A good summary of the various joint types can be found here: https://www.iforce2d.net/b2dtut/joints-overview

[RevoluteJoint]
Type = revolute;
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
Rotation = [Float]
MinRotation = [Float]
MaxRotation = [Float]
MotorSpeed = [Float]
MaxMotorTorque = [Float]

[PrismaticJoint]
Type = prismatic;
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
Rotation = [Float]
TranslationAxis = [Vector]
MinTranslation = [Float]
MaxTranslation = [Float]
MotorSpeed = [Float]
MaxMotorForce = [Float]

[SpringJoint]
Type = spring
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
Length = [Float]
Frequency = [Float]
Damping = [Float]

[RopeJoint]
Type = rope
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
Length = [Float]

[PulleyJoint]
Type = pulley
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
ParentGroundAnchor = [Vector]
ChildGroundAnchor = [Vector]
ParentLength = [Float]
MaxParentLength = [Float]
ChildLength = [Float]
MaxChildLength = [Float]
LengthRatio = [Float]

[SuspensionJoint]
Type = suspension;
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
TranslationAxis = [Vector]
MinTranslation = [Float]
MaxTranslation = [Float]
MotorSpeed = [Float]
MaxMotorForce = [Float]

[WeldJoint]
Type = weld;
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
Rotation = [Float]

[FrictionJoint]
Type = friction;
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
MaxForce = [Float]
MaxTorque = [Float]

[GearJoint]
Type = gear
ParentAnchor = [Vector]
ChildAnchor = [Vector]
Collide = true|false
ParentJoint = [String]
ChildJoint = [String]
JointRatio = [Float]

Here's a list of common properties for the joints. Note that not all of the joins support these properties.

• Type: Defines the type of the joint. Available types are: revolute, prismatic, spring, rope, pulley, suspension, weld, friction and gear.
• ParentAnchor: The position the parent object is joined at, defined in local parent's space.
• ChildAnchor: The position the child object is joined at, defined in local child's space.
• Collide: Defines if collision between parent and child object is allowed.
• Rotation: Default rotation between parent and child bodies, in degrees. If none is provided, the current rotation difference between both bodies will be used.
• MotorSpeed: Only used if MaxMotorTorque is also defined. In degrees / seconds.
• MaxMotorTorque: Only used if MotorSpeed is also defined.

• MinRotation: Only used if MaxRotation is also defined.
• MaxRotation: Only used if MinRotation is also defined.

• TranslationAxis: Should be normalized.
• MinTranslation: In meters, only used if MaxTranslation is also defined.
• MaxTranslation: In meters, only used if MinTranslation is also defined.

• Length: In meters. If not defined, the current distance between parent and child bodies will be used.
• Frequency: In hertz.
• Damping: Between 0 (min) and 1 (max)

• Length: In meters. If not defined, the current distance between parent and child bodies will be used.

• ParentGroundAnchor
• ChildGroundAnchor
• ParentLength: In meters. If not defined, the current distance between parent and its ground anchor will be used;
• MaxParentLength: In meters. If not defined ParentLength + LengthRatio * ChildLength will be used;
• ChildLength: In meters. If not defined, the current distance between child and its ground anchor will be used;
• MaxChildLength: In meters. If not defined ParentLength + LengthRatio * ChildLength will be used;
• LengthRatio

• TranslationAxis: Should be normalized;
• MinTranslation: In meters; Only used if MaxTranslation is also defined;
• MaxTranslation: In meters; Only used if MinTranslation is also defined;

Does not have any properties except those defined in the summary.

• Collide = true|false: Allows collision between joint's parent and child bodies. Defaults to false;
• MaxForce:
• MaxTorque:

• ParentJoint: Should be a revolute or prismatic joint already existing on the parent.
• ChildJoint: Should be a revolute or prismatic joint already existing on the child.
• JointRatio