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diff --git a/Source/FieldSolver/SpectralSolver/AnyFFT.H b/Source/FieldSolver/SpectralSolver/AnyFFT.H
new file mode 100644
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+++ b/Source/FieldSolver/SpectralSolver/AnyFFT.H
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+#ifndef ANYFFT_H_
+#define ANYFFT_H_
+
+#ifdef AMREX_USE_GPU
+#  include <cufft.h>
+#else
+#  include <fftw3.h>
+#endif
+
+#include <AMReX_LayoutData.H>
+
+/**
+ * Wrapper around FFT libraries. The header file defines the API and the base types
+ * (Complex and VendorFFTPlan), and the implementation for different FFT libraries is
+ * done in different cpp files. This wrapper only depends on the underlying FFT library
+ * AND on AMReX (There is no dependence on WarpX).
+ */
+namespace AnyFFT
+{
+    // First, define library-dependent types (complex, FFT plan)
+
+    /** Complex type for FFT, depends on FFT library */
+#ifdef AMREX_USE_GPU
+#  ifdef AMREX_USE_FLOAT
+    using Complex = cuComplex;
+#  else
+    using Complex = cuDoubleComplex;
+#  endif
+#else
+#  ifdef AMREX_USE_FLOAT
+    using Complex = fftwf_complex;
+#  else
+    using Complex = fftw_complex;
+#  endif
+#endif
+
+    /** Library-dependent FFT plans type, which holds one fft plan per box
+     * (plans are only initialized for the boxes that are owned by the local MPI rank).
+     */
+#ifdef AMREX_USE_GPU
+    using VendorFFTPlan = cufftHandle;
+#else
+#  ifdef AMREX_USE_FLOAT
+    using VendorFFTPlan = fftwf_plan;
+#  else
+    using VendorFFTPlan = fftw_plan;
+#  endif
+#endif
+
+    // Second, define library-independent API
+
+    /** Direction in which the FFT is performed. */
+    enum struct direction {R2C, C2R};
+
+    /** This struct contains the vendor FFT plan and additional metadata
+     */
+    struct FFTplan
+    {
+        amrex::Real* m_real_array; /**< pointer to real array */
+        Complex* m_complex_array; /**< pointer to complex array */
+        VendorFFTPlan m_plan; /**< Vendor FFT plan */
+        direction m_dir;  /**< direction (C2R or R2C) */
+        int m_dim; /**< Dimensionality of the FFT plan */
+    };
+
+    /** Collection of FFT plans, one FFTplan per box */
+    using FFTplans = amrex::LayoutData<FFTplan>;
+
+    /** \brief create FFT plan for the backend FFT library.
+     * \param[in] real_size Size of the real array, along each dimension.
+     *                      Only the first dim elements are used.
+     * \param[out] real_array Real array from/to where R2C/C2R FFT is performed
+     * \param[out] complex_array Complex array to/from where R2C/C2R FFT is performed
+     * \param[in] dir direction, either R2C or C2R
+     * \param[in] dim direction, number of dimensions of the arrays. Must be <= AMREX_SPACEDIM.
+     */
+    FFTplan CreatePlan(const amrex::IntVect& real_size, amrex::Real * const real_array,
+                       Complex * const complex_array, const direction dir, const int dim);
+
+    /** \brief Destroy library FFT plan.
+     * \param[out] fft_plan plan to destroy
+     */
+    void DestroyPlan(FFTplan& fft_plan);
+
+    /** \brief Perform FFT with backend library.
+     * \param[out] fft_plan plan for which the FFT is performed
+     */
+    void Execute(FFTplan& fft_plan);
+}
+
+#endif // ANYFFT_H_