'Error Code: ConstraintSeeds. Error Number: 2006. Error Message: A seeds constraint was violated.'

Question

todo.js:186 Error adding todo: AnchorError: AnchorError caused by account: todo_account.
Error Code: ConstraintSeeds. Error Number: 2006. Error Message: A seeds constraint was violated.
Program log: Left:
Program log: DXYxVwuSVkUVzBCBnfLLygAE8gueEUMXUFXyez3J94Kx
Program log: Right:
Program log: 7TYqbwfHNTvVpbT9q4QX7iKBEqpL3ojm9144Adpbgfbo
    at AnchorError.parse (index.js:1277:20)
    at translateError (index.js:1361:37)
    at Object.rpc [as addTodo] (index.js:5002:23)
    at async addTodo (todo.js:169:24)
    at async handleSubmit (index.js:37:13)

addTodo function

const addTodo = async (event, publicKey) => {
        event.preventDefault(); // Prevent default form submission behavior
    
        // Check if input is empty
        if (!input.trim()) {
            console.error("Input cannot be empty");
            return; // Prevent adding empty todos
        }
    
        // Ensure that the wallet is initialized
        if (!initialized || !publicKey) {
            console.error("Wallet is not initialized or public key is not available");
            return;
        }
    
        try {
            // Generate PDA for the todo account using the correct seeds
            const [todoAccount] = await PublicKey.findProgramAddress(
                [Buffer.from("TODO_STATE"), publicKey.toBuffer(), Buffer.from([todos.length])],
                program.programId
            );
    
            // Check if user profile exists
            const [profilePda] = PublicKey.findProgramAddressSync(
                [Buffer.from('USER_STATE'), publicKey.toBuffer()],
                program.programId
            );
    
            const userProfileAccount = await program.account.userProfile.fetchNullable(profilePda);
            if (!userProfileAccount) {
                toast.error('User profile not found. Please initialize your user first.');
                return;
            }
    
            // Call the program to add a todo
            const tx = await program.rpc.addTodo(
                input,
                {
                    accounts: {
                        todoAccount: todoAccount,
                        userProfile: profilePda,
                        authority: publicKey,
                        systemProgram: SystemProgram.programId,
                    },
                }
            );
    
            console.log("Todo added successfully:", tx);
            
            // Reset the input field after a successful submission
            setInput('');
        } catch (error) {
            console.error("Error adding todo:", error);
            toast.error(`Error adding todo: ${error.message}`);
        }
    };

pages/index.js

import { WalletMultiButton } from '@solana/wallet-adapter-react-ui';
import { useTodo } from '../hooks/todo';
import Loading from '../components/Loading';
import TodoSection from '../components/todo/TodoSection';
import styles from '../styles/Home.module.css';
import { useEffect, useState } from 'react';
import { useWallet } from '@solana/wallet-adapter-react';

const Home = () => {
    const { connected, publicKey } = useWallet();
    const {
        initialized,
        initializeUser,
        loading,
        transactionPending,
        todos,
        input,
        setInput,
        addTodo,
        markTodo,
    } = useTodo();

    const [clientInitialized, setClientInitialized] = useState(false);

    useEffect(() => {
        setClientInitialized(true);
    }, []);

    if (!clientInitialized) {
        return null;
    }

    const handleSubmit = async (event) => {
        event.preventDefault();
        // Ensure publicKey is available before calling addTodo
        if (publicKey) {
            await addTodo(event, publicKey); // Pass publicKey directly to addTodo
        } else {
            console.error("Wallet not connected. Unable to add todo.");
        }
    };

    return (
        <div className={styles.container}>
            <div className={styles.actionsContainer}>
                {initialized ? (
                    <div className={styles.todoInput}>
                        <form onSubmit={handleSubmit}>
                            <input
                                value={input}
                                onChange={(e) => setInput(e.target.value)}
                                id={styles.inputField}
                                type="text"
                                placeholder='Create a new todo...'
                            />
                            <button type="submit" disabled={transactionPending}>
                                Add
                            </button>
                        </form>
                    </div>
                ) : (
                    <button type="button" className={styles.button} onClick={initializeUser} disabled={transactionPending}>
                        Initialize
                    </button>
                )}
                <WalletMultiButton />
            </div>

            <div className={styles.mainContainer}>
                <Loading loading={loading}>
                    <TodoSection 
                        title="Tasks" 
                        todos={todos ? todos.filter(todo => !todo.account.marked) : []} 
                        action={markTodo} 
                    />
                    <TodoSection 
                        title="Completed" 
                        todos={todos ? todos.filter(todo => todo.account.marked) : []} 
                        action={markTodo} 
                    />
                </Loading>
            </div>
        </div>
    );
};

export default Home;

Answer 1

The error is coming from the todo_account.

The address derived from your frontend is different from the one your program.

That is what the 2006 anchor error code means,

anchor error codes -> https://github.com/coral-xyz/anchor/blob/36e336aba0aab93a6d168118667f5970336a02a0/ts/packages/anchor-errors/src/index.ts#L41