diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 5cb61e0..8188ce1 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -524,7 +524,8 @@ checksum = "90e5c1c8368803113bf0c9584fc495a58b86dc8a29edbf8fe877d21d9507e797"
 [[package]]
 name = "equihash"
 version = "0.2.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab579d7cf78477773b03e80bc2f89702ef02d7112c711d54ca93dcdce68533d5"
 dependencies = [
  "blake2b_simd",
  "byteorder",
@@ -533,7 +534,8 @@ dependencies = [
 [[package]]
 name = "f4jumble"
 version = "0.1.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0a83e8d7fd0c526af4aad893b7c9fe41e2699ed8a776a6c74aecdeafe05afc75"
 dependencies = [
  "blake2b_simd",
 ]
@@ -1062,7 +1064,7 @@ dependencies = [
  "serde",
  "subtle",
  "tracing",
- "zcash_note_encryption 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "zcash_note_encryption",
 ]
 
 [[package]]
@@ -1422,6 +1424,7 @@ dependencies = [
  "fallible-iterator",
  "fallible-streaming-iterator",
  "hashlink",
+ "lazy_static",
  "libsqlite3-sys",
  "memchr",
  "smallvec",
@@ -1452,7 +1455,8 @@ checksum = "4501abdff3ae82a1c1b477a17252eb69cee9e66eb915c1abaa4f44d873df9f09"
 [[package]]
 name = "schemer"
 version = "0.2.0"
-source = "git+https://github.com/aschampion/schemer.git?rev=6726b60f43f72c6e24a18d31be0ec7d42829e5e1#6726b60f43f72c6e24a18d31be0ec7d42829e5e1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48f0ed79b582101b59740acd981e58eaa3bf8c4b1179e9a0124a7df1e08e98b3"
 dependencies = [
  "daggy",
  "log",
@@ -1462,8 +1466,9 @@ dependencies = [
 
 [[package]]
 name = "schemer-rusqlite"
-version = "0.2.0"
-source = "git+https://github.com/aschampion/schemer.git?rev=6726b60f43f72c6e24a18d31be0ec7d42829e5e1#6726b60f43f72c6e24a18d31be0ec7d42829e5e1"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1f34ab2dd976536b8518fe5b868756cf6e6caec89f38d8b6f432ba27f1d5f27"
 dependencies = [
  "rusqlite",
  "schemer",
@@ -2050,7 +2055,8 @@ dependencies = [
 [[package]]
 name = "zcash_address"
 version = "0.2.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "804268e702b664fc09d3e2ce82786d0addf4ae57ba6976469be63e09066bf9f7"
 dependencies = [
  "bech32",
  "bs58",
@@ -2060,8 +2066,9 @@ dependencies = [
 
 [[package]]
 name = "zcash_client_backend"
-version = "0.5.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee7748e874300bf574bdb524108b8967d3e58685aa1705dd2efbcfabb21b89d7"
 dependencies = [
  "base64",
  "bech32",
@@ -2085,14 +2092,15 @@ dependencies = [
  "which",
  "zcash_address",
  "zcash_encoding",
- "zcash_note_encryption 0.2.0 (git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d)",
+ "zcash_note_encryption",
  "zcash_primitives",
 ]
 
 [[package]]
 name = "zcash_client_sqlite"
-version = "0.3.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9625b097932fc26f4b549042eafff922b57bcd421edba408abf6334a97298636"
 dependencies = [
  "bs58",
  "group",
@@ -2112,7 +2120,8 @@ dependencies = [
 [[package]]
 name = "zcash_encoding"
 version = "0.2.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f03391b81727875efa6ac0661a20883022b6fba92365dc121c48fa9b00c5aac0"
 dependencies = [
  "byteorder",
  "nonempty",
@@ -2131,22 +2140,11 @@ dependencies = [
  "subtle",
 ]
 
-[[package]]
-name = "zcash_note_encryption"
-version = "0.2.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
-dependencies = [
- "chacha20",
- "chacha20poly1305",
- "cipher 0.4.3",
- "rand_core",
- "subtle",
-]
-
 [[package]]
 name = "zcash_primitives"
-version = "0.8.1"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7e33ec9068388e8de106a78268f90487d6975b171ee197aef16cc64c093486d"
 dependencies = [
  "aes",
  "bip0039",
@@ -2175,13 +2173,14 @@ dependencies = [
  "subtle",
  "zcash_address",
  "zcash_encoding",
- "zcash_note_encryption 0.2.0 (git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d)",
+ "zcash_note_encryption",
 ]
 
 [[package]]
 name = "zcash_proofs"
-version = "0.8.0"
-source = "git+https://github.com/zcash/librustzcash.git?rev=6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d#6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77381adc72286874e563ee36ba99953946abcbd195ada45440a2754ca823d407"
 dependencies = [
  "bellman",
  "blake2b_simd",
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index ad64461..95e32a7 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -19,10 +19,10 @@ secp256k1 = "0.21"
 secrecy = "0.8"
 
 zcash_address = { version = "0.2" }
-zcash_client_backend = { version = "0.5", features = ["transparent-inputs", "unstable"] }
-zcash_client_sqlite = { version = "0.3", features = ["transparent-inputs", "unstable"] }
-zcash_primitives = "0.8.1"
-zcash_proofs = "0.8"
+zcash_client_backend = { version = "0.6", features = ["transparent-inputs", "unstable"] }
+zcash_client_sqlite = { version = "0.4", features = ["transparent-inputs", "unstable"] }
+zcash_primitives = "0.9"
+zcash_proofs = "0.9"
 
 [build-dependencies]
 cbindgen = "0.14"
@@ -35,18 +35,6 @@ crate-type = ["staticlib"]
 [profile.release]
 lto = true
 
-# Revision corresponds to zcash_primitives 0.6.0 plus the NU5 mainnet activation height.
-# We also need zcash_client_backend and zcash_client_sqlite, which haven't been published
-# with NU5 updates yet.
-[patch.crates-io]
-zcash_address = { git = 'https://github.com/zcash/librustzcash.git', rev='6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d' }
-zcash_client_backend = { git = 'https://github.com/zcash/librustzcash.git', rev='6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d' }
-zcash_client_sqlite = { git = 'https://github.com/zcash/librustzcash.git', rev='6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d' }
-zcash_primitives = { git = 'https://github.com/zcash/librustzcash.git', rev='6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d' }
-zcash_proofs = { git = 'https://github.com/zcash/librustzcash.git', rev='6047c1d0030b2a40abd35cbc7ba15bd2bd63fc8d' }
-schemer = { git = "https://github.com/aschampion/schemer.git", rev = "6726b60f43f72c6e24a18d31be0ec7d42829e5e1" }
-schemer-rusqlite = { git = "https://github.com/aschampion/schemer.git", rev = "6726b60f43f72c6e24a18d31be0ec7d42829e5e1" }
-
 [features]
 mainnet = ["zcash_client_sqlite/mainnet"]
 testnet = []
diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index 9533169..edca8d0 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -1,3 +1,5 @@
+#![deny(unsafe_op_in_unsafe_fn)]
+
 use failure::format_err;
 use ffi_helpers::panic::catch_panic;
 use schemer::MigratorError;
@@ -20,21 +22,22 @@ use zcash_address::{
 use zcash_client_backend::{
     address::{RecipientAddress, UnifiedAddress},
     data_api::{
-        chain::{scan_cached_blocks, validate_chain},
-        error::Error,
+        chain::{self, scan_cached_blocks, validate_chain},
         wallet::{
-            create_spend_to_address, decrypt_and_store_transaction, shield_transparent_funds,
+            decrypt_and_store_transaction, input_selection::GreedyInputSelector,
+            shield_transparent_funds, spend,
         },
         WalletRead, WalletWrite,
     },
     encoding::{decode_extended_full_viewing_key, decode_extended_spending_key, AddressCodec},
+    fees::{fixed, zip317, DustOutputPolicy},
     keys::{DecodingError, Era, UnifiedFullViewingKey, UnifiedSpendingKey},
     wallet::{OvkPolicy, WalletTransparentOutput},
+    zip321::{Payment, TransactionRequest},
 };
 #[allow(deprecated)]
 use zcash_client_sqlite::wallet::get_rewind_height;
 use zcash_client_sqlite::{
-    error::SqliteClientError,
     wallet::init::{init_accounts_table, init_blocks_table, init_wallet_db, WalletMigrationError},
     BlockDb, NoteId, WalletDb,
 };
@@ -46,6 +49,8 @@ use zcash_primitives::{
     memo::{Memo, MemoBytes},
     transaction::{
         components::{Amount, OutPoint, TxOut},
+        fees::fixed::FeeRule as FixedFeeRule,
+        fees::zip317::FeeRule as Zip317FeeRule,
         Transaction,
     },
     zip32::AccountId,
@@ -86,10 +91,9 @@ unsafe fn wallet_db(
     db_data_len: usize,
     network: Network,
 ) -> Result<WalletDb<Network>, failure::Error> {
-    let db_data = Path::new(OsStr::from_bytes(slice::from_raw_parts(
-        db_data,
-        db_data_len,
-    )));
+    let db_data = Path::new(OsStr::from_bytes(unsafe {
+        slice::from_raw_parts(db_data, db_data_len)
+    }));
     WalletDb::for_path(db_data, network)
         .map_err(|e| format_err!("Error opening wallet database connection: {}", e))
 }
@@ -105,10 +109,9 @@ unsafe fn wallet_db(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 unsafe fn block_db(cache_db: *const u8, cache_db_len: usize) -> Result<BlockDb, failure::Error> {
-    let cache_db = Path::new(OsStr::from_bytes(slice::from_raw_parts(
-        cache_db,
-        cache_db_len,
-    )));
+    let cache_db = Path::new(OsStr::from_bytes(unsafe {
+        slice::from_raw_parts(cache_db, cache_db_len)
+    }));
     BlockDb::for_path(cache_db)
         .map_err(|e| format_err!("Error opening block source database connection: {}", e))
 }
@@ -130,7 +133,7 @@ pub extern "C" fn zcashlc_last_error_length() -> i32 {
 ///   pointer::offset.
 #[no_mangle]
 pub unsafe extern "C" fn zcashlc_error_message_utf8(buf: *mut c_char, length: i32) -> i32 {
-    ffi_helpers::error_handling::error_message_utf8(buf, length)
+    unsafe { ffi_helpers::error_handling::error_message_utf8(buf, length) }
 }
 
 /// Clears the record of the last error message.
@@ -160,7 +163,7 @@ pub extern "C" fn zcashlc_clear_last_error() {
 /// - The total size `seed_len` must be no larger than `isize::MAX`. See the safety documentation
 ///   of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_init_data_database(
+pub unsafe extern "C" fn zcashlc_init_data_database(
     db_data: *const u8,
     db_data_len: usize,
     seed: *const u8,
@@ -221,9 +224,10 @@ impl FFIBinaryKey {
 #[no_mangle]
 pub unsafe extern "C" fn zcashlc_free_binary_key(ptr: *mut FFIBinaryKey) {
     if !ptr.is_null() {
-        let key: Box<FFIBinaryKey> = Box::from_raw(ptr);
-        let key_slice: &mut [u8] = slice::from_raw_parts_mut(key.encoding, key.encoding_len);
-        drop(Box::from_raw(key_slice));
+        let key: Box<FFIBinaryKey> = unsafe { Box::from_raw(ptr) };
+        let key_slice: &mut [u8] =
+            unsafe { slice::from_raw_parts_mut(key.encoding, key.encoding_len) };
+        drop(unsafe { Box::from_raw(key_slice) });
     }
 }
 
@@ -260,7 +264,7 @@ pub unsafe extern "C" fn zcashlc_free_binary_key(ptr: *mut FFIBinaryKey) {
 ///
 /// [ZIP 316]: https://zips.z.cash/zip-0316
 #[no_mangle]
-pub extern "C" fn zcashlc_create_account(
+pub unsafe extern "C" fn zcashlc_create_account(
     db_data: *const u8,
     db_data_len: usize,
     seed: *const u8,
@@ -341,11 +345,11 @@ impl FFIEncodedKeys {
 #[no_mangle]
 pub unsafe extern "C" fn zcashlc_free_keys(ptr: *mut FFIEncodedKeys) {
     if !ptr.is_null() {
-        let s: Box<FFIEncodedKeys> = Box::from_raw(ptr);
+        let s: Box<FFIEncodedKeys> = unsafe { Box::from_raw(ptr) };
 
-        let slice: &mut [FFIEncodedKey] = slice::from_raw_parts_mut(s.ptr, s.len);
+        let slice: &mut [FFIEncodedKey] = unsafe { slice::from_raw_parts_mut(s.ptr, s.len) };
         for k in slice.into_iter() {
-            zcashlc_string_free(k.encoding)
+            unsafe { zcashlc_string_free(k.encoding) }
         }
         drop(s);
     }
@@ -369,7 +373,7 @@ pub unsafe extern "C" fn zcashlc_free_keys(ptr: *mut FFIEncodedKeys) {
 /// - The total size `ufvks_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_init_accounts_table_with_keys(
+pub unsafe extern "C" fn zcashlc_init_accounts_table_with_keys(
     db_data: *const u8,
     db_data_len: usize,
     ufvks_ptr: *mut FFIEncodedKey,
@@ -423,7 +427,7 @@ pub unsafe extern "C" fn zcashlc_derive_spending_key(
 ) -> *mut FFIBinaryKey {
     let res = catch_panic(|| {
         let network = parse_network(network_id)?;
-        let seed = slice::from_raw_parts(seed, seed_len);
+        let seed = unsafe { slice::from_raw_parts(seed, seed_len) };
         let account = if account >= 0 {
             account as u32
         } else {
@@ -487,7 +491,7 @@ unsafe fn decode_usk(
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when you are done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_spending_key_to_full_viewing_key(
+pub unsafe extern "C" fn zcashlc_spending_key_to_full_viewing_key(
     usk_ptr: *const u8,
     usk_len: usize,
     network_id: u32,
@@ -524,7 +528,7 @@ pub extern "C" fn zcashlc_spending_key_to_full_viewing_key(
 /// - The memory referenced by `sapling_tree_hex` must not be mutated for the duration of the
 ///   function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_init_blocks_table(
+pub unsafe extern "C" fn zcashlc_init_blocks_table(
     db_data: *const u8,
     db_data_len: usize,
     height: i32,
@@ -571,7 +575,7 @@ pub extern "C" fn zcashlc_init_blocks_table(
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_current_address(
+pub unsafe extern "C" fn zcashlc_get_current_address(
     db_data: *const u8,
     db_data_len: usize,
     account: i32,
@@ -617,7 +621,7 @@ pub extern "C" fn zcashlc_get_current_address(
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_next_available_address(
+pub unsafe extern "C" fn zcashlc_get_next_available_address(
     db_data: *const u8,
     db_data_len: usize,
     account: i32,
@@ -664,7 +668,7 @@ pub extern "C" fn zcashlc_get_next_available_address(
 /// - Call [`zcashlc_free_keys`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_list_transparent_receivers(
+pub unsafe extern "C" fn zcashlc_list_transparent_receivers(
     db_data: *const u8,
     db_data_len: usize,
     account_id: i32,
@@ -718,7 +722,7 @@ pub extern "C" fn zcashlc_list_transparent_receivers(
 /// - Call [`zcashlc_free_typecodes`] to free the memory associated with the returned
 ///   pointer when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_typecodes_for_unified_address_receivers(
+pub unsafe extern "C" fn zcashlc_get_typecodes_for_unified_address_receivers(
     ua: *const c_char,
     len_ret: *mut usize,
 ) -> *mut u32 {
@@ -759,7 +763,7 @@ pub extern "C" fn zcashlc_get_typecodes_for_unified_address_receivers(
 #[no_mangle]
 pub unsafe extern "C" fn zcashlc_free_typecodes(data: *mut u32, len: usize) {
     if !data.is_null() {
-        let s = Box::from_raw(slice::from_raw_parts_mut(data, len));
+        let s = unsafe { Box::from_raw(slice::from_raw_parts_mut(data, len)) };
         drop(s);
     }
 }
@@ -786,7 +790,7 @@ impl zcash_address::TryFromRawAddress for UnifiedAddressParser {
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_transparent_receiver_for_unified_address(
+pub unsafe extern "C" fn zcashlc_get_transparent_receiver_for_unified_address(
     ua: *const c_char,
 ) -> *mut c_char {
     let res = catch_panic(|| {
@@ -827,7 +831,7 @@ pub extern "C" fn zcashlc_get_transparent_receiver_for_unified_address(
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_sapling_receiver_for_unified_address(
+pub unsafe extern "C" fn zcashlc_get_sapling_receiver_for_unified_address(
     ua: *const c_char,
 ) -> *mut c_char {
     let res = catch_panic(|| {
@@ -862,7 +866,7 @@ pub extern "C" fn zcashlc_get_sapling_receiver_for_unified_address(
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_is_valid_shielded_address(
+pub unsafe extern "C" fn zcashlc_is_valid_shielded_address(
     address: *const c_char,
     network_id: u32,
 ) -> bool {
@@ -969,7 +973,7 @@ impl TryFromAddress for AddressMetadata {
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_address_metadata(
+pub unsafe extern "C" fn zcashlc_get_address_metadata(
     address: *const c_char,
     network_id_ret: *mut u32,
     addr_kind_ret: *mut u32,
@@ -1014,7 +1018,7 @@ pub extern "C" fn zcashlc_get_address_metadata(
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_is_valid_transparent_address(
+pub unsafe extern "C" fn zcashlc_is_valid_transparent_address(
     address: *const c_char,
     network_id: u32,
 ) -> bool {
@@ -1044,7 +1048,7 @@ fn is_valid_transparent_address(address: &str, network: &Network) -> bool {
 /// - `extsk` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `extsk` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_is_valid_sapling_extended_spending_key(
+pub unsafe extern "C" fn zcashlc_is_valid_sapling_extended_spending_key(
     extsk: *const c_char,
     network_id: u32,
 ) -> bool {
@@ -1068,7 +1072,7 @@ pub extern "C" fn zcashlc_is_valid_sapling_extended_spending_key(
 /// - `key` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `key` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_is_valid_viewing_key(key: *const c_char, network_id: u32) -> bool {
+pub unsafe extern "C" fn zcashlc_is_valid_viewing_key(key: *const c_char, network_id: u32) -> bool {
     let res =
         catch_panic(|| {
             let network = parse_network(network_id)?;
@@ -1092,7 +1096,7 @@ pub extern "C" fn zcashlc_is_valid_viewing_key(key: *const c_char, network_id: u
 /// - The memory referenced by `ufvk` must not be mutated for the duration of the
 ///   function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_is_valid_unified_full_viewing_key(
+pub unsafe extern "C" fn zcashlc_is_valid_unified_full_viewing_key(
     ufvk: *const c_char,
     network_id: u32,
 ) -> bool {
@@ -1114,7 +1118,7 @@ pub extern "C" fn zcashlc_is_valid_unified_full_viewing_key(
 /// - The memory referenced by `address` must not be mutated for the duration of the
 ///   function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_is_valid_unified_address(
+pub unsafe extern "C" fn zcashlc_is_valid_unified_address(
     address: *const c_char,
     network_id: u32,
 ) -> bool {
@@ -1147,7 +1151,7 @@ fn is_valid_unified_address(address: &str, network: &Network) -> bool {
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_balance(
+pub unsafe extern "C" fn zcashlc_get_balance(
     db_data: *const u8,
     db_data_len: usize,
     account: i32,
@@ -1190,7 +1194,7 @@ pub extern "C" fn zcashlc_get_balance(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_verified_balance(
+pub unsafe extern "C" fn zcashlc_get_verified_balance(
     db_data: *const u8,
     db_data_len: usize,
     account: i32,
@@ -1236,7 +1240,7 @@ pub extern "C" fn zcashlc_get_verified_balance(
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_verified_transparent_balance(
+pub unsafe extern "C" fn zcashlc_get_verified_transparent_balance(
     db_data: *const u8,
     db_data_len: usize,
     address: *const c_char,
@@ -1258,7 +1262,7 @@ pub extern "C" fn zcashlc_get_verified_transparent_balance(
             })
             .and_then(|anchor| {
                 (&db_data)
-                    .get_unspent_transparent_outputs(&taddr, anchor)
+                    .get_unspent_transparent_outputs(&taddr, anchor, &[])
                     .map_err(|e| {
                         format_err!("Error while fetching verified transparent balance: {}", e)
                     })
@@ -1287,7 +1291,7 @@ pub extern "C" fn zcashlc_get_verified_transparent_balance(
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_verified_transparent_balance_for_account(
+pub unsafe extern "C" fn zcashlc_get_verified_transparent_balance_for_account(
     db_data: *const u8,
     db_data_len: usize,
     network_id: u32,
@@ -1325,7 +1329,7 @@ pub extern "C" fn zcashlc_get_verified_transparent_balance_for_account(
                             .iter()
                             .map(|(taddr, _)| {
                                 db_data
-                                    .get_unspent_transparent_outputs(&taddr, anchor)
+                                    .get_unspent_transparent_outputs(&taddr, anchor, &[])
                                     .map_err(|e| {
                                         format_err!(
                                             "Error while fetching verified transparent balance: {}",
@@ -1360,7 +1364,7 @@ pub extern "C" fn zcashlc_get_verified_transparent_balance_for_account(
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_total_transparent_balance(
+pub unsafe extern "C" fn zcashlc_get_total_transparent_balance(
     db_data: *const u8,
     db_data_len: usize,
     address: *const c_char,
@@ -1381,7 +1385,7 @@ pub extern "C" fn zcashlc_get_total_transparent_balance(
             })
             .and_then(|anchor| {
                 (&db_data)
-                    .get_unspent_transparent_outputs(&taddr, anchor)
+                    .get_unspent_transparent_outputs(&taddr, anchor, &[])
                     .map_err(|e| {
                         format_err!("Error while fetching total transparent balance: {}", e)
                     })
@@ -1409,7 +1413,7 @@ pub extern "C" fn zcashlc_get_total_transparent_balance(
 /// - `address` must be non-null and must point to a null-terminated UTF-8 string.
 /// - The memory referenced by `address` must not be mutated for the duration of the function call.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_total_transparent_balance_for_account(
+pub unsafe extern "C" fn zcashlc_get_total_transparent_balance_for_account(
     db_data: *const u8,
     db_data_len: usize,
     network_id: u32,
@@ -1468,7 +1472,7 @@ pub extern "C" fn zcashlc_get_total_transparent_balance_for_account(
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_received_memo_as_utf8(
+pub unsafe extern "C" fn zcashlc_get_received_memo_as_utf8(
     db_data: *const u8,
     db_data_len: usize,
     id_note: i64,
@@ -1508,20 +1512,22 @@ pub extern "C" fn zcashlc_get_received_memo_as_utf8(
 ///   documentation of pointer::offset.
 /// - `memo_bytes_ret` must be non-null and must point to an allocated 512-byte region of memory.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_received_memo(
+pub unsafe extern "C" fn zcashlc_get_received_memo(
     db_data: *const u8,
     db_data_len: usize,
     id_note: i64,
     memo_bytes_ret: *mut u8,
     network_id: u32,
 ) -> bool {
-    zcashlc_get_memo(
-        db_data,
-        db_data_len,
-        NoteId::ReceivedNoteId(id_note),
-        memo_bytes_ret,
-        network_id,
-    )
+    unsafe {
+        zcashlc_get_memo(
+            db_data,
+            db_data_len,
+            NoteId::ReceivedNoteId(id_note),
+            memo_bytes_ret,
+            network_id,
+        )
+    }
 }
 
 /// Returns the memo for a note by copying the corresponding bytes to the received
@@ -1536,7 +1542,7 @@ pub extern "C" fn zcashlc_get_received_memo(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 /// - `memo_bytes_ret` must be non-null and must point to an allocated 512-byte region of memory.
-fn zcashlc_get_memo(
+unsafe fn zcashlc_get_memo(
     db_data: *const u8,
     db_data_len: usize,
     note_id: NoteId,
@@ -1574,7 +1580,7 @@ fn zcashlc_get_memo(
 /// - Call [`zcashlc_string_free`] to free the memory associated with the returned pointer
 ///   when done using it.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_sent_memo_as_utf8(
+pub unsafe extern "C" fn zcashlc_get_sent_memo_as_utf8(
     db_data: *const u8,
     db_data_len: usize,
     id_note: i64,
@@ -1614,20 +1620,22 @@ pub extern "C" fn zcashlc_get_sent_memo_as_utf8(
 ///   documentation of pointer::offset.
 /// - `memo_bytes_ret` must be non-null and must point to an allocated 512-byte region of memory.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_sent_memo(
+pub unsafe extern "C" fn zcashlc_get_sent_memo(
     db_data: *const u8,
     db_data_len: usize,
     id_note: i64,
     memo_bytes_ret: *mut u8,
     network_id: u32,
 ) -> bool {
-    zcashlc_get_memo(
-        db_data,
-        db_data_len,
-        NoteId::SentNoteId(id_note),
-        memo_bytes_ret,
-        network_id,
-    )
+    unsafe {
+        zcashlc_get_memo(
+            db_data,
+            db_data_len,
+            NoteId::SentNoteId(id_note),
+            memo_bytes_ret,
+            network_id,
+        )
+    }
 }
 
 /// Checks that the scanned blocks in the data database, when combined with the recent
@@ -1662,7 +1670,7 @@ pub extern "C" fn zcashlc_get_sent_memo(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_validate_combined_chain(
+pub unsafe extern "C" fn zcashlc_validate_combined_chain(
     db_cache: *const u8,
     db_cache_len: usize,
     db_data: *const u8,
@@ -1682,9 +1690,9 @@ pub extern "C" fn zcashlc_validate_combined_chain(
 
         if let Err(e) = val_res {
             match e {
-                SqliteClientError::BackendError(Error::InvalidChain(upper_bound, _)) => {
-                    let upper_bound_u32 = u32::from(upper_bound);
-                    Ok(upper_bound_u32 as i32)
+                chain::error::Error::Chain(chain_error) => {
+                    let height_u32 = u32::from(chain_error.at_height());
+                    Ok(height_u32 as i32)
                 }
                 _ => Err(format_err!("Error while validating chain: {}", e)),
             }
@@ -1708,7 +1716,7 @@ pub extern "C" fn zcashlc_validate_combined_chain(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_get_nearest_rewind_height(
+pub unsafe extern "C" fn zcashlc_get_nearest_rewind_height(
     db_data: *const u8,
     db_data_len: usize,
     height: i32,
@@ -1760,7 +1768,7 @@ pub extern "C" fn zcashlc_get_nearest_rewind_height(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_rewind_to_height(
+pub unsafe extern "C" fn zcashlc_rewind_to_height(
     db_data: *const u8,
     db_data_len: usize,
     height: i32,
@@ -1810,7 +1818,7 @@ pub extern "C" fn zcashlc_rewind_to_height(
 /// - The total size `db_data_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_scan_blocks(
+pub unsafe extern "C" fn zcashlc_scan_blocks(
     db_cache: *const u8,
     db_cache_len: usize,
     db_data: *const u8,
@@ -1857,7 +1865,7 @@ pub extern "C" fn zcashlc_scan_blocks(
 /// - The total size `script_bytes_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_put_utxo(
+pub unsafe extern "C" fn zcashlc_put_utxo(
     db_data: *const u8,
     db_data_len: usize,
     txid_bytes: *const u8,
@@ -1919,7 +1927,7 @@ pub extern "C" fn zcashlc_put_utxo(
 /// - The total size `tx_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_decrypt_and_store_transaction(
+pub unsafe extern "C" fn zcashlc_decrypt_and_store_transaction(
     db_data: *const u8,
     db_data_len: usize,
     tx: *const u8,
@@ -1986,7 +1994,7 @@ pub extern "C" fn zcashlc_decrypt_and_store_transaction(
 /// - The total size `output_params_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_create_to_address(
+pub unsafe extern "C" fn zcashlc_create_to_address(
     db_data: *const u8,
     db_data_len: usize,
     usk_ptr: *const u8,
@@ -2000,6 +2008,7 @@ pub extern "C" fn zcashlc_create_to_address(
     output_params_len: usize,
     network_id: u32,
     min_confirmations: u32,
+    use_zip317_fees: bool,
 ) -> i64 {
     let res = catch_panic(|| {
         let network = parse_network(network_id)?;
@@ -2046,18 +2055,51 @@ pub extern "C" fn zcashlc_create_to_address(
 
         let prover = LocalTxProver::new(spend_params, output_params);
 
-        create_spend_to_address(
-            &mut db_data,
-            &network,
-            prover,
-            &usk,
-            &to,
-            value,
-            memo,
-            OvkPolicy::Sender,
-            min_confirmations,
-        )
-        .map_err(|e| format_err!("Error while sending funds: {}", e))
+        let req = TransactionRequest::new(vec![Payment {
+            recipient_address: to,
+            amount: value,
+            memo: memo,
+            label: None,
+            message: None,
+            other_params: vec![],
+        }])
+        .map_err(|e| format_err!("Error creating transaction request: {:?}", e))?;
+
+        if use_zip317_fees {
+            let input_selector = GreedyInputSelector::new(
+                zip317::SingleOutputChangeStrategy::new(Zip317FeeRule::standard()),
+                DustOutputPolicy::default(),
+            );
+
+            spend(
+                &mut db_data,
+                &network,
+                prover,
+                &input_selector,
+                &usk,
+                req,
+                OvkPolicy::Sender,
+                min_confirmations,
+            )
+            .map_err(|e| format_err!("Error while sending funds: {}", e))
+        } else {
+            let input_selector = GreedyInputSelector::new(
+                fixed::SingleOutputChangeStrategy::new(FixedFeeRule::standard()),
+                DustOutputPolicy::default(),
+            );
+
+            spend(
+                &mut db_data,
+                &network,
+                prover,
+                &input_selector,
+                &usk,
+                req,
+                OvkPolicy::Sender,
+                min_confirmations,
+            )
+            .map_err(|e| format_err!("Error while sending funds: {}", e))
+        }
     });
     unwrap_exc_or(res, -1)
 }
@@ -2082,7 +2124,7 @@ pub extern "C" fn zcashlc_branch_id_for_height(height: i32, network_id: u32) ->
 #[allow(clippy::not_unsafe_ptr_arg_deref)]
 pub unsafe extern "C" fn zcashlc_string_free(s: *mut c_char) {
     if !s.is_null() {
-        let s = CString::from_raw(s);
+        let s = unsafe { CString::from_raw(s) };
         drop(s);
     }
 }
@@ -2115,7 +2157,7 @@ pub unsafe extern "C" fn zcashlc_string_free(s: *mut c_char) {
 /// - The total size `output_params_len` must be no larger than `isize::MAX`. See the safety
 ///   documentation of pointer::offset.
 #[no_mangle]
-pub extern "C" fn zcashlc_shield_funds(
+pub unsafe extern "C" fn zcashlc_shield_funds(
     db_data: *const u8,
     db_data_len: usize,
     usk_ptr: *const u8,
@@ -2126,6 +2168,7 @@ pub extern "C" fn zcashlc_shield_funds(
     output_params: *const u8,
     output_params_len: usize,
     network_id: u32,
+    use_zip317_fees: bool,
 ) -> i64 {
     let res = catch_panic(|| {
         let network = parse_network(network_id)?;
@@ -2177,16 +2220,41 @@ pub extern "C" fn zcashlc_shield_funds(
             .cloned()
             .collect();
 
-        shield_transparent_funds(
-            &mut update_ops,
-            &network,
-            LocalTxProver::new(spend_params, output_params),
-            &usk,
-            &taddrs,
-            &memo_bytes,
-            ANCHOR_OFFSET,
-        )
-        .map_err(|e| format_err!("Error while shielding transaction: {}", e))
+        if use_zip317_fees {
+            let input_selector = GreedyInputSelector::new(
+                zip317::SingleOutputChangeStrategy::new(Zip317FeeRule::standard()),
+                DustOutputPolicy::default(),
+            );
+
+            shield_transparent_funds(
+                &mut update_ops,
+                &network,
+                LocalTxProver::new(spend_params, output_params),
+                &input_selector,
+                &usk,
+                &taddrs,
+                &memo_bytes,
+                ANCHOR_OFFSET,
+            )
+            .map_err(|e| format_err!("Error while shielding transaction: {}", e))
+        } else {
+            let input_selector = GreedyInputSelector::new(
+                fixed::SingleOutputChangeStrategy::new(FixedFeeRule::standard()),
+                DustOutputPolicy::default(),
+            );
+
+            shield_transparent_funds(
+                &mut update_ops,
+                &network,
+                LocalTxProver::new(spend_params, output_params),
+                &input_selector,
+                &usk,
+                &taddrs,
+                &memo_bytes,
+                ANCHOR_OFFSET,
+            )
+            .map_err(|e| format_err!("Error while shielding transaction: {}", e))
+        }
     });
     unwrap_exc_or(res, -1)
 }