Entity Documentation - minecraft:rail_sensor

Enables minecart-type entities to detect powered rails and respond to activation state changes. Triggers events when the entity passes over activated or deactivated rails, enabling custom minecart behaviors like launching at boosted speed, stopping at braking rails, or triggering special effects at detector rails.

Rail Sensor Properties

Name	Default Value	Type	Description	Example Values
check_block_types	false	Boolean true/false	If true, on tick this entity will trigger its on_deactivate behavior	Command Block Minecart: true
eject_on_activate	true	Boolean true/false	If true, this entity will eject all of its riders when it passes over an activated rail	Minecart: true
eject_on_deactivate	false	Boolean true/false	If true, this entity will eject all of its riders when it passes over a deactivated rail
on_activate	not set	Minecraft Event Trigger	Event to call when the rail is activated	Command Block Minecart: {"event":"minecraft:command_block_activate"}, Hopper Minecart: {"event":"minecraft:hopper_deactivate"}, Tnt Minecart: {"event":"minecraft:on_prime","filters":{"all_of":[{"domain":"tntexplodes","operator":"==","test":"is_game_rule","value":true}]}}
on_deactivate	not set	Minecraft Event Trigger	Event to call when the rail is deactivated	Command Block Minecart: {"event":"minecraft:command_block_deactivate"}, Hopper Minecart: {"event":"minecraft:hopper_activate"}
tick_command_block_on_activate	true	Boolean true/false	If true, command blocks will start ticking when passing over an activated rail	Command Block Minecart: true
tick_command_block_on_deactivate	false	Boolean true/false	If false, command blocks will stop ticking when passing over a deactivated rail

Samples

Command Block Minecart

At /minecraft:entity/component_groups/minecraft:command_block_active/minecraft:rail_sensor/:

"minecraft:rail_sensor": {
  "check_block_types": true,
  "on_deactivate": {
    "event": "minecraft:command_block_deactivate"
  },
  "eject_on_activate": false,
  "eject_on_deactivate": false,
  "tick_command_block_on_activate": true,
  "tick_command_block_on_deactivate": false
}

At /minecraft:entity/component_groups/minecraft:command_block_inactive/minecraft:rail_sensor/:

"minecraft:rail_sensor": {
  "check_block_types": false,
  "eject_on_activate": false,
  "eject_on_deactivate": false,
  "on_activate": {
    "event": "minecraft:command_block_activate"
  },
  "tick_command_block_on_activate": true,
  "tick_command_block_on_deactivate": false
}

Hopper Minecart

At /minecraft:entity/component_groups/minecraft:hopper_active/minecraft:rail_sensor/:

"minecraft:rail_sensor": {
  "on_activate": {
    "event": "minecraft:hopper_deactivate"
  }
}

At /minecraft:entity/component_groups/minecraft:hopper_inactive/minecraft:rail_sensor/:

"minecraft:rail_sensor": {
  "on_deactivate": {
    "event": "minecraft:hopper_activate"
  }
}

Minecart

"minecraft:rail_sensor": {
  "eject_on_activate": true
}

Tnt Minecart

At /minecraft:entity/component_groups/minecraft:inactive/minecraft:rail_sensor/:

"minecraft:rail_sensor": {
  "on_activate": {
    "event": "minecraft:on_prime",
    "filters": {
      "all_of": [
        {
          "domain": "tntexplodes",
          "operator": "==",
          "test": "is_game_rule",
          "value": true
        }
      ]
    }
  }
}

At /minecraft:entity/component_groups/minecraft:instant_explode_tnt/minecraft:rail_sensor/:

"minecraft:rail_sensor": {}