diff --git a/remote.go b/remote.go
index 47866ed..ebf1fd4 100644
--- a/remote.go
+++ b/remote.go
@@ -13,9 +13,11 @@ extern void _setup_callbacks(git_remote_callbacks *callbacks);
 
 */
 import "C"
-import (
-	"unsafe"
-)
+import "unsafe"
+
+type TransferProgress struct {
+	ptr *C.git_transfer_progress
+}
 
 type RemoteCompletion uint
 const (
@@ -26,47 +28,10 @@ const (
 
 type ProgressCallback func(str string) int
 type CompletionCallback func(RemoteCompletion) int
-type CredentialsCallback func(url string, username_from_url string, allowed_types uint) int // FIXME
-type TransferProgressCallback func() int // FIXME
+type CredentialsCallback func(url string, username_from_url string, allowed_types CredType) (int, Cred)
+type TransferProgressCallback func(stats TransferProgress) int
 type UpdateTipsCallback func(refname string, a *Oid, b *Oid) int
 
-//export progressCallback
-func progressCallback(_str *C.char, _len C.int, data unsafe.Pointer) int {
-	callbacks := (*RemoteCallbacks)(data)
-	str := C.GoStringN(_str, _len)	
-	return callbacks.ProgressCallback(str)
-}
-
-//export completionCallback
-func completionCallback(completion_type C.git_remote_completion_type, data unsafe.Pointer) int {
-	callbacks := (*RemoteCallbacks)(data)
-	return callbacks.CompletionCallback((RemoteCompletion)(completion_type))
-}
-
-//export credentialsCallback
-func credentialsCallback(_cred **C.git_cred, _url *C.char, _username_from_url *C.char, allowed_types uint, data unsafe.Pointer) int {
-	callbacks := (*RemoteCallbacks)(data)
-	//cred := C.GoString(_cred)
-	url := C.GoString(_url)
-	username_from_url := C.GoString(_username_from_url)
-	return callbacks.CredentialsCallback(url, username_from_url, allowed_types)
-}
-
-//export transferProgressCallback
-func transferProgressCallback(stats C.git_transfer_progress, data unsafe.Pointer) int {
-	callbacks := (*RemoteCallbacks)(data)
-	return callbacks.TransferProgressCallback()
-}
-
-//export updateTipsCallback
-func updateTipsCallback(_refname *C.char, _a *C.git_oid, _b *C.git_oid, data unsafe.Pointer) int {
-	callbacks := (*RemoteCallbacks)(data)
-	refname := C.GoString(_refname)
-	a := newOidFromC(_a)
-	b := newOidFromC(_b)
-	return callbacks.UpdateTipsCallback(refname, a, b)
-}
-
 type RemoteCallbacks struct {
 	ProgressCallback
 	CompletionCallback
@@ -83,3 +48,82 @@ func populateRemoteCallbacks(ptr *C.git_remote_callbacks, callbacks *RemoteCallb
 	C._setup_callbacks(ptr)
 	ptr.payload = unsafe.Pointer(callbacks)
 }
+
+//export progressCallback
+func progressCallback(_str *C.char, _len C.int, data unsafe.Pointer) int {
+	callbacks := (*RemoteCallbacks)(data)
+	if callbacks.ProgressCallback == nil {
+		return 0
+	}
+	str := C.GoStringN(_str, _len)
+	return callbacks.ProgressCallback(str)
+}
+
+//export completionCallback
+func completionCallback(completion_type C.git_remote_completion_type, data unsafe.Pointer) int {
+	callbacks := (*RemoteCallbacks)(data)
+	if callbacks.CompletionCallback == nil {
+		return 0
+	}
+	return callbacks.CompletionCallback((RemoteCompletion)(completion_type))
+}
+
+//export credentialsCallback
+func credentialsCallback(_cred **C.git_cred, _url *C.char, _username_from_url *C.char, allowed_types uint, data unsafe.Pointer) int {
+	callbacks := (*RemoteCallbacks)(data)
+	if callbacks.CredentialsCallback == nil {
+		return 0
+	}
+	url := C.GoString(_url)
+	username_from_url := C.GoString(_username_from_url)
+	ret, cred := callbacks.CredentialsCallback(url, username_from_url, (CredType)(allowed_types))
+	if gcred, ok := cred.(gitCred); ok {
+		*_cred = gcred.ptr
+	}
+	return ret
+}
+
+//export transferProgressCallback
+func transferProgressCallback(stats *C.git_transfer_progress, data unsafe.Pointer) int {
+	callbacks := (*RemoteCallbacks)(data)
+	if callbacks.TransferProgressCallback == nil {
+		return 0
+	}
+	return callbacks.TransferProgressCallback(TransferProgress{stats})
+}
+
+//export updateTipsCallback
+func updateTipsCallback(_refname *C.char, _a *C.git_oid, _b *C.git_oid, data unsafe.Pointer) int {
+	callbacks := (*RemoteCallbacks)(data)
+	if callbacks.UpdateTipsCallback == nil {
+		return 0
+	}
+	refname := C.GoString(_refname)
+	a := newOidFromC(_a)
+	b := newOidFromC(_b)
+	return callbacks.UpdateTipsCallback(refname, a, b)
+}
+
+func (o TransferProgress) TotalObjects() uint {
+	return uint(o.ptr.total_objects)
+}
+
+func (o TransferProgress) IndexedObjects() uint {
+	return uint(o.ptr.indexed_objects)
+}
+
+func (o TransferProgress) ReceivedObjects() uint {
+	return uint(o.ptr.received_objects)
+}
+
+func (o TransferProgress) LocalObjects() uint {
+	return uint(o.ptr.local_objects)
+}
+
+func (o TransferProgress) TotalDeltas() uint {
+	return uint(o.ptr.total_deltas)
+}
+
+func (o TransferProgress) ReceivedBytes() uint {
+	return uint(o.ptr.received_bytes)
+}
diff --git a/transport.go b/transport.go
new file mode 100644
index 0000000..e97a70c
--- /dev/null
+++ b/transport.go
@@ -0,0 +1,79 @@
+package git
+
+/*
+#include <git2.h>
+#include <git2/errors.h>
+*/
+import "C"
+import "unsafe"
+
+type CredType uint
+const (
+	CredTypeUserpassPlaintext CredType = C.GIT_CREDTYPE_USERPASS_PLAINTEXT
+	CredTypeSshKey		           = C.GIT_CREDTYPE_SSH_KEY
+	CredTypeSshCustom 		   = C.GIT_CREDTYPE_SSH_CUSTOM
+	CredTypeDefault			   = C.GIT_CREDTYPE_DEFAULT
+)
+
+type Cred interface {
+	HasUsername() bool
+	Type() CredType
+}
+
+type gitCred struct {
+	ptr *C.git_cred
+}
+
+func (o gitCred) HasUsername() bool {
+	if C.git_cred_has_username(o.ptr) == 1 {
+		return true
+	}
+	return false
+}
+
+func (o gitCred) Type() CredType {
+	return (CredType)(o.ptr.credtype);
+}
+
+func credFromC(ptr *C.git_cred) Cred {
+	return gitCred{ptr}
+}
+
+func NewCredUserpassPlaintext(username string, password string) (int, Cred) {
+	cred := gitCred{}
+	cusername := C.CString(username)
+	defer C.free(unsafe.Pointer(cusername))
+	cpassword := C.CString(password)
+	defer C.free(unsafe.Pointer(cpassword))
+	ret := C.git_cred_userpass_plaintext_new(&cred.ptr, cusername, cpassword)
+	return int(ret), cred
+}
+
+func NewCredSshKey(username string, publickey string, privatekey string, passphrase string) (int, Cred) {
+	cred := gitCred{}
+	cusername := C.CString(username)
+	defer C.free(unsafe.Pointer(cusername))
+	cpublickey := C.CString(publickey)
+	defer C.free(unsafe.Pointer(cpublickey))
+	cprivatekey := C.CString(privatekey)
+	defer C.free(unsafe.Pointer(cprivatekey))
+	cpassphrase := C.CString(passphrase)
+	defer C.free(unsafe.Pointer(cpassphrase))
+	ret := C.git_cred_ssh_key_new(&cred.ptr, cusername, cpublickey, cprivatekey, cpassphrase)
+	return int(ret), cred
+}
+
+func NewCredSshKeyFromAgent(username string) (int, Cred) {
+	cred := gitCred{}
+	cusername := C.CString(username)
+	defer C.free(unsafe.Pointer(cusername))
+	ret := C.git_cred_ssh_key_from_agent(&cred.ptr, cusername)
+	return int(ret), cred
+}
+
+func NewCredDefault() (int, Cred) {
+	cred := gitCred{}
+	ret := C.git_cred_default_new(&cred.ptr)
+	return int(ret), cred
+}
+