diff --git a/app/Makefile.version b/app/Makefile.version
index 82feb033..5e6df4ea 100644
--- a/app/Makefile.version
+++ b/app/Makefile.version
@@ -3,4 +3,4 @@ APPVERSION_M=4
 # This is the minor version
 APPVERSION_N=2
 # This is the patch version
-APPVERSION_P=3
+APPVERSION_P=4
diff --git a/app/src/apdu_handler.c b/app/src/apdu_handler.c
index 32397f21..31156be7 100644
--- a/app/src/apdu_handler.c
+++ b/app/src/apdu_handler.c
@@ -145,12 +145,6 @@ void handleApdu(volatile uint32_t *flags, volatile uint32_t *tx, uint32_t rx) {
                     break;
                 }
 
-                case INS_SIGN_SAPLING: {
-                    CHECK_PIN_VALIDATED()
-                    handleSignSapling();
-                    break;
-                }
-
                 default:
                     THROW(APDU_CODE_INS_NOT_SUPPORTED);
             }
diff --git a/app/src/coin.h b/app/src/coin.h
index e0dbaa75..ade19f29 100644
--- a/app/src/coin.h
+++ b/app/src/coin.h
@@ -66,15 +66,12 @@ extern "C" {
 
 #define INS_GET_VERSION                   0x00
 #define INS_GET_ADDR_SECP256K1            0x01
-#define INS_SIGN_SECP256K1                0x02
 #define INS_GET_ADDR_SAPLING_DIV          0x10
 #define INS_GET_ADDR_SAPLING              0x11
-#define INS_SIGN_SAPLING                  0x12
 
 #define INS_GET_DIV_LIST                  0x09
 
 #define INS_INIT_TX                       0xa0
-#define INS_KEY_EXCHANGE                  0xaa
 #define INS_EXTRACT_SPEND                 0xa1
 #define INS_EXTRACT_OUTPUT                0xa2
 #define INS_CHECKANDSIGN                  0xa3
@@ -85,7 +82,6 @@ extern "C" {
 #define INS_GET_OVK                       0xf1
 #define INS_GET_NF                        0xf2
 #define INS_GET_FVK                       0xf3
-#define INS_CRASH_TEST                    0xff
 
 typedef enum { key_ivk = 0, key_ovk = 1, key_fvk = 2, nf = 3 } key_type_e;
 
diff --git a/app/src/handlers/handler_signing.h b/app/src/handlers/handler_signing.h
index e3176abb..e741d7ec 100644
--- a/app/src/handlers/handler_signing.h
+++ b/app/src/handlers/handler_signing.h
@@ -333,7 +333,3 @@ __Z_INLINE void handleCheckandSign(volatile uint32_t *tx, uint32_t rx) {
     *tx = 32;
     THROW(APDU_CODE_OK);
 }
-
-__Z_INLINE void handleSignSapling() {
-    THROW(APDU_CODE_COMMAND_NOT_ALLOWED);
-}
diff --git a/docs/APDUSPEC.md b/docs/APDUSPEC.md
index 4a2717b5..ee63f1e9 100644
--- a/docs/APDUSPEC.md
+++ b/docs/APDUSPEC.md
@@ -68,7 +68,7 @@ The general structure of commands and responses is as follows:
 
 ---
 
-### GET_VERSION
+### INS_GET_VERSION
 
 #### Command
 
@@ -198,7 +198,7 @@ If a diversifier was not valid, zero-bytes are returned (so always 220 bytes are
 
 ---
 
-### INS_GET_IVK_SAPLING
+### INS_GET_IVK
 
 Returns a sapling incoming viewing key.
 Forced user confirmation (So P1 needs to be 0x01).
@@ -225,7 +225,7 @@ Also returns the default diversifier (starting from index 0).
 
 ---
 
-### INS_GET_OVK_SAPLING
+### INS_GET_OVK
 
 Returns a sapling outgoing viewing key. Forced user confirmation (So P1 needs to be 0x01).
 
@@ -249,7 +249,7 @@ Returns a sapling outgoing viewing key. Forced user confirmation (So P1 needs to
 
 ---
 
-### INS_GET_FVK_SAPLING
+### INS_GET_FVK
 
 Returns a sapling full viewing key fvk = (ak, nk, ovk). Forced user confirmation (So P1 needs to be 0x01).
 
@@ -275,7 +275,7 @@ Returns a sapling full viewing key fvk = (ak, nk, ovk). Forced user confirmation
 
 ---
 
-### INS_GET_NF_SAPLING
+### INS_GET_NF
 
 Returns a sapling nullifier. TODO: Forced user confirmation (So P1 needs to be 0x01).
 
@@ -397,7 +397,7 @@ Data is defined as:
 
 Returns a proof generating key (PGK) and randomness (rcv and alpha) for a sapling spend.
 
-- This command requires you already called the INS_INIT_TX_SAPLING.
+- This command requires you already called the INS_INIT_TX.
 - This command requires that it is needed to extract spendinfo.
 
 #### Command
@@ -425,7 +425,7 @@ Returns a proof generating key (PGK) and randomness (rcv and alpha) for a saplin
 
 Returns randomness (rcv and rseed (after ZIP202) and optional Hash_Seed) for a sapling output.
 
-- This command requires you already called the INS_INIT_TX_SAPLING.
+- This command requires you already called the INS_INIT_TX.
 - This command requires you already called the correct number of INS_GET_SPENDINFO.
 - This command requires that it is needed to extract outputinfo.
 
@@ -560,7 +560,7 @@ Data is defined as:
 
 ---
 
-### INS_GET_EXTRACT_TRANSSSIG
+### INS_EXTRACT_TRANSSIG
 
 Returns a SECP256K1 signature for a sapling transparent input if available. Othrewise, it returns only an error code.
 
diff --git a/docs/previuos/zcash_workflow_v1.md b/docs/previuos/zcash_workflow_v1.md
new file mode 100644
index 00000000..46779294
--- /dev/null
+++ b/docs/previuos/zcash_workflow_v1.md
@@ -0,0 +1,199 @@
+Zcash ledger, first connect:
+- Address generation
+- Sharing address with host
+- Sharing IVK with host
+//TODO: change to APDU API
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host
+  participant N as Network
+  H ->> LC: compute_address(path: u32)
+  activate LC
+  LC -->> LF: store_ivk(ivk) ?
+  Note over LF: potentially store (path, IVK)
+  LC ->> H: address: (diversifier, pk_d)
+  LC ->> H: incoming viewing key: ivk
+  deactivate LC
+  Note over H,LC: show address on both screens?
+```
+
+Zcash ledger, syncing
+- Sharing IVK with host
+- Decrypt incoming notes and verification note commitments
+- TODO: what to do with matching notes?
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host
+  participant N as Network
+  H ->> LC: get_ivk(path: u32)
+  #add minor confirmation
+  activate LC
+  LC -->> LF: retrieve_ivk(path) ?
+  LF -->> LC: ivk ?
+  Note over LC: compute_ivk(path)
+  LC ->> H: ivk
+  deactivate LC
+  activate H
+  H ->> N: get_unspend_notes()
+  N ->> H: [unspend_notes]
+  Note over H: [matching_notes] = decrypt_all_unspend_notes(ivk, [unspend_notes])
+  Note over H: store [matching_notes] (d, pk_d, v, rcm)
+  deactivate H
+```
+
+Zcash ledger, make shielded transaction phase 1
+- Verify outputs on screen
+
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host
+  participant N as Network
+
+  Note over H: show amount, address, memo-fields per output
+  Note over H: validate amount <= total_amount
+  H ->> LC: initiate_transaction()
+N ->> H: anchor of note?
+N ->> H: metadata
+Note over H: input note selection (path, note)
+
+  activate LC
+  loop Every output note
+  H ->> LC: verify_output(d, pk_d, value, memo)
+  Note over H,LC: approve amount and address and verify on screens
+  Note over H,LC: approve hash of memo and verify on screens
+  LC ->> H: approval of output
+  LC ->> LF: store_output_data(d,pk_d,value,memo)
+  end
+  deactivate LC
+  #compute value balance and approve
+  Note over LC,H: continue if all approved
+  ```
+
+  Zcash ledger, make shielded transaction phase 2
+- Process outputs and store in flash
+- Compute hash of all outputs
+
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host
+  participant N as Network
+  activate LC
+  loop Every output note
+  H ->> LC: make_transaction(path) #TODO: which path??? fixed one makes sense??
+  Note over LC: compute random rcm
+  LC ->> LF: update_rcmnew(rcm)
+  LF ->> LC: (d,pk_d,value)
+  Note over LC: compute value/note commitments
+  LC ->> LF: update_valuecommitsum(vc)
+  LC ->> LF: value/note commitments
+  LC ->> H: value/note commitments
+  LF ->> LC: d,pk_d, value, memo
+  Note over LC: compute eph, c_out, c_enc 
+  LC ->> LF: eph, c_out, c_enc 
+  LC ->> H: eph, c_out, c_enc 
+  deactivate LC
+  activate H
+  H -->> LC: get_proof_key(path) #is this necessary?
+  LC -->> H: proof_key
+  Note over H: ZK proof of output note
+  H ->> LC: zk_proof
+  deactivate H
+  activate LC
+  LC ->> LF: zk_proof
+  end
+  Note over LC: perform shieldedoutput_hash
+  LC ->> H: shielded_output_hash
+  LC ->> LF: shielded_output_hash
+  deactivate LC
+  ```
+
+Zcash ledger, make shielded transaction phase 3
+- Process spends and store in flash
+- Store RCM values in flash
+- Compute hash of all outputs
+
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host
+  participant N as Network
+  loop Every spend note
+  N ->> H: anchor of note?
+  H ->> LC: spend_this_note(path, valuecommit, rcm, anchor)  # Do we need to verify here that rcm is correct? Is the zkproof of the spend the old one in the blockchain? #what about the valuecommit?
+  LC ->> LF: (path, valuecommit, anchor)
+  LC -->> H: proof_gen_key(path) ? #is this needed
+
+  activate LC
+  LC ->> LF: update_rcmvalue(rcm)
+  LC ->> LF: update_valuecommitsum(vc) #???
+
+  note over LC: compute nullifier
+  LC ->> H: nullifier
+  LC ->> LF: nullifier
+
+  note over LC: compute randomized verification key
+  LC ->> H: randomized verification key
+  LC ->> LF: (path, randomizer value, randomized verification key)
+  deactivate LC
+
+  Note over H: ZK proof of spend note
+  H ->> LC: zk_proof
+  LC ->> LF: zk_proof
+
+  end
+  Note over LC: perform shieldedspend_hash
+  LC ->> LF: shieldedspend_hash #does the host actually need this?
+  LC ->> H: shieldedspend_hash
+```
+
+Zcash ledger, make shielded transaction phase 4
+- Host gives all remaining transaction (meta) data
+- Ledger does the complete TX_HASH_ALL
+- Final approval of transaction?
+- Ledger signs the necessary parts and shares with host
+- Host sends transaction blob to network
+
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host
+  participant N as Network
+  
+  H -->> N: retrieve meta_data from network?
+  N -->> H: meta_data
+
+  H ->> LC: meta_data transaction
+  LC ->> LF: meta_data transaction
+
+  Note over LC: compute valuebalance and commitment
+  LC ->> LF: valuebalance and commitment
+  Note over LF,LC: verify rcm_secretkey/publickey
+
+  Note over LF,LC: perform_tx_hash_all over all data in flash
+
+  LC ->> H: tx_hash_all
+
+  Note over LC,H: final verification/approval of tx before signing?
+
+  LC ->> H: sign(rcm_secretkey, tx_hash_all)
+  loop Every spend note
+  LF ->> LC: randomized value
+  Note over LC: get_secret_key(path)
+  Note over LC: sign(sk, randomized value, tx_hash_all)
+  LC ->> H: spend_auth_sign
+  end
+
+  Note over H: make raw transaction blob
+  H ->> N: raw_transaction_blob
+
+```
\ No newline at end of file
diff --git a/docs/zcash_workflow_version2.md b/docs/previuos/zcash_workflow_v2.md
similarity index 99%
rename from docs/zcash_workflow_version2.md
rename to docs/previuos/zcash_workflow_v2.md
index 8721170b..275f02d6 100644
--- a/docs/zcash_workflow_version2.md
+++ b/docs/previuos/zcash_workflow_v2.md
@@ -74,7 +74,7 @@ Zcash ledger, make shielded transaction phase 1
   end
   deactivate LC
   Note over LC,H: continue if all approved
-  ```
+```
 
   Zcash ledger, make shielded transaction phase 2
 - Process outputs and store in flash
@@ -114,14 +114,14 @@ Zcash ledger, make shielded transaction phase 1
   LC ->> H: shielded_output_hash
   LC ->> LF: shielded_output_hash
   deactivate LC
-  ```
+```
 
 Zcash ledger, make shielded transaction phase 3
 - Process spends and store in flash
 - Store RCM values in flash
 - Compute hash of all outputs
 
-  ```mermaid
+```mermaid
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
@@ -162,7 +162,7 @@ Zcash ledger, make shielded transaction phase 4
 - Ledger signs the necessary parts and shares with host
 - Host sends transaction blob to network
 
-  ```mermaid
+```mermaid
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
diff --git a/docs/zcash_workflow.md b/docs/zcash_workflow.md
index a885b003..b6545a32 100644
--- a/docs/zcash_workflow.md
+++ b/docs/zcash_workflow.md
@@ -7,7 +7,8 @@ Zcash ledger, first connect:
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
-  participant H as Host
+  participant H as Host (JS)
+  participant Z as Zcashtools
   participant N as Network
   H ->> LC: compute_address(path: u32)
   activate LC
@@ -27,7 +28,8 @@ Zcash ledger, syncing
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
-  participant H as Host
+  participant H as Host (JS)
+  participant Z as Zcashtools
   participant N as Network
   H ->> LC: get_ivk(path: u32)
   #add minor confirmation
@@ -47,153 +49,164 @@ Zcash ledger, syncing
 
 Zcash ledger, make shielded transaction phase 1
 - Verify outputs on screen
+- Verify enough balance
+- Put relevant data in flash storage
 
 ```mermaid
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
-  participant H as Host
+  participant H as Host (JS)
+  participant Z as Zcashtools
   participant N as Network
 
   Note over H: show amount, address, memo-fields per output
-  Note over H: validate amount <= total_amount
-  H ->> LC: initiate_transaction()
-N ->> H: anchor of note?
-N ->> H: metadata
-Note over H: input note selection (path, note)
+  Note over H: Shuffle shielded spends/outputs
+  Note over H: Treat change address as regular output
+  Note over H: Make sure amount_in - amount_out = tx-fee
+  H ->> LC: TX_INPUT_LENGTHS 
+  H ->> LC: T_INPUT_DATA 
+  H ->> LC: T_OUTPUT_DATA
+  H ->> LC: S_SPEND_DATA
+  H ->> LC: S_OUTPUT_DATA
+  Note over LC,H: check input/outputdata on screen and verify
+  Note over LC: Continue if approved
+  loop Every transparent input
+  LC ->> LF: T_INPUT_DATA
+  end
 
-  activate LC
-  loop Every output note
-  H ->> LC: verify_output(d, pk_d, value, memo)
-  Note over H,LC: approve amount and address and verify on screens
-  Note over H,LC: approve hash of memo and verify on screens
-  LC ->> H: approval of output
-  LC ->> LF: store_output_data(d,pk_d,value,memo)
+  loop Every transparent output
+  LC ->> LF: T_OUTPUT_DATA
   end
-  deactivate LC
-  #compute value balance and approve
-  Note over LC,H: continue if all approved
-  ```
 
-  Zcash ledger, make shielded transaction phase 2
-- Process outputs and store in flash
-- Compute hash of all outputs
+  loop Every shielded spend
+  Note over LC: Random numbers rcv/alpha
+  LC ->> LF: S_SPEND_DATA, RND_DATA
+  end
 
-```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host
-  participant N as Network
-  activate LC
-  loop Every output note
-  H ->> LC: make_transaction(path) #TODO: which path??? fixed one makes sense??
-  Note over LC: compute random rcm
-  LC ->> LF: update_rcmnew(rcm)
-  LF ->> LC: (d,pk_d,value)
-  Note over LC: compute value/note commitments
-  LC ->> LF: update_valuecommitsum(vc)
-  LC ->> LF: value/note commitments
-  LC ->> H: value/note commitments
-  LF ->> LC: d,pk_d, value, memo
-  Note over LC: compute eph, c_out, c_enc 
-  LC ->> LF: eph, c_out, c_enc 
-  LC ->> H: eph, c_out, c_enc 
-  deactivate LC
-  activate H
-  H -->> LC: get_proof_key(path) #is this necessary?
-  LC -->> H: proof_key
-  Note over H: ZK proof of output note
-  H ->> LC: zk_proof
-  deactivate H
-  activate LC
-  LC ->> LF: zk_proof
+  loop Every shielded output
+  Note over LC: Random numbers rcv/rcm/esk
+  LC ->> LF: S_OUTPUT_DATA, RND_DATA
   end
-  Note over LC: perform shieldedoutput_hash
-  LC ->> H: shielded_output_hash
-  LC ->> LF: shielded_output_hash
-  deactivate LC
-  ```
+```
 
-Zcash ledger, make shielded transaction phase 3
-- Process spends and store in flash
-- Store RCM values in flash
-- Compute hash of all outputs
+  Zcash ledger, make shielded transaction phase 2
+- Host processes everything, uses zcashtools builder
+- Host asks ledger for random values to use
+- Host initiates builder
 
-  ```mermaid
+```mermaid
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
-  participant H as Host
+  participant H as Host (JS)
+  participant Z as Zcashtools
   participant N as Network
-  loop Every spend note
-  N ->> H: anchor of note?
-  H ->> LC: spend_this_note(path, valuecommit, rcm, anchor)  # Do we need to verify here that rcm is correct? Is the zkproof of the spend the old one in the blockchain? #what about the valuecommit?
-  LC ->> LF: (path, valuecommit, anchor)
-  LC -->> H: proof_gen_key(path) ? #is this needed
-
-  activate LC
-  LC ->> LF: update_rcmvalue(rcm)
-  LC ->> LF: update_valuecommitsum(vc) #???
-
-  note over LC: compute nullifier
-  LC ->> H: nullifier
-  LC ->> LF: nullifier
-
-  note over LC: compute randomized verification key
-  LC ->> H: randomized verification key
-  LC ->> LF: (path, randomizer value, randomized verification key)
-  deactivate LC
-
-  Note over H: ZK proof of spend note
-  H ->> LC: zk_proof
-  LC ->> LF: zk_proof
+  H ->> Z: builder_init()
+  H ->> Z: add_transparent_inputs(txdata)
+  H ->> Z: add_transparent_outputs(txdata)
+  loop Every shielded spend
+  H ->> LC: get_spend_data ()
+  LF ->> LC: spend_data
+  LC ->> H: proofkey, rnd (rcv/alpha)
+  H ->> Z: add_sapling_spend(txdata, proofkey, rnd)
+  end
 
+  loop Every shielded output
+  H ->> LC: get_output_data ()
+  LF ->> LC: output_data
+  LC ->> H: rnd (rcv/rcm/esk)
+  H ->> Z: add_sapling_output(txdata, rnd)
   end
-  Note over LC: perform shieldedspend_hash
-  LC ->> LF: shieldedspend_hash #does the host actually need this?
-  LC ->> H: shieldedspend_hash
 ```
 
+
 Zcash ledger, make shielded transaction phase 4
-- Host gives all remaining transaction (meta) data
+- Host gives all remaining transaction data
 - Ledger does the complete TX_HASH_ALL
-- Final approval of transaction?
 - Ledger signs the necessary parts and shares with host
 - Host sends transaction blob to network
 
-  ```mermaid
+```mermaid
   sequenceDiagram
   participant LF as Ledger flash storage
   participant LC as Ledger computation 
-  participant H as Host
+  participant H as Host (JS)
+  participant Z as Zcashtools
   participant N as Network
   
   H -->> N: retrieve meta_data from network?
   N -->> H: meta_data
+  H ->> Z: build()
+  Z ->> H: raw_tx_blob
+
+  H ->> LC: t_in_script_data
+  H ->> LC: spend_data
+  H ->> LC: output_data
+  H ->> LC: sighash_data
+  
+  LF ->> LC: t_output_data
+  Note over LC: outputshash = hash(t_output_data)
+  Note over LC: check outputshash == sighash_data[outputshash]
+
+  LF ->> LC: valuebalance
+  Note over LC: check valuebalance
 
-  H ->> LC: meta_data transaction
-  LC ->> LF: meta_data transaction
+  Note over LC: check joinsplits (empty)
 
-  Note over LC: compute valuebalance and commitment
-  LC ->> LF: valuebalance and commitment
-  Note over LF,LC: verify rcm_secretkey/publickey
+  loop Every shielded spend
+  LF ->> LC: S_SPEND_DATA, RND_DATA
+  Note over LC: check spend data (CV, RK, NF)
+  end
 
-  Note over LF,LC: perform_tx_hash_all over all data in flash
+  loop Every shielded output
+  LF ->> LC: S_OUTPUT_DATA, RND_DATA
+  Note over LC: check output data (CV, CMU, (ENC_C, ENC_OUT))
+  end
 
-  LC ->> H: tx_hash_all
+  loop Every transparent input
+  LF ->> LC: T_INPUT_DATA
+  Note over LC: check t_input data (script, script_from_pk, value)
+  Note over LC: sighash_all_script = hash_sigall(sighash_data, t_in_script_data)
+  Note over LC: secp256k1_sign (sighash_all_script)
+  LC ->> LF: transparent_signature
+  end
 
-  Note over LC,H: final verification/approval of tx before signing?
+  loop Every shielded spend
+  LF ->> LC: S_SPEND_DATA, RND_DATA
+  Note over LC: sighash_all (sighash_data)
+  Note over LC: jubjub_sign(ask, alpha, sighash_all)
+  LC ->> LF: spend_signature
+  end
+LC ->> H: all_ok
+
+```
+
+Zcash ledger, make shielded transaction phase 5
+- Finalize tx
+
+```mermaid
+  sequenceDiagram
+  participant LF as Ledger flash storage
+  participant LC as Ledger computation 
+  participant H as Host (JS)
+  participant Z as Zcashtools
+  participant N as Network
+  
+  loop Every transparent input
+  H ->> LC: next_transparent_signature
+  LF ->> LC: transparent_signature
+  LC ->> H: transparent_signature
+  end
+  H ->> Z: add_transparent_signatures(t_signatures)
 
-  LC ->> H: sign(rcm_secretkey, tx_hash_all)
-  loop Every spend note
-  LF ->> LC: randomized value
-  Note over LC: get_secret_key(path)
-  Note over LC: sign(sk, randomized value, tx_hash_all)
-  LC ->> H: spend_auth_sign
+  loop Every shielded spend
+  H ->> LC: next_spend_signature
+  LF ->> LC: spend_signature
+  LC ->> H: spend_signature
   end
+  H ->> Z: add_spend_signatures(s_signatures)
 
-  Note over H: make raw transaction blob
-  H ->> N: raw_transaction_blob
+  Z ->> N: send_raw_tx
 
 ```
\ No newline at end of file
diff --git a/docs/zcash_workflow_version3.md b/docs/zcash_workflow_version3.md
deleted file mode 100644
index 2f915c1a..00000000
--- a/docs/zcash_workflow_version3.md
+++ /dev/null
@@ -1,212 +0,0 @@
-Zcash ledger, first connect:
-- Address generation
-- Sharing address with host
-- Sharing IVK with host
-//TODO: change to APDU API
-```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host (JS)
-  participant Z as Zcashtools
-  participant N as Network
-  H ->> LC: compute_address(path: u32)
-  activate LC
-  LC -->> LF: store_ivk(ivk) ?
-  Note over LF: potentially store (path, IVK)
-  LC ->> H: address: (diversifier, pk_d)
-  LC ->> H: incoming viewing key: ivk
-  deactivate LC
-  Note over H,LC: show address on both screens?
-```
-
-Zcash ledger, syncing
-- Sharing IVK with host
-- Decrypt incoming notes and verification note commitments
-- TODO: what to do with matching notes?
-```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host (JS)
-  participant Z as Zcashtools
-  participant N as Network
-  H ->> LC: get_ivk(path: u32)
-  #add minor confirmation
-  activate LC
-  LC -->> LF: retrieve_ivk(path) ?
-  LF -->> LC: ivk ?
-  Note over LC: compute_ivk(path)
-  LC ->> H: ivk
-  deactivate LC
-  activate H
-  H ->> N: get_unspend_notes()
-  N ->> H: [unspend_notes]
-  Note over H: [matching_notes] = decrypt_all_unspend_notes(ivk, [unspend_notes])
-  Note over H: store [matching_notes] (d, pk_d, v, rcm)
-  deactivate H
-```
-
-Zcash ledger, make shielded transaction phase 1
-- Verify outputs on screen
-- Verify enough balance
-- Put relevant data in flash storage
-
-```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host (JS)
-  participant Z as Zcashtools
-  participant N as Network
-
-  Note over H: show amount, address, memo-fields per output
-  Note over H: Shuffle shielded spends/outputs
-  Note over H: Treat change address as regular output
-  Note over H: Make sure amount_in - amount_out = tx-fee
-  H ->> LC: TX_INPUT_LENGTHS 
-  H ->> LC: T_INPUT_DATA 
-  H ->> LC: T_OUTPUT_DATA
-  H ->> LC: S_SPEND_DATA
-  H ->> LC: S_OUTPUT_DATA
-  Note over LC,H: check input/outputdata on screen and verify
-  Note over LC: Continue if approved
-  loop Every transparent input
-  LC ->> LF: T_INPUT_DATA
-  end
-
-  loop Every transparent output
-  LC ->> LF: T_OUTPUT_DATA
-  end
-
-  loop Every shielded spend
-  Note over LC: Random numbers rcv/alpha
-  LC ->> LF: S_SPEND_DATA, RND_DATA
-  end
-
-  loop Every shielded output
-  Note over LC: Random numbers rcv/rcm/esk
-  LC ->> LF: S_OUTPUT_DATA, RND_DATA
-  end
-  ```
-
-  Zcash ledger, make shielded transaction phase 2
-- Host processes everything, uses zcashtools builder
-- Host asks ledger for random values to use
-- Host initiates builder
-
-```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host (JS)
-  participant Z as Zcashtools
-  participant N as Network
-  H ->> Z: builder_init()
-  H ->> Z: add_transparent_inputs(txdata)
-  H ->> Z: add_transparent_outputs(txdata)
-  loop Every shielded spend
-  H ->> LC: get_spend_data ()
-  LF ->> LC: spend_data
-  LC ->> H: proofkey, rnd (rcv/alpha)
-  H ->> Z: add_sapling_spend(txdata, proofkey, rnd)
-  end
-
-  loop Every shielded output
-  H ->> LC: get_ouput_data ()
-  LF ->> LC: output_data
-  LC ->> H: rnd (rcv/rcm/esk)
-  H ->> Z: add_sapling_outpu(txdata, rnd)
-  end
-  ```
-
-
-Zcash ledger, make shielded transaction phase 4
-- Host gives all remaining transaction data
-- Ledger does the complete TX_HASH_ALL
-- Ledger signs the necessary parts and shares with host
-- Host sends transaction blob to network
-
-  ```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host (JS)
-  participant Z as Zcashtools
-  participant N as Network
-  
-  H -->> N: retrieve meta_data from network?
-  N -->> H: meta_data
-  H ->> Z: build()
-  Z ->> H: raw_tx_blob
-
-  H ->> LC: t_in_script_data
-  H ->> LC: spend_data
-  H ->> LC: output_data
-  H ->> LC: sighash_data
-  
-  LF ->> LC: t_output_data
-  Note over LC: outputshash = hash(t_output_data)
-  Note over LC: check outputshash == sighash_data[outputshash]
-
-  LF ->> LC: valuebalance
-  Note over LC: check valuebalance
-
-  Note over LC: check joinsplits (empty)
-
-  loop Every shielded spend
-  LF ->> LC: S_SPEND_DATA, RND_DATA
-  Note over LC: check spend data (CV, RK, NF)
-  end
-
-  loop Every shielded output
-  LF ->> LC: S_OUTPUT_DATA, RND_DATA
-  Note over LC: check output data (CV, CMU, (ENC_C, ENC_OUT))
-  end
-
-  loop Every transparent input
-  LF ->> LC: T_INPUT_DATA
-  Note over LC: check t_input data (script, script_from_pk, value)
-  Note over LC: sighash_all_script = hash_sigall(sighash_data, t_in_script_data)
-  Note over LC: secp256k1_sign (sighash_all_script)
-  LC ->> LF: transparent_signature
-  end
-
-  loop Every shielded spend
-  LF ->> LC: S_SPEND_DATA, RND_DATA
-  Note over LC: sighash_all (sighash_data)
-  Note over LC: jubjub_sign(ask, alpha, sighash_all)
-  LC ->> LF: spend_signature
-  end
-LC ->> H: all_ok
-
-```
-
-Zcash ledger, make shielded transaction phase 5
-- Finalize tx
-
-  ```mermaid
-  sequenceDiagram
-  participant LF as Ledger flash storage
-  participant LC as Ledger computation 
-  participant H as Host (JS)
-  participant Z as Zcashtools
-  participant N as Network
-  
-  loop Every transparent input
-  H ->> LC: next_transparent_signature
-  LF ->> LC: transparent_signature
-  LC ->> H: transparent_signature
-  end
-  H ->> Z: add_transparent_signatures(t_signatures)
-
-  loop Every shielded spend
-  H ->> LC: next_spend_signature
-  LF ->> LC: spend_signature
-  LC ->> H: spend_signature
-  end
-  H ->> Z: add_spend_signatures(s_signatures)
-
-  Z ->> N: send_raw_tx
-
-```
\ No newline at end of file
diff --git a/tests_zemu/snapshots/fl-mainmenu/00004.png b/tests_zemu/snapshots/fl-mainmenu/00004.png
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index a78e6827..d84dc33b 100644
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index a78e6827..d84dc33b 100644
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diff --git a/tests_zemu/snapshots/sp-mainmenu/00004.png b/tests_zemu/snapshots/sp-mainmenu/00004.png
index 500d0b8f..5ebb8454 100644
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diff --git a/tests_zemu/snapshots/sp-mainmenu/00010.png b/tests_zemu/snapshots/sp-mainmenu/00010.png
index 500d0b8f..5ebb8454 100644
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diff --git a/tests_zemu/snapshots/st-mainmenu/00004.png b/tests_zemu/snapshots/st-mainmenu/00004.png
index f07b2ba3..8b04780e 100644
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diff --git a/tests_zemu/snapshots/x-mainmenu/00004.png b/tests_zemu/snapshots/x-mainmenu/00004.png
index 500d0b8f..5ebb8454 100644
Binary files a/tests_zemu/snapshots/x-mainmenu/00004.png and b/tests_zemu/snapshots/x-mainmenu/00004.png differ
diff --git a/tests_zemu/snapshots/x-mainmenu/00010.png b/tests_zemu/snapshots/x-mainmenu/00010.png
index 500d0b8f..5ebb8454 100644
Binary files a/tests_zemu/snapshots/x-mainmenu/00010.png and b/tests_zemu/snapshots/x-mainmenu/00010.png differ
diff --git a/zcashtools/Cargo.lock b/zcashtools/Cargo.lock
index 553a48a6..91663eb7 100644
--- a/zcashtools/Cargo.lock
+++ b/zcashtools/Cargo.lock
@@ -451,7 +451,7 @@ dependencies = [
 [[package]]
 name = "equihash"
 version = "0.1.0"
-source = "git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae#112eedd27b2e51b9e1b77603a776cd78e738c3ae"
+source = "git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c#ce278848fef35903db46c3dced41658e90bbeb3c"
 dependencies = [
  "blake2b_simd",
  "byteorder",
@@ -665,8 +665,28 @@ dependencies = [
 
 [[package]]
 name = "ledger-zcash"
+version = "2.0.0"
+source = "git+https://github.com/Zondax/ledger-zcash-rs?tag=v2.0.0#e5f3e6d633ea316759b153c7edacaaabf580f32c"
+dependencies = [
+ "byteorder",
+ "cfg-if",
+ "educe",
+ "hex",
+ "lazy_static",
+ "ledger-transport",
+ "ledger-zondax-generic",
+ "log",
+ "serde",
+ "sha2 0.10.8",
+ "thiserror",
+ "tokio",
+ "zx-bip44",
+]
+
+[[package]]
+name = "ledger-zcash-app-builder"
 version = "0.11.2"
-source = "git+https://github.com/Zondax/ledger-zcash-rs?rev=3bad2fa4a7870270627edc25ebdb5b4818fd1855#3bad2fa4a7870270627edc25ebdb5b4818fd1855"
+source = "git+https://github.com/Zondax/ledger-zcash-tools?tag=v2.0.0#5e8588cc0fef85a74c22d1012ed951b7b44a5097"
 dependencies = [
  "arrayvec",
  "byteorder",
@@ -678,7 +698,8 @@ dependencies = [
  "jubjub",
  "lazy_static",
  "ledger-transport",
- "ledger-zcash-builder",
+ "ledger-zcash",
+ "ledger-zcash-chain-builder",
  "ledger-zondax-generic",
  "log",
  "rand_core",
@@ -693,9 +714,9 @@ dependencies = [
 ]
 
 [[package]]
-name = "ledger-zcash-builder"
+name = "ledger-zcash-chain-builder"
 version = "0.11.2"
-source = "git+https://github.com/Zondax/ledger-zcash-rs?rev=3bad2fa4a7870270627edc25ebdb5b4818fd1855#3bad2fa4a7870270627edc25ebdb5b4818fd1855"
+source = "git+https://github.com/Zondax/ledger-zcash-tools?tag=v2.0.0#5e8588cc0fef85a74c22d1012ed951b7b44a5097"
 dependencies = [
  "bellman",
  "blake2b_simd",
@@ -720,7 +741,7 @@ dependencies = [
  "sha2 0.10.8",
  "thiserror",
  "tokio",
- "zcash_note_encryption 0.1.0 (git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae)",
+ "zcash_note_encryption 0.1.0 (git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c)",
  "zcash_primitives",
  "zcash_proofs",
 ]
@@ -1592,7 +1613,7 @@ dependencies = [
 [[package]]
 name = "zcash_encoding"
 version = "0.1.0"
-source = "git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae#112eedd27b2e51b9e1b77603a776cd78e738c3ae"
+source = "git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c#ce278848fef35903db46c3dced41658e90bbeb3c"
 dependencies = [
  "byteorder",
  "nonempty",
@@ -1613,7 +1634,7 @@ dependencies = [
 [[package]]
 name = "zcash_note_encryption"
 version = "0.1.0"
-source = "git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae#112eedd27b2e51b9e1b77603a776cd78e738c3ae"
+source = "git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c#ce278848fef35903db46c3dced41658e90bbeb3c"
 dependencies = [
  "chacha20",
  "chacha20poly1305",
@@ -1624,7 +1645,7 @@ dependencies = [
 [[package]]
 name = "zcash_primitives"
 version = "0.6.0"
-source = "git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae#112eedd27b2e51b9e1b77603a776cd78e738c3ae"
+source = "git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c#ce278848fef35903db46c3dced41658e90bbeb3c"
 dependencies = [
  "aes",
  "bip0039",
@@ -1654,13 +1675,13 @@ dependencies = [
  "sha2 0.9.9",
  "subtle",
  "zcash_encoding",
- "zcash_note_encryption 0.1.0 (git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae)",
+ "zcash_note_encryption 0.1.0 (git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c)",
 ]
 
 [[package]]
 name = "zcash_proofs"
 version = "0.6.0"
-source = "git+https://github.com/Zondax/librustzcash?rev=112eedd27b2e51b9e1b77603a776cd78e738c3ae#112eedd27b2e51b9e1b77603a776cd78e738c3ae"
+source = "git+https://github.com/Zondax/librustzcash?rev=ce278848fef35903db46c3dced41658e90bbeb3c#ce278848fef35903db46c3dced41658e90bbeb3c"
 dependencies = [
  "bellman",
  "blake2b_simd",
@@ -1680,8 +1701,8 @@ name = "zcashtool"
 version = "0.1.0"
 dependencies = [
  "env_logger",
- "ledger-zcash",
- "ledger-zcash-builder",
+ "ledger-zcash-app-builder",
+ "ledger-zcash-chain-builder",
  "log",
  "neon",
  "neon-serde",
diff --git a/zcashtools/Cargo.toml b/zcashtools/Cargo.toml
index 28f590b4..9607a839 100644
--- a/zcashtools/Cargo.toml
+++ b/zcashtools/Cargo.toml
@@ -8,8 +8,8 @@ opt-level = "s"
 overflow-checks = true
 
 [patch.crates-io]
-ledger-zcash-builder = { git = "https://github.com/Zondax/ledger-zcash-rs", rev = "3bad2fa4a7870270627edc25ebdb5b4818fd1855" }
-ledger-zcash = { git = "https://github.com/Zondax/ledger-zcash-rs", rev = "3bad2fa4a7870270627edc25ebdb5b4818fd1855" }
+ledger-zcash-chain-builder = { git = "https://github.com/Zondax/ledger-zcash-tools", tag = "v2.0.0" }
+ledger-zcash-app-builder = { git = "https://github.com/Zondax/ledger-zcash-tools", tag = "v2.0.0" }
 
-# ledger-zcash-builder = { path = "../../ledger-zcash-rs/ledger-zcash-builder" }
-# ledger-zcash = { path = "../../ledger-zcash-rs/ledger-zcash" }
+# ledger-zcash-chain-builder = { path = "../../ledger-zcash-tools/ledger-zcash-chain-builder" }
+# ledger-zcash-app-builder = { path = "../../ledger-zcash-tools/ledger-zcash-app-builder" }
diff --git a/zcashtools/neon/native/Cargo.toml b/zcashtools/neon/native/Cargo.toml
index b3a526fc..ce3622b7 100644
--- a/zcashtools/neon/native/Cargo.toml
+++ b/zcashtools/neon/native/Cargo.toml
@@ -19,14 +19,14 @@ serde_derive = "1"
 serde = "1"
 log = "0.4"
 snafu = { version = "0.8.2" }
-zcash_primitives = { git = "https://github.com/Zondax/librustzcash", rev = "112eedd27b2e51b9e1b77603a776cd78e738c3ae", features = ["transparent-inputs"], package = "zcash_primitives" }
+zcash_primitives = { git = "https://github.com/Zondax/librustzcash", rev = "ce278848fef35903db46c3dced41658e90bbeb3c", features = ["transparent-inputs"], package = "zcash_primitives" }
 
 neon-serde = { git = "https://github.com/Zondax/neon-serde", branch = "master", default-features = false, features = [
     "napi-6",
 ] }
 
-ledger-zcash-builder = { git = "https://github.com/Zondax/ledger-zcash-rs", rev = "3bad2fa4a7870270627edc25ebdb5b4818fd1855", package = "ledger-zcash-builder"  }
-ledger-zcash =  { git = "https://github.com/Zondax/ledger-zcash-rs", rev = "3bad2fa4a7870270627edc25ebdb5b4818fd1855", package = "ledger-zcash"  }
+ledger-zcash-chain-builder = { git = "https://github.com/Zondax/ledger-zcash-tools", tag = "v2.0.0", package = "ledger-zcash-chain-builder"  }
+ledger-zcash-app-builder =  { git = "https://github.com/Zondax/ledger-zcash-tools", tag = "v2.0.0", package = "ledger-zcash-app-builder"  }
 
 [dev-dependencies]
 serde = { version = "1", features = ["derive"] }
diff --git a/zcashtools/neon/native/src/lib.rs b/zcashtools/neon/native/src/lib.rs
index 83ceaab8..4b064bbc 100644
--- a/zcashtools/neon/native/src/lib.rs
+++ b/zcashtools/neon/native/src/lib.rs
@@ -1,9 +1,9 @@
-use ledger_zcash_builder::data::{
+use ledger_zcash_chain_builder::data::{
     HsmTxData, InitData, OutputBuilderInfo, SpendBuilderInfo, TransactionSignatures,
     TransparentInputBuilderInfo, TransparentOutputBuilderInfo,
 };
-use ledger_zcash_builder::errors::Error;
-use ledger_zcash_builder::{hsmauth, txbuilder, txprover};
+use ledger_zcash_chain_builder::errors::Error;
+use ledger_zcash_chain_builder::{hsmauth, txbuilder, txprover};
 use neon::prelude::*;
 use std::cell::RefCell;
 use std::path::Path;
@@ -45,7 +45,7 @@ fn calculate_zip0317_fee(mut cx: FunctionContext) -> JsResult<JsNumber> {
     ];
 
     let fee: u64 =
-        ledger_zcash::builder::Builder::calculate_zip0317_fee(n_tin, n_tout, n_spend, n_sout)
+        ledger_zcash_app_builder::builder::Builder::calculate_zip0317_fee(n_tin, n_tout, n_spend, n_sout)
             .into();
 
     Ok(cx.number(fee as f64))
diff --git a/zcashtools/neon/native/tests/builder_test.rs b/zcashtools/neon/native/tests/builder_test.rs
index 61e6f01b..09d3a82a 100644
--- a/zcashtools/neon/native/tests/builder_test.rs
+++ b/zcashtools/neon/native/tests/builder_test.rs
@@ -1,6 +1,6 @@
 use env_logger::Env;
-use ledger_zcash::builder::Builder as ZcashBuilder;
-use ledger_zcash_builder::{
+use ledger_zcash_app_builder::builder::Builder as ZcashBuilder;
+use ledger_zcash_chain_builder::{
     data::{OutputBuilderInfo, SpendBuilderInfo},
     txbuilder::Builder,
 };
diff --git a/zcashtools/neon/native/tests/builder_test2.rs b/zcashtools/neon/native/tests/builder_test2.rs
index 8c17cffc..c7f13b85 100644
--- a/zcashtools/neon/native/tests/builder_test2.rs
+++ b/zcashtools/neon/native/tests/builder_test2.rs
@@ -1,6 +1,6 @@
 use env_logger::Env;
-use ledger_zcash::builder::Builder as ZcashBuilder;
-use ledger_zcash_builder::{
+use ledger_zcash_app_builder::builder::Builder as ZcashBuilder;
+use ledger_zcash_chain_builder::{
     data::{TransparentInputBuilderInfo, TransparentOutputBuilderInfo},
     txbuilder::Builder,
 };