icrc-ledger
ICRC Ledger Standards
What This Is
ICRC-1 is the fungible token standard on Internet Computer, defining transfer, balance, and metadata interfaces. ICRC-2 extends it with approve/transferFrom (allowance) mechanics, enabling third-party spending like ERC-20 on Ethereum.
Prerequisites
- For Motoko: mops with
core = "2.3.1"in mops.toml - For Rust:
ic-cdk = "0.19",candid = "0.10",icrc-ledger-types = "0.1"in Cargo.toml
Canister IDs
| Token | Ledger Canister ID | Decimals |
|---|---|---|
| ICP | ryjl3-tyaaa-aaaaa-aaaba-cai |
8 |
| ckBTC | mxzaz-hqaaa-aaaar-qaada-cai |
8 |
| ckETH | ss2fx-dyaaa-aaaar-qacoq-cai |
18 |
More from dfinity/icskills
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Guides use of the icp command-line tool for building and deploying Internet Computer applications. Covers project configuration (icp.yaml), recipes, environments, canister lifecycle, and identity management. Use when building, deploying, or managing any IC project. Use when the user mentions icp, dfx, canister deployment, local network, or project setup. Do NOT use for canister-level programming patterns like access control, inter-canister calls, or stable memory — use domain-specific skills instead.
134internet-identity
Integrate Internet Identity authentication. Covers passkey and OpenID login flows, delegation handling, and principal-per-app isolation. Use when adding login, sign-in, auth, passkeys, or Internet Identity to a frontend or canister. Do NOT use for wallet integration or ICRC signer flows — use wallet-integration instead.
126asset-canister
Deploy frontend assets to the IC. Covers certified assets, SPA routing with .ic-assets.json5, content encoding, and programmatic uploads. Use when hosting a frontend, deploying static files, or setting up SPA routing on IC. Do NOT use for canister-level code patterns or custom domain setup — use custom-domains instead.
126stable-memory
Persist canister state across upgrades. Covers StableBTreeMap and MemoryManager in Rust, persistent actor in Motoko, and upgrade hook patterns. Use when dealing with canister upgrades, data persistence, data lost after upgrade, stable storage, StableBTreeMap, pre_upgrade traps, or heap vs stable memory. Do NOT use for inter-canister calls or access control — use multi-canister or canister-security instead.
121https-outcalls
Make HTTPS requests from canisters to external web APIs. Covers transform functions for consensus, cycle cost management, response size limits, and idempotency patterns. Use when a canister needs to call an external API, fetch data from the web, or make HTTP requests. Do NOT use for EVM/Ethereum calls — use evm-rpc instead.
121canister-security
IC-specific security patterns for canister development in Motoko and Rust. Covers access control, anonymous principal rejection, reentrancy prevention (CallerGuard pattern), async safety (saga pattern), callback trap handling, cycle drain protection, and safe upgrade patterns. Use when writing or modifying any canister that modifies state, handles tokens, makes inter-canister calls, or implements access control.
119