---
title: "add_storyboard_sound: Add a sound to a film"
description: "Place ready audio the account already holds — a voice-over, music or an audio upload — on a film as a sound card."
canonical_url: "https://meetkuro.com/agents/tools/add_storyboard_sound/"
updated: 2026-11-03
locale: "en"
tool: "add_storyboard_sound"
scopes: ["storyboards.write"]
---

# add_storyboard_sound

**Add a sound to a film**

Place ready audio the account already holds — a voice-over, music or an audio upload — on a film as a sound card. from_scene is the first scene it covers (absent is the start); offsets, the source window, length (loop, once, in_full) and gain_db are optional, and a card that names neither length nor gain lands as a hand-drop would. Sounds are listed in the answer's sounds array, numbered from 1. One undo step; undo_storyboard takes it back. Spends no credits.

## Scope

- `storyboards.write` — Authors, edits, renders and deletes storyboards. Reading a board rides media.read, and the two board tools that spend need generation.write as well.

## Behaviour

- **Writes**: Creates or changes items in the caller's own account.
- **Adds or updates**: Adds or updates; nothing the caller already has is deleted or overwritten.
- **Stays in the account**: Stays inside the caller's private Kuro account: any media provider it calls acts on Kuro's account, and the result is visible to no one else.

## Credits

What the tool's description says about credits, verbatim:

- Spends no credits.

## Inputs

| Name | Type | Required | Details |
| --- | --- | --- | --- |
| `storyboard_id` | string | yes | uuid |
| `reference` | object (type: "upload") or object (type: "generation") | yes | — |
| `from_scene` | integer | no | First scene the card covers. Absent means from the start. — > 0 |
| `start_offset_seconds` | number | no | ≥ 0 |
| `source_in_seconds` | number | no | ≥ 0 |
| `source_out_seconds` | number or null | no | — |
| `loop_duration_seconds` | number or null | no | — |
| `length` | string | no | one of "loop", "once", "in_full" |
| `gain_db` | integer | no | ≥ -40; ≤ 0 |

## Example call

A `tools/call` request with the required arguments only, each a placeholder read off the schema. Replace them before sending.

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "add_storyboard_sound",
    "arguments": {
      "storyboard_id": "00000000-0000-4000-8000-000000000000",
      "reference": {
        "type": "upload",
        "upload_id": "00000000-0000-4000-8000-000000000000"
      }
    }
  }
}
```

## Input schema

As the server sends it in `tools/list`:

```json
{
  "type": "object",
  "properties": {
    "storyboard_id": {
      "type": "string",
      "format": "uuid"
    },
    "reference": {
      "anyOf": [
        {
          "type": "object",
          "properties": {
            "type": {
              "type": "string",
              "const": "upload"
            },
            "upload_id": {
              "type": "string",
              "format": "uuid"
            }
          },
          "required": [
            "type",
            "upload_id"
          ],
          "additionalProperties": false
        },
        {
          "type": "object",
          "properties": {
            "type": {
              "type": "string",
              "const": "generation"
            },
            "generation_id": {
              "type": "string",
              "format": "uuid"
            }
          },
          "required": [
            "type",
            "generation_id"
          ],
          "additionalProperties": false
        }
      ]
    },
    "from_scene": {
      "type": "integer",
      "exclusiveMinimum": 0,
      "description": "First scene the card covers. Absent means from the start."
    },
    "start_offset_seconds": {
      "type": "number",
      "minimum": 0
    },
    "source_in_seconds": {
      "type": "number",
      "minimum": 0
    },
    "source_out_seconds": {
      "anyOf": [
        {
          "type": "number",
          "exclusiveMinimum": 0
        },
        {
          "type": "null"
        }
      ]
    },
    "loop_duration_seconds": {
      "anyOf": [
        {
          "type": "number",
          "exclusiveMinimum": 0
        },
        {
          "type": "null"
        }
      ]
    },
    "length": {
      "type": "string",
      "enum": [
        "loop",
        "once",
        "in_full"
      ]
    },
    "gain_db": {
      "type": "integer",
      "minimum": -40,
      "maximum": 0
    }
  },
  "required": [
    "storyboard_id",
    "reference"
  ],
  "additionalProperties": false
}
```

## Related tools

- [`undo_storyboard`](https://meetkuro.com/agents/tools/undo_storyboard.md): Take back YOUR last gesture on a film, or redo the one you took back.
- [`create_storyboard`](https://meetkuro.com/agents/tools/create_storyboard.md): Make a film three ways: from a brief you have written as scenes, from media the account already holds, or from a video you have already analysed.

---

## About Kuro

Kuro is an AI picture studio: prompt-driven images, clips, voice-overs and music, and storyboard-backed films with consistent characters across every scene.

Agents connect over MCP and can generate directly:

```
claude mcp add kuro https://api.meetkuro.com/mcp --transport http
```

The app is at https://app.meetkuro.com and requires an account.

Each guide, model page, comparison and free tool page on this site (not a tool's variants, and not the index pages) has a Markdown twin at its own URL plus `.md`, and so do /benchmarks/, the English /agents/ page (as /agents.md) and the MCP tool reference. Every tool: https://meetkuro.com/agents/tools/