diff --git a/examples/Example001_Solvers.jl b/examples/Example001_Solvers.jl
index 672053661..2f41dba01 100644
--- a/examples/Example001_Solvers.jl
+++ b/examples/Example001_Solvers.jl
@@ -28,25 +28,25 @@ function main(; n = 10, Plotter = nothing, assembly = :edgwwise, kwargs...)
 
     eps = 1.0e-2
 
-    function reaction(f, u, node)
+    function reaction(f, u, node, data=nothing)
         f[1] = u[1]^2
     end
 
-    function flux(f, u, edge)
+    function flux(f, u, edge, data=nothing)
         f[1] = eps * (u[1, 1]^2 - u[1, 2]^2)
     end
 
-    function source(f, node)
+    function source(f, node, data=nothing)
         x1 = node[1] - 0.5
         x2 = node[2] - 0.5
         f[1] = exp(-20.0 * (x1^2 + x2^2))
     end
 
-    function storage(f, u, node)
+    function storage(f, u, node, data=nothing)
         f[1] = u[1]
     end
 
-    function bcondition(f, u, node)
+    function bcondition(f, u, node, data=nothing)
         boundary_dirichlet!(f,
                             u,
                             node;
diff --git a/examples/Example002_EdgeReaction.jl b/examples/Example002_EdgeReaction.jl
index dd015ffd5..9e7de41f1 100644
--- a/examples/Example002_EdgeReaction.jl
+++ b/examples/Example002_EdgeReaction.jl
@@ -46,18 +46,18 @@ function main(; nref = 0, dim = 2, Plotter = nothing, verbose = "and", case = :c
         i1 = 6
     end
 
-    function storage!(y, u, node)
+    function storage!(y, u, node, data=nothing)
         y[1] = u[1]
     end
 
-    function flux!(y, u, edge)
+    function flux!(y, u, edge, data=nothing)
         y[1] = u[1, 1] - u[1, 2]
     end
 
     # Three ways to give a constant reaction term. As a consequence,
     # these need to yield the same solution.
     # 1: classical node reaction, multiplied  by control volume size
-    function reaction!(y, u, node)
+    function reaction!(y, u, node, data=nothing)
         y[1] = -1
     end
 
@@ -76,7 +76,7 @@ function main(; nref = 0, dim = 2, Plotter = nothing, verbose = "and", case = :c
     #
     #  τ=1/h    v= s*h/2d = σ*h^2/2d 
     #                
-    function edgereaction!(y, u, edge)
+    function edgereaction!(y, u, edge, data=nothing)
         h = meas(edge)
         y[1] = -1 * h^2 / (2 * dim)
     end
@@ -88,14 +88,14 @@ function main(; nref = 0, dim = 2, Plotter = nothing, verbose = "and", case = :c
     # we had before
     ϕ = grid[Coordinates][1, :]
 
-    function edgereaction2!(y, u, edge)
+    function edgereaction2!(y, u, edge, data=nothing)
         ϕK = ϕ[edge.node[1]]
         ϕL = ϕ[edge.node[2]]
         y[1] = -(ϕK - ϕL) * (ϕK - ϕL) / 2
     end
 
     if case == :compare_max
-        function bcondition!(y, u, node)
+        function bcondition!(y, u, node, data=nothing)
             boundary_dirichlet!(y, u, node; species = 1, region = 1, value = 0)
             boundary_dirichlet!(y, u, node; species = 1, region = 2, value = 0)
             boundary_dirichlet!(y, u, node; species = 1, region = 3, value = 0)
@@ -130,7 +130,7 @@ function main(; nref = 0, dim = 2, Plotter = nothing, verbose = "and", case = :c
     end
 
     if case == :compare_flux
-        function bcondition2!(y, u, node)
+        function bcondition2!(y, u, node, data=nothing)
             boundary_dirichlet!(y, u, node; species = 1, region = i1, value = 0)
         end
 
diff --git a/examples/Example101_Laplace1D.jl b/examples/Example101_Laplace1D.jl
index beeeb2f2c..3cfe9cb5d 100644
--- a/examples/Example101_Laplace1D.jl
+++ b/examples/Example101_Laplace1D.jl
@@ -96,7 +96,7 @@ function main()
 
     ## Flux function which describes the flux
     ## between neighboring control volumes
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = u[1, 1] - u[1, 2]
     end
 
diff --git a/examples/Example105_NonlinearPoisson1D.jl b/examples/Example105_NonlinearPoisson1D.jl
index 8dcb161e1..0cb263fe6 100644
--- a/examples/Example105_NonlinearPoisson1D.jl
+++ b/examples/Example105_NonlinearPoisson1D.jl
@@ -38,12 +38,12 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
 
     ## Flux function which describes the flux
     ## between neighboring control volumes
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = ϵ * (u[1, 1] - u[1, 2])
     end
 
     ## Source term
-    function source!(f, node)
+    function source!(f, node, data=nothing)
         if node[1] <= 0.5
             f[1] = 1
         else
@@ -52,7 +52,7 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
     end
 
     ## Reaction term
-    function reaction!(f, u, node)
+    function reaction!(f, u, node, data=nothing)
         f[1] = exp(u[1]) - exp(-u[1])
     end
 
diff --git a/examples/Example106_NonlinearDiffusion1D.jl b/examples/Example106_NonlinearDiffusion1D.jl
index 1366fe501..45557746a 100644
--- a/examples/Example106_NonlinearDiffusion1D.jl
+++ b/examples/Example106_NonlinearDiffusion1D.jl
@@ -44,12 +44,12 @@ function main(; n = 20, m = 2, Plotter = nothing, verbose = false,
 
     ## Flux function which describes the flux
     ## between neighboring control volumes
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = u[1, 1]^m - u[1, 2]^m
     end
 
     ## Storage term
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         f[1] = u[1]
     end
 
diff --git a/examples/Example107_NonlinearStorage1D.jl b/examples/Example107_NonlinearStorage1D.jl
index 9942067ef..ab8033338 100644
--- a/examples/Example107_NonlinearStorage1D.jl
+++ b/examples/Example107_NonlinearStorage1D.jl
@@ -40,7 +40,7 @@ function main(; n = 20, m = 2.0, Plotter = nothing, verbose = false,
 
     ## Flux function which describes the flux
     ## between neighboring control volumes
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = u[1, 1] - u[1, 2]
     end
 
@@ -49,7 +49,7 @@ function main(; n = 20, m = 2.0, Plotter = nothing, verbose = false,
     ## Storage term
     ## This needs to be regularized as its derivative
     ## at 0 is infinity
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         f[1] = (ϵ + u[1])^(1.0 / m)
     end
 
diff --git a/examples/Example108_OrdinaryDiffEq1D.jl b/examples/Example108_OrdinaryDiffEq1D.jl
index f38ba53ba..5436fbe25 100644
--- a/examples/Example108_OrdinaryDiffEq1D.jl
+++ b/examples/Example108_OrdinaryDiffEq1D.jl
@@ -44,12 +44,12 @@ function main(; n = 20, m = 2, Plotter = nothing, verbose = false,
 
     ## Flux function which describes the flux
     ## between neighboring control volumes
-    function flux!(f, u, edge)
+    function flux!(f, u, edg, data=nothing)
         f[1] = u[1, 1]^m - u[1, 2]^m
     end
 
     ## Storage term
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         f[1] = u[1]
     end
 
diff --git a/examples/Example110_ReactionDiffusion1D_TwoSpecies.jl b/examples/Example110_ReactionDiffusion1D_TwoSpecies.jl
index a319053f9..26d1b3cef 100644
--- a/examples/Example110_ReactionDiffusion1D_TwoSpecies.jl
+++ b/examples/Example110_ReactionDiffusion1D_TwoSpecies.jl
@@ -29,20 +29,20 @@ function main(; n = 100, Plotter = nothing, verbose = false, unknown_storage = :
     eps::Vector{Float64} = [1.0, 1.0]
 
     physics = VoronoiFVM.Physics(
-                                 ; reaction = function (f, u, node)
+                                 ; reaction = function (f, u, node, data=nothing)
                                      f[1] = u[1] * u[2]
                                      f[2] = -u[1] * u[2]
                                  end,
-                                 flux = function (f, u, edge)
+                                 flux = function (f, u, edge, data=nothing)
                                      nspecies = 2
                                      f[1] = eps[1] * (u[1, 1] - u[1, 2]) *
                                             (0.01 + u[2, 1] + u[2, 2])
                                      f[2] = eps[2] * (u[2, 1] - u[2, 2]) *
                                             (0.01 + u[1, 1] + u[1, 2])
-                                 end, source = function (f, node)
+                                 end, source = function (f, node, data=nothing)
                                      f[1] = 1.0e-4 * (0.01 + node[1])
                                      f[2] = 1.0e-4 * (0.01 + 1.0 - node[1])
-                                 end, storage = function (f, u, node)
+                                 end, storage = function (f, u, node, data=nothing)
                                      f[1] = u[1]
                                      f[2] = u[2]
                                  end)
diff --git a/examples/Example115_HeterogeneousCatalysis1D.jl b/examples/Example115_HeterogeneousCatalysis1D.jl
index dd4b2a8da..f3c534ea8 100644
--- a/examples/Example115_HeterogeneousCatalysis1D.jl
+++ b/examples/Example115_HeterogeneousCatalysis1D.jl
@@ -77,19 +77,19 @@ function main(; n = 10, Plotter = nothing, verbose = false, tend = 1,
     ## Diffusion flux for species A and B
     D_A = 1.0
     D_B = 1.0e-2
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[iA] = D_A * (u[iA, 1] - u[iA, 2])
         f[iB] = D_B * (u[iB, 1] - u[iB, 2])
     end
 
     ## Storage term of species A and B
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         f[iA] = u[iA]
         f[iB] = u[iB]
     end
 
     ## Source term for species a around 0.5
-    function source!(f, node)
+    function source!(f, node, data=nothing)
         x1 = node[1] - 0.5
         f[iA] = exp(-100 * x1^2)
     end
@@ -110,7 +110,7 @@ function main(; n = 10, Plotter = nothing, verbose = false, tend = 1,
     R_AC(u_A, u_C) = kp_AC * u_A * (1 - u_C) - km_AC * u_C
     R_BC(u_B, u_C) = kp_BC * u_B * (1 - u_C) - km_BC * u_C
 
-    function breaction!(f, u, node)
+    function breaction!(f, u, node, data=nothing)
         if node.region == 1
             f[iA] = S * R_AC(u[iA], u[iC])
             f[iB] = S * R_BC(u[iB], u[iC])
@@ -119,7 +119,7 @@ function main(; n = 10, Plotter = nothing, verbose = false, tend = 1,
     end
 
     ## This is for the term \partial_t u_C at the boundary
-    function bstorage!(f, u, node)
+    function bstorage!(f, u, node, data=nothing)
         if node.region == 1
             f[iC] = u[iC]
         end
diff --git a/examples/Example120_ThreeRegions1D.jl b/examples/Example120_ThreeRegions1D.jl
index 5618182ed..d29b36536 100644
--- a/examples/Example120_ThreeRegions1D.jl
+++ b/examples/Example120_ThreeRegions1D.jl
@@ -31,7 +31,7 @@ function main(; n = 30, Plotter = nothing, plot_grid = false, verbose = false,
     eps = [1, 1, 1]
     k = [1, 1, 1]
 
-    function reaction(f, u, node)
+    function reaction(f, u, node, data=nothing)
         if node.region == 1
             f[1] = k[1] * u[1]
             f[2] = -k[1] * u[1]
@@ -43,7 +43,7 @@ function main(; n = 30, Plotter = nothing, plot_grid = false, verbose = false,
         end
     end
 
-    function source(f, node)
+    function source(f, node, data=nothing)
         if node.region == 1
             f[1] = 1.0e-4 * (3.0 - node[1])
         end
@@ -54,20 +54,20 @@ function main(; n = 30, Plotter = nothing, plot_grid = false, verbose = false,
         ## write into the result also where
         ## the corresponding species has not been enabled
         ## Species information is used to prevent the assembly.
-        flux = function (f, u, edge)
+        flux = function (f, u, edge, data=nothing)
             for i = 1:3
                 f[i] = eps[i] * (u[i, 1] - u[i, 2])
             end
         end
 
-        storage = function (f, u, node)
+        storage = function (f, u, node, data=nothing)
             f .= u
         end
     else
         ## This is the "old" way:
         ## Write into result only where
         ## the corresponding species has been enabled
-        flux = function (f, u, edge)
+        flux = function (f, u, edge, data=nothing)
             if edge.region == 1
                 f[1] = eps[1] * (u[1, 1] - u[1, 2])
                 f[2] = eps[2] * (u[2, 1] - u[2, 2])
@@ -79,7 +79,7 @@ function main(; n = 30, Plotter = nothing, plot_grid = false, verbose = false,
             end
         end
 
-        storage = function (f, u, node)
+        storage = function (f, u, node, data=nothing)
             if node.region == 1
                 f[1] = u[1]
                 f[2] = u[2]
diff --git a/examples/Example121_PoissonPointCharge1D.jl b/examples/Example121_PoissonPointCharge1D.jl
index a73e353c7..e0b01060c 100644
--- a/examples/Example121_PoissonPointCharge1D.jl
+++ b/examples/Example121_PoissonPointCharge1D.jl
@@ -40,16 +40,16 @@ function main(; nref = 0, Plotter = nothing, verbose = false, unknown_storage =
 
     Q::Float64 = 0.0
 
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = u[1, 1] - u[1, 2]
     end
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         f[1] = u[1]
     end
 
     ## Define boundary reaction defining charge
     ## Note that the term  is written on  the left hand side, therefore the - sign
-    function breaction!(f, u, node)
+    function breaction!(f, u, node, data=nothing)
         if node.region == 3
             f[1] = -Q
         end
diff --git a/examples/Example125_TestFunctions1D.jl b/examples/Example125_TestFunctions1D.jl
index 02d4bb0c3..80a4a2535 100644
--- a/examples/Example125_TestFunctions1D.jl
+++ b/examples/Example125_TestFunctions1D.jl
@@ -19,13 +19,13 @@ function main(; n = 100, Plotter = nothing, verbose = false, unknown_storage = :
     eps::Vector{Float64} = [1, 1.0e-1]
 
     physics = VoronoiFVM.Physics(
-                                 ; reaction = function (f, u, node)
+                                 ; reaction = function (f, u, node, data=nothing)
                                      f[1] = 10 * (u[1] - u[2])
                                      f[2] = 10 * (u[2] - u[1])
-                                 end, flux = function (f, u, edge)
+                                 end, flux = function (f, u, edge, data=nothing)
                                      f[1] = eps[1] * (u[1, 1] - u[1, 2])
                                      f[2] = eps[2] * (u[2, 1] - u[2, 2])
-                                 end, storage = function (f, u, node)
+                                 end, storage = function (f, u, node, data=nothing)
                                      f[1] = u[1]
                                      f[2] = u[2]
                                  end)
diff --git a/examples/Example201_Laplace2D.jl b/examples/Example201_Laplace2D.jl
index 8aeca4947..32c55bc94 100644
--- a/examples/Example201_Laplace2D.jl
+++ b/examples/Example201_Laplace2D.jl
@@ -14,7 +14,7 @@ import Metis
 
 ## Flux function which describes the flux
 ## between neighboring control volumes
-function g!(f, u, edge)
+function g!(f, u, edge, data=nothing)
     f[1] = u[1, 1] - u[1, 2]
 end
 
diff --git a/examples/Example203_CoordinateSystems.jl b/examples/Example203_CoordinateSystems.jl
index d89a12732..1fe7fd2a7 100644
--- a/examples/Example203_CoordinateSystems.jl
+++ b/examples/Example203_CoordinateSystems.jl
@@ -17,7 +17,7 @@ function plot(grid, numerical, exact, Plotter)
     scalarplot!(vis[2, 1], grid, exact; title = "exact", show = true)
 end
 
-function flux(f, u, edge)
+function flux(f, u, edge, data=nothing)
     f[1] = u[1, 1] - u[1, 2]
 end
 
@@ -41,7 +41,7 @@ function maindisk(; nref = 0, r2 = 5.0, Plotter = nothing, assembly = :edgewise)
     R = collect(0:h:r2)
     grid = simplexgrid(R)
     circular_symmetric!(grid)
-    source(f, node) = f[1] = 1.0
+    source(f, node, data=nothing) = f[1] = 1.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
     sol = solve(sys)
@@ -70,7 +70,7 @@ function maincylinder(;
     Z = collect(z1:h:z2)
     grid = simplexgrid(R, Z)
     circular_symmetric!(grid)
-    source(f, node) = f[1] = 1.0
+    source(f, node, data=nothing) = f[1] = 1.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
     sol = solve(sys)
@@ -101,7 +101,7 @@ function maincylinder_unstruct(;
     h = 0.1 * 2.0^(-nref)
     grid = simplexgrid(joinpath(pkgdir(VoronoiFVM), "assets", "cyl_unstruct.sg"))
     circular_symmetric!(grid)
-    source(f, node) = f[1] = 1.0
+    source(f, node, data=nothing) = f[1] = 1.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
     sol = solve(sys)
@@ -129,7 +129,7 @@ function mainring(; nref = 0, r1 = 1.0, r2 = 5.0, Plotter = nothing, assembly =
     R = collect(r1:h:r2)
     grid = simplexgrid(R)
     circular_symmetric!(grid)
-    source(f, node) = f[1] = 0.0
+    source(f, node, data=nothing) = f[1] = 0.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 1, value = 1.0)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
@@ -158,7 +158,7 @@ function maincylindershell(;
     Z = collect(z1:h:z2)
     grid = simplexgrid(R, Z)
     circular_symmetric!(grid)
-    source(f, node) = f[1] = 0.0
+    source(f, node, data=nothing) = f[1] = 0.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 4, value = 1.0)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
@@ -188,7 +188,7 @@ function mainsphere(; nref = 0, r2 = 5.0, Plotter = nothing, assembly = :edgewis
     R = collect(0:h:r2)
     grid = simplexgrid(R)
     spherical_symmetric!(grid)
-    source(f, node) = f[1] = 1.0
+    source(f, node, data=nothing) = f[1] = 1.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
     sol = solve(sys)
@@ -221,7 +221,7 @@ function mainsphereshell(;
     R = collect(r1:h:r2)
     grid = simplexgrid(R)
     spherical_symmetric!(grid)
-    source(f, node) = f[1] = 0.0
+    source(f, node, data=nothing) = f[1] = 0.0
     sys = VoronoiFVM.System(grid; source, flux, species = [1], assembly = assembly)
     boundary_dirichlet!(sys; species = 1, region = 1, value = 1.0)
     boundary_dirichlet!(sys; species = 1, region = 2, value = 0.0)
diff --git a/examples/Example204_HagenPoiseuille.jl b/examples/Example204_HagenPoiseuille.jl
index 806f06bfe..8f31d96f5 100644
--- a/examples/Example204_HagenPoiseuille.jl
+++ b/examples/Example204_HagenPoiseuille.jl
@@ -32,14 +32,14 @@ function main(; nref = 0, Plotter = nothing, D = 0.01, v = 1.0, tend = 100, cin
     evelo = edgevelocities(grid, fhp)
     bfvelo = bfacevelocities(grid, fhp)
 
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         vd = evelo[edge.index] / D
         bp = fbernoulli(vd)
         bm = fbernoulli(-vd)
         f[1] = D * (bp * u[1] - bm * u[2])
     end
 
-    function outflow!(f, u, node)
+    function outflow!(f, u, node, data=nothing)
         if node.region == 2
             f[1] = bfvelo[node.ibnode, node.ibface] * u[1]
         end
diff --git a/examples/Example205_StagnationPoint.jl b/examples/Example205_StagnationPoint.jl
index 9d3fbeb33..ae6965f7a 100644
--- a/examples/Example205_StagnationPoint.jl
+++ b/examples/Example205_StagnationPoint.jl
@@ -50,14 +50,14 @@ function main(; nref = 0, gridname = nothing, Plotter = nothing, D = 0.01, v = 1
     evelo = edgevelocities(grid, frz)
     bfvelo = bfacevelocities(grid, frz)
 
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         vd = evelo[edge.index] / D
         bp = fbernoulli(vd)
         bm = fbernoulli(-vd)
         f[1] = D * (bp * u[1] - bm * u[2])
     end
 
-    function outflow!(f, u, node)
+    function outflow!(f, u, node, data=nothing)
         if node.region == Γ_out
             f[1] = bfvelo[node.ibnode, node.ibface] * u[1]
         end
diff --git a/examples/Example206_JouleHeat.jl b/examples/Example206_JouleHeat.jl
index 3b31c9fad..22b9bdfac 100644
--- a/examples/Example206_JouleHeat.jl
+++ b/examples/Example206_JouleHeat.jl
@@ -61,24 +61,24 @@ function main(; nref = 0, Plotter = nothing, verbose = "and", unknown_storage =
     λ::Float64 = 1
     c::Float64 = 1
 
-    function storage!(y, u, node)
+    function storage!(y, u, node, data=nothing)
         y[iT] = c * u[iT]
     end
 
     κ(T) = κ0 * exp(α * (T - T0))
 
-    function flux!(y, u, edge)
+    function flux!(y, u, edge, data=nothing)
         y[iϕ] = κ(y[iT]) * (u[iϕ, 1] - u[iϕ, 2])
         y[iT] = λ * (u[iT, 1] - u[iT, 2])
     end
 
     ## The convention in VoronoiFVM.jl is to have all terms depending on the solution
     ## on the left hand side of the equation. That is why we have the minus sign here.
-    function jouleheat!(y, u, edge)
+    function jouleheat!(y, u, edge, data=nothing)
         y[iT] = -κ(y[iT]) * (u[iϕ, 1] - u[iϕ, 2]) * (u[iϕ, 1] - u[iϕ, 2])
     end
 
-    function bcondition!(y, u, node)
+    function bcondition!(y, u, node, data=nothing)
         boundary_dirichlet!(y, u, node; species = iϕ, region = 1, value = -10)
         boundary_dirichlet!(y, u, node; species = iϕ, region = 2, value = 10)
 
diff --git a/examples/Example207_NonlinearPoisson2D.jl b/examples/Example207_NonlinearPoisson2D.jl
index 69c53d892..edb3132b2 100644
--- a/examples/Example207_NonlinearPoisson2D.jl
+++ b/examples/Example207_NonlinearPoisson2D.jl
@@ -22,15 +22,15 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
 
     eps = 1.0e-2
 
-    physics = VoronoiFVM.Physics(; reaction = function (f, u, node)
+    physics = VoronoiFVM.Physics(; reaction = function (f, u, node, data=nothing)
                                      f[1] = u[1]^2
-                                 end, flux = function (f, u, edge)
+                                 end, flux = function (f, u, edge, data=nothing)
                                      f[1] = eps * (u[1, 1]^2 - u[1, 2]^2)
-                                 end, source = function (f, node)
+                                 end, source = function (f, node, data=nothing)
                                      x1 = node[1] - 0.5
                                      x2 = node[2] - 0.5
                                      f[1] = exp(-20.0 * (x1^2 + x2^2))
-                                 end, storage = function (f, u, node)
+                                 end, storage = function (f, u, node, data=nothing)
                                      f[1] = u[1]
                                  end)
     sys = VoronoiFVM.System(grid, physics; unknown_storage, assembly = assembly)
diff --git a/examples/Example215_NonlinearPoisson2D_BoundaryReaction.jl b/examples/Example215_NonlinearPoisson2D_BoundaryReaction.jl
index e17e76eb2..a5d2bd93c 100644
--- a/examples/Example215_NonlinearPoisson2D_BoundaryReaction.jl
+++ b/examples/Example215_NonlinearPoisson2D_BoundaryReaction.jl
@@ -18,7 +18,7 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
     grid = simplexgrid(X, Y)
 
     eps = 1.0e-2
-    physics = VoronoiFVM.Physics(; breaction = function (f, u, node)
+    physics = VoronoiFVM.Physics(; breaction = function (f, u, node, data=nothing)
                                      if node.region == 2
                                          f[1] = 1 * (u[1] - u[2])
                                          f[2] = 1 * (u[2] - u[1])
@@ -26,10 +26,10 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
                                          f[1] = 0
                                          f[2] = 0
                                      end
-                                 end, flux = function (f, u, edge)
+                                 end, flux = function (f, u, edge, data=nothing)
                                      f[1] = eps * (u[1, 1] - u[1, 2])
                                      f[2] = eps * (u[2, 1] - u[2, 2])
-                                 end, storage = function (f, u, node)
+                                 end, storage = function (f, u, node, data=nothing)
                                      f[1] = u[1]
                                      f[2] = u[2]
                                  end)
diff --git a/examples/Example220_NonlinearPoisson2D_BoundarySpecies.jl b/examples/Example220_NonlinearPoisson2D_BoundarySpecies.jl
index 1739fadc9..ce1a76813 100644
--- a/examples/Example220_NonlinearPoisson2D_BoundarySpecies.jl
+++ b/examples/Example220_NonlinearPoisson2D_BoundarySpecies.jl
@@ -18,24 +18,24 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
     k = 1.0
     eps::Float64 = 1.0
     physics = VoronoiFVM.Physics(;
-                                 breaction = function (f, u, node)
+                                 breaction = function (f, u, node, data=nothing)
                                      if node.region == 2
                                          f[1] = k * (u[1] - u[3])
                                          f[3] = k * (u[3] - u[1]) + k * (u[3] - u[2])
                                          f[2] = k * (u[2] - u[3])
                                      end
-                                 end, bstorage = function (f, u, node)
+                                 end, bstorage = function (f, u, node, data=nothing)
                                      if node.region == 2
                                          f[3] = u[3]
                                      end
-                                 end, flux = function (f, u, edge)
+                                 end, flux = function (f, u, edge, data=nothing)
                                      f[1] = eps * (u[1, 1] - u[1, 2])
                                      f[2] = eps * (u[2, 1] - u[2, 2])
-                                 end, source = function (f, node)
+                                 end, source = function (f, node, data=nothing)
                                      x1 = node[1] - 0.5
                                      x2 = node[2] - 0.5
                                      f[1] = exp(-20.0 * (x1^2 + x2^2))
-                                 end, storage = function (f, u, node)
+                                 end, storage = function (f, u, node, data=nothing)
                                      f[1] = u[1]
                                      f[2] = u[2]
                                  end)
diff --git a/examples/Example221_EquationBlockPrecon.jl b/examples/Example221_EquationBlockPrecon.jl
index 4c0e2379b..767613547 100644
--- a/examples/Example221_EquationBlockPrecon.jl
+++ b/examples/Example221_EquationBlockPrecon.jl
@@ -48,7 +48,7 @@ function main(;dim=1, nref=0, Plotter = nothing, plot_grid = false, verbose = fa
     eps = [1, 1, 1]
     k = [1, 1, 1]
 
-    function reaction(f, u, node)
+    function reaction(f, u, node, data=nothing)
         if node.region == 1
             f[1] = k[1] * u[1]
             f[2] = -k[1] * u[1]
@@ -60,13 +60,13 @@ function main(;dim=1, nref=0, Plotter = nothing, plot_grid = false, verbose = fa
         end
     end
 
-    function source(f, node)
+    function source(f, node, data=nothing)
         if node.region == 1
             f[1] = 1.0e-4 * (3.0 - node[1])
         end
     end
 
-    flux = function (f, u, edge)
+    flux = function (f, u, edge, data=nothing)
         if edge.region == 1
             f[1] = eps[1] * (u[1, 1] - u[1, 2])
             f[2] = eps[2] * (u[2, 1] - u[2, 2])
@@ -77,8 +77,8 @@ function main(;dim=1, nref=0, Plotter = nothing, plot_grid = false, verbose = fa
             f[3] = eps[3] * (u[3, 1] - u[3, 2])
         end
     end
-    
-    storage = function (f, u, node)
+
+    storage = function (f, u, node, data=nothing)
         if node.region == 1
             f[1] = u[1]
             f[2] = u[2]
diff --git a/examples/Example225_TestFunctions2D.jl b/examples/Example225_TestFunctions2D.jl
index 3d9dccd1a..31c4e0990 100644
--- a/examples/Example225_TestFunctions2D.jl
+++ b/examples/Example225_TestFunctions2D.jl
@@ -126,23 +126,23 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
         Γ_where_T_equal_0 = [4]
     end
 
-    function storage(f, u, node)
+    function storage(f, u, node, data=nothing)
         f .= u
     end
 
-    function flux(f, u, edge)
+    function flux(f, u, edge, data=nothing)
         f[1] = u[1, 1] - u[1, 2]
         f[2] = u[2, 1] - u[2, 2]
     end
 
     r(u1, u2) = u1 - 0.1 * u2
 
-    function reaction(f, u, node)
+    function reaction(f, u, node, data=nothing)
         f[1] = r(u[1], u[2])
         f[2] = -r(u[1], u[2])
     end
 
-    function source(f, node)
+    function source(f, node, data=nothing)
         f[1] = 1.0
     end
 
diff --git a/examples/Example226_BoundaryIntegral.jl b/examples/Example226_BoundaryIntegral.jl
index b96d19d79..975c13a00 100644
--- a/examples/Example226_BoundaryIntegral.jl
+++ b/examples/Example226_BoundaryIntegral.jl
@@ -27,15 +27,15 @@ function main(; n = 10, Plotter = nothing, verbose = false, unknown_storage = :s
         Γ_where_T_equal_0 = [4]
     end
 
-    function storage(f, u, node)
+    function storage(f, u, node, data=nothing)
         f .= u
     end
 
-    function flux(f, u, edge)
+    function flux(f, u, edge, data=nothing)
         f[1] = u[1, 1] - u[1, 2]
     end
 
-    function breaction(f, u, node)
+    function breaction(f, u, node, data=nothing)
         if node.region == Γ_where_T_equal_1[1]
             f[1] = u[1]^2
         end
diff --git a/examples/Example230_BoundaryFlux.jl b/examples/Example230_BoundaryFlux.jl
index c85b07414..4aab98a06 100644
--- a/examples/Example230_BoundaryFlux.jl
+++ b/examples/Example230_BoundaryFlux.jl
@@ -58,15 +58,15 @@ function main(; n = 2 * 10, # n musst be an even number
 
     #### discretization functions ####
 
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = d1 * (u[1, 1] - u[1, 2])
     end
 
-    function reaction!(f, u, node)
+    function reaction!(f, u, node, data=nothing)
         f[1] = k1[node.index] * u[1]
     end
 
-    function source!(f, node::VoronoiFVM.Node)
+    function source!(f, node::VoronoiFVM.Node, data=nothing)
         f[1] = c1[node.index]
     end
 
@@ -103,26 +103,26 @@ function main(; n = 2 * 10, # n musst be an even number
     c2 = 1.0
 
     #### discretization functions for bulk species ####
-    function flux2D!(f, u, edge)
+    function flux2D!(f, u, edge, data=nothing)
         f[ispec_2D] = d2 * (u[ispec_2D, 1] - u[ispec_2D, 2])
     end
 
-    function reaction2D!(f, u, node)
+    function reaction2D!(f, u, node, data=nothing)
         f[ispec_2D] = k2 * u[ispec_2D]
     end
 
-    function source2D!(f, node)
+    function source2D!(f, node, data=nothing)
         f[ispec_2D] = c2
     end
 
     #### discretization functions for boundary species at active boundary ####
-    function bflux!(f, u, bedge)
+    function bflux!(f, u, bedge, data=nothing)
         if bedge.region == active_boundary
             f[ispec_boundary] = db * (u[ispec_boundary, 1] - u[ispec_boundary, 2])
         end
     end
 
-    function breaction!(f, u, bnode)
+    function breaction!(f, u, bnode, data=nothing)
         if bnode.region == active_boundary
             if bnode.coord[2, bnode.index] <= 0.5
                 kb = kmax
@@ -134,7 +134,7 @@ function main(; n = 2 * 10, # n musst be an even number
         end
     end
 
-    function bsource!(f, bnode)
+    function bsource!(f, bnode, data=nothing)
         if bnode.region == active_boundary
             if bnode.coord[2, bnode.index] <= 0.5
                 cb = 0.0
diff --git a/examples/Example301_Laplace3D.jl b/examples/Example301_Laplace3D.jl
index af4469dd7..9a83e4b79 100644
--- a/examples/Example301_Laplace3D.jl
+++ b/examples/Example301_Laplace3D.jl
@@ -12,11 +12,11 @@ using GridVisualize
 
 ## Flux function which describes the flux
 ## between neighboring control volumes
-function g!(f, u, edge)
+function g!(f, u, edge, data=nothing)
     f[1] = u[1, 1] - u[1, 2]
 end
 
-function s(f, node)
+function s(f, node, data=nothing)
     n = view(node.coord, :, node.index)
     f[1] = n[1] * sin(5.0 * n[2]) * exp(n[3])
 end
diff --git a/examples/Example311_HeatEquation_BoundaryDiffusion.jl b/examples/Example311_HeatEquation_BoundaryDiffusion.jl
index 7ad3b738e..ebd82966d 100644
--- a/examples/Example311_HeatEquation_BoundaryDiffusion.jl
+++ b/examples/Example311_HeatEquation_BoundaryDiffusion.jl
@@ -38,17 +38,17 @@ function main(n = 1; assembly = :edgewise)
     eps = 1.0e0  # bulk heat conduction coefficient
     eps_surf = 1.0e-2 # surface diffusion coefficient
     k = 1.0    # transmission coefficient
-    physics = VoronoiFVM.Physics(; flux = function (f, u, edge)
+    physics = VoronoiFVM.Physics(; flux = function (f, u, edge, data=nothing)
                                      f[1] = eps * (u[1, 1] - u[1, 2])
                                  end,
-                                 bflux = function (f, u, edge)
+                                 bflux = function (f, u, edge, data=nothing)
                                      if edge.region == breg
                                          f[2] = eps_surf * (u[2, 1] - u[2, 2])
                                      else
                                          f[2] = 0.0
                                      end
                                  end,
-                                 breaction = function (f, u, node)
+                                 breaction = function (f, u, node, data=nothing)
                                      if node.region == breg
                                          f[1] = k * (u[1] - u[2])
                                          f[2] = k * (u[2] - u[1])
@@ -57,16 +57,16 @@ function main(n = 1; assembly = :edgewise)
                                          f[2] = 0.0
                                      end
                                  end,
-                                 bsource = function (f, bnode)
+                                 bsource = function (f, bnode, data=nothing)
                                      x1 = bnode[1] - 0.5
                                      x2 = bnode[2] - 0.5
                                      x3 = bnode[3] - 0.5
                                      f[2] = 1.0e4 * exp(-20.0 * (x1^2 + x2^2 + x3^2))
-                                 end, bstorage = function (f, u, node)
+                                 end, bstorage = function (f, u, node, data=nothing)
                                      if node.region == breg
                                          f[2] = u[2]
                                      end
-                                 end, storage = function (f, u, node)
+                                 end, storage = function (f, u, node, data=nothing)
                                      f[1] = u[1]
                                  end)
 
diff --git a/examples/Example406_WeirdReaction.jl b/examples/Example406_WeirdReaction.jl
index 7d63d67d4..f3c68bca1 100644
--- a/examples/Example406_WeirdReaction.jl
+++ b/examples/Example406_WeirdReaction.jl
@@ -72,19 +72,19 @@ function main(; n = 10,
     ## Diffusion flux for species A and B
     D_A = 1.0
     D_B = 1.0e-2
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[iA] = D_A * (u[iA, 1] - u[iA, 2])
         f[iB] = D_B * (u[iB, 1] - u[iB, 2])
     end
 
     ## Storage term of species A and B
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         f[iA] = u[iA]
         f[iB] = u[iB]
     end
 
     ## Source term for species a around 0.5
-    function source!(f, node)
+    function source!(f, node, data=nothing)
         x1 = node[1] - 0.5
         f[iA] = exp(-100 * x1^2)
     end
@@ -94,7 +94,7 @@ function main(; n = 10,
     kp_AB = 1.0
     km_AB = 0.1
 
-    function breaction!(f, u, node)
+    function breaction!(f, u, node, data=nothing)
         if node.region == 1
             R = kp_AB * exp(u[iC]) * u[iA] - exp(-u[iC]) * km_AB * u[iB]
             f[iA] += R
diff --git a/examples/Example410_ManySpecies.jl b/examples/Example410_ManySpecies.jl
index 5a631d27f..ac1feeb97 100644
--- a/examples/Example410_ManySpecies.jl
+++ b/examples/Example410_ManySpecies.jl
@@ -17,7 +17,7 @@ using LinearAlgebra
 function main(; n = 11, nspec = 50, Plotter = nothing, unknown_storage = :dense, assembly = :edgewise)
     grid = simplexgrid(range(0, 1; length = n))
 
-    function flux(f, u, edge)
+    function flux(f, u, edge, data=nothing)
         for ispec = 1:nspec
             f[ispec] = u[ispec, 1] - u[ispec, 2]
         end
diff --git a/examples/Example420_DiscontinuousQuantities.jl b/examples/Example420_DiscontinuousQuantities.jl
index 113c42b33..12ce1e404 100644
--- a/examples/Example420_DiscontinuousQuantities.jl
+++ b/examples/Example420_DiscontinuousQuantities.jl
@@ -74,7 +74,7 @@ function main(; N = 5, Plotter = nothing, unknown_storage = :sparse, assembly =
 
     ##For both quantities, we define simple diffusion fluxes:
 
-    function flux(f, u, edge)
+    function flux(f, u, edge, data=nothing)
         f[dspec] = u[dspec, 1] - u[dspec, 2]
         f[cspec] = u[cspec, 1] - u[cspec, 2]
     end
@@ -82,7 +82,7 @@ function main(; N = 5, Plotter = nothing, unknown_storage = :sparse, assembly =
     d1 = 1
     q1 = 0.2
 
-    function breaction(f, u, bnode)
+    function breaction(f, u, bnode, data=nothing)
 
         # left outer boundary value for dspec
         if bnode.region == 1
diff --git a/examples/Example421_AbstractQuantities_TestFunctions.jl b/examples/Example421_AbstractQuantities_TestFunctions.jl
index 61dea7003..1c4e3f083 100644
--- a/examples/Example421_AbstractQuantities_TestFunctions.jl
+++ b/examples/Example421_AbstractQuantities_TestFunctions.jl
@@ -67,7 +67,7 @@ function main(; N = 3, Plotter = nothing, unknown_storage = :sparse, assembly =
     ##########################################################
     icc = 1 # for system without AbstractQuantities
 
-    function flux!(f, u, edge) # analogous as for other system
+    function flux!(f, u, edge, data=nothing) # analogous as for other system
         f[icc] = u[icc, 1] - u[icc, 2]
     end
 
diff --git a/examples/Example422_InterfaceQuantities.jl b/examples/Example422_InterfaceQuantities.jl
index b1e4fa2d5..38cbfd56f 100644
--- a/examples/Example422_InterfaceQuantities.jl
+++ b/examples/Example422_InterfaceQuantities.jl
@@ -68,7 +68,7 @@ function main(; n = 5, Plotter = nothing, tend = 20.0, unknown_storage = :sparse
     NA = [10.0, 0.0]
     ND = [0.0, 10.0]
 
-    function storage!(f, u, node)
+    function storage!(f, u, node, data=nothing)
         etan = -((u[iphin] - u[ipsi]))
         etap = ((u[iphip] - u[ipsi]))
 
@@ -78,7 +78,7 @@ function main(; n = 5, Plotter = nothing, tend = 20.0, unknown_storage = :sparse
         f[ipsi] = 0.0
     end
 
-    function reaction!(f, u, node)
+    function reaction!(f, u, node, data=nothing)
         etan = -((u[iphin] - u[ipsi]))
         etap = ((u[iphip] - u[ipsi]))
 
@@ -91,7 +91,7 @@ function main(; n = 5, Plotter = nothing, tend = 20.0, unknown_storage = :sparse
         f[iphip] = recomb
     end
 
-    function flux!(f, u, node)
+    function flux!(f, u, node, data=nothing)
         f[ipsi] = -(u[ipsi, 2] - u[ipsi, 1])
 
         ########################
@@ -107,7 +107,7 @@ function main(; n = 5, Plotter = nothing, tend = 20.0, unknown_storage = :sparse
         f[iphip] = -(bp * exp(etap2) - bm * exp(etap1))
     end
 
-    function breaction!(f, u, bnode)
+    function breaction!(f, u, bnode, data=nothing)
         if bnode.region == bjunction
             # left values
             nleft = exp(-((u[iphin, 1] - u[ipsi])))
@@ -136,7 +136,7 @@ function main(; n = 5, Plotter = nothing, tend = 20.0, unknown_storage = :sparse
         end
     end
 
-    function bstorage!(f, u, bnode)
+    function bstorage!(f, u, bnode, data=nothing)
         f[ipsi] = 0.0
 
         if bnode.region == bjunction
diff --git a/examples/Example430_ParameterDerivativesStationary.jl b/examples/Example430_ParameterDerivativesStationary.jl
index e87a1034f..fe483790e 100644
--- a/examples/Example430_ParameterDerivativesStationary.jl
+++ b/examples/Example430_ParameterDerivativesStationary.jl
@@ -27,15 +27,15 @@ function f(P; n = 10)
     nspecies = 1
     ispec = 1
 
-    function flux!(f, u, edge)
+    function flux!(f, u, edge, data=nothing)
         f[1] = (1 + p) * (u[1, 1]^2 - u[1, 2]^2)
     end
 
-    function r!(f, u, edge)
+    function r!(f, u, edge, data=nothing)
         f[1] = p * u[1]^5
     end
 
-    function bc!(f, u, node)
+    function bc!(f, u, node, data=nothing)
         boundary_dirichlet!(f, u, node, ispec, 1, 0.0)
         boundary_dirichlet!(f, u, node, ispec, 3, p)
     end
@@ -139,17 +139,17 @@ end
 
 #########################################################################
 
-function fluxh!(f, u, edge)
+function fluxh!(f, u, edge, data=nothing)
     p = parameters(u)[1]
     f[1] = (1 + p) * (u[1, 1]^2 - u[1, 2]^2)
 end
 
-function rh!(f, u, edge)
+function rh!(f, u, edge, data=nothing)
     p = parameters(u)[1]
     f[1] = p * u[1]^5
 end
 
-function bch!(f, u, node)
+function bch!(f, u, node, data=nothing)
     p = parameters(u)[1]
     boundary_dirichlet!(f, u, node, 1, 1, 0.0)
     boundary_dirichlet!(f, u, node, 1, 3, p)
diff --git a/pluto-examples/api-update.jl b/pluto-examples/api-update.jl
index 3ef501867..d2d4f9d52 100644
--- a/pluto-examples/api-update.jl
+++ b/pluto-examples/api-update.jl
@@ -77,25 +77,25 @@ n = 100
 begin
     h = 1.0 / convert(Float64, n)
     const eps = 1.0e-2
-    function reaction(f, u, node)
+    function reaction(f, u, node, data=nothing)
         f[1] = u[1]^2
     end
 
-    function flux(f, u, edge)
+    function flux(f, u, edge, data=nothing)
         f[1] = eps * (u[1, 1]^2 - u[1, 2]^2)
     end
 
-    function source(f, node)
+    function source(f, node, data=nothing)
         x1 = node[1] - 0.5
         x2 = node[2] - 0.5
         f[1] = exp(-20.0 * (x1^2 + x2^2))
     end
 
-    function storage(f, u, node)
+    function storage(f, u, node, data=nothing)
         f[1] = u[1]
     end
 
-    function bcondition(f, u, node)
+    function bcondition(f, u, node, data=nothing)
         boundary_dirichlet!(f,
                             u,
                             node;
@@ -265,7 +265,7 @@ The following example gives some information in this respect:
 D = 0.1
 
 # ╔═╡ 2ff77259-7a81-4c54-a291-cbc20ee56c5d
-function xflux(f, u, edge)
+function xflux(f, u, edge, data=nothing)
     f[1] = D * (u[1, 1]^2 - u[1, 2]^2)
 end
 
@@ -300,7 +300,7 @@ But we can also look for the reasons of the allocations. Here, global values sho
 const D1 = 0.1
 
 # ╔═╡ c40f1954-4fb7-48b2-ab4c-cdf6459b7383
-function xflux1(f, u, edge)
+function xflux1(f, u, edge, data=nothing)
     f[1] = D1 * (u[1, 1]^2 - u[1, 2]^2)
 end
 
@@ -331,14 +331,14 @@ The `VoronoiFVM.Physics` struct almost never was used outside of the constructor
 grid1 = simplexgrid(0:0.1:1);
 
 # ╔═╡ 90bbf212-c6c8-44f0-8132-4a98f094750e
-function multispecies_flux(y, u, edge)
+function multispecies_flux(y, u, edge, data=nothing)
     for i = 1:(edge.nspec)
         y[i] = u[i, 1] - u[i, 2]
     end
 end
 
 # ╔═╡ adff41d1-9398-4a66-9a8e-e03809973fa6
-function test_reaction(y, u, node)
+function test_reaction(y, u, node, data=nothing)
     y[1] = u[1]
     y[2] = -u[1]
 end
@@ -376,7 +376,7 @@ space and time dependent boundary conditions. One can specify them either in `br
 """
 
 # ╔═╡ ec188c81-3374-4eed-9b7e-e22350886df2
-function bcond2(y, u, bnode)
+function bcond2(y, u, bnode, data=nothing)
     boundary_neumann!(y, u, bnode; species = 1, region = 1, value = sin(bnode.time))
     boundary_dirichlet!(y, u, bnode; species = 2, region = 2, value = 0)
 end;
@@ -429,7 +429,7 @@ This example also demonstrates position dependent boundary values.
 """
 
 # ╔═╡ a71086fa-4ec6-4842-a4e1-6a6b60441fc2
-function bcond3(y, u, bnode)
+function bcond3(y, u, bnode, data=nothing)
     boundary_dirichlet!(y, u, bnode; region = 4, value = bnode[2])
     boundary_dirichlet!(y, u, bnode; region = 2, value = -bnode[2])
 end;
@@ -469,7 +469,7 @@ Another new keyword argument is `inival` which allows to pass an initial value w
 """
 
 # ╔═╡ 1e12afcf-cf46-4672-9434-44fa8af95ef7
-reaction4(y, u, bnode) = y[1] = -bnode[1]^2 + u[1]^4;
+reaction4(y, u, bnode, data=nothing) = y[1] = -bnode[1]^2 + u[1]^4;
 
 # ╔═╡ 938ef63c-58c4-41a0-b3dd-4eb76987a4d7
 bc4(args...) = boundary_dirichlet!(args...; value = 0);
diff --git a/pluto-examples/flux-reconstruction.jl b/pluto-examples/flux-reconstruction.jl
index 264b19c32..85c44df91 100644
--- a/pluto-examples/flux-reconstruction.jl
+++ b/pluto-examples/flux-reconstruction.jl
@@ -239,13 +239,13 @@ md"""
 src(x) = exp(-x^2 / 0.01)
 
 # ╔═╡ aec97834-1612-49ab-a19b-7fd74c83228f
-source1d(y, node) = y[1] = src(node[1])
+source1d(y, node, data=nothing) = y[1] = src(node[1])
 
 # ╔═╡ 387f52d0-926e-445d-9e3e-afebbc7207f6
-flux1d(y, u, edge) = y[1] = u[1, 1]^2 - u[1, 2]^2
+flux1d(y, u, edge, data=nothing) = y[1] = u[1, 1]^2 - u[1, 2]^2
 
 # ╔═╡ 3793696c-c934-4e56-a1e7-887fc2181970
-function bc1d(y, u, bnode)
+function bc1d(y, u, bnode, data=nothing)
     boundary_dirichlet!(y, u, bnode; region = 1, value = 0.01)
     boundary_dirichlet!(y, u, bnode; region = 2, value = 0.01)
 end
diff --git a/pluto-examples/interfaces1d.jl b/pluto-examples/interfaces1d.jl
index 45ee88710..e2b2703f6 100644
--- a/pluto-examples/interfaces1d.jl
+++ b/pluto-examples/interfaces1d.jl
@@ -114,7 +114,7 @@ Define the diffusion flux for the two species in their respective subdomains
 """
 
 # ╔═╡ 6aabfbe1-de7d-49ba-8144-6d364b21b34f
-function flux!(f, u, edge)
+function flux!(f, u, edge, data=nothing)
     if edge.region == 1
         f[1] = u[1, 1] - u[1, 2]
     end
@@ -206,7 +206,7 @@ This means we set ``f_1(u_1,u_2)=0`` and ``f_2(u_1,u_2)=0``.
 """
 
 # ╔═╡ 8f210696-fcf4-47bc-a5a2-c561ad7efcbd
-function noreaction(f, u, node) end
+function noreaction(f, u, node, data=nothing) end
 
 # ╔═╡ 57e8515e-3be1-4478-af98-430501438ee7
 system1 = make_system(noreaction);
@@ -248,7 +248,7 @@ begin
 end
 
 # ╔═╡ 1328b4bf-2d64-4b02-a910-1995da8be28b
-function mal_reaction(f, u, node)
+function mal_reaction(f, u, node, data=nothing)
     if node.region == 3
         react = k1 * u[1] - k2 * u[2]
         f[1] = react
@@ -281,7 +281,7 @@ Setting ``k_1,k_2`` to a large number leads to another special case of the above
 """
 
 # ╔═╡ 9eaea813-2628-47d0-9d36-54c367689142
-function penalty_reaction(f, u, node)
+function penalty_reaction(f, u, node, data=nothing)
     if node.region == 3
         react = 1.0e10 * (u[1] - u[2])
         f[1] = react
@@ -306,7 +306,7 @@ Instead of enforcing continuity, one can enforce a fixed jump.
 const jump = 0.2
 
 # ╔═╡ 7331db49-7ace-468e-87d8-56ab5d900905
-function penalty_jump_reaction(f, u, node)
+function penalty_jump_reaction(f, u, node, data=nothing)
     if node.region == 3
         react = 1.0e10 * (u[1] - u[2] - jump)
         f[1] = react
@@ -341,7 +341,7 @@ According to the mass action law, this is implemented via
 const k_r = 1000
 
 # ╔═╡ 39a0db1b-3a4e-4108-b43f-d4e578c92608
-function recombination(f, u, node)
+function recombination(f, u, node, data=nothing)
     if node.region == 3
         react = k_r * (u[1] * u[2])
         f[1] = react
@@ -389,7 +389,7 @@ and therefore another special case of the mass action law condition.
 const d = 1
 
 # ╔═╡ 58d8831b-ad66-4f77-a33a-933c15c46a52
-function thinlayer(f, u, node)
+function thinlayer(f, u, node, data=nothing)
     if node.region == 3
         react = (u[1] - u[2]) / d
         f[1] = react
@@ -477,7 +477,7 @@ For both quantities, we define simple diffusion fluxes:
 """
 
 # ╔═╡ 719f206a-5b9f-4d78-8778-1d89edb2bc4d
-function flux2(f, u, edge)
+function flux2(f, u, edge, data=nothing)
     f[dspec] = u[dspec, 1] - u[dspec, 2]
     f[cspec] = u[cspec, 1] - u[cspec, 2]
 end
@@ -503,7 +503,7 @@ const d1 = 0.1
 const q1 = 0.2
 
 # ╔═╡ d6e1c6c7-060d-4c2f-8054-d8f33f54bd55
-function breaction2(f, u, node)
+function breaction2(f, u, node, data=nothing)
     if node.region > 2
         react = (u[dspec, 1] - u[dspec, 2]) / d1
         f[dspec, 1] = react
diff --git a/pluto-examples/nonlinear-solvers.jl b/pluto-examples/nonlinear-solvers.jl
index 07add338c..c8b800dac 100644
--- a/pluto-examples/nonlinear-solvers.jl
+++ b/pluto-examples/nonlinear-solvers.jl
@@ -51,17 +51,17 @@ Define a nonlinear Poisson equation to have an example. Let ``Ω=(0,10)`` and de
 X = 0:0.001:1
 
 # ╔═╡ c8eda836-d719-4412-895e-c3a24fec21ec
-flux(y, u, edge) = y[1] = u[1, 1] - u[1, 2];
+flux(y, u, edge, data=nothing) = y[1] = u[1, 1] - u[1, 2];
 
 # ╔═╡ c09f5dfc-fc47-4952-8051-54731ec2b00b
-function reaction(y, u, node)
+function reaction(y, u, node, data=nothing)
     eplus = exp(u[1])
     eminus = 1 / eplus
     y[1] = eplus - eminus
 end
 
 # ╔═╡ eab04557-5084-4174-b275-b4d4399238e5
-function bc(y, u, node)
+function bc(y, u, node, data=nothing)
     boundary_dirichlet!(y, u, node; region = 1, value = 100)
     boundary_dirichlet!(y, u, node; region = 2, value = 0.0)
 end;
@@ -194,7 +194,7 @@ If the solution is unsuccessful, the parameter stepsize is halved and solution i
 """
 
 # ╔═╡ a71cbcd4-310e-47a8-94f9-1159995a7711
-function pbc(y, u, node)
+function pbc(y, u, node, data=nothing)
     boundary_dirichlet!(y, u, node; region = 1, value = 100 * embedparam(node))
     boundary_dirichlet!(y, u, node; region = 2, value = 0)
 end;
@@ -202,7 +202,7 @@ end;
 # ╔═╡ 89435c65-0520-4430-8727-9d013df6182d
 system2 = VoronoiFVM.System(X;
                             flux = flux,
-                            reaction = function (y, u, node)
+                            reaction = function (y, u, node, data=nothing)
                                 reaction(y, u, node)
 
                                 y[1] = y[1] * embedparam(node)
diff --git a/pluto-examples/ode-brusselator.jl b/pluto-examples/ode-brusselator.jl
index 34b25f935..702bbcde8 100644
--- a/pluto-examples/ode-brusselator.jl
+++ b/pluto-examples/ode-brusselator.jl
@@ -61,19 +61,19 @@ end;
 
 
 # ╔═╡ 2fb1c53a-7ff8-4ac9-ae78-83bcbc57c926
-function bruss_storage(f,u,node)
+function bruss_storage(f,u,node,data=nothing)
 	f[1]=u[1]
 	f[2]=u[2]
 end;
 
 # ╔═╡ 71b7e770-5cd4-4671-a76a-8e29eda04eec
-function bruss_diffusion(f,u,edge)
+function bruss_diffusion(f,u,edge,data=nothing)
 	f[1]=bruss_D_1*(u[1,1]-u[1,2])
-	f[2]=bruss_D_2*(u[2,1]-u[2,2])	
+	f[2]=bruss_D_2*(u[2,1]-u[2,2])
 end;
 
 # ╔═╡ f1e7a242-d631-4624-b0c0-ac44f139d77c
-function bruss_reaction(f,u,node)
+function bruss_reaction(f,u,node,data=nothing)
     f[1]= (bruss_B+1.0)*u[1]-bruss_A-u[1]^2*u[2]
     f[2]= u[1]^2*u[2]-bruss_B*u[1]
 end;
diff --git a/pluto-examples/ode-diffusion1d.jl b/pluto-examples/ode-diffusion1d.jl
index 7aaca0f87..2475d036d 100644
--- a/pluto-examples/ode-diffusion1d.jl
+++ b/pluto-examples/ode-diffusion1d.jl
@@ -73,11 +73,11 @@ function create_porous_medium_problem(n,m)
     X=collect(-1:h:1)
     grid=VoronoiFVM.Grid(X)
 
-    function flux!(f,u,edge)
+    function flux!(f,u,edge,data=nothing)
         f[1]=u[1,1]^m-u[1,2]^m
     end
 
-    storage!(f,u,node)= f[1]=u[1]
+    storage!(f,u,node,data=nothing)= f[1]=u[1]
 
 	sys=VoronoiFVM.System(grid,flux=flux!,storage=storage!, species=1)
     sys,X
diff --git a/pluto-examples/ode-nlstorage1d.jl b/pluto-examples/ode-nlstorage1d.jl
index b9fc055c7..c3c2842cd 100644
--- a/pluto-examples/ode-nlstorage1d.jl
+++ b/pluto-examples/ode-nlstorage1d.jl
@@ -90,7 +90,7 @@ md"""
 """
 
 # ╔═╡ 54aef797-210b-4eea-95b4-e0bdcb478c1d
-    function flux!(f,u,edge)
+    function flux!(f,u,edge,data=nothing)
         f[1]=u[1,1]-u[1,2]
     end
 
@@ -100,7 +100,7 @@ Storage term needs to be regularized as its derivative at 0 is infinity:
 """
 
 # ╔═╡ 3790d063-8a3d-429b-8a59-05cfc35b6878
-    function storage!(f,u,node)
+    function storage!(f,u,node,data=nothing)
         f[1]=(ε+u[1])^(1.0/m)
     end
 
@@ -136,12 +136,12 @@ we see that the problem structure does not fit into the setting of that package
 """
 
 # ╔═╡ d495a088-69dd-4f4e-964c-88638958799a
-function dae_storage!(y,u,node)
+function dae_storage!(y,u,node,data=nothing)
 	y[1]=u[2]
 end
 
 # ╔═╡ 4c09ec49-c4d6-4c5a-8f73-8a736acaff61
-function dae_reaction!(y,u,node)
+function dae_reaction!(y,u,node,data=nothing)
 	y[2]= u[2]^m-u[1]
 end
 
diff --git a/pluto-examples/problemcase.jl b/pluto-examples/problemcase.jl
index f97c0bce1..f584106ba 100644
--- a/pluto-examples/problemcase.jl
+++ b/pluto-examples/problemcase.jl
@@ -334,19 +334,19 @@ function trsolve(grid;
                  Δp = 1.0,
                  ϕ = [1, 1],
                  tend = 100,)
-    function flux(y, u, edge)
+    function flux(y, u, edge, data=nothing)
         y[ip] = κ[edge.region] * (u[ip, 1] - u[ip, 2])
         bp, bm = fbernoulli_pm(y[ip] / D[edge.region])
         y[ic] = D[edge.region] * (bm * u[ic, 1] - bp * u[ic, 2])
     end
 
-    function stor(y, u, node)
+    function stor(y, u, node, data=nothing)
         y[ip] = 0
         y[ic] = ϕ[node.region] * u[ic]
     end
 
     dim = dim_space(grid)
-    function bc(y, u, bnode)
+    function bc(y, u, bnode, data=nothing)
         c0 = ramp(bnode.time; dt = (0, 0.001), du = (0, 1))
         boundary_dirichlet!(y, u, bnode, ic, Γ_in, c0)
         boundary_dirichlet!(y, u, bnode, ic, Γ_out, 0)
@@ -466,11 +466,11 @@ md"""
 
 # ╔═╡ bb3a50ed-32e7-4305-87d8-4093c054a4d2
 function rdsolve(grid; D = [1.0e-12, 1.0], R = [1, 0.1])
-    function flux(y, u, edge)
+    function flux(y, u, edge, data=nothing)
         y[1] = D[edge.region] * (u[1, 1] - u[1, 2])
     end
 
-    function rea(y, u, node)
+    function rea(y, u, node, data=nothing)
         y[1] = R[node.region] * u[1]
     end
     function bc(args...)
diff --git a/src/vfvm_physics.jl b/src/vfvm_physics.jl
index dd408a0a3..5a77273c2 100644
--- a/src/vfvm_physics.jl
+++ b/src/vfvm_physics.jl
@@ -93,7 +93,7 @@ struct Physics{Flux <: Function,
                GenericOperatorSparsity <: Function,
                Data} <: AbstractPhysics
     """
-    Flux between neighboring control volumes: `flux(f,u,edge)` or `flux(f,u,edge,data)`
+    Flux between neighboring control volumes: `flux(f,u,edge,data)`
     should return in `f[i]` the flux of species i along the edge joining circumcenters
     of neighboring control volumes.  u is a  2D array such that for species i,
     `u[i,1]` and `u[i,2]` contain the unknown values at the corresponding ends of the edge.
@@ -101,7 +101,7 @@ struct Physics{Flux <: Function,
     flux::Flux
 
     """
-    Storage term (term under time derivative): `storage(f,u,node)` or `storage(f,u,node,data)` 
+    Storage term (term under time derivative): `storage(f,u,node,data)`
 
     It should return in `f[i]` the storage term for the i-th equation. `u[i]` contains the value of
     the i-th unknown.
@@ -109,7 +109,7 @@ struct Physics{Flux <: Function,
     storage::Storage
 
     """
-    Reaction term:  `reaction(f,u,node)` or `reaction(f,u,node,data)` 
+    Reaction term: `reaction(f,u,node,data)`
 
     It should return in `f[i]` the reaction term for the i-th equation. `u[i]` contains the value of
     the i-th unknown.
@@ -117,7 +117,7 @@ struct Physics{Flux <: Function,
     reaction::Reaction
 
     """
-    Edge reaction term:  `edgereaction(f,u,edge)` or `edgereaction(f,u,edge,data)` 
+    Edge reaction term: `edgereaction(f,u,edge,data)`
 
     It should return in `f[i]` the reaction term for the i-th equation. `u[i]` contains the value of
     the i-th unknown.  u is a  2D array such that for species i,
@@ -126,7 +126,7 @@ struct Physics{Flux <: Function,
     edgereaction::EdgeReaction
 
     """
-    Source term: `source(f,node)` or `source(f,node,data)`.
+    Source term: `source(f,node,data)`.
 
     It should return the in `f[i]` the value of the source term for the i-th equation.
     """
@@ -134,31 +134,31 @@ struct Physics{Flux <: Function,
 
     """
     Flux between neighboring control volumes on the boundary. Called on edges
-    fully adjacent to the boundary: `bflux(f,u,bedge)` or `bflux(f,u,bedge,data)
+    fully adjacent to the boundary: `bflux(f,u,bedge,data)
     """
     bflux::BFlux
 
     """
-    Boundary reaction term:  `breaction(f,u,node)` or `breaction(f,u,node,data)` 
+    Boundary reaction term: `breaction(f,u,node,data)`
     Similar to reaction, but restricted to the inner or outer boundaries.
     """
     breaction::BReaction
 
     """
-    Boundary source term: `bsource(f,node)` or `bsource(f,node,data)`.
+    Boundary source term: `bsource(f,node,data)`.
 
     It should return in `f[i]` the value of the source term for the i-th equation.
     """
     bsource::BSource
 
     """
-    Boundary storage term: `bstorage(f,u,node)` or `bstorage(f,u,node,data)` 
+    Boundary storage term: `bstorage(f,u,node,data)`
     Similar to storage, but restricted to the inner or outer boundaries.
     """
     bstorage::BStorage
 
     """
-    Outflow boundary term  `boutflow(f,u,edge)` or `boutflow(f,u,edge,data)` 
+    Outflow boundary term  `boutflow(f,u,edge,data)`
     This function is called for edges (including interior ones) which have at least one ode
     on one of the outflow boundaries. Within this function,
     [`outflownode`](@ref) and  [`isoutflownode`](@ref) can be used to identify
@@ -250,6 +250,21 @@ function Physics(; num_species = 0,
         bsource == nosrc ? bsource = nosrc2 : true
         bstorage == nofunc ? bstorage = nofunc2 : true
         boutflow == nofunc ? boutflow = nofunc2 : true
+
+
+        # deprecation check: callbacks without a `data` argument are not supported in future versions
+        callbacks = [flux, reaction, edgereaction, storage, source, bflux, breaction, bsource, bstorage, boutflow]
+        for f in callbacks
+            # ignore dummy functions
+            if !(f in [nofunc2, default_storage2, nosrc2])
+                # check whether the callbacks have a method with 3 or 4 arguments, respectively
+                nn = nothing
+                if ( f in [flux, reaction, edgereaction, storage, bflux, breaction, bstorage, boutflow] && !applicable(f,nn,nn,nn,nn) ) ||
+                   ( f in [source, bsource] && !applicable(f,nn,nn,nn) )
+                    @warn "using VoronoiFVM.Physics callback $(nameof(f)) without a `data` argument is now deprecated"
+                end
+            end
+        end
     end
 
     return Physics(flux,
diff --git a/src/vfvm_testfunctions.jl b/src/vfvm_testfunctions.jl
index 94e15f279..8f6777123 100644
--- a/src/vfvm_testfunctions.jl
+++ b/src/vfvm_testfunctions.jl
@@ -32,10 +32,10 @@ $(TYPEDSIGNATURES)
 Constructor for TestFunctionFactory from System
 """
 function TestFunctionFactory(system::AbstractSystem; control = SolverControl())
-    physics = Physics(; flux = function (f, u, edge)
+    physics = Physics(; flux = function (f, u, edge, data=nothing)
                           f[1] = u[1] - u[2]
                       end,
-                      storage = function (f, u, node)
+                      storage = function (f, u, node, data=nothing)
                           f[1] = u[1]
                       end)
     tfsystem = System(system.grid, physics; unknown_storage = :dense)
diff --git a/test/runtests.jl b/test/runtests.jl
index 60c1d13ad..629c28cc6 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -19,9 +19,9 @@ end
 
 function run_all_tests(; run_notebooks = false, notebooksonly = false)
     if !notebooksonly
-        # @testset "basictest" begin
-        #     run_tests_from_directory(@__DIR__, "test_")
-        # end
+        @testset "basictest" begin
+            run_tests_from_directory(@__DIR__, "test_")
+        end
 
         @testset "Development Examples" begin
             run_tests_from_directory(joinpath(@__DIR__, "..", "examples"), "Example0")
diff --git a/test/test_diffeq.jl b/test/test_diffeq.jl
index c27cb2740..cb3f38a48 100644
--- a/test/test_diffeq.jl
+++ b/test/test_diffeq.jl
@@ -6,13 +6,13 @@ using Test
 
 function test_matrices(nspec)
     grid = simplexgrid(0:1.0:5)
-    function flux(y, u, edge)
+    function flux(y, u, edge, data=nothing)
         for i = 1:length(y)
             y[i] = u[i, 1] - u[i, 2]
         end
     end
 
-    function storage(y, u, node)
+    function storage(y, u, node, data=nothing)
         for i = 1:length(y)
             y[i] = i * u[i]
         end