Low-temperature magnetism of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>KAgF</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>

KAgF3 is a quasi-one-dimensional quantum antiferromagnet hosting a series of intriguing structural and magnetic transitions. Here we use powder neutron diffraction, μSR spectroscopy, and density functional theory calculations to elucidate the low-temperature magnetic phases. Below TN1=29K we find that the material orders as an A-type antiferromagnet with an ordered moment of 0.52μB. Both neutrons and muons provide evidence for an intermediate phase at temperatures TN1<T<TN2 with TN2≈66 K from a previous magnetometry study. However, the evidence is at the limit of detection and its nature remains an open problem.