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

# Captive Core

> Captive Core invokes the stellar-core binary as a subprocess to stream ledgers from the Stellar network.

Captive Core invokes the `stellar-core` binary as a subprocess to stream ledgers from the Stellar network. It can be used to stream a ledger range from the past or to stream new ledgers whenever they are confirmed by the network.

## Prerequisites

Using captive Core requires stellar-core binary to be [installed](https://developers.stellar.org/docs/validators/admin-guide/installation.md) first.

### Installation

1. Install Stellar Core:
   * Option 1: Build from source by following the [Installation Guide](https://developers.stellar.org/docs/validators/admin-guide/installation.md#installing-from-source)
   * Option 2: Install via a package manager by referring to the [Package-based Installation Guide](https://developers.stellar.org/docs/validators/admin-guide/installation.md#package-based-installation)

2. Verify installation:

   ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
   ./stellar-core version
   ```

## Configuration and Usage

Set the captive core configuration for target Stellar network in TOML format. This configuration requires at a minimum:

* The **passphrase** of the Stellar network you want to connect to.
* The path to **history archives**, necessary for initialization.

**Step 1: Generate a `CaptiveCoreToml` configuration**

```go theme={"theme":{"light":"github-light","dark":"github-dark"}}
captiveCoreToml, err := ledgerbackend.NewCaptiveCoreTomlFromData(
    ledgerbackend.PubnetDefaultConfig,
    ledgerbackend.CaptiveCoreTomlParams{
        NetworkPassphrase:  network.PublicNetworkPassphrase,
        HistoryArchiveURLs: network.PublicNetworkhistoryArchiveURLs,
    },
)

if err != nil {
    // Handle error
}
```

**Step 2: Construct a `CaptiveCoreConfig` object**

Next, create a CaptiveCoreConfig object. This object combines the CaptiveCoreToml configuration with the path to your stellar-core binary and other necessary parameters.

```go theme={"theme":{"light":"github-light","dark":"github-dark"}}
config := ledgerbackend.CaptiveCoreConfig{
    BinaryPath:         "/usr/local/bin/stellar-core", // Adjust to your stellar-core binary path
    NetworkPassphrase:  network.PublicNetworkPassphrase,
    HistoryArchiveURLs: network.PublicNetworkhistoryArchiveURLs,
    Toml:               captiveCoreToml,
}
```

**Step 3: Instantiate `CaptiveStellarCore`**

Finally, create a `CaptiveStellarCore` instance using the `NewCaptive` function. This function manages the complete lifecycle of the stellar-core process, including communication with your application.

```go theme={"theme":{"light":"github-light","dark":"github-dark"}}
captiveStellarCoreBackend, err := ledgerbackend.NewCaptive(config)
if err != nil {
    // Handle error
}
```

The `captiveStellarCoreBackend` can now be used to retrieve ledger data within a specified range. For detailed usage, refer to the [code samples](https://developers.stellar.org/docs/data/indexers/build-your-own/ingest-sdk/examples).