diff --git a/applications/test/dictionary/testDictAPI b/applications/test/dictionary/testDictAPI
new file mode 100644
index 0000000000000000000000000000000000000000..e6091cb9d0b4aff850b3d63b0261f35ab9af5384
--- /dev/null
+++ b/applications/test/dictionary/testDictAPI
@@ -0,0 +1,19 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  v1812                                 |
+|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      testDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+_FOAM_API  $FOAM_API;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/vtkPVFoam/vtkPVFoam.C b/applications/utilities/postProcessing/graphics/PVReaders/vtkPVFoam/vtkPVFoam.C
index 1cf6e69aaf718c77be7f598239d47d94d0c4a38b..794949c3f9105ada66b53eef3b9648debc04b84e 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/vtkPVFoam/vtkPVFoam.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/vtkPVFoam/vtkPVFoam.C
@@ -30,6 +30,7 @@ License
 #include "areaFaMesh.H"
 #include "faMesh.H"
 #include "fvMesh.H"
+#include "foamVersion.H"
 #include "Time.H"
 #include "patchZones.H"
 #include "IOobjectList.H"
@@ -314,6 +315,9 @@ Foam::vtkPVFoam::vtkPVFoam
         fullCasePath = cwd();
     }
 
+    // OPENFOAM API
+    setEnv("FOAM_API", std::to_string(foamVersion::api), true);
+
     // The name of the executable, unless already present in the environment
     setEnv("FOAM_EXECUTABLE", "paraview", false);
 
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/vtkPVblockMesh/vtkPVblockMesh.C b/applications/utilities/postProcessing/graphics/PVReaders/vtkPVblockMesh/vtkPVblockMesh.C
index 6a9037c38540e54f51f46a3ed603652210c35b1e..efec807d266af56655fd4865ace86adefa4e5817 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/vtkPVblockMesh/vtkPVblockMesh.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/vtkPVblockMesh/vtkPVblockMesh.C
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2017-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -29,6 +29,7 @@ License
 // OpenFOAM includes
 #include "blockMesh.H"
 #include "blockMeshTools.H"
+#include "foamVersion.H"
 #include "Time.H"
 #include "patchZones.H"
 #include "StringStream.H"
@@ -206,6 +207,9 @@ Foam::vtkPVblockMesh::vtkPVblockMesh
         fullCasePath = cwd();
     }
 
+    // OPENFOAM API
+    setEnv("FOAM_API", std::to_string(foamVersion::api), true);
+
     // The name of the executable, unless already present in the environment
     setEnv("FOAM_EXECUTABLE", "paraview", false);
 
diff --git a/etc/config.csh/unset b/etc/config.csh/unset
index 3041f8931a973ced95b85f6e66432900d2c04263..8a453c36891b46025b889e7032025202742206e6 100644
--- a/etc/config.csh/unset
+++ b/etc/config.csh/unset
@@ -3,7 +3,7 @@
 # \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
 #  \\    /   O peration     |
 #   \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-#    \\/     M anipulation  | Copyright (C) 2016-2017 OpenCFD Ltd.
+#    \\/     M anipulation  | Copyright (C) 2016-2019 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM, licensed under GNU General Public License
@@ -73,6 +73,7 @@ unsetenv WM_THIRD_PARTY_DIR
 #------------------------------------------------------------------------------
 # Unset FOAM_* environment variables
 
+unsetenv FOAM_API
 unsetenv FOAM_APPBIN
 unsetenv FOAM_APP
 unsetenv FOAM_CODE_TEMPLATES
diff --git a/etc/config.sh/unset b/etc/config.sh/unset
index 4d3c5fd0e410a089790bedaeee7d73d3f891a2d4..2153e87f94cd6ce9701985513b65dd69892c44f9 100644
--- a/etc/config.sh/unset
+++ b/etc/config.sh/unset
@@ -3,7 +3,7 @@
 # \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
 #  \\    /   O peration     |
 #   \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-#    \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
+#    \\/     M anipulation  | Copyright (C) 2016-2019 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM, licensed under GNU General Public License
@@ -63,6 +63,7 @@ unset WM_THIRD_PARTY_DIR
 #------------------------------------------------------------------------------
 # Unset FOAM_* environment variables
 
+unset FOAM_API
 unset FOAM_APPBIN
 unset FOAM_APP
 unset FOAM_CODE_TEMPLATES
diff --git a/src/OpenFOAM/global/argList/argList.C b/src/OpenFOAM/global/argList/argList.C
index f7c622e746b4d68748bd08f7228def6815957556..51fc94869d065dd9e6ab7b51d9b5d042cfac5f2e 100644
--- a/src/OpenFOAM/global/argList/argList.C
+++ b/src/OpenFOAM/global/argList/argList.C
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2015-2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2015-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -672,6 +672,9 @@ void Foam::argList::setCasePaths()
     globalCase_ = caseDir.name();
     case_       = globalCase_;  // The (processor) local case name
 
+    // OPENFOAM API
+    setEnv("FOAM_API", std::to_string(foamVersion::api), true);
+
     // Global case (directory) and case-name as environment variables
     setEnv("FOAM_CASE", caseDir, true);
     setEnv("FOAM_CASENAME", globalCase_, true);
diff --git a/src/OpenFOAM/global/argList/argList.H b/src/OpenFOAM/global/argList/argList.H
index e569e02e5256b78141c58c1cdf881a869f089831..a33bfda34317693ac5de5b824fdd0c285683c342 100644
--- a/src/OpenFOAM/global/argList/argList.H
+++ b/src/OpenFOAM/global/argList/argList.H
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2016-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -57,6 +57,8 @@ Description
     may be present for some solvers or utilities.
 
     Environment variables set by argList or by Time:
+      - \par FOAM_API
+        The value of foamVersion::api
       - \par FOAM_CASE
         The path of the global case.
         It is the same for serial and parallel jobs.