diff --git a/ml4opf/layers/projection.jl b/ml4opf/layers/projection.jl
new file mode 100644
index 0000000..e55ee74
--- /dev/null
+++ b/ml4opf/layers/projection.jl
@@ -0,0 +1,97 @@
+using OPFGenerator
+using Ipopt, HiGHS, Clarabel
+
+const PM = OPFGenerator.PowerModels
+const JuMP = OPFGenerator.JuMP
+const MOI = OPFGenerator.JuMP.MOI
+
+
+function projection(
+    OPF::Type{<:OPFGenerator.AbstractFormulation},
+    data::OPFGenerator.OPFData,
+    solution,
+    optimizer
+)
+    opf = OPFGenerator.build_opf(OPF, data, optimizer)
+
+    obj = 0.0
+    for v in VARS_MAP[OPF]
+        if haskey(solution, v)
+            obj += sum((solution[v] .- opf.model[v]) .^ 2)
+        end
+    end
+
+    JuMP.set_objective(opf.model, MOI.MIN_SENSE, obj)
+
+    OPFGenerator.solve!(opf)
+
+    d = OPFGenerator.extract_result(opf)
+
+    return Tuple([
+        d["primal"][string(v)] for v in VARS_MAP[OPF]
+    ]), nothing
+end
+
+VARS_MAP = Dict{Type{<:OPFGenerator.AbstractFormulation}, Vector{Symbol}}(
+    OPFGenerator.ACOPF => [:pg, :qg, :pf, :pt, :qf, :qt, :vm, :va],
+    OPFGenerator.DCOPF => [:pg, :pf, :va],
+    OPFGenerator.SOCOPF => [:pg, :qg, :pf, :pt, :qf, :qt, :w, :wr, :wi],
+)
+
+
+function ac_projection(pd, qd, pg, qg, vm, va)
+    data = deepcopy(base_data)
+    data.pd .= pd
+    data.qd .= qd
+    return projection(
+        OPFGenerator.ACOPF,
+        data,
+        Dict(
+            :pg => pg,
+            :qg => qg,
+            :vm => vm,
+            :va => va
+        ),
+        Ipopt.Optimizer
+    )
+end
+
+
+function dc_projection(pd, pg, pf, va)
+    data = deepcopy(base_data)
+    data.pd .= pd
+    return projection(
+        OPFGenerator.DCOPF,
+        data,
+        Dict(
+            :pg => pg,
+            :pf => pf,
+            :va => va
+        ),
+        HiGHS.Optimizer
+    )
+end
+
+
+function soc_projection(pd, qd, pg, qg, w, wr, wi)
+    data = deepcopy(base_data)
+    data.pd .= pd
+    data.qd .= qd
+    return projection(
+        OPFGenerator.SOCOPF,
+        data,
+        Dict(
+            :pg => pg,
+            :qg => qg,
+            :w => w,
+            :wr => wr,
+            :wi => wi
+        ),
+        Clarabel.Optimizer
+    )
+end
+
+
+function no_backward(args...)
+    throw(ArgumentError("Projection layer does not support backpropagation."))
+end
\ No newline at end of file
diff --git a/ml4opf/layers/projection.py b/ml4opf/layers/projection.py
new file mode 100644
index 0000000..3b4f1b9
--- /dev/null
+++ b/ml4opf/layers/projection.py
@@ -0,0 +1,81 @@
+try:
+    from juliapkg import add, resolve
+    add("OPFGenerator", "5d2523b5-5e96-4b1c-8178-da2b93e9175f", url="https://github.com/AI4OPT/OPFGenerator")
+    add("Ipopt", "b6b21f68-93f8-5de0-b562-5493be1d77c9")
+    add("HiGHS", "87dc4568-4c63-4d18-b0c0-bb2238e4078b")
+    add("Clarabel", "61c947e1-3e6d-4ee4-985a-eec8c727bd6e")
+    add("DLPack", "53c2dc0f-f7d5-43fd-8906-6c0220547083")
+    add("Zygote", "e88e6eb3-aa80-5325-afca-941959d7151f")
+    resolve()
+    from juliafunction import JuliaFunction
+    from juliacall import Main
+except ImportError as e:
+    raise ImportError("The projection layer depends on juliafunction. Please install it by running \n\tpip install git+https://github.com/klamike/juliafunction") from e
+
+from ml4opf.formulations.problem import OPFProblem
+from ml4opf.formulations.ac.problem import ACProblem
+from ml4opf.formulations.dc.problem import DCProblem
+from ml4opf.formulations.soc.problem import SOCProblem
+from ml4opf import warn, __path__ as ml4opf_path
+
+
+def make_projection_function(problem: OPFProblem):
+    """Create a projectionn layer for the given OPF problem.
+    
+    The following configurations are currently supported:
+
+        - ACProblem: input (pd, qd) with outputs (pg, qg, vm, va)
+
+        - DCProblem: input (pd) with outputs (pg, pf, va)
+
+        - SOCProblem: input (pd, qd) with outputs (pg, qg, w, wr, wi)
+
+
+    Note only one case can be loaded at a time (but different formulations for the same case are okay).
+
+    To parallelize batch samples using Julia threading,
+    set `PYTHON_JULIACALL_THREADS` and `PYTHON_JULIACALL_HANDLE_SIGNALS="yes"`.
+
+    Refer to the JuliaCall documentation on multi-threading in Julia for more details.
+    """
+    warn(
+        """The projection layer is an experimental feature.\n"""
+        """The following configurations are currently supported: \n"""
+        """- ACProblem: input (pd, qd) with outputs (pg, qg, vm, va) \n"""
+        """- DCProblem: input (pd) with outputs (pg, pf, va) \n"""
+        """- SOCProblem: input (pd, qd) with outputs (pg, qg, w, wr, wi) \n"""
+    )
+    Main.seval(f'using OPFGenerator; const PM = OPFGenerator.PowerModels')
+    Main.seval(f'config = nothing; base_data = nothing')
+
+    if "pglib_case" not in problem.case_data["config"] and "case_file" not in problem.case_data["config"]:
+        problem.case_data["config"]["pglib_case"] = problem.case_data["config"]["ref"]
+
+    Main.config = problem.case_data["config"]
+    Main.seval("base_data = config |> OPFGenerator._get_case_info |> first |> PM.parse_file |> PM.make_basic_network |> OPFGenerator.OPFData")
+    if isinstance(problem, ACProblem):
+        return JuliaFunction(
+            forward="ac_projection",
+            backward="no_backward",
+            batch_dims=[0] * 6,
+            include=f"{ml4opf_path[0]}/layers/projection.jl",
+            setup_code="base_data = Main.base_data",
+        )
+    elif isinstance(problem, DCProblem):
+        return JuliaFunction(
+            forward="dc_projection",
+            backward="no_backward",
+            batch_dims=[0] * 4,
+            include=f"{ml4opf_path[0]}/layers/projection.jl",
+            setup_code="base_data = Main.base_data",
+        )
+    elif isinstance(problem, SOCProblem):
+        return JuliaFunction(
+            forward="soc_projection",
+            backward="no_backward",
+            batch_dims=[0] * 7,
+            include=f"{ml4opf_path[0]}/layers/projection.jl",
+            setup_code="base_data = Main.base_data",
+        )
+    else:
+        raise ValueError(f"Unsupported problem type: {type(problem)}")
\ No newline at end of file