_parameters async

create_spare_parameters(
    ctx: Context,
    node_path: str,
    parameters: list[dict[str, Any]],
    folder_name: str | None = None,
    folder_type: str = "Tabs",
) -> dict

Batch-create multiple spare parameters in one call, optionally in a folder tab.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parameters	list[dict[str, Any]]	List of parameter specs. Each dict has keys: parm_name (str), parm_type (str: "float"/"int"/"string"/"toggle"/"menu"), label (str), default_value (optional), min_val (optional), max_val (optional).	required
folder_name	str | None	If provided, wraps all parameters in a named folder tab.	None
folder_type	str	Folder style: "Tabs", "Collapsible", or "Simple".	'Tabs'

get_expression async

get_expression(ctx: Context, node_path: str, parm_name: str) -> dict

Get the expression on a parameter.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Parameter name.	required

get_parameter async

get_parameter(ctx: Context, node_path: str, parm_name: str) -> dict

Get the value and metadata of a parameter.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Parameter name.	required

get_parameter_schema async

get_parameter_schema(
    ctx: Context,
    node_path: str,
    parm_name: str | None = None,
    filter: str | None = None,
) -> dict

Get the template schema for parameter(s) on a node.

Most nodes have dozens of parameters; many have 100+. Always use parm_name or filter unless you genuinely need the full list.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str | None	Exact parameter name for a single-parameter lookup.	None
filter	str | None	Substring to match against parameter name or label (case-insensitive). Use instead of dumping all params.	None

get_parameters async

get_parameters(
    ctx: Context,
    node_path: str,
    patterns: list[str] | None = None,
    include_defaults: bool = False,
) -> dict

Read many parameter values at once, matched by name or label substring.

The batch counterpart of set_parameters. Several unrelated groups of settings ("flame", "wind", "buoy") come back in one call instead of one call each, and unlike get_node_card these are the live values on this node rather than the defaults for its type.

Parameters:

Name	Type	Description	Default
node_path	str	Node to read.	required
patterns	list[str] | None	Substrings matched against parameter name and label. Omit for everything, up to the cap.	None
include_defaults	bool	Also report whether each value is still the default.	False

link_parameters async

link_parameters(
    ctx: Context,
    source_path: str,
    source_parm: str,
    dest_path: str,
    dest_parm: str,
) -> dict

Create a channel reference from one parameter to another.

Parameters:

Name	Type	Description	Default
source_path	str	Source node path.	required
source_parm	str	Source parameter name.	required
dest_path	str	Destination node path.	required
dest_parm	str	Destination parameter name.	required

lock_parameter async

lock_parameter(
    ctx: Context, node_path: str, parm_name: str, locked: bool
) -> dict

Lock or unlock a parameter.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Parameter name.	required
locked	bool	True to lock, False to unlock.	required

revert_parameter async

revert_parameter(ctx: Context, node_path: str, parm_name: str) -> dict

Revert a parameter to its default value.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Parameter name.	required

set_expression async

set_expression(
    ctx: Context,
    node_path: str,
    parm_name: str,
    expression: str,
    language: str = "hscript",
) -> dict

Set an expression on a parameter.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Parameter name.	required
expression	str	Expression string.	required
language	str	"hscript" (default) or "python".	'hscript'

set_parameter async

set_parameter(
    ctx: Context, node_path: str, parm_name: str, value: Value
) -> dict

Set a parameter value.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
parm_name	str	Parameter name.	required
value	Value	New value (int, float, string, bool, or list).	required

set_parameters async

set_parameters(ctx: Context, node_path: str, params: dict[str, Any]) -> dict

Batch-set multiple parameters on a node.

Parameters:

Name	Type	Description	Default
node_path	str	Node path.	required
params	dict[str, Any]	Mapping of parameter names to values.	required