> ## Documentation Index
> Fetch the complete documentation index at: https://cosmos-docs-cosmjs-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Signing & Wallet Errors

> Errors from key management, mnemonic handling, HD derivation, and signing operations.

These errors occur during key management, mnemonic handling, HD derivation, wallet encryption, and signing operations. They help diagnose issues with wallet setup and transaction signing.

## Address Not Found in Wallet

Every wallet implementation throws this error when asked to sign for an address
it does not hold:

```
"Address cosmos1abc... not found in wallet"
```

This applies to `Secp256k1HdWallet`, `DirectSecp256k1HdWallet`,
`Secp256k1Wallet`, `DirectSecp256k1Wallet`, and the Ledger signer.

Fix: only sign for addresses returned by `wallet.getAccounts()`.

## Invalid Mnemonic

Thrown by `EnglishMnemonic` (and by extension all `fromMnemonic` factory methods)
when the BIP-39 mnemonic is invalid — wrong word count, unknown words, or bad
checksum:

```typescript theme={"system"}
import { DirectSecp256k1HdWallet } from "@cosmjs/proto-signing";

try {
  const wallet = await DirectSecp256k1HdWallet.fromMnemonic("invalid words here");
} catch (error) {
  // BIP-39 validation error from EnglishMnemonic (@cosmjs/crypto) / @scure/bip39
}
```

## HD Derivation Path Errors

Thrown by `Slip10` when the derivation path is malformed:

| Error                                                  | Cause                             |
| ------------------------------------------------------ | --------------------------------- |
| `"Path string must start with 'm'"`                    | Missing `m` prefix                |
| `"Syntax error while reading path component"`          | Malformed path segment            |
| `"Component value too high. Must not exceed 2**31-1."` | Index out of BIP-32 range         |
| `"Normal keys are not allowed with ed25519"`           | Ed25519 requires hardened indices |

## Invalid Key Errors

```
"input data is not a valid secp256k1 private key"   // Wrong length or invalid key bytes
"Invalid pubkey length"                               // Expected 33 (compressed) or 65 (uncompressed)
"Signature must be 64 bytes long."                    // r + s must be exactly 64 bytes
```

## Account Sequence Mismatch

Not a CosmJS-specific error, but a common chain-level rejection. When the
sequence number in the signed transaction does not match the account's current
sequence on-chain, the node rejects it during CheckTx:

```
BroadcastTxError: Broadcasting transaction failed with code 32 (codespace: sdk).
Log: account sequence mismatch, expected 42, got 41
```

Fix: re-query the account sequence before signing, or avoid concurrent
transactions from the same account.

## Encryption / Decryption Errors

Wallet serialization uses XChaCha20-Poly1305 encryption. Deserialization throws
when the password is wrong or the data is corrupted:

```typescript theme={"system"}
try {
  const wallet = await DirectSecp256k1HdWallet.deserialize(serialized, "wrong-password");
} catch (error) {
  // Decryption failure from @noble/ciphers
}
```

The only supported algorithm is `xchacha20poly1305-ietf`. Using anything else
throws:

```
"Unsupported encryption algorithm: '...'"
```