Methods and systems are disclosed for mapping the coordinate systems of devices for AR applications. A third device may receive a first pose from a first device associated with a first coordinate system and a second pose from a second device associated with a second coordinate system. The third device may receive an image that includes fiducial markers presented by each of the first device and the second device. The first pose and the portion of the image including the first fiducial marker may define a first set of 3D coordinates. The second pose and the portion of the image including the second fiducial marker may define a second set of 3D coordinates. A coordinate-system transform can be generated from a correspondence between the first set and the second of 3D coordinates. The coordinate-system transform may be transmitted to the first device and/or the second device.