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

# Create Index

Creates and returns a new encrypted index based on the provided configuration.

```cpp theme={null}
std::unique_ptr<cyborg::EncryptedIndex> 
    CreateIndex(const std::string index_name,
                const std::array<uint8_t, 32>& index_key,
                const IndexConfig& index_config,
                const std::optional<size_t>& max_cache_size = 0,
                cyborg::Logger* logger = nullptr);
```

### Parameters

| Parameter        | Type                                  | Description                                                                                    |
| ---------------- | ------------------------------------- | ---------------------------------------------------------------------------------------------- |
| `index_name`     | `std::string`                         | Name of the index to create (must be unique).                                                  |
| `index_key`      | `std::array<uint8_t, 32>`             | 32-byte encryption key for the index, used to secure index data.                               |
| `index_config`   | [`IndexConfig`](../types#indexconfig) | Configuration for the index type (e.g., IVFFlat, IVFPQ).                                       |
| `max_cache_size` | `std::optional<size_t>`               | *(Optional)* Maximum size for the local cache (default is `0`).                                |
| `logger`         | [`cyborg::Logger*`](./logger)         | *(Optional)* Pointer to a logger instance for capturing operation logs (default is `nullptr`). |

### Returns

`std::unique_ptr<cyborg::EncryptedIndex>`: A pointer to the newly created index ([`EncryptedIndex`](../encrypted-index)).

### Exceptions

<AccordionGroup>
  <Accordion title="std::invalid_argument">
    * Throws if the index name is not unique.
    * Throws if the index configuration is invalid.
  </Accordion>

  <Accordion title="std::runtime_exception">
    * Throws if the index could not be created.
  </Accordion>
</AccordionGroup>

### Example Usage

```cpp theme={null}
#include "cyborgdb_core/client.hpp"
#include "cyborgdb_core/encrypted_index.hpp"
#include "cyborgdb_core/logger.hpp"
#include <array>

// ... Initialize the client ...

// Create a secure 32-byte key (example: all zeros)
std::array<uint8_t, 32> index_key = {0};

// Example vector dimensionality & number of lists
const size_t vector_dim = 1024;
const size_t num_lists = 128;

// Create an index configuration (e.g., using an IVFFlat configuration)
IndexIVFFlat index_config(vector_dim, num_lists, DistanceMetric::euclidean);

// Optional: Create and configure a logger
cyborg::Logger logger;
logger.Configure(LogLevel::Info, true, "index_creation.log");

auto index = client.CreateIndex("my_index", index_key, index_config, 1000, &logger);
```