diff --git a/Cargo.toml b/Cargo.toml
index d1fd338..e4e67a4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,19 +37,31 @@ rayon = "1.5.1"
 byteorder = "1.4.3"
 tiny-bip39 = "0.8"
 rand = "0.8.4"
-rusqlite = "^0.25.3"
+rusqlite = { version = "^0.24", features = ["bundled"] }
+
+#[dependencies.zcash_client_backend]
+#git = "https://github.com/zcash/librustzcash.git"
+#rev = "d50bb12a97da768dc8f3ee39b81f84262103e6eb"
+#
+#[dependencies.zcash_primitives]
+#git = "https://github.com/zcash/librustzcash.git"
+#rev = "d50bb12a97da768dc8f3ee39b81f84262103e6eb"
+#
+#[dependencies.zcash_proofs]
+#git = "https://github.com/zcash/librustzcash.git"
+#rev = "d50bb12a97da768dc8f3ee39b81f84262103e6eb"
 
 [dependencies.zcash_client_backend]
-git = "https://github.com/zcash/librustzcash.git"
-rev = "d50bb12a97da768dc8f3ee39b81f84262103e6eb"
+path = "/home/hanh/projects/librustzcash/zcash_client_backend"
 
 [dependencies.zcash_primitives]
-git = "https://github.com/zcash/librustzcash.git"
-rev = "d50bb12a97da768dc8f3ee39b81f84262103e6eb"
+path = "/home/hanh/projects/librustzcash/zcash_primitives"
 
 [dependencies.zcash_proofs]
-git = "https://github.com/zcash/librustzcash.git"
-rev = "d50bb12a97da768dc8f3ee39b81f84262103e6eb"
+path = "/home/hanh/projects/librustzcash/zcash_proofs"
+
+[dependencies.zcash_params]
+path = "../zcash_params"
 
 [build-dependencies]
 tonic-build = "0.4.2"
diff --git a/src/builder.rs b/src/builder.rs
index f5f9ec9..382f5bc 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -17,13 +17,13 @@ struct CTreeBuilder {
     prev_tree: CTree,
     next_tree: CTree,
     start: usize,
+    total_len: usize,
     depth: usize,
     offset: Option<Node>,
 }
 
 impl Builder<CTree, ()> for CTreeBuilder {
     fn collect(&mut self, commitments: &[Node], _context: &()) -> usize {
-        // assert!(!commitments.is_empty() || self.left.is_some() || self.right.is_some());
         assert!(self.right.is_none() || self.left.is_some()); // R can't be set without L
 
         let offset: Option<Node>;
@@ -37,26 +37,30 @@ impl Builder<CTree, ()> for CTreeBuilder {
             m = commitments.len();
         };
 
-        let n = if self.depth == 0 {
-            if m % 2 == 0 {
-                self.next_tree.left = Some(*Self::get(commitments, m - 2, &offset));
-                self.next_tree.right = Some(*Self::get(commitments, m - 1, &offset));
-                m - 2
-            } else {
-                self.next_tree.left = Some(*Self::get(commitments, m - 1, &offset));
-                self.next_tree.right = None;
-                m - 1
+        let n =
+            if self.total_len > 0 {
+                if self.depth == 0 {
+                    if m % 2 == 0 {
+                        self.next_tree.left = Some(*Self::get(commitments, m - 2, &offset));
+                        self.next_tree.right = Some(*Self::get(commitments, m - 1, &offset));
+                        m - 2
+                    } else {
+                        self.next_tree.left = Some(*Self::get(commitments, m - 1, &offset));
+                        self.next_tree.right = None;
+                        m - 1
+                    }
+                } else {
+                    if m % 2 == 0 {
+                        self.next_tree.parents.push(None);
+                        m
+                    } else {
+                        let last_node = Self::get(commitments, m - 1, &offset);
+                        self.next_tree.parents.push(Some(*last_node));
+                        m - 1
+                    }
+                }
             }
-        } else {
-            if m % 2 == 0 {
-                self.next_tree.parents.push(None);
-                m
-            } else {
-                let last_node = Self::get(commitments, m - 1, &offset);
-                self.next_tree.parents.push(Some(*last_node));
-                m - 1
-            }
-        };
+        else { 0 };
         assert_eq!(n % 2, 0);
 
         self.offset = offset;
@@ -93,12 +97,16 @@ impl Builder<CTree, ()> for CTreeBuilder {
     }
 
     fn finalize(self, _context: &()) -> CTree {
-        self.next_tree
+        if self.total_len > 0 {
+            self.next_tree
+        } else {
+            self.prev_tree
+        }
     }
 }
 
 impl CTreeBuilder {
-    fn new(prev_tree: CTree) -> CTreeBuilder {
+    fn new(prev_tree: CTree, len: usize) -> CTreeBuilder {
         let start = prev_tree.get_position();
         CTreeBuilder {
             left: prev_tree.left,
@@ -106,6 +114,7 @@ impl CTreeBuilder {
             prev_tree,
             next_tree: CTree::new(),
             start,
+            total_len: len,
             depth: 0,
             offset: None,
         }
@@ -133,25 +142,13 @@ impl CTreeBuilder {
         Self::get_opt(commitments, index, offset).unwrap()
     }
 
-    fn adjusted_start(&self, prev: &Option<Node>, depth: usize) -> usize {
-        if depth != 0 && prev.is_some() {
+    fn adjusted_start(&self, prev: &Option<Node>, _depth: usize) -> usize {
+        if prev.is_some() {
             self.start - 1
         } else {
             self.start
         }
     }
-
-    fn clone_trimmed(&self, mut depth: usize) -> CTree {
-        if depth == 0 {
-            return CTree::new()
-        }
-        let mut tree = self.next_tree.clone();
-        while depth > 0 && depth <= tree.parents.len() && tree.parents[depth - 1].is_none() {
-            depth -= 1;
-        }
-        tree.parents.truncate(depth);
-        tree
-    }
 }
 
 fn combine_level(commitments: &mut [Node], offset: Option<Node>, n: usize, depth: usize) -> usize {
@@ -218,6 +215,12 @@ impl Builder<Witness, CTreeBuilder> for WitnessBuilder {
             }
         }
 
+        // println!("D {}", depth);
+        // println!("O {:?}", offset.map(|r| hex::encode(r.repr)));
+        // println!("R {:?}", right.map(|r| hex::encode(r.repr)));
+        // for c in commitments.iter() {
+        //     println!("{}", hex::encode(c.repr));
+        // }
         let p1 = self.p + 1;
         let has_p1 = p1 >= context.adjusted_start(&right, depth) && p1 < context.start + commitments.len();
         if has_p1 {
@@ -244,32 +247,41 @@ impl Builder<Witness, CTreeBuilder> for WitnessBuilder {
     }
 
     fn finalize(mut self, context: &CTreeBuilder) -> Witness {
-        let tree = &self.witness.tree;
-        let mut num_filled = self.witness.filled.len();
-
-        if self.witness.position + 1 == context.next_tree.get_position() {
+        if context.total_len == 0 {
             self.witness.cursor = CTree::new();
-        }
-        else {
-            let mut depth = 0;
-            loop {
-                let is_none = if depth == 0 { // check if this level is occupied
-                    tree.right.is_none()
-                } else {
-                    depth > tree.parents.len() || tree.parents[depth - 1].is_none()
-                };
-                if is_none {
-                    if num_filled > 0 {
-                        num_filled -= 1; // we filled it
-                    } else {
-                        break
-                    }
-                }
-                depth += 1;
-                // loop terminates because we are eventually going to run out of ancestors and filled
-            }
 
-            self.witness.cursor = context.clone_trimmed(depth - 1);
+            let mut final_position = context.prev_tree.get_position() as u32;
+            let mut witness_position = self.witness.tree.get_position() as u32;
+            assert_ne!(witness_position, 0);
+            witness_position = witness_position - 1;
+
+            // look for first not equal bit in MSB order
+            final_position = final_position.reverse_bits();
+            witness_position = witness_position.reverse_bits();
+            let mut bit: i32 = 31;
+            // reverse bits because it is easier to do in LSB
+            // it should not underflow because these numbers are not equal
+            while bit >= 0 {
+                if final_position & 1 != witness_position & 1 {
+                    break;
+                }
+                final_position >>= 1;
+                witness_position >>= 1;
+                bit -= 1;
+            }
+            // look for the first bit set in final_position after
+            final_position >>= 1;
+            bit -= 1;
+            while bit >= 0 {
+                if final_position & 1 == 1 {
+                    break;
+                }
+                final_position >>= 1;
+                bit -= 1;
+            }
+            if bit >= 0 {
+                self.witness.cursor = context.prev_tree.clone_trimmed(bit as usize)
+            }
         }
         self.witness
     }
@@ -281,10 +293,7 @@ pub fn advance_tree(
     prev_witnesses: &[Witness],
     mut commitments: &mut [Node],
 ) -> (CTree, Vec<Witness>) {
-    if commitments.is_empty() {
-        return (prev_tree, prev_witnesses.to_vec());
-    }
-    let mut builder = CTreeBuilder::new(prev_tree);
+    let mut builder = CTreeBuilder::new(prev_tree, commitments.len());
     let mut witness_builders: Vec<_> = prev_witnesses
         .iter()
         .map(|witness| WitnessBuilder::new(&builder, witness.clone(), commitments.len()))
@@ -295,11 +304,11 @@ pub fn advance_tree(
             b.collect(commitments, &builder);
         }
         let nn = combine_level(commitments, builder.offset, n, builder.depth);
-        commitments = &mut commitments[0..nn];
         builder.up();
         for b in witness_builders.iter_mut() {
             b.up();
         }
+        commitments = &mut commitments[0..nn];
     }
 
     let witnesses = witness_builders
@@ -318,24 +327,35 @@ mod tests {
     use zcash_primitives::merkle_tree::{CommitmentTree, IncrementalWitness};
     use zcash_primitives::sapling::Node;
     use crate::chain::DecryptedNote;
+    use crate::print::{print_witness, print_witness2, print_tree, print_ctree};
 
     #[test]
     fn test_advance_tree() {
-        const NUM_NODES: usize = 1000;
-        const NUM_CHUNKS: usize = 50;
-        const WITNESS_PERCENT: f64 = 1.0; // percentage of notes that are ours
-        let witness_freq = (100.0 / WITNESS_PERCENT) as usize;
+        for num_nodes in 1..=10 {
+            for num_chunks in 1..=10 {
+                test_advance_tree_helper(num_nodes, num_chunks, 100.0);
+            }
+        }
+
+        test_advance_tree_helper(100, 50, 1.0);
+        // test_advance_tree_helper(2, 10, 100.0);
+        // test_advance_tree_helper(1, 40, 100.0);
+        // test_advance_tree_helper(10, 2, 100.0);
+    }
+
+    fn test_advance_tree_helper(num_nodes: usize, num_chunks: usize, witness_percent: f64) {
+        let witness_freq = (100.0 / witness_percent) as usize;
 
         let mut tree1: CommitmentTree<Node> = CommitmentTree::empty();
         let mut tree2 = CTree::new();
         let mut ws: Vec<IncrementalWitness<Node>> = vec![];
         let mut ws2: Vec<Witness> = vec![];
-        for i in 0..NUM_CHUNKS {
+        for i in 0..num_chunks {
             println!("{}", i);
             let mut nodes: Vec<_> = vec![];
-            for j in 0..NUM_NODES {
+            for j in 0..num_nodes {
                 let mut bb = [0u8; 32];
-                let v = i * NUM_NODES + j;
+                let v = i * num_nodes + j;
                 bb[0..8].copy_from_slice(&v.to_be_bytes());
                 let node = Node::new(bb);
                 tree1.append(node).unwrap();
@@ -343,7 +363,7 @@ mod tests {
                     w.append(node).unwrap();
                 }
                 if v % witness_freq == 0 {
-                // if v == 499 {
+                // if v == 0 {
                     let w = IncrementalWitness::from_tree(&tree1);
                     ws.push(w);
                     ws2.push(Witness::new(v, 0, None));
@@ -356,6 +376,13 @@ mod tests {
             ws2 = new_witnesses;
         }
 
+        // Push an empty block
+        // It will calculate the tail of the tree
+        // This step is required at the end of a series of chunks
+        let (new_tree, new_witnesses) = advance_tree(tree2, &ws2, &mut []);
+        tree2 = new_tree;
+        ws2 = new_witnesses;
+
         // check final state
         let mut bb1: Vec<u8> = vec![];
         tree1.write(&mut bb1).unwrap();
@@ -364,6 +391,11 @@ mod tests {
         tree2.write(&mut bb2).unwrap();
 
         let equal = bb1.as_slice() == bb2.as_slice();
+        if !equal {
+            println!("FAILED FINAL STATE");
+            print_tree(&tree1);
+            print_ctree(&tree2);
+        }
 
         println!("# witnesses = {}", ws.len());
 
@@ -378,6 +410,16 @@ mod tests {
 
             if bb1.as_slice() != bb2.as_slice() {
                 failed_index = Some(i);
+                println!("FAILED AT {}", i);
+                if let Some(ref c) = w1.cursor {
+                    print_tree(c);
+                }
+                else { println!("NONE"); }
+
+                println!("GOOD");
+                print_witness(&w1);
+                println!("BAD");
+                print_witness2(&w2);
             }
         }
 
diff --git a/src/chain.rs b/src/chain.rs
index 5356929..ce6f206 100644
--- a/src/chain.rs
+++ b/src/chain.rs
@@ -40,7 +40,7 @@ pub async fn download_chain(
 ) -> anyhow::Result<Vec<CompactBlock>> {
     let mut cbs: Vec<CompactBlock> = Vec::new();
     let mut s = start_height + 1;
-    while s < end_height {
+    while s <= end_height {
         let e = (s + MAX_CHUNK - 1).min(end_height);
         let range = BlockRange {
             start: Some(BlockId {
@@ -68,10 +68,14 @@ pub struct DecryptNode {
     fvks: Vec<ExtendedFullViewingKey>,
 }
 
+#[derive(Eq, Hash, PartialEq)]
+pub struct Nf(pub [u8; 32]);
+
 pub struct DecryptedBlock {
     pub height: u32,
     pub notes: Vec<DecryptedNote>,
     pub count_outputs: u32,
+    pub spends: Vec<Nf>,
 }
 
 #[derive(Clone)]
@@ -79,7 +83,7 @@ pub struct DecryptedNote {
     pub ivk: ExtendedFullViewingKey,
     pub note: Note,
     pub pa: PaymentAddress,
-    pub position: usize,
+    pub position_in_block: usize,
 
     pub height: u32,
     pub txid: Vec<u8>,
@@ -90,8 +94,15 @@ pub struct DecryptedNote {
 fn decrypt_notes(block: &CompactBlock, fvks: &[ExtendedFullViewingKey]) -> DecryptedBlock {
     let height = BlockHeight::from_u32(block.height as u32);
     let mut count_outputs = 0u32;
+    let mut spends: Vec<Nf> = vec![];
     let mut notes: Vec<DecryptedNote> = vec![];
     for (tx_index, vtx) in block.vtx.iter().enumerate() {
+        for cs in vtx.spends.iter() {
+            let mut nf = [0u8; 32];
+            nf.copy_from_slice(&cs.nf);
+            spends.push(Nf(nf));
+        }
+
         for (output_index, co) in vtx.outputs.iter().enumerate() {
             let mut cmu = [0u8; 32];
             cmu.copy_from_slice(&co.cmu);
@@ -113,7 +124,7 @@ fn decrypt_notes(block: &CompactBlock, fvks: &[ExtendedFullViewingKey]) -> Decry
                         ivk: fvk.clone(),
                         note,
                         pa,
-                        position: count_outputs as usize,
+                        position_in_block: count_outputs as usize,
                         height: block.height as u32,
                         tx_index,
                         txid: vtx.hash.clone(),
@@ -126,6 +137,7 @@ fn decrypt_notes(block: &CompactBlock, fvks: &[ExtendedFullViewingKey]) -> Decry
     }
     DecryptedBlock {
         height: block.height as u32,
+        spends,
         notes,
         count_outputs,
     }
@@ -160,6 +172,15 @@ async fn get_tree_state(client: &mut CompactTxStreamerClient<Channel>, height: u
     rep.tree
 }
 
+pub async fn send_transaction(client: &mut CompactTxStreamerClient<Channel>, raw_tx: &[u8], height: u32) -> anyhow::Result<String> {
+    let raw_tx = RawTransaction {
+        data: raw_tx.to_vec(),
+        height: height as u64
+    };
+    let rep = client.send_transaction(Request::new(raw_tx)).await?.into_inner();
+    Ok(rep.error_message)
+}
+
 /* Using the IncrementalWitness */
 #[allow(dead_code)]
 fn calculate_tree_state_v1(
@@ -187,7 +208,7 @@ fn calculate_tree_state_v1(
                     w.append(node).unwrap();
                 }
                 if let Some(nn) = n {
-                    if i == nn.position {
+                    if i == nn.position_in_block {
                         let w = IncrementalWitness::from_tree(&tree_state);
                         witnesses.push(w);
                         n = notes.next();
@@ -226,7 +247,7 @@ pub fn calculate_tree_state_v2(cbs: &[CompactBlock], blocks: &[DecryptedBlock])
                 nodes.push(node);
 
                 if let Some(nn) = n {
-                    if i == nn.position {
+                    if i == nn.position_in_block {
                         positions.push(p);
                         n = notes.next();
                     }
diff --git a/src/commitment.rs b/src/commitment.rs
index 267bd6a..73916ec 100644
--- a/src/commitment.rs
+++ b/src/commitment.rs
@@ -174,6 +174,15 @@ impl CTree {
         p
     }
 
+    pub fn clone_trimmed(&self, depth: usize) -> CTree {
+        let mut tree = self.clone();
+        tree.parents.truncate(depth);
+        if let Some(None) = tree.parents.last() { // Remove trailing None
+            tree.parents.truncate(depth - 1);
+        }
+        tree
+    }
+
     pub fn to_commitment_tree(&self) -> CommitmentTree<Node> {
         let mut bb: Vec<u8> = vec![];
         self.write(&mut bb).unwrap();
diff --git a/src/db.rs b/src/db.rs
index 0bb7291..09c0848 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -1,5 +1,11 @@
-use rusqlite::{Connection, params, OptionalExtension};
+use rusqlite::{Connection, params, OptionalExtension, NO_PARAMS};
 use crate::{Witness, CTree};
+use zcash_primitives::sapling::{Note, Diversifier, Rseed, Node};
+use zcash_primitives::zip32::ExtendedFullViewingKey;
+use zcash_primitives::merkle_tree::IncrementalWitness;
+use std::collections::HashMap;
+use crate::chain::Nf;
+use zcash_primitives::consensus::{Parameters, NetworkUpgrade};
 
 pub struct DbAdapter {
     connection: Connection,
@@ -12,9 +18,13 @@ pub struct ReceivedNote {
     pub value: u64,
     pub rcm: Vec<u8>,
     pub nf: Vec<u8>,
-    pub is_change: bool,
-    pub memo: Vec<u8>,
-    pub spent: bool,
+    pub spent: Option<u32>,
+}
+
+pub struct SpendableNote {
+    pub note: Note,
+    pub diversifier: Diversifier,
+    pub witness: IncrementalWitness<Node>,
 }
 
 impl DbAdapter {
@@ -26,16 +36,22 @@ impl DbAdapter {
     }
 
     pub fn init_db(&self) -> anyhow::Result<()> {
+        self.connection.execute("CREATE TABLE IF NOT EXISTS accounts (
+            id_account INTEGER PRIMARY KEY,
+            sk TEXT NOT NULL UNIQUE,
+            ivk TEXT NOT NULL,
+            address TEXT NOT NULL)", NO_PARAMS)?;
+
         self.connection.execute("CREATE TABLE IF NOT EXISTS blocks (
             height INTEGER PRIMARY KEY,
             hash BLOB NOT NULL,
-            sapling_tree BLOB NOT NULL)", [])?;
+            sapling_tree BLOB NOT NULL)", NO_PARAMS)?;
 
         self.connection.execute("CREATE TABLE IF NOT EXISTS transactions (
             id_tx INTEGER PRIMARY KEY,
             txid BLOB NOT NULL UNIQUE,
             height INTEGER,
-            tx_index INTEGER)", [])?;
+            tx_index INTEGER)", NO_PARAMS)?;
 
         self.connection.execute("CREATE TABLE IF NOT EXISTS received_notes (
             id_note INTEGER PRIMARY KEY,
@@ -47,24 +63,25 @@ impl DbAdapter {
             value INTEGER NOT NULL,
             rcm BLOB NOT NULL,
             nf BLOB NOT NULL UNIQUE,
-            is_change INTEGER NOT NULL,
-            memo BLOB,
             spent INTEGER,
-            FOREIGN KEY (tx) REFERENCES transactions(id_tx),
-            FOREIGN KEY (spent) REFERENCES transactions(id_tx),
-            CONSTRAINT tx_output UNIQUE (tx, output_index))", [])?;
+            CONSTRAINT tx_output UNIQUE (tx, output_index))", NO_PARAMS)?;
 
         self.connection.execute("CREATE TABLE IF NOT EXISTS sapling_witnesses (
             id_witness INTEGER PRIMARY KEY,
             note INTEGER NOT NULL,
             height INTEGER NOT NULL,
             witness BLOB NOT NULL,
-            FOREIGN KEY (note) REFERENCES received_notes(id_note),
-            CONSTRAINT witness_height UNIQUE (note, height))", [])?;
+            CONSTRAINT witness_height UNIQUE (note, height))", NO_PARAMS)?;
 
         Ok(())
     }
 
+    pub fn store_account(&self, sk: &str, ivk: &str, address: &str) -> anyhow::Result<()> {
+        self.connection.execute("INSERT INTO accounts(sk, ivk, address) VALUES (?1, ?2, ?3)
+            ON CONFLICT DO NOTHING", params![sk, ivk, address])?;
+        Ok(())
+    }
+
     pub fn trim_to_height(&mut self, height: u32) -> anyhow::Result<()> {
         let tx = self.connection.transaction()?;
         tx.execute("DELETE FROM blocks WHERE height >= ?1", params![height])?;
@@ -77,53 +94,70 @@ impl DbAdapter {
     }
 
     pub fn store_block(&self, height: u32, hash: &[u8], tree: &CTree) -> anyhow::Result<()> {
+        log::info!("+block");
         let mut bb: Vec<u8> = vec![];
         tree.write(&mut bb)?;
         self.connection.execute("INSERT INTO blocks(height, hash, sapling_tree)
         VALUES (?1, ?2, ?3)
         ON CONFLICT DO NOTHING", params![height, hash, &bb])?;
+        log::info!("-block");
         Ok(())
     }
 
     pub fn store_transaction(&self, txid: &[u8], height: u32, tx_index: u32) -> anyhow::Result<u32> {
+        log::info!("+transaction");
         self.connection.execute("INSERT INTO transactions(txid, height, tx_index)
         VALUES (?1, ?2, ?3)
         ON CONFLICT DO NOTHING", params![txid, height, tx_index])?;
         let id_tx: u32 = self.connection.query_row("SELECT id_tx FROM transactions WHERE txid = ?1", params![txid], |row| row.get(0))?;
+        log::info!("-transaction {}", id_tx);
         Ok(id_tx)
     }
 
     pub fn store_received_note(&self, note: &ReceivedNote, id_tx: u32, position: usize) -> anyhow::Result<u32> {
-        self.connection.execute("INSERT INTO received_notes(tx, height, position, output_index, diversifier, value, rcm, nf, is_change, memo, spent)
-        VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11)
-        ON CONFLICT DO NOTHING", params![id_tx, note.height, position, note.output_index, note.diversifier, note.value, note.rcm, note.nf, note.is_change, note.memo, note.spent])?;
+        log::info!("+received_note {}", id_tx);
+        self.connection.execute("INSERT INTO received_notes(tx, height, position, output_index, diversifier, value, rcm, nf, spent)
+        VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9)
+        ON CONFLICT DO NOTHING", params![id_tx, note.height, position as u32, note.output_index, note.diversifier, note.value as i64, note.rcm, note.nf, note.spent])?;
         let id_note: u32 = self.connection.query_row("SELECT id_note FROM received_notes WHERE tx = ?1 AND output_index = ?2", params![id_tx, note.output_index], |row| row.get(0))?;
+        log::info!("-received_note");
         Ok(id_note)
     }
 
     pub fn store_witnesses(&self, witness: &Witness, height: u32, id_note: u32) -> anyhow::Result<()> {
+        log::info!("+witnesses");
         let mut bb: Vec<u8> = vec![];
         witness.write(&mut bb)?;
-        println!("{} {}", height, id_note);
         self.connection.execute("INSERT INTO sapling_witnesses(note, height, witness) VALUES (?1, ?2, ?3)
         ON CONFLICT DO NOTHING", params![id_note, height, bb])?;
+        log::info!("-witnesses");
         Ok(())
     }
 
     pub fn get_balance(&self) -> anyhow::Result<u64> {
-        let balance: u64 = self.connection.query_row("SELECT SUM(value) FROM received_notes WHERE spent = 0", [], |row| row.get(0))?;
-        Ok(balance)
+        let balance: Option<i64> = self.connection.query_row("SELECT SUM(value) FROM received_notes WHERE spent IS NULL", NO_PARAMS, |row| row.get(0))?;
+        Ok(balance.unwrap_or(0) as u64)
     }
 
-    pub fn get_last_height(&self) -> anyhow::Result<Option<u32>> {
-        let height: Option<u32> = self.connection.query_row("SELECT MAX(height) FROM blocks", [], |row| row.get(0)).optional()?;
+    pub fn get_last_sync_height(&self) -> anyhow::Result<Option<u32>> {
+        let height: Option<u32> = self.connection.query_row("SELECT MAX(height) FROM blocks", NO_PARAMS, |row| row.get(0))?;
+        Ok(height)
+    }
+
+    pub fn get_db_height(&self) -> anyhow::Result<u32> {
+        let height: u32 = self.get_last_sync_height()?.unwrap_or_else(|| {
+            crate::NETWORK
+                .activation_height(NetworkUpgrade::Sapling)
+                .unwrap()
+                .into()
+        });
         Ok(height)
     }
 
     pub fn get_tree(&self) -> anyhow::Result<(CTree, Vec<Witness>)> {
         let res = self.connection.query_row(
             "SELECT height, sapling_tree FROM blocks WHERE height = (SELECT MAX(height) FROM blocks)",
-            [], |row| {
+            NO_PARAMS, |row| {
                 let height: u32 = row.get(0)?;
                 let tree: Vec<u8> = row.get(1)?;
                 Ok((height, tree))
@@ -148,6 +182,89 @@ impl DbAdapter {
             None => (CTree::new(), vec![])
         })
     }
+
+    pub fn get_nullifiers(&self) -> anyhow::Result<HashMap<Nf, u32>> {
+        let mut statement = self.connection.prepare(
+            "SELECT id_note, nf FROM received_notes WHERE spent = 0")?;
+        let nfs_res = statement.query_map(NO_PARAMS, |row| {
+            let id_note: u32 = row.get(0)?;
+            let nf_vec: Vec<u8> = row.get(1)?;
+            let mut nf = [0u8; 32];
+            nf.clone_from_slice(&nf_vec);
+            Ok((id_note, nf))
+        })?;
+        let mut nfs: HashMap<Nf, u32> = HashMap::new();
+        for n in nfs_res {
+            let n = n?;
+            nfs.insert(Nf(n.1), n.0);
+        }
+
+        Ok(nfs)
+    }
+
+    pub fn get_spendable_notes(&self, anchor_height: u32, fvk: &ExtendedFullViewingKey) -> anyhow::Result<Vec<SpendableNote>> {
+        let mut statement = self.connection.prepare(
+            "SELECT diversifier, value, rcm, witness FROM received_notes r, sapling_witnesses w WHERE spent IS NULL
+            AND w.height = (
+	            SELECT MAX(height) FROM sapling_witnesses WHERE height <= ?1
+            ) AND r.id_note = w.note")?;
+        let notes = statement.query_map(params![anchor_height], |row| {
+            let diversifier: Vec<u8> = row.get(0)?;
+            let value: i64 = row.get(1)?;
+            let rcm: Vec<u8> = row.get(2)?;
+            let witness: Vec<u8> = row.get(3)?;
+
+            let mut diversifer_bytes = [0u8; 11];
+            diversifer_bytes.copy_from_slice(&diversifier);
+            let diversifier = Diversifier(diversifer_bytes);
+            let mut rcm_bytes = [0u8; 32];
+            rcm_bytes.copy_from_slice(&rcm);
+            let rcm = jubjub::Fr::from_bytes(&rcm_bytes).unwrap();
+            let rseed = Rseed::BeforeZip212(rcm);
+            let witness = IncrementalWitness::<Node>::read(&*witness).unwrap();
+
+            let pa = fvk.fvk.vk.to_payment_address(diversifier).unwrap();
+            let note = pa.create_note(value as u64, rseed).unwrap();
+            Ok(SpendableNote {
+                note,
+                diversifier,
+                witness
+            })
+        })?;
+        let mut spendable_notes: Vec<SpendableNote> = vec![];
+        for n in notes {
+            spendable_notes.push(n?);
+        }
+
+        Ok(spendable_notes)
+    }
+
+    pub fn mark_spent(&self, id: u32, height: u32) -> anyhow::Result<()> {
+        log::info!("+mark_spent");
+        self.connection.execute("UPDATE received_notes SET spent = ?1 WHERE id_note = ?2", params![height, id])?;
+        log::info!("-mark_spent");
+        Ok(())
+    }
+
+    pub fn get_sk(&self, account: u32) -> anyhow::Result<String> {
+        log::info!("+get_sk");
+        let ivk = self.connection.query_row("SELECT sk FROM accounts WHERE id_account = ?1", params![account], |row | {
+            let ivk: String = row.get(0)?;
+            Ok(ivk)
+        })?;
+        log::info!("-get_sk");
+        Ok(ivk)
+    }
+
+    pub fn get_ivk(&self, account: u32) -> anyhow::Result<String> {
+        log::info!("+get_ivk");
+        let ivk = self.connection.query_row("SELECT ivk FROM accounts WHERE id_account = ?1", params![account], |row | {
+            let ivk: String = row.get(0)?;
+            Ok(ivk)
+        })?;
+        log::info!("-get_ivk");
+        Ok(ivk)
+    }
 }
 
 #[cfg(test)]
@@ -172,9 +289,7 @@ mod tests {
             value: 0,
             rcm: vec![],
             nf: vec![],
-            is_change: false,
-            memo: vec![],
-            spent: false
+            spent: None
         }, id_tx, 5).unwrap();
         let witness = Witness {
             position: 10,
diff --git a/src/lib.rs b/src/lib.rs
index c4872ca..3aff65c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,7 +3,7 @@ use zcash_primitives::consensus::Network;
 #[path = "generated/cash.z.wallet.sdk.rpc.rs"]
 pub mod lw_rpc;
 
-pub const NETWORK: Network = Network::MainNetwork;
+pub const NETWORK: Network = Network::TestNetwork;
 
 mod builder;
 mod chain;
@@ -12,6 +12,7 @@ mod scan;
 mod key;
 mod db;
 mod wallet;
+mod print;
 
 pub use crate::builder::advance_tree;
 pub use crate::chain::{
@@ -24,3 +25,4 @@ pub use crate::lw_rpc::*;
 pub use crate::scan::{scan_all, sync_async, latest_height};
 pub use crate::key::{get_secret_key, get_address, get_viewing_key};
 pub use crate::db::DbAdapter;
+pub use crate::wallet::{Wallet, DEFAULT_ACCOUNT};
diff --git a/src/main/warp_cli.rs b/src/main/warp_cli.rs
index 1b3b1ac..f0530d5 100644
--- a/src/main/warp_cli.rs
+++ b/src/main/warp_cli.rs
@@ -1,40 +1,59 @@
-use sync::{sync_async, DbAdapter};
+use sync::{DbAdapter, Wallet, DEFAULT_ACCOUNT};
 use bip39::{Language, Mnemonic};
 use rand::rngs::OsRng;
 use rand::RngCore;
 
 const DB_NAME: &str = "zec.db";
 
+fn init() {
+    let db = DbAdapter::new(DB_NAME).unwrap();
+    db.init_db().unwrap();
+}
+
 #[tokio::main]
 #[allow(dead_code)]
 async fn test() -> anyhow::Result<()> {
     dotenv::dotenv().unwrap();
     env_logger::init();
 
-    let ivk = dotenv::var("IVK").unwrap();
-    {
-        let db = DbAdapter::new(DB_NAME)?;
-        db.init_db()?;
-    }
-    sync_async(&ivk, 50000, DB_NAME, |height| {
+    let seed = dotenv::var("SEED").unwrap();
+    let address = dotenv::var("ADDRESS").unwrap();
+    let progress = |height| {
         log::info!("Height = {}", height);
-    }).await?;
+    };
+    let wallet = Wallet::new(DB_NAME);
+    wallet.new_account_with_seed(&seed).unwrap();
+    wallet.sync(DEFAULT_ACCOUNT, progress).await.unwrap();
+    let tx_id = wallet.send_payment(DEFAULT_ACCOUNT, &address, 1000).await.unwrap();
+    println!("TXID = {}", tx_id);
 
     Ok(())
 }
 
+#[allow(dead_code)]
+fn test_make_wallet() {
+    let mut entropy = [0u8; 32];
+    OsRng.fill_bytes(&mut entropy);
+    let mnemonic = Mnemonic::from_entropy(&entropy, Language::English).unwrap();
+    let phrase = mnemonic.phrase();
+    println!("Seed Phrase: {}", phrase);
+}
+
 #[allow(dead_code)]
 fn test_rewind() {
     let mut db = DbAdapter::new(DB_NAME).unwrap();
-    db.trim_to_height(1_250_000).unwrap();
+    db.trim_to_height(1460000).unwrap();
+}
+
+fn test_get_balance() {
+    let db = DbAdapter::new(DB_NAME).unwrap();
+    let balance = db.get_balance().unwrap();
+    println!("Balance = {}", (balance as f64) / 100_000_000.0);
 }
 
 fn main() {
+    init();
     // test_rewind();
     test().unwrap();
-    // let mut entropy = [0u8; 32];
-    // OsRng.fill_bytes(&mut entropy);
-    // let mnemonic = Mnemonic::from_entropy(&entropy, Language::English).unwrap();
-    // let phrase = mnemonic.phrase();
-    // println!("Seed Phrase: {}", phrase);
+    test_get_balance();
 }
diff --git a/src/print.rs b/src/print.rs
new file mode 100644
index 0000000..90958a2
--- /dev/null
+++ b/src/print.rs
@@ -0,0 +1,56 @@
+use zcash_primitives::sapling::Node;
+use zcash_primitives::merkle_tree::{CommitmentTree, IncrementalWitness};
+use crate::{Witness, CTree};
+
+#[allow(dead_code)]
+pub fn print_node(n: &Node) {
+    println!("{:?}", hex::encode(n.repr));
+}
+
+#[allow(dead_code)]
+pub fn print_tree(t: &CommitmentTree<Node>) {
+    println!("{:?}", t.left.map(|n| hex::encode(n.repr)));
+    println!("{:?}", t.right.map(|n| hex::encode(n.repr)));
+    for p in t.parents.iter() {
+        println!("{:?}", p.map(|n| hex::encode(n.repr)));
+    }
+}
+
+#[allow(dead_code)]
+pub fn print_witness(w: &IncrementalWitness<Node>) {
+    println!("Tree");
+    print_tree(&w.tree);
+    println!("Filled");
+    for n in w.filled.iter() {
+        print_node(n);
+    }
+    println!("Cursor");
+    w.cursor.as_ref().map(|c| print_tree(c));
+}
+
+pub fn print_ctree(t: &CTree) {
+    println!("Tree");
+    println!("{:?}", t.left.map(|n| hex::encode(n.repr)));
+    println!("{:?}", t.right.map(|n| hex::encode(n.repr)));
+    for p in t.parents.iter() {
+        println!("{:?}", p.map(|n| hex::encode(n.repr)));
+    }
+}
+
+#[allow(dead_code)]
+pub fn print_witness2(w: &Witness) {
+    let t = &w.tree;
+    print_ctree(t);
+    println!("Filled");
+    for n in w.filled.iter() {
+        print_node(n);
+    }
+    let t = &w.cursor;
+    println!("Cursor");
+    println!("{:?}", t.left.map(|n| hex::encode(n.repr)));
+    println!("{:?}", t.right.map(|n| hex::encode(n.repr)));
+    for p in t.parents.iter() {
+        println!("{:?}", p.map(|n| hex::encode(n.repr)));
+    }
+
+}
\ No newline at end of file
diff --git a/src/scan.rs b/src/scan.rs
index 9d2c92e..f5547e3 100644
--- a/src/scan.rs
+++ b/src/scan.rs
@@ -10,6 +10,9 @@ use log::info;
 use crate::db::{DbAdapter, ReceivedNote};
 use ff::PrimeField;
 use zcash_primitives::zip32::ExtendedFullViewingKey;
+use crate::chain::Nf;
+use std::sync::Arc;
+use tokio::sync::Mutex;
 
 pub async fn scan_all(fvks: &[ExtendedFullViewingKey]) -> anyhow::Result<()> {
     let decrypter = DecryptNode::new(fvks.to_vec());
@@ -35,7 +38,7 @@ pub async fn scan_all(fvks: &[ExtendedFullViewingKey]) -> anyhow::Result<()> {
     info!("# Witnesses {}", witnesses.len());
     for w in witnesses.iter() {
         let mut bb: Vec<u8> = vec![];
-        w.write(&mut bb).unwrap();
+        w.write(&mut bb)?;
         log::debug!("{}", hex::encode(&bb));
     }
 
@@ -45,6 +48,10 @@ pub async fn scan_all(fvks: &[ExtendedFullViewingKey]) -> anyhow::Result<()> {
 }
 
 struct Blocks(Vec<CompactBlock>);
+struct BlockMetadata {
+    height: u32,
+    hash: [u8; 32],
+}
 
 impl std::fmt::Debug for Blocks {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -52,69 +59,76 @@ impl std::fmt::Debug for Blocks {
     }
 }
 
-fn get_db_height(db_path: &str) -> anyhow::Result<u32> {
-    let db = DbAdapter::new(db_path).unwrap();
-    let height: u32 = db.get_last_height()?.unwrap_or_else(|| {
-        crate::NETWORK
-            .activation_height(NetworkUpgrade::Sapling)
-            .unwrap()
-            .into()
-    });
-    Ok(height)
-}
+pub type ProgressCallback = Arc<Mutex<dyn Fn(u32) + Send>>;
 
-pub async fn sync_async(ivk: &str, chunk_size: u32, db_path: &str, progress_callback: impl Fn(u32) + Send + 'static) -> anyhow::Result<()> {
+pub async fn sync_async(ivk: &str, chunk_size: u32, db_path: &str, target_height_offset: u32, progress_callback: ProgressCallback) -> anyhow::Result<()> {
     let db_path = db_path.to_string();
     let fvk =
         decode_extended_full_viewing_key(NETWORK.hrp_sapling_extended_full_viewing_key(), &ivk)
-            .unwrap()
-            .unwrap();
+            ?.ok_or_else(|| anyhow::anyhow!("Invalid key"))?;
     let decrypter = DecryptNode::new(vec![fvk]);
 
     let mut client = connect_lightwalletd().await?;
-    let start_height = get_db_height(&db_path)?;
+    let start_height = {
+        let db = DbAdapter::new(&db_path)?;
+        db.get_db_height()?
+    };
     let end_height = get_latest_height(&mut client).await?;
+    let end_height = (end_height - target_height_offset).max(start_height);
 
     let (downloader_tx, mut download_rx) = mpsc::channel::<Range<u32>>(2);
-    let (processor_tx, mut processor_rx) = mpsc::channel::<Blocks>(2);
+    let (processor_tx, mut processor_rx) = mpsc::channel::<Blocks>(1);
     let (completed_tx, mut completed_rx) = mpsc::channel::<()>(1);
 
-    tokio::spawn(async move {
-        let mut client = connect_lightwalletd().await.unwrap();
+    let downloader = tokio::spawn(async move {
+        let mut client = connect_lightwalletd().await?;
         while let Some(range) = download_rx.recv().await {
-            log::info!("{:?}", range);
-            let blocks = download_chain(&mut client, range.start, range.end).await.unwrap();
+            log::info!("+ {:?}", range);
+            let blocks = download_chain(&mut client, range.start, range.end).await?;
+            log::info!("- {:?}", range);
             let b = Blocks(blocks);
-            processor_tx.send(b).await.unwrap();
+            processor_tx.send(b).await?;
         }
         log::info!("download completed");
         drop(processor_tx);
 
-        // Ok::<_, anyhow::Error>(())
+        Ok::<_, anyhow::Error>(())
     });
 
-    tokio::spawn(async move {
-        let db = DbAdapter::new(&db_path).unwrap();
-        let (mut tree, mut witnesses) = db.get_tree().unwrap();
-        let mut pos = tree.get_position();
-        // let mut tree = CTree::new();
-        // let mut witnesses: Vec<Witness> = vec![];
+    let proc_callback = progress_callback.clone();
+
+    let processor = tokio::spawn(async move {
+        let db = DbAdapter::new(&db_path)?;
+        let mut nfs = db.get_nullifiers()?;
+
+        let (mut tree, mut witnesses) = db.get_tree()?;
+        let mut absolute_position_at_block_start = tree.get_position();
+        let mut last_block: Option<BlockMetadata> = None;
         while let Some(blocks) = processor_rx.recv().await {
             log::info!("{:?}", blocks);
             if blocks.0.is_empty() { continue }
 
             let dec_blocks = decrypter.decrypt_blocks(&blocks.0);
             for b in dec_blocks.iter() {
+                for nf in b.spends.iter() {
+                    if let Some(&id) = nfs.get(nf) {
+                        println!("NF FOUND {} {}", id, b.height);
+                        db.mark_spent(id, b.height)?;
+                    }
+                }
                 if !b.notes.is_empty() {
                     log::info!("{} {}", b.height, b.notes.len());
+                    for nf in b.spends.iter() {
+                        println!("{}", hex::encode(nf.0));
+                    }
                 }
                 for n in b.notes.iter() {
-                    let p = pos + n.position;
+                    let p = absolute_position_at_block_start + n.position_in_block;
 
                     let note = &n.note;
-                    let id_tx = db.store_transaction(&n.txid, n.height, n.tx_index as u32).unwrap();
+                    let id_tx = db.store_transaction(&n.txid, n.height, n.tx_index as u32)?;
                     let rcm = note.rcm().to_repr();
-                    let nf = note.nf(&n.ivk.fvk.vk, n.position as u64);
+                    let nf = note.nf(&n.ivk.fvk.vk, p as u64);
 
                     let id_note = db.store_received_note(&ReceivedNote {
                         height: n.height,
@@ -123,15 +137,14 @@ pub async fn sync_async(ivk: &str, chunk_size: u32, db_path: &str, progress_call
                         value: note.value,
                         rcm: rcm.to_vec(),
                         nf: nf.0.to_vec(),
-                        is_change: false, // TODO: it's change the ovk matches too
-                        memo: vec![],
-                        spent: false
-                    }, id_tx, n.position).unwrap();
+                        spent: None
+                    }, id_tx, n.position_in_block)?;
+                    nfs.insert(Nf(nf.0), id_note);
 
                     let w = Witness::new(p as usize, id_note, Some(n.clone()));
                     witnesses.push(w);
                 }
-                pos += b.count_outputs as usize;
+                absolute_position_at_block_start += b.count_outputs as usize;
             }
 
             let mut nodes: Vec<Node> = vec![];
@@ -150,19 +163,37 @@ pub async fn sync_async(ivk: &str, chunk_size: u32, db_path: &str, progress_call
             tree = new_tree;
             witnesses = new_witnesses;
 
-            let last_block = blocks.0.last().unwrap();
-            let last_height = last_block.height as u32;
-            db.store_block(last_height, &last_block.hash, &tree).unwrap();
-            for w in witnesses.iter() {
-                db.store_witnesses(w, last_height, w.id_note).unwrap();
+            if let Some(block) = blocks.0.last() {
+                let mut hash = [0u8; 32];
+                hash.copy_from_slice(&block.hash);
+                last_block = Some(BlockMetadata {
+                    height: block.height as u32,
+                    hash,
+                });
             }
-
-            progress_callback(blocks.0[0].height as u32);
+            let callback = proc_callback.lock().await;
+            callback(blocks.0[0].height as u32);
         }
 
-        progress_callback(end_height);
+        // Finalize scan
+        let (new_tree, new_witnesses) = advance_tree(tree, &witnesses, &mut []);
+        tree = new_tree;
+        witnesses = new_witnesses;
+
+        if let Some(last_block) = last_block {
+            let last_height = last_block.height;
+            db.store_block(last_height, &last_block.hash, &tree)?;
+            for w in witnesses.iter() {
+                db.store_witnesses(w, last_height, w.id_note)?;
+            }
+        }
+
+        // let callback = progress_callback.lock()?;
+        // callback(end_height);
         log::info!("Witnesses {}", witnesses.len());
         drop(completed_tx);
+
+        Ok::<_, anyhow::Error>(())
     });
 
     let mut height = start_height;
@@ -181,10 +212,20 @@ pub async fn sync_async(ivk: &str, chunk_size: u32, db_path: &str, progress_call
     completed_rx.recv().await;
     log::info!("completed");
 
+    let res = tokio::try_join!(downloader, processor);
+    match res {
+        Ok((a, b)) => {
+            if let Err(err) = a { log::info!("Downloader error = {}", err) }
+            if let Err(err) = b { log::info!("Processor error = {}", err) }
+        },
+        Err(err) => log::info!("Sync error = {}", err),
+    }
+
     Ok(())
 }
 
-pub async fn latest_height() -> u32 {
-    let mut client = connect_lightwalletd().await.unwrap();
-    get_latest_height(&mut client).await.unwrap()
+pub async fn latest_height() -> anyhow::Result<u32> {
+    let mut client = connect_lightwalletd().await?;
+    let height = get_latest_height(&mut client).await?;
+    Ok(height)
 }
diff --git a/src/wallet.rs b/src/wallet.rs
new file mode 100644
index 0000000..d963a38
--- /dev/null
+++ b/src/wallet.rs
@@ -0,0 +1,150 @@
+use crate::{NETWORK, get_latest_height, connect_lightwalletd, DbAdapter, get_secret_key, get_viewing_key, get_address};
+use zcash_client_backend::address::RecipientAddress;
+use zcash_primitives::transaction::components::Amount;
+use zcash_primitives::transaction::builder::Builder;
+use zcash_client_backend::encoding::decode_extended_spending_key;
+use zcash_primitives::consensus::{Parameters, BlockHeight, BranchId};
+use zcash_primitives::zip32::ExtendedFullViewingKey;
+use zcash_client_backend::data_api::wallet::ANCHOR_OFFSET;
+use rand::prelude::SliceRandom;
+use rand::rngs::OsRng;
+use zcash_proofs::prover::LocalTxProver;
+use crate::chain::send_transaction;
+use zcash_params::{SPEND_PARAMS, OUTPUT_PARAMS};
+use std::sync::Arc;
+use tokio::sync::Mutex;
+use crate::scan::ProgressCallback;
+use zcash_primitives::transaction::components::amount::DEFAULT_FEE;
+
+pub const DEFAULT_ACCOUNT: u32 = 1;
+const DEFAULT_CHUNK_SIZE: u32 = 100_000;
+
+pub struct Wallet {
+    db_path: String,
+    db: DbAdapter,
+    prover: LocalTxProver,
+}
+
+impl Wallet {
+    pub fn new(db_path: &str) -> Wallet {
+        let prover = LocalTxProver::from_bytes(SPEND_PARAMS, OUTPUT_PARAMS);
+        let db = DbAdapter::new(db_path).unwrap();
+        db.init_db().unwrap();
+        Wallet {
+            db_path: db_path.to_string(),
+            db,
+            prover,
+        }
+    }
+
+    pub fn new_account_with_seed(&self, seed: &str) -> anyhow::Result<()> {
+        let sk = get_secret_key(&seed).unwrap();
+        let vk = get_viewing_key(&sk).unwrap();
+        let pa = get_address(&vk).unwrap();
+        self.db.store_account(&sk, &vk, &pa)?;
+        Ok(())
+    }
+
+    async fn scan_async(&self, ivk: &str, chunk_size: u32, target_height_offset: u32, progress_callback: ProgressCallback) -> anyhow::Result<()> {
+        crate::scan::sync_async(ivk, chunk_size, &self.db_path, target_height_offset, progress_callback).await
+    }
+
+    pub async fn get_latest_height() -> anyhow::Result<u32> {
+        let mut client = connect_lightwalletd().await?;
+        let last_height = get_latest_height(&mut client).await?;
+        Ok(last_height)
+    }
+
+    pub async fn sync(&self, account: u32, progress_callback: impl Fn(u32) + Send + 'static) -> anyhow::Result<()> {
+        let ivk = self.db.get_ivk(account)?;
+        let cb = Arc::new(Mutex::new(progress_callback));
+        self.scan_async(&ivk, DEFAULT_CHUNK_SIZE, 10, cb.clone()).await?;
+        self.scan_async(&ivk, DEFAULT_CHUNK_SIZE, 0, cb.clone()).await?;
+        Ok(())
+    }
+
+    pub fn get_balance(&self) -> anyhow::Result<u64> {
+        self.db.get_balance()
+    }
+
+    pub async fn send_payment(&self, account: u32, to_address: &str, amount: u64) -> anyhow::Result<String> {
+        let secret_key = self.db.get_sk(account)?;
+        let to_addr = RecipientAddress::decode(&NETWORK, to_address)
+            .ok_or(anyhow::anyhow!("Invalid address"))?;
+        let target_amount = Amount::from_u64(amount).unwrap();
+        let skey = decode_extended_spending_key(NETWORK.hrp_sapling_extended_spending_key(), &secret_key)?.unwrap();
+        let extfvk = ExtendedFullViewingKey::from(&skey);
+        let (_, change_address) = extfvk.default_address().unwrap();
+        let ovk = extfvk.fvk.ovk;
+        let last_height = Self::get_latest_height().await?;
+        let mut builder = Builder::new(NETWORK, BlockHeight::from_u32(last_height));
+        let anchor_height = self.db.get_last_sync_height()?.ok_or_else(|| anyhow::anyhow!("No spendable notes"))?;
+        let anchor_height = anchor_height.min(last_height - ANCHOR_OFFSET);
+        log::info!("Anchor = {}", anchor_height);
+        let mut notes = self.db.get_spendable_notes(anchor_height, &extfvk)?;
+        notes.shuffle(&mut OsRng);
+        log::info!("Spendable notes = {}", notes.len());
+
+        let mut amount = target_amount;
+        amount += DEFAULT_FEE;
+        for n in notes {
+            if amount.is_positive() {
+                let a = amount.min(Amount::from_u64(n.note.value).unwrap());
+                amount -= a;
+                let merkle_path = n.witness.path().unwrap();
+                builder.add_sapling_spend(skey.clone(), n.diversifier, n.note.clone(), merkle_path)?;
+            }
+        }
+        if amount.is_positive() {
+            anyhow::bail!("Not enough balance")
+        }
+
+        builder.send_change_to(Some(ovk), change_address);
+        match to_addr {
+            RecipientAddress::Shielded(pa) => builder.add_sapling_output(Some(ovk), pa, target_amount, None),
+            RecipientAddress::Transparent(t_address) => builder.add_transparent_output(&t_address, target_amount),
+        }?;
+
+        let consensus_branch_id = BranchId::for_height(&NETWORK, BlockHeight::from_u32(last_height));
+        let (tx, _) = builder.build(consensus_branch_id, &self.prover)?;
+        let mut raw_tx: Vec<u8> = vec![];
+        tx.write(&mut raw_tx)?;
+
+        let mut client = connect_lightwalletd().await?;
+        let tx_id = send_transaction(&mut client, &raw_tx, last_height).await?;
+        Ok(tx_id)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{get_secret_key, get_viewing_key, get_address};
+    use crate::wallet::Wallet;
+
+    #[tokio::test]
+    async fn test_wallet_seed() {
+        dotenv::dotenv().unwrap();
+        env_logger::init();
+
+        let seed = dotenv::var("SEED").unwrap();
+        let wallet = Wallet::new("zec.db");
+        wallet.new_account_with_seed(&seed).unwrap();
+    }
+
+    #[tokio::test]
+    async fn test_payment() {
+        dotenv::dotenv().unwrap();
+        env_logger::init();
+
+        let seed = dotenv::var("SEED").unwrap();
+        let sk = get_secret_key(&seed).unwrap();
+        let vk = get_viewing_key(&sk).unwrap();
+        println!("{}", vk);
+        let pa = get_address(&vk).unwrap();
+        println!("{}", pa);
+        let wallet = Wallet::new("zec.db");
+
+        let tx_id = wallet.send_payment(1, &pa, 1000).await.unwrap();
+        println!("TXID = {}", tx_id);
+    }
+}
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