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

# Using chains with Tier 2 support

> Embedded wallets via raw signing with helper methods and EOA support

Tier 2 chains provide embedded wallet support via raw signing with helper methods and EOA support. Gas handling and policies are not yet supported. Because many chains share the same elliptic curves — secp256k1 (EVM) and Ed25519 (Solana) — a single Dynamic embedded wallet can sign transactions across all of them without creating new wallets or asking users to authenticate again.

## How it works

1. Create an EVM and Solana embedded wallet for the user using Dynamic
2. Extract the public key from the appropriate root wallet
3. Apply chain-specific hashing and encoding to derive the chain address
4. Use Dynamic's raw signing to sign chain-native transactions

No additional keys or wallets are created. The user authenticates once with Dynamic and gets access to all derived chains.

## User Management

> [!NOTE]
>
> Tier 2 chains are not natively supported in Dynamic's UI or session model. You are responsible for managing the user-facing experience: displaying derived addresses, associating them with your user records, and handling any chain-specific account state yourself.

## Key Security Warning

> [!WARNING]
>
> **Exporting the root wallet key exposes all derived addresses.** The EVM and Solana embedded wallet private keys are the cryptographic root of every Tier 2 address derived from them. If you export the EVM or Solana private key, anyone with that key can independently derive and control all associated Tier 2 addresses across every chain. Never expose root wallet keys unless you have explicitly designed for that use case.

## Supported Tier 2 Chains

| Chain | Curve | Root Wallet | Implementation |
| - | - | - | - |
| [Aptos](https://docs.dynamic.xyz/docs/javascript/reference/tier-2-chains/aptos.md) | Ed25519 | Solana | `SHA3-256(pubkey ∥ 0x00)` |
| [Algorand](https://docs.dynamic.xyz/docs/javascript/reference/tier-2-chains/algorand.md) | Ed25519 | Solana | base32-encoded pubkey |
| [Cosmos](https://docs.dynamic.xyz/docs/javascript/reference/tier-2-chains/cosmos.md) | secp256k1 | EVM | `bech32(RIPEMD-160(SHA-256(pubkey)))` |
| Spark | BIP-340 | Bitcoin | — |

## Bitcoin Signing

Bitcoin is a Tier 1 chain with full embedded wallet support. The Bitcoin embedded wallet uses **BIP-340 (Schnorr/Taproot)** signing via the FROST protocol — the same underlying approach as EVM (ECDSA) and Solana (EdDSA) embedded wallets. Using the Bitcoin embedded wallet as a signing root for other BIP-340-compatible chains works the same way as the EVM and Solana Tier 2 patterns, but documentation is not yet published. BIP-340-based chains without published guides are [Tier 3](https://docs.dynamic.xyz/docs/embedded-wallets/chains/tier-3-chains.md) for now. Reach out if you need guidance.

## Extending to other chains

Any chain that uses secp256k1 or Ed25519 can be supported using the same pattern — derive the address from the matching root wallet and sign using Dynamic's raw signing. If a chain uses a different curve or encoding, see [chains with Tier 3 support](https://docs.dynamic.xyz/docs/embedded-wallets/chains/tier-3-chains.md) or reach out to discuss native SDK support.

## Get started

* **JavaScript / headless SDK** — See the [technical overview for chains with Tier 2 support](https://docs.dynamic.xyz/docs/javascript/reference/tier-2-chains/overview.md) for shared setup, utility functions, and a full walkthrough using Aptos as an example.
* **React Native** — See the [React Native guide for chains with Tier 2 support](https://docs.dynamic.xyz/docs/react-native/chains/tier-2-chains/overview.md) for the same patterns using the React Native client SDK.

Then navigate to the specific chain page for complete implementation details.


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