The elder wand of telecom wizards would coherently change the color of light. But while the laws of physics do allow mutating the photon chroma, all attempts to date have been very inefficient for large frequency mismatches. PALANTIRI will initiate a technological breakthrough by providing a viable development path for integrating the coherent and efficient interconversion of information between microwaves and light on a chip. We propose a radically new approach building on quadripartite (microwave photon-magnon-phonon-optical photon) hybridization process. The idea is to exploit opto-mechanical effects while inserting a magnetic element that maintains high cooperativity both with a mechanical mode through magneto-acoustic coupling and with the microwave antenna through inductive coupling, while exploiting magnetic texture to achieve perfect matching of the microwave precession profile with the optical mode. This opportunity has recently emerged from progress in material science, which allows the fabrication of freestanding micron-size slabs of ultra-high quality magnetic insulator yttrium iron garnet. The suspension greatly suppresses any leakage of phononic or photonic oscillating energy through the substrate. PALANTIRI’s scientific objectives are to deliver within 42 months a proof of principle on-chip analog coherent frequency converter with efficiency of the order of unity (TRL2). The delivered phase-sensitive device will provide the breakthroughs needed to achieve a radical expansion of the connectivity capacity of a backhaul network for enabling high-speed internet access for everyone from any location. It will also provide the elementary brick to build the quantum-ready internet infrastructure of the future. To achieve these goals, our consortium consists of six academic partners (CEA, MLU, CNRS, TUD, ICN2, MPG) from four EU countries (FR, DE, NL, ES) and one industrial partner (TSST). The global budget of the proposal is 3,3M€.