> For the complete documentation index, see [llms.txt](https://docs.zebec.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zebec.io/zebec-silver-card/silver-card-sdk/configuration-parameters.md).

# Configuration Parameters

#### ZebecCardService

To create an instance of `ZebecCardService`, you need:

* **signer**: An instance of `ethers.Signer`.
* **chainId**: The ID of the blockchain (see list of supported chains below).
* **apiConfig**: Object containing `apiKey` and `encryptionKey`.
* **sdkConfig (optional)**: SDK-specific settings, such as:
  * `sandbox`: Boolean, set to `true` for testnets.

#### ZebecCardTAOService

To create an instance of `ZebecCardTAOService`, you need:

* **signer**: An instance of `Keyring` or `Signer`.
* **apiConfig**: Object containing `apiKey` and `encryptionKey`.
* **sdkConfig (optional)**: SDK-specific settings, such as:
  * `sandbox`: Boolean, set to `true` for testnets.

#### EVM Supported Chains

| Chain               | Chain ID                        |
| ------------------- | ------------------------------- |
| Ethereum            | Mainnet (1), Sepolia (11155111) |
| Binance Smart Chain | Mainnet (56), Testnet (97)      |
| Base                | Mainnet (8453)                  |