Play Session

Play Session: Spawn, change and check actors while your game runs in Play In Editor. Unreal Engine 5 command reference with parameters and examples.

7 commands. Each shows its parameters and an example, and has a copyable deep link, so you (or an AI agent) can jump straight to one.

spawn_runtime_actors

Spawn 1 to 1000 actors or Blueprints into a running play session, near a player or at a location

Parameter	Type	Required	Description
class	string	Yes	Actor class: a Blueprint path (/Game/AI/BP_Enemy), a bare Blueprint name, a class path, or a native class name
count	int	No	How many, 1 to 1000
world	string	No
location	json	No	Center of the group as [x,y,z] or "x,y,z"; omit to spawn in front of a player
rotation	json	No	Rotation of every actor as [pitch,yaw,roll]; omit to face the player (or zero with --location)
player	int	No	Without --location: the player controller index to spawn near
distance	float	No	Without --location: how far in front of the player the group's center is
pattern	string	No	grid, ring, random or point (default point for one actor, grid for more)
spacing	float	No	Space between actors in a grid or ring
radius	float	No	Radius of a random pattern, and the smallest ring radius
on_navmesh	bool	No	Put every point on the navigation mesh
snap_to_ground	bool	No	Stand each actor on static ground
properties	json	No	Property path to value, set before the construction script and BeginPlay, e.g. {"Health":50,"CharacterMovement.MaxWalkSpeed":300}
replicate	bool	No	Server only: turn actor replication on (or off with =false) for these actors, whatever the class says
replicate_movement	bool	No	Server only: turn movement replication on or off for these actors
ai	bool	No	Pawns on the server get an AI controller by default; =false leaves them without one
ai_controller	string	No	AI controller class instead of the pawn's AIControllerClass
behavior_tree	string	No	Behavior Tree asset each AI controller runs
tags	stringlist	No	Extra actor tags
batch	string	No	Name for this group, used by the other runtime commands (default <Class>_<n>); an existing name adds to that batch
collision	string	No	When a spot is blocked: adjust (default; move it free), always (spawn in place) or skip_if_blocked

example

  cfa spawn_runtime_actors --class /Game/AI/BP_Enemy --count 100 --on-navmesh --behavior-tree /Game/AI/BT_Enemy
  cfa spawn_runtime_actors --class BP_Pickup --count 12 --pattern ring --radius 600 --replicate
  cfa spawn_runtime_actors --class /Game/BP_Crate --location "[0,0,200]" --properties '{"Health":50}'
  cfa spawn_runtime_actors --class BP_Marker --world client1

list_runtime_actors

Count and list play-session actors per world, server and each client

Parameter	Type	Required	Description
world	string	No	server, client1..., all_clients, instance:N or all (default)
batch	string	No	Only this batch
class	string	No	Only classes whose name contains this text
filter	string	No	Only actor names that contain this text
tag	string	No	Only actors with this tag
spawned_only	bool	No	Only actors the runtime commands spawned; false lists every actor
max_results	int	No	Most rows over all worlds; counts stay complete

example

  cfa list_runtime_actors --batch enemies
  cfa list_runtime_actors --world client1 --batch enemies --max-results 5
  cfa list_runtime_actors --world server --spawned-only=false --class Character

get_runtime_actor

One play-session actor: role, replication, transform, AI, client copies, variables

Parameter	Type	Required	Description
actor	string	Yes	Actor name in that world, from list_runtime_actors
world	string	No
component	string	No	Read a component of the actor instead, by name
property_path	string	No	Return only this property's value
filter	string	No	Properties whose name contains this text, from every class of the actor
max_results	int	No	Most properties listed

example

  cfa get_runtime_actor --actor BP_Enemy_C_3
  cfa get_runtime_actor --actor BP_Enemy_C_3 --world client1 --property-path Health
  cfa get_runtime_actor --actor BP_Enemy_C_3 --component CharacterMovement --filter Speed

set_runtime_actor_properties

Change properties of running actors; replicated ones reach every client

Parameter	Type	Required	Description
properties	json	Yes	Property path to value, e.g. {"Health":25,"Stats.Armor":3}
actor	string	No	One actor by name; give actor or batch
batch	string	No	Every actor of a batch in that world
world	string	No
component	string	No	Write to a component of each actor instead, by name

example

  cfa set_runtime_actor_properties --batch enemies --properties '{"Health":25}'
  cfa set_runtime_actor_properties --actor BP_Door_C_0 --properties '{"bIsOpen":true}'
  cfa set_runtime_actor_properties --batch enemies --component CharacterMovement --properties '{"MaxWalkSpeed":150}'

call_runtime_function

Call a function, event or RPC on running actors with named arguments

Parameter	Type	Required	Description
function	string	Yes	Function, event or RPC name
args	json	No	Argument name to value, e.g. {"Amount":5}
actor	string	No	One actor by name; give actor or batch
batch	string	No	Every actor of a batch in that world
world	string	No
component	string	No	Call it on a component of each actor instead, by name

example

  cfa call_runtime_function --actor BP_Enemy_C_3 --function TakeHit --args '{"Damage":10}'
  cfa call_runtime_function --batch enemies --function K2_SetActorLocation --args '{"NewLocation":[0,0,300]}'
  cfa call_runtime_function --actor BP_Door_C_0 --function MulticastOpen

destroy_runtime_actors

Destroy an actor, a batch, or every spawned actor of a play world

Parameter	Type	Required	Description
actor	string	No	One actor by name
batch	string	No	Every actor of a batch
all_spawned	bool	No	Every actor the runtime commands spawned in that world
world	string	No

example

  cfa destroy_runtime_actors --batch enemies
  cfa destroy_runtime_actors --actor BP_Enemy_C_3
  cfa destroy_runtime_actors --all-spawned

validate_runtime_actors

Check a batch with a verdict: alive, AI running, a matching copy on every client

Parameter	Type	Required	Description
actor	string	No	One actor by name; give actor or batch
batch	string	No	Every actor of a batch
world	string	No

example

  cfa validate_runtime_actors --batch enemies
  cfa validate_runtime_actors --actor BP_Door_C_0

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Parameter

Type

Required

Description

class

string

Yes

Actor class: a Blueprint path (/Game/AI/BP_Enemy), a bare Blueprint name, a class path, or a native class name

count

int

How many, 1 to 1000

world

string

location

json

Center of the group as [x,y,z] or "x,y,z"; omit to spawn in front of a player

rotation

json

Rotation of every actor as [pitch,yaw,roll]; omit to face the player (or zero with --location)

player

int

Without --location: the player controller index to spawn near

distance

float

Without --location: how far in front of the player the group's center is

pattern

string

grid, ring, random or point (default point for one actor, grid for more)

spacing

float

Space between actors in a grid or ring

radius

float

Radius of a random pattern, and the smallest ring radius

on_navmesh

bool

Put every point on the navigation mesh

snap_to_ground

bool

Stand each actor on static ground

properties

json

Property path to value, set before the construction script and BeginPlay, e.g. {"Health":50,"CharacterMovement.MaxWalkSpeed":300}

replicate

bool

Server only: turn actor replication on (or off with =false) for these actors, whatever the class says

replicate_movement

bool

Server only: turn movement replication on or off for these actors

bool

Pawns on the server get an AI controller by default; =false leaves them without one

ai_controller

string

AI controller class instead of the pawn's AIControllerClass

behavior_tree

string

Behavior Tree asset each AI controller runs