## Create Session

`client.Beta.Chat.New(ctx, params) (*BetaChatNewResponse, error)`

**post** `/api/v1/chat`

Create a chat session, optionally bound to indexes (locked after the first message).

### Parameters

- `params BetaChatNewParams`

  - `OrganizationID param.Field[string]`

    Query param

  - `ProjectID param.Field[string]`

    Query param

  - `IndexIDs param.Field[[]string]`

    Body param: Indexes this session will retrieve from. Once set and the first message has been sent, the source set is locked for the session's lifetime. Leave null to create an unbound session.

### Returns

- `type BetaChatNewResponse struct{…}`

  Summary of a chat session, including its title and last run metadata.

  - `LastUpdatedAt string`

    ISO-format timestamp showing when the session was last updated.

  - `SessionID string`

    Unique session identifier.

  - `GeneratedTitle string`

    Auto-generated title derived from the first user message.

  - `IndexIDs []string`

    Indexes this session is bound to. Null on unbound sessions.

  - `JobMetadata BetaChatNewResponseJobMetadata`

    Token usage and status from the most recent run. Null if the session has not been run yet.

    - `DurationMs float64`

    - `Error string`

    - `ExportConfigIDs []string`

    - `IsError bool`

    - `TotalInputTokens int64`

    - `TotalOutputTokens int64`

    - `Turns int64`

### Example

```go
package main

import (
  "context"
  "fmt"

  "github.com/stainless-sdks/llamacloud-prod-go"
  "github.com/stainless-sdks/llamacloud-prod-go/option"
)

func main() {
  client := llamacloudprod.NewClient(
    option.WithAPIKey("My API Key"),
  )
  chat, err := client.Beta.Chat.New(context.TODO(), llamacloudprod.BetaChatNewParams{

  })
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", chat.SessionID)
}
```

#### Response

```json
{
  "last_updated_at": "2026-04-22T12:34:41.342245",
  "session_id": "ses-abc123",
  "generated_title": "What were the main findings in Q3?...",
  "index_ids": [
    "idx-abc123",
    "idx-def456"
  ],
  "job_metadata": {
    "duration_ms": 0,
    "error": "error",
    "export_config_ids": [
      "string"
    ],
    "is_error": true,
    "total_input_tokens": 0,
    "total_output_tokens": 0,
    "turns": 0
  }
}
```