diff --git a/command/install.go b/command/install.go
index ddee672b7..a619dd59a 100644
--- a/command/install.go
+++ b/command/install.go
@@ -42,6 +42,6 @@ var installCmd = &cobra.Command{
 
 func init() {
 	installCmd.Flags().BoolVarP(&force, "force", "f", false, "Force a new installation")
-	installCmd.Flags().StringVarP(&libDir, "libDir", "d", "/usr/local/lib", "Target directory to install the library")
+	installCmd.Flags().StringVarP(&libDir, "libDir", "d", "", "Target directory to install the library")
 	RootCmd.AddCommand(installCmd)
 }
diff --git a/examples/v3/provider_test.go b/examples/v3/provider_test.go
index 5064fb856..0f25b2d07 100644
--- a/examples/v3/provider_test.go
+++ b/examples/v3/provider_test.go
@@ -23,6 +23,7 @@ var pactDir = fmt.Sprintf("%s/pacts", dir)
 // 2. go test -v -run TestProvider
 func TestV3HTTPProvider(t *testing.T) {
 	v3.SetLogLevel("DEBUG")
+	v3.CheckVersion()
 
 	// Start provider API in the background
 	go startServer()
diff --git a/v3/http.go b/v3/http.go
index b4e2b836f..844327126 100644
--- a/v3/http.go
+++ b/v3/http.go
@@ -18,12 +18,12 @@ import (
 	"time"
 
 	"github.com/pact-foundation/pact-go/utils"
+	"github.com/pact-foundation/pact-go/v3/internal/native/mockserver"
 	native "github.com/pact-foundation/pact-go/v3/internal/native/mockserver"
 )
 
 func init() {
 	initLogging()
-	native.Init()
 }
 
 // QueryStringStyle allows a user to specific the v2 query string serialisation format
@@ -121,7 +121,8 @@ type httpMockProvider struct {
 	v3Interactions []*InteractionV3
 
 	// fsm state of the interaction
-	state string
+	state      string
+	mockserver *mockserver.MockServer
 }
 
 // MockServerConfig stores the address configuration details of the server for the current executing test
@@ -168,6 +169,9 @@ func (p *httpMockProvider) validateConfig() error {
 		return fmt.Errorf("error: unable to find free port, mock server will fail to start")
 	}
 
+	p.mockserver = &mockserver.MockServer{}
+	p.mockserver.Init()
+
 	return nil
 }
 
@@ -195,8 +199,8 @@ func (p *httpMockProvider) ExecuteTest(integrationTest func(MockServerConfig) er
 	// Clean interactions
 	p.cleanInteractions()
 
-	port, err := native.CreateMockServer(formatJSONObject(serialisedPact), fmt.Sprintf("%s:%d", p.config.Host, p.config.Port), p.config.TLS)
-	defer native.CleanupMockServer(p.config.Port)
+	port, err := p.mockserver.CreateMockServer(formatJSONObject(serialisedPact), fmt.Sprintf("%s:%d", p.config.Host, p.config.Port), p.config.TLS)
+	defer p.mockserver.CleanupMockServer(p.config.Port)
 	if err != nil {
 		return err
 	}
@@ -213,7 +217,7 @@ func (p *httpMockProvider) ExecuteTest(integrationTest func(MockServerConfig) er
 	}
 
 	// Run Verification Process
-	res, mismatches := native.Verify(p.config.Port, p.config.PactDir)
+	res, mismatches := p.mockserver.Verify(p.config.Port, p.config.PactDir)
 	p.displayMismatches(mismatches)
 
 	if !res {
@@ -225,7 +229,7 @@ func (p *httpMockProvider) ExecuteTest(integrationTest func(MockServerConfig) er
 
 // TODO: pretty print this to make it really easy to understand the problems
 // See existing Pact/Ruby code examples
-func (p *httpMockProvider) displayMismatches(mismatches []native.MismatchedRequest) {
+func (p *httpMockProvider) displayMismatches(mismatches []mockserver.MismatchedRequest) {
 	if len(mismatches) > 0 {
 		log.Println("[INFO] pact validation failed, errors: ")
 		for _, m := range mismatches {
@@ -259,7 +263,7 @@ func (p *httpMockProvider) displayMismatches(mismatches []native.MismatchedReque
 func (p *httpMockProvider) WritePact() error {
 	log.Println("[DEBUG] write pact file")
 	if p.config.Port != 0 {
-		return native.WritePactFile(p.config.Port, p.config.PactDir)
+		return p.mockserver.WritePactFile(p.config.Port, p.config.PactDir)
 	}
 	return errors.New("pact server not yet started")
 }
diff --git a/v3/installer/installer.go b/v3/installer/installer.go
index ca53dbb0a..b3b8f9c83 100644
--- a/v3/installer/installer.go
+++ b/v3/installer/installer.go
@@ -5,6 +5,7 @@ package installer
 import (
 	"fmt"
 	"log"
+	"os"
 	"os/exec"
 	"path"
 	"runtime"
@@ -13,20 +14,9 @@ import (
 	getter "github.com/hashicorp/go-getter"
 	goversion "github.com/hashicorp/go-version"
 
-	// can't use these packages, because then the CLI installer wouldn't work - go won't run without it!
-	// "github.com/pact-foundation/pact-go/v3/internal/native/verifier"
-	// mockserver "github.com/pact-foundation/pact-go/v3/internal/native/mockserver"
-
 	"github.com/spf13/afero"
 )
 
-// Installer manages the underlying Ruby installation
-// (eventual) implementation requirements
-// 1. Download OS specific artifacts if not pre-installed - DONE
-// 1. Check the semver range of pre-installed artifacts - DONE
-// 1. Enable global configuration (environment vars, config files, code options e.g. (`PACT_GO_SHARED_LIBRARY_PATH`))
-// 1. Allow users to specify where they pre-install their artifacts (e.g. /usr/local/lib)
-
 // Installer is used to check the Pact Go installation is setup correctly, and can automatically install
 // packages if required
 type Installer struct {
@@ -80,18 +70,13 @@ func (i *Installer) Force(force bool) {
 func (i *Installer) CheckInstallation() error {
 
 	// Check if files exist
-	// --> Check versions of existing installed files
+	// --> Check if existing installed files
 	if !i.force {
 		if err := i.checkPackageInstall(); err == nil {
 			return nil
 		}
 	}
 
-	// Check if override package path exists
-	// -> if it does, copy files from existing location
-	// --> Check versions of these files
-	// --> copy files to lib dir
-
 	// Download dependencies
 	if err := i.downloadDependencies(); err != nil {
 		return err
@@ -102,29 +87,32 @@ func (i *Installer) CheckInstallation() error {
 		return err
 	}
 
+	// Double check files landed correctly (can't execute 'version' call here,
+	// because of dependency on the native libs we're trying to download!)
 	if err := i.checkPackageInstall(); err != nil {
 		return fmt.Errorf("unable to verify downloaded/installed dependencies: %s", err)
 	}
 
-	// --> Check if download is disabled (return error if downloads are disabled)
-	// --> download files to lib dir
-
 	return nil
 }
 
 func (i *Installer) getLibDir() string {
-	if i.libDir == "" {
-		return "/usr/local/lib"
+	if i.libDir != "" {
+		return i.libDir
 	}
 
-	return i.libDir
+	env := os.Getenv(downloadEnvVar)
+	if env != "" {
+		return env
+	}
+
+	return "/usr/local/lib"
 }
 
 // checkPackageInstall discovers any existing packages, and checks installation of a given binary using semver-compatible checks
 func (i *Installer) checkPackageInstall() error {
 	for pkg, info := range packages {
 
-		log.Println("[DEBUG] checking version for lib", info.libName, "semver range", info.semverRange)
 		dst, _ := i.getLibDstForPackage(pkg)
 
 		if _, err := i.fs.Stat(dst); err != nil {
@@ -132,9 +120,16 @@ func (i *Installer) checkPackageInstall() error {
 			return err
 		}
 
-		// if err := checkVersion(info.libName, info.testCommand(), info.semverRange); err != nil {
-		// 	return err
-		// }
+		lib, ok := LibRegistry[pkg]
+
+		if ok {
+			log.Println("[INFO] checking version", lib.Version(), "for lib", info.libName, "within semver range", info.semverRange)
+			if err := checkVersion(info.libName, lib.Version(), info.semverRange); err != nil {
+				return err
+			}
+		} else {
+			log.Println("[DEBUG] lib registry is currently not populated for package", pkg, "this is probably because the package is currently being installed")
+		}
 	}
 
 	return nil
@@ -226,6 +221,27 @@ var setOSXInstallName = func(file string, lib string) error {
 	return err
 }
 
+func checkVersion(lib, version, versionRange string) error {
+	log.Println("[DEBUG] checking version", version, "of", lib, "against semver constraint", versionRange)
+
+	v, err := goversion.NewVersion(version)
+	if err != nil {
+		return err
+	}
+
+	constraints, err := goversion.NewConstraint(versionRange)
+	if err != nil {
+		return err
+	}
+
+	if constraints.Check(v) {
+		log.Println("[DEBUG]", v, "satisfies constraints", v, constraints)
+		return nil
+	}
+
+	return fmt.Errorf("version %s of %s does not match constraint %s", version, lib, versionRange)
+}
+
 // download template structure: "https://github.com/pact-foundation/pact-reference/releases/download/PACKAGE-vVERSION/LIBNAME-OS-ARCH.EXTENSION.gz"
 var downloadTemplate = "https://github.com/pact-foundation/pact-reference/releases/download/%s-v%s/%s-%s-%s.%s.gz"
 
@@ -245,12 +261,12 @@ type packageInfo struct {
 	libName     string
 	version     string
 	semverRange string
-	testCommand func() string
 }
 
 const (
-	verifierPackage   = "pact_verifier_ffi"
-	mockServerPackage = "libpact_mock_server_ffi"
+	VerifierPackage   = "pact_verifier_ffi"
+	MockServerPackage = "libpact_mock_server_ffi"
+	downloadEnvVar    = "PACT_GO_LIB_DOWNLOAD_PATH"
 	linux             = "linux"
 	windows           = "windows"
 	osx               = "osx"
@@ -258,45 +274,24 @@ const (
 )
 
 var packages = map[string]packageInfo{
-	verifierPackage: {
+	VerifierPackage: {
 		libName:     "libpact_verifier_ffi",
 		version:     "0.0.2",
 		semverRange: ">= 0.0.2, < 1.0.0",
-		// testCommand: func() string {
-		// 	return (&verifier.Verifier{}).Version()
-		// },
 	},
-	mockServerPackage: {
+	MockServerPackage: {
 		libName:     "libpact_mock_server_ffi",
 		version:     "0.0.15",
 		semverRange: ">= 0.0.15, < 1.0.0",
-		// testCommand: func() string {
-		// 	return mockserver.Version()
-		// },
 	},
 }
 
-func checkVersion(lib, version, versionRange string) error {
-	log.Println("[DEBUG] checking version", version, "of", lib, "against semver constraint", versionRange)
-
-	v, err := goversion.NewVersion(version)
-	if err != nil {
-		return err
-	}
-
-	constraints, err := goversion.NewConstraint(versionRange)
-	if err != nil {
-		return err
-	}
-
-	if constraints.Check(v) {
-		log.Println("[DEBUG]", v, "satisfies constraints", v, constraints)
-		return nil
-	}
-
-	return fmt.Errorf("version %s of %s does not match constraint %s", version, lib, versionRange)
+type Versioner interface {
+	Version() string
 }
 
+var LibRegistry = map[string]Versioner{}
+
 type downloader interface {
 	download(src string, dst string) error
 }
diff --git a/v3/installer/installer_test.go b/v3/installer/installer_test.go
index a76378fa5..f22bb1dff 100644
--- a/v3/installer/installer_test.go
+++ b/v3/installer/installer_test.go
@@ -24,7 +24,7 @@ func TestInstallerDownloader(t *testing.T) {
 		}{
 			{
 				name: "mock server - linux x86",
-				pkg:  mockServerPackage,
+				pkg:  MockServerPackage,
 				want: "https://github.com/pact-foundation/pact-reference/releases/download/libpact_mock_server_ffi-v0.0.15/libpact_mock_server_ffi-linux-x86_64.so.gz",
 				test: Installer{
 					os:   linux,
@@ -33,7 +33,7 @@ func TestInstallerDownloader(t *testing.T) {
 			},
 			{
 				name: "mock server - osx x86",
-				pkg:  mockServerPackage,
+				pkg:  MockServerPackage,
 				want: "https://github.com/pact-foundation/pact-reference/releases/download/libpact_mock_server_ffi-v0.0.15/libpact_mock_server_ffi-osx-x86_64.dylib.gz",
 				test: Installer{
 					os:   osx,
@@ -42,7 +42,7 @@ func TestInstallerDownloader(t *testing.T) {
 			},
 			{
 				name: "mock server - linux x86",
-				pkg:  mockServerPackage,
+				pkg:  MockServerPackage,
 				want: "https://github.com/pact-foundation/pact-reference/releases/download/libpact_mock_server_ffi-v0.0.15/libpact_mock_server_ffi-windows-x86_64.dll.gz",
 				test: Installer{
 					os:   windows,
@@ -80,7 +80,7 @@ func TestInstallerDownloader(t *testing.T) {
 		defer func() { packages = oldPackages }()
 
 		packages = map[string]packageInfo{
-			verifierPackage: {
+			VerifierPackage: {
 				libName:     "libpact_verifier_ffi",
 				version:     "0.0.2",
 				semverRange: ">= 0.8.3, < 1.0.0",
@@ -88,7 +88,7 @@ func TestInstallerDownloader(t *testing.T) {
 					return "0.8.0"
 				},
 			},
-			mockServerPackage: {
+			MockServerPackage: {
 				libName:     "libpact_mock_server_ffi",
 				version:     "0.0.15",
 				semverRange: ">= 0.0.15, < 1.0.0",
diff --git a/v3/internal/checker/checker.go b/v3/internal/checker/checker.go
new file mode 100644
index 000000000..b0b2823de
--- /dev/null
+++ b/v3/internal/checker/checker.go
@@ -0,0 +1,20 @@
+package checker
+
+import (
+	"github.com/pact-foundation/pact-go/v3/installer"
+	"github.com/pact-foundation/pact-go/v3/internal/native/mockserver"
+	"github.com/pact-foundation/pact-go/v3/internal/native/verifier"
+)
+
+func CheckInstall() error {
+	// initialised the lib registry
+	installer.LibRegistry[installer.MockServerPackage] = &mockserver.MockServer{}
+	installer.LibRegistry[installer.VerifierPackage] = &verifier.Verifier{}
+
+	i, err := installer.NewInstaller()
+	if err != nil {
+		return err
+	}
+
+	return i.CheckInstallation()
+}
diff --git a/v3/internal/native/mockserver/mock_server.go b/v3/internal/native/mockserver/mock_server.go
index adf561dcd..1e4e1b0a0 100644
--- a/v3/internal/native/mockserver/mock_server.go
+++ b/v3/internal/native/mockserver/mock_server.go
@@ -72,8 +72,10 @@ type MismatchedRequest struct {
 	Type       string
 }
 
+type MockServer struct{}
+
 // Init initialises the library
-func Init() {
+func (m *MockServer) Init() {
 	log.Println("[DEBUG] initialising rust mock server interface")
 	logLevel := C.CString("LOG_LEVEL")
 	defer free(logLevel)
@@ -83,7 +85,7 @@ func Init() {
 
 // CreateMockServer creates a new Mock Server from a given Pact file.
 // Returns the port number it started on or an error if failed
-func CreateMockServer(pact string, address string, tls bool) (int, error) {
+func (m *MockServer) CreateMockServer(pact string, address string, tls bool) (int, error) {
 	log.Println("[DEBUG] mock server starting on address:", address)
 	cPact := C.CString(pact)
 	cAddress := C.CString(address)
@@ -129,10 +131,10 @@ func CreateMockServer(pact string, address string, tls bool) (int, error) {
 
 // Verify verifies that all interactions were successful. If not, returns a slice
 // of Mismatch-es. Does not write the pact or cleanup server.
-func Verify(port int, dir string) (bool, []MismatchedRequest) {
+func (m *MockServer) Verify(port int, dir string) (bool, []MismatchedRequest) {
 	res := C.mock_server_matched(C.int(port))
 
-	mismatches := MockServerMismatchedRequests(port)
+	mismatches := m.MockServerMismatchedRequests(port)
 	log.Println("[DEBUG] mock server mismatches:", len(mismatches))
 
 	return int(res) == 1, mismatches
@@ -140,7 +142,7 @@ func Verify(port int, dir string) (bool, []MismatchedRequest) {
 
 // MockServerMismatchedRequests returns a JSON object containing any mismatches from
 // the last set of interactions.
-func MockServerMismatchedRequests(port int) []MismatchedRequest {
+func (m *MockServer) MockServerMismatchedRequests(port int) []MismatchedRequest {
 	log.Println("[DEBUG] mock server determining mismatches:", port)
 	var res []MismatchedRequest
 
@@ -151,7 +153,7 @@ func MockServerMismatchedRequests(port int) []MismatchedRequest {
 }
 
 // CleanupMockServer frees the memory from the previous mock server.
-func CleanupMockServer(port int) bool {
+func (m *MockServer) CleanupMockServer(port int) bool {
 	log.Println("[DEBUG] mock server cleaning up port:", port)
 	res := C.cleanup_mock_server(C.int(port))
 
@@ -186,7 +188,7 @@ var (
 )
 
 // WritePactFile writes the Pact to file.
-func WritePactFile(port int, dir string) error {
+func (m *MockServer) WritePactFile(port int, dir string) error {
 	log.Println("[DEBUG] writing pact file for mock server on port:", port, ", dir:", dir)
 	cDir := C.CString(dir)
 	defer free(cDir)
@@ -228,7 +230,7 @@ func GetTLSConfig() *tls.Config {
 }
 
 // Version returns the current semver FFI interface version
-func Version() string {
+func (m *MockServer) Version() string {
 	v := C.version()
 
 	return C.GoString(v)
diff --git a/v3/internal/native/mockserver/mock_server_lib.go b/v3/internal/native/mockserver/mock_server_lib.go
index f203ba0c4..6dd89e952 100644
--- a/v3/internal/native/mockserver/mock_server_lib.go
+++ b/v3/internal/native/mockserver/mock_server_lib.go
@@ -1,9 +1,9 @@
 package mockserver
 
 /*
-#cgo darwin,amd64 LDFLAGS: -lpact_mock_server_ffi
+#cgo darwin,amd64 LDFLAGS: -L/opt/pact/lib -Wl,-rpath -Wl,/opt/pact/lib -Wl,-rpath -Wl,/tmp -Wl,-rpath -Wl,/usr/local/lib -lpact_mock_server_ffi
 #cgo windows,amd64 LDFLAGS: -lpact_mock_server_ffi
-#cgo linux,amd64 LDFLAGS: -L/tmp -L/usr/local/lib -Wl,-rpath -Wl,/tmp -Wl,-rpath -Wl,/usr/local/lib -lpact_mock_server_ffi
+#cgo linux,amd64 LDFLAGS: -Wl,-rpath -Wl,/opt/pact/lib -Wl,-rpath -Wl,/tmp -Wl,-rpath -Wl,/usr/local/lib -lpact_mock_server_ffi
 
 // Mac OSX (until https://github.com/pact-foundation/pact-reference/pull/93 is done)
 //  install_name_tool -id "libpact_mock_server_ffi" libpact_mock_server_ffi.dylib
diff --git a/v3/internal/native/verifier/verifier_lib.go b/v3/internal/native/verifier/verifier_lib.go
index 861a5d0e6..87cb7126a 100644
--- a/v3/internal/native/verifier/verifier_lib.go
+++ b/v3/internal/native/verifier/verifier_lib.go
@@ -1,9 +1,9 @@
 package verifier
 
 /*
-#cgo darwin,amd64 LDFLAGS: -lpact_verifier_ffi
+#cgo darwin,amd64 LDFLAGS: -L/opt/pact/lib -Wl,-rpath -Wl,/opt/pact/lib -Wl,-rpath -Wl,/tmp -Wl,-rpath -Wl,/usr/local/lib -lpact_verifier_ffi
 #cgo windows,amd64 LDFLAGS: -lpact_verifier_ffi
-#cgo linux,amd64 LDFLAGS: -L/tmp -L/usr/local/lib -Wl,-rpath -Wl,/tmp -Wl,-rpath -Wl,/usr/local/lib -lpact_verifier_ffi
+#cgo linux,amd64 LDFLAGS: -Wl,-rpath -Wl,/opt/pact/lib -Wl,-rpath -Wl,/tmp -Wl,-rpath -Wl,/usr/local/lib -lpact_verifier_ffi
 
 // Mac OSX (until https://github.com/pact-foundation/pact-reference/pull/93 is done)
 // install_name_tool -id "libpact_verifier_ffi.dylib" /usr/local/lib/libpact_verifier_ffi.dylib
diff --git a/v3/version.go b/v3/version.go
new file mode 100644
index 000000000..267a47ef0
--- /dev/null
+++ b/v3/version.go
@@ -0,0 +1,18 @@
+package v3
+
+import (
+	"log"
+
+	"github.com/pact-foundation/pact-go/v3/internal/checker"
+)
+
+// CheckVersion checks if the currently installed version is within semver range
+// and will attempt to download the files to the default or configured directory if
+// incorrect
+func CheckVersion() {
+	if err := checker.CheckInstall(); err != nil {
+		log.Fatal("check version failed:", err)
+	}
+
+	log.Println("[DEBUG] version check completed")
+}