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

# Spark support on Turnkey

[Spark](https://www.spark.money/) is a Bitcoin Layer 2 network that uses an identity key system for on-chain addressing. Turnkey supports Spark address derivation and signing via plain [BIP-340 Schnorr](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki) signatures.

The supported address formats are:

| Network | Address Format                 | HRP       |
| ------- | ------------------------------ | --------- |
| Mainnet | `ADDRESS_FORMAT_SPARK_MAINNET` | `spark`   |
| Regtest | `ADDRESS_FORMAT_SPARK_REGTEST` | `sparkrt` |

### BIP-32 derivation path

Spark uses a unique BIP-32 purpose number (`8797555`) rather than the standard BIP-44 coin type system. The default derivation path for the identity key is:

```
m/8797555'/{account}'/0'
```

When creating a wallet account via the Turnkey dashboard or API, select `ADDRESS_FORMAT_SPARK_MAINNET` or `ADDRESS_FORMAT_SPARK_REGTEST` and the path will be set automatically.

<Note>
  Only `secp256k1` keys are supported for Spark. Attempting to use an ed25519 key will result in an error.
</Note>

## Schnorr signing

Spark transactions are signed using **plain BIP-340 Schnorr** — specifically, without the Taproot key tweak described [here](/bitcoin#schnorr-signatures-and-tweaks) that Bitcoin P2TR addresses require. This is an important distinction: passing a Spark address as the `signWith` parameter to `SIGN_RAW_PAYLOAD` triggers plain Schnorr signing, while passing a Bitcoin Taproot (P2TR) address triggers tweaked Schnorr signing per [BIP-341](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki).

Use the [`SIGN_RAW_PAYLOAD`](/api-reference/activities/sign-raw-payload) or [`SIGN_RAW_PAYLOAD_V2`](/api-reference/activities/sign-raw-payload) activity to sign Spark payloads. The `hashFunction` field should match how the payload was prepared (e.g. `HASH_FUNCTION_NO_OP` if you are passing a pre-hashed payload).

The returned signature will always have `V = "00"` since Schnorr signatures do not use a recovery ID.

### Signing scheme selection

Turnkey automatically selects the correct signing scheme based on the address format associated with your key:

| Address type          | Signing scheme            |
| --------------------- | ------------------------- |
| Bitcoin P2TR          | Tweaked Schnorr (BIP-341) |
| Spark Mainnet/Regtest | Plain Schnorr (BIP-340)   |
| All others            | ECDSA                     |

## Networks supported

* **Spark Mainnet** — `ADDRESS_FORMAT_SPARK_MAINNET`
* **Spark Regtest** — `ADDRESS_FORMAT_SPARK_REGTEST`

## Key features

* **secp256k1 signing**: Turnkey fully supports the secp256k1 curve used by Spark
* **Plain BIP-340 Schnorr**: Distinct from the tweaked Schnorr used for Bitcoin Taproot — no key tweak is applied
* **Bech32m addressing**: Spark identity key addresses are Bech32m-encoded canonical protobuf payloads
* **Spark-specific BIP-32 purpose**: Derivation path uses purpose `8797555` per the Spark protocol spec

## SDK Example

* [`examples/with-spark-schnorr`](https://github.com/tkhq/sdk/tree/main/examples/with-spark-schnorr): demonstrates wallet initialization, SO authentication and token minting + sending on Spark using Turnkey!

## Additional resources

* [Spark addressing specification](https://docs.spark.money/wallets/addressing)
* [Spark CLI reference](https://docs.spark.money/tools/cli)
* [BIP-340: Schnorr Signatures for secp256k1](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki)

If you're building on Spark and have questions about integrating with Turnkey, contact us at [hello@turnkey.com](mailto:hello@turnkey.com), on [X](https://x.com/turnkeyhq/), or [on Slack](https://join.slack.com/t/clubturnkey/shared_invite/zt-3aemp2g38-zIh4V~3vNpbX5PsSmkKxcQ).