{
  "schema_version": "1.0",
  "id": "relation.joint.rigid",
  "version": "1.0.0",
  "relation_type": "rigid",
  "endpoint_rules": {
    "source_port": "port.rotation.coaxial",
    "target_port": "port.rotation.coaxial",
    "axis_relation": "coaxial"
  },
  "constraint_rules": ["axes_coaxial", "angular_speeds_equal", "torque_capacity_compatible"],
  "kinematic_effect": {"equation": "omega_source = omega_target"},
  "capability_refs": [
    "capability.kinematics.graph",
    "capability.validation.rigid"
  ],
  "maturity": "production"
}