# ICRC-1: Where can I find the ICR1 implementation ledger code? I need the installation argument struct **URL:** \ **Category:** Developers\ **Created:** [October 10, 2024, 5:27am UTC](https://forum.dfinity.org/t/icrc-1-where-can-i-find-the-icr1-implementation-ledger-code-i-need-the-installation-argument-struct/36035 "2024-10-10T05:27:10Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![vincentes](https://avatars.discourse-cdn.com/v4/letter/v/858c86/32.png) [@vincentes](https://forum.dfinity.org/u/vincentes)\ **Post date:** [October 10, 2024, 5:27am UTC](https://forum.dfinity.org/t/icrc-1-where-can-i-find-the-icr1-implementation-ledger-code-i-need-the-installation-argument-struct/36035/1 "2024-10-10T05:27:10Z")
I’m using this configuration in my `dfx.json`. ```auto "icrc1_ledger_canister": { "type": "custom", "candid": "https://raw.githubusercontent.com/dfinity/ic/d87954601e4b22972899e9957e800406a0a6b929/rs/rosetta-api/icrc1/ledger/ledger.did", "wasm": "https://download.dfinity.systems/ic/d87954601e4b22972899e9957e800406a0a6b929/canisters/ic-icrc1-ledger.wasm.gz", "remote": { "id": { "ic": "ryjl3-tyaaa-aaaaa-aaaba-cai" } } } ``` However, the issue that I have is that there’s a mismatch between the types in my ICRC1 deployment installation arguments. Note: I’m using PocketIC to test the deployment. ```auto let icrc1_deploy_args = ICRC1Args::Init(ICRC1InitArgs { token_symbol: "MCK".to_string(), token_name: "Mock Token".to_string(), minting_account: Account { owner: caller, subaccount: None, }, transfer_fee: candid::Nat(1_000_000.to_biguint().unwrap()), metadata: vec![], initial_balances: vec![ ( Account { owner: caller, subaccount: None, }, candid::Nat(mint_amount.to_biguint().unwrap()), ), ], archive_options: ArchiveOptions { num_blocks_to_archive: candid::Nat(10.to_biguint().unwrap()), trigger_threshold: candid::Nat(5.to_biguint().unwrap()), controller_id: caller, max_transactions_per_response: None, max_message_size_bytes: None, cycles_for_archive_creation: None, node_max_memory_size_bytes: None, }, feature_flags: Some(FeatureFlags { icrc2: false }), decimals: Some(candid::Nat(3.to_biguint().unwrap())), // Assuming 8 decimals, adjust as needed maximum_number_of_accounts: None, accounts_overflow_trim_quantity: None, fee_collector_account: None, max_memo_length: None, }); pic.install_canister(icrc_ledger, icrc_wasm_module, encode_one(icrc1_deploy_args).unwrap(), Some(caller)); ``` The error I am getting is the following: ```auto thread 'tests::intent_tests::should_transfer_icrc1' panicked at /Users/vincxntes/.cargo/registry/src/index.crates.io-6f17d22bba15001f/pocket-ic-5.0.0/src/nonblocking.rs:840:10: called `Result::unwrap()` on an `Err` value: UserError(UserError { code: CanisterCalledTrap, description: "Error from Canister lqy7q-dh777-77777-aaaaq-cai: Canister called `ic0.trap` with message: failed to decode call arguments: Custom(Fail to decode argument 0 from table0 to variant {\n Upgrade : opt record {\n token_symbol : opt text;\n transfer_fee : opt nat;\n metadata : opt vec record {\n text;\n variant { Int : int; Nat : nat; Blob : vec nat8; Text : text };\n };\n maximum_number_of_accounts : opt nat64;\n accounts_overflow_trim_quantity : opt nat64;\n change_fee_collector : opt variant {\n SetTo : record { owner : principal; subaccount : opt vec nat8 };\n Unset;\n };\n max_memo_length : opt nat16;\n token_name : opt text;\n feature_flags : opt record { icrc2 : bool };\n };\n Init : record {\n decimals : opt nat8;\n token_symbol : text;\n transfer_fee : nat;\n metadata : vec record {\n text;\n variant { Int : int; Nat : nat; Blob : vec nat8; Text : text };\n };\n minting_account : record { owner : principal; subaccount : opt vec nat8 };\n initial_balances : vec record {\n record { owner : principal; subaccount : opt vec nat8 };\n nat;\n };\n maximum_number_of_accounts : opt nat64;\n accounts_overflow_trim_quantity : opt nat64;\n fee_collector_account : opt record {\n owner : principal;\n subaccount : opt vec nat8;\n };\n archive_options : record {\n num_blocks_to_archive : nat64;\n max_transactions_per_response : opt nat64;\n trigger_threshold : nat64;\n max_message_size_bytes : opt nat64;\n cycles_for_archive_creation : opt nat64;\n node_max_memory_size_bytes : opt nat64;\n controller_id : principal;\n };\n max_memo_length : opt nat16;\n token_name : text;\n feature_flags : opt record { icrc2 : bool };\n };\n}\n\nCaused by:\n 0: input: 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_0a0005000000011dcc9ac7f36ced820f399b6e7a16eaac06a04aea82cc55917650270bdc02000a4d6f636b20546f6b656e0100\n table: type table0 = variant { 813_882_492 : table1; 815_032_112 : table16 }\n type table1 = record {\n 881_753_886 : table2;\n 902_112_242 : table3;\n 1_075_439_471 : table4;\n 1_735_349_527 : table3;\n 2_014_659_076 : table3;\n 2_122_741_893 : table9;\n 2_991_647_664 : table13;\n 3_754_599_569 : table2;\n 4_168_372_670 : table14;\n }\n type table10 = variant { 224_199_069 : table11; 974_938_825 }\n type table11 = record { 947_296_307 : principal; 1_349_681_965 : table12 }\n type table12 = opt table8\n type table13 = opt nat16\n type table14 = opt table15\n type table15 = record { 3_067_731_911 : bool }\n type table16 = record {\n 308_955_842 : table3;\n 881_753_886 : text;\n 902_112_242 : nat;\n 1_075_439_471 : table5;\n 1_092_281_774 : table11;\n 1_448_514_098 : table17;\n 1_735_349_527 : table3;\n 2_014_659_076 : table3;\n 2_152_701_186 : table19;\n 2_755_523_233 : table20;\n 2_991_647_664 : table3;\n 3_754_599_569 : text;\n 4_168_372_670 : table14;\n }\n type table17 = vec table18\n type table18 = record { table11; nat }\n type table19 = opt table11\n type table2 = opt text\n type table20 = record {\n 440_423_070 : nat;\n 978_359_218 : table3;\n 1_831_422_628 : nat;\n 2_380_371_424 : table3;\n 3_172_150_372 : table3;\n 3_371_803_667 : table3;\n 3_856_016_094 : principal;\n }\n type table3 = opt nat\n type table4 = opt table5\n type table5 = vec table6\n type table6 = record { text; table7 }\n type table7 = variant {\n 3_654_863 : int;\n 3_900_609 : nat;\n 737_307_005 : table8;\n 936_573_133 : text;\n }\n type table8 = vec nat8\n type table9 = opt table10\n wire_type: nat, expect_type: nat64\n 1: Subtyping error: TypeInner :: Nat64).\nConsider gracefully handling failures from this canister or altering the canister to handle exceptions. See documentation: http://internetcomputer.org/docs/current/references/execution-errors#trapped-explicitly" }) ``` TLDR: The error seems to be caused by a mismatch between the expected and actual data types: - **Wire Type** : `nat` - **Expected Type** : `nat64` My current installation struct (coded based on my interpretion of these type mismatch errors) ```auto #[derive(CandidType, Serialize, Deserialize, Clone, Debug)] pub enum ICRC1Args { Init(ICRC1InitArgs), Upgrade(ICRC1UpgradeArgs), } #[derive(CandidType, Serialize, Deserialize, Clone, Debug)] pub struct ICRC1InitArgs { pub token_symbol: String, pub token_name: String, pub minting_account: Account, pub transfer_fee: Nat, pub metadata: Vec<(String, MetadataValue)>, pub initial_balances: Vec<(Account, Nat)>, pub archive_options: ArchiveOptions, pub feature_flags: Option, pub decimals: Option, pub maximum_number_of_accounts: Option, pub accounts_overflow_trim_quantity: Option, pub fee_collector_account: Option, pub max_memo_length: Option, } ``` I need to get the actual struct defined in the coded canister (the one retrieved via the dfx.json) so that I can use that for my installation arguments in my PocketIC tests. ---
**Author:** ![h1teshtr1path1](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/h1teshtr1path1/32/24662_2.png) [@h1teshtr1path1](https://forum.dfinity.org/u/h1teshtr1path1)\ **Post date:** [October 10, 2024, 5:36am UTC](https://forum.dfinity.org/t/icrc-1-where-can-i-find-the-icr1-implementation-ledger-code-i-need-the-installation-argument-struct/36035/2 "2024-10-10T05:36:03Z")
Hello @vincentes , i think this should help : > ---
**Author:** ![vincentes](https://avatars.discourse-cdn.com/v4/letter/v/858c86/32.png) [@vincentes](https://forum.dfinity.org/u/vincentes)\ **Post date:** [October 10, 2024, 3:05pm UTC](https://forum.dfinity.org/t/icrc-1-where-can-i-find-the-icr1-implementation-ledger-code-i-need-the-installation-argument-struct/36035/4 "2024-10-10T15:05:47Z")
What type do I use in Rust for candid nat64? I’m using nat and it’s saying that there’s a type mismatch between `nat` and `nat64`. ---
**Author:** ![sea-snake](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/sea-snake/32/7243_2.png) [@sea-snake](https://forum.dfinity.org/u/sea-snake)\ **Post date:** [October 10, 2024, 4:26pm UTC](https://forum.dfinity.org/t/icrc-1-where-can-i-find-the-icr1-implementation-ledger-code-i-need-the-installation-argument-struct/36035/5 "2024-10-10T16:26:33Z")
[https://internetcomputer.org/docs/current/references/candid-ref#type-natn-and-intn](https://internetcomputer.org/docs/current/references/candid-ref#type-natn-and-intn) `u64` should be the Rust equivalent of candid `nat64`.