Transfer Checked

Program CPI guide for Light Token transfer with decimal validation. Includes step-by-step implementation and full code examples.

1. TransferChecked validates that the decimals parameter matches the mint’s decimals.
2. Use TransferCheckedCpi for Light-to-Light transfers in on-chain programs when you need decimal verification without interface routing.
3. For transfers involving SPL or Token 2022 accounts, use Transfer Interface instead. It uses transferChecked under the hood.

Agent skill

Install the agent skill:

npx skills add https://zkcompression.com

See the AI tools guide for dedicated skills.

TypeScript Client

transferChecked is called automatically under the hood by transferInterface and createTransferInterfaceInstructions. You do not need to call it directly.

Rust Client

TransferChecked is called automatically under the hood by TransferInterface. You do not need to call it directly.

Program

Guide

Find a full code example at the end.

1. Transfer Checked with CPI

   invoke (External signer)

   use light_token::instruction::TransferCheckedCpi;
   
   TransferCheckedCpi {
       source: source.clone(),
       mint: mint.clone(),
       destination: destination.clone(),
       amount,
       decimals,
       authority: authority.clone(),
       system_program: system_program.clone(),
       max_top_up: None,
       fee_payer: None,
   }
   .invoke()?;
   

   invoke_signed (PDA signer)

   use light_token::instruction::TransferCheckedCpi;
   
   let signer_seeds = authority_seeds!(bump);
   
   TransferCheckedCpi {
       source: source.clone(),
       mint: mint.clone(),
       destination: destination.clone(),
       amount,
       decimals,
       authority: authority.clone(),
       system_program: system_program.clone(),
       max_top_up: None,
       fee_payer: None,
   }
   .invoke_signed(&[signer_seeds])?;
   

Full Code Example

View the source code and full example with shared test utilities.

lib.rs

#![allow(unexpected_cfgs, deprecated)]

use anchor_lang::prelude::*;
use light_token::instruction::TransferCheckedCpi;

declare_id!("HXmfewpozFdxhM8BayL9v5541gwoGMXTrUoip5KySs2f");

#[program]
pub mod light_token_anchor_transfer_checked {
    use super::*;

    pub fn transfer_checked(
        ctx: Context<TransferCheckedAccounts>,
        amount: u64,
        decimals: u8,
    ) -> Result<()> {
        TransferCheckedCpi {
            source: ctx.accounts.source.to_account_info(),
            mint: ctx.accounts.mint.to_account_info(),
            destination: ctx.accounts.destination.to_account_info(),
            amount,
            decimals,
            authority: ctx.accounts.authority.to_account_info(),
            system_program: ctx.accounts.system_program.to_account_info(),
            fee_payer: ctx.accounts.fee_payer.to_account_info(),
        }
        .invoke()?;
        Ok(())
    }
}

#[derive(Accounts)]
pub struct TransferCheckedAccounts<'info> {
    /// CHECK: Light token program for CPI
    pub light_token_program: AccountInfo<'info>,
    /// CHECK: Validated by light-token CPI
    #[account(mut)]
    pub source: AccountInfo<'info>,
    /// CHECK: Validated by light-token CPI
    pub mint: AccountInfo<'info>,
    /// CHECK: Validated by light-token CPI
    #[account(mut)]
    pub destination: AccountInfo<'info>,
    pub authority: Signer<'info>,
    #[account(mut)]
    pub fee_payer: Signer<'info>,
    pub system_program: Program<'info, System>,
}

AI Prompt

Add transfer-checked CPI to an Anchor program

CopiedCopy promptOpen in Cursor

---
description: Add transfer-checked CPI to an Anchor program
allowed-tools: Bash, Read, Write, Edit, Glob, Grep, WebFetch, AskUserQuestion, Task, TaskCreate, TaskGet, TaskList, TaskUpdate, TaskOutput, mcp__deepwiki, mcp__zkcompression
---

## Add transfer-checked CPI to an Anchor program

Context:
- Guide: https://zkcompression.com/light-token/cookbook/transfer-checked
- Skills and resources index: https://zkcompression.com/skill.md
- SPL to Light reference: https://zkcompression.com/api-reference/solana-to-light-comparison
- Crate: light-token (TransferCheckedCpi)
- Example: https://github.com/Lightprotocol/examples-light-token/tree/main/programs/anchor/basic-instructions/transfer-checked

Key CPI struct: `light_token::instruction::TransferCheckedCpi`

Note: TransferInterface uses TransferChecked under the hood for Light-to-Light transfers.
Use TransferChecked/TransferCheckedCpi directly only when you need Light-to-Light without interface routing.

### 1. Index project
- Grep `declare_id|#\[program\]|anchor_lang|Account<|Pubkey|invoke|transfer|decimals|amount` across src/
- Glob `**/*.rs` and `**/Cargo.toml` for project structure
- Identify: program ID, existing instructions, account structs, token accounts
- Read Cargo.toml — note existing dependencies and framework version
- Task subagent (Grep/Read/WebFetch) if project has multiple crates to scan in parallel

### 2. Read references
- WebFetch the guide above — review the Program tab CPI code samples
- WebFetch skill.md — check for a dedicated skill and resources matching this task
- TaskCreate one todo per phase below to track progress

### 3. Clarify intention
- AskUserQuestion: what is the goal? (add transfer-checked to existing program, new program from scratch, migrate from SPL transfer_checked)
- AskUserQuestion: should the authority be an external signer or a PDA? (determines invoke vs invoke_signed)
- Summarize findings and wait for user confirmation before implementing

### 4. Create plan
- Based on steps 1–3, draft an implementation plan: which files to modify, what code to add, dependency changes
- Follow the guide's step order: Build TransferCheckedCpi struct → call .invoke() or .invoke_signed()
- If anything is unclear or ambiguous, loop back to step 3 (AskUserQuestion)
- Present the plan to the user for approval before proceeding

### 5. Implement
- Add deps if missing: Bash `cargo add light-token anchor-lang@0.31`
- Follow the guide and the approved plan
- Write/Edit to create or modify files
- TaskUpdate to mark each step done

### 6. Verify
- Bash `anchor build`
- Bash `anchor test` if tests exist
- TaskUpdate to mark complete

### Tools
- mcp__zkcompression__SearchLightProtocol("<query>") for API details
- mcp__deepwiki__ask_question("Lightprotocol/light-protocol", "<q>") for architecture
- Task subagent with Grep/Read/WebFetch for parallel lookups
- TaskList to check remaining work

Related Guides

Transfer interface

Wrap and unwrap

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