> For the complete documentation index, see [llms.txt](https://docs.powerpointgeneratorapi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.powerpointgeneratorapi.com/examples/chart/additional-data.md).

# Additional data

1. Select the shape by `name` you want to modify. See [here](/knowledge-base/finding-shape-names.md) to find shape names.
2. Use `additional_data` to insert custom values directly into specific cells. 
3. Each `cell_target` defines the starting cell where the data will be written.
4. `Additional_data` is not tied to the chart’s data range, so you can add data anywhere. It's useful for when you want to add helper values, metadata, or computed fields without affecting the main chart series.

Reference: [chart](/json-template-syntax/shapes/chart.md)

Download: [input.zip](https://drive.google.com/uc?export=download\&id=1RjhuXp3a-I531dgZBia3_80O6akhWQO8) | [output.pptx](https://drive.google.com/uc?export=download\&id=1CynZMM_5aPHuI4wjGAwVTCm1hwSkNtAC)

{% columns %}
{% column width="41.66666666666667%" %}

<figure><img src="/files/rPdVQEprnXvtRB7TjIMn" alt=""><figcaption></figcaption></figure>

***

<figure><img src="/files/aXwABXDyrQVbv0qY6wST" alt=""><figcaption></figcaption></figure>
{% endcolumn %}

{% column width="58.33333333333333%" %}
{% code lineNumbers="true" %}

```json
{
    "presentation": {
        "template": "template.pptx",
        "slides": [
            {
                "slide_index": 0,
                "shapes": [
                    {
                        "name": "Chart 5",
                        "additional_data": [
                            {
                                "cell_target": "B22",
                                "data": [
                                    [
                                        0.2,
                                        0.3,
                                        0.35
                                    ],
                                    [
                                        0.4,
                                        0.5,
                                        "0.45%"
                                    ]
                                ]
                            },
                            {
                                "cell_target": "A2",
                                "data": [
                                    [
                                        " ",
                                        35,
                                        0.6
                                    ],
                                    [
                                        "maj",
                                        0.5,
                                        58
                                    ]
                                ]
                            },
                            {
                                "cell_target": "A4",
                                "data": [
                                    [
                                        "Category 3",
                                        5,
                                        10
                                    ]
                                ]
                            },
                            {
                                "cell_target": "AA5",
                                "data": [
                                    [
                                        0.5,
                                        0.2
                                    ],
                                    [
                                        0.455,
                                        0.7234
                                    ]
                                ]
                            }
                        ]
                    }
                ]
            }
        ]
    }
}
```

{% endcode %}
{% endcolumn %}
{% endcolumns %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.powerpointgeneratorapi.com/examples/chart/additional-data.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.