Chart updates

Chart updates replace the data inside a chart that was already generated (or uploaded), without regenerating the deck. The chart’s type, colours, legend, axis formatting, and position on the slide are preserved — only the categories, series values, and optional data rows change.

NPS stacked bar chart with original survey data. — Before update

Same NPS chart with refreshed survey data — promoter percentages increased, detractor percentages decreased. — After update

When to use chart updates vs. regeneration

Use chart updates when you want to refresh chart data in a deck that already exists — either one the API generated, or one a user edited manually in PowerPoint. Layout, formatting, and any manual edits to other slides are preserved. Use full regeneration when the deck structure itself needs to change (different slides, different tables, different layouts).

Endpoint

PUT /api/v1/presentations/{presentation_id}/update-charts

The same endpoint handles two input modes:

JSON body — reference a presentation already in storage by its ID
Multipart form — upload a .pptx file and update charts in it in one request

JSON body (presentation already in storage)

PUT /api/v1/presentations/gen_abc123/update-charts
X-API-Key: your-api-key
Content-Type: application/json

{
  "updates": [
    {
      "slide_index": 6,
      "chart_index": 0,
      "chart_data": {
        "categories": ["Acme Corp", "TechFlow Inc", "DataSync Ltd", "CloudFirst", "Innovate Labs", "SecureNet", "GrowthMetrics", "Nexus Digital"],
        "series": [
          { "name": "Promoters (9-10)", "values": [50, 42, 18, 35, 48, 36, 15, 46] },
          { "name": "Passives (7-8)", "values": [30, 33, 30, 35, 32, 38, 28, 30] },
          { "name": "Detractors (0-6)", "values": [20, 25, 52, 30, 20, 26, 57, 24] }
        ],
        "data_rows": [
          ["n=", "156", "142", "89", "178", "201", "134", "67", "188"],
          ["NPS", "+30", "+17", "-34", "+5", "+28", "+10", "-42", "+22"]
        ],
        "data_table_header_column": true
      }
    }
  ]
}

The presentation_id path parameter accepts:

gen_xxx — from slide generation, deck generation, or chart updates
pres_xxx — older direct-return generation output, if present

Multipart form (upload a .pptx and update it)

Use this when a user has edited a deck manually in PowerPoint and you want to refresh chart data in the edited file.

PUT /api/v1/presentations/{presentation_id}/update-charts
X-API-Key: your-api-key
Content-Type: multipart/form-data

file: (binary .pptx)
updates: [{"slide_index": 6, "chart_index": 0, "chart_data": {...}}]

The updates field is a JSON string in the form body. When a file is uploaded, the path parameter is ignored — the response returns a new cupd_xxx ID for the updated file.

Response

{
  "presentation_id": "gen_abc123",
  "status": "completed",
  "slides_updated": 1,
  "file_size": 7450000,
  "download_url": "https://storage.example.com/download...",
  "download_url_expires_in": 3600,
  "created_at": "2024-01-15T10:45:00Z"
}

Update fields

Each entry in the updates array targets one chart:

Field	Type	Required	Description
`slide_index`	integer	yes	Zero-based slide index in the presentation
`chart_index`	integer	no (default `0`)	Zero-based chart index on the slide
`chart_data`	object	yes	New chart data (see below)

`chart_data` fields

Field	Type	Required	Description
`categories`	string[]	yes	Category labels for the x-axis
`series`	object[]	yes	One object per series: `{ "name": "...", "values": [...] }`
`data_rows`	string[][]	no	Rows rendered in the data table beneath the chart
`data_table_header_column`	bool	no (default `true`)	Whether the first value in each `data_rows` entry is a row header
`data_table_format`	object	no	Font overrides for the data table: `font_name`, `font_size`, `bold`, `italic`, `color`
`chart_type`	string	no	Override the chart type (e.g. `"stacked_bar"`, `"clustered_column"`)
`title`	string	no	Override the chart title text
`title_format`	object	no	Font overrides for the chart title
`legend`	object	no	Legend position and formatting
`value_axis`	object	no	Value axis formatting (min, max, labels)
`category_axis`	object	no	Category axis formatting
`show_bar_labels`	bool	no (default `false`)	Show value labels on bars
`bar_label_mode`	string	no (default `"total"`)	What bar labels show: `"total"` (sum of the bar’s values) or `"percent"` (the bar’s share of the grand total across bars)
`bar_label_decimals`	integer	no	Fixed decimal places for bar label values (0–4)
`show_data_table`	bool	no (default `false`)	Show the built-in PowerPoint data table
`caption`	string	no	Caption text below the chart

Only categories and series are required. Omitted fields are left unchanged from the existing chart. Existing bar labels are recalculated from the new values in their existing mode — percent labels stay percentages without resending the label fields.

Slide index after pagination

slide_index refers to the output presentation, not the original input array. If a table slide paginated into multiple pages during generation, subsequent slide indexes shift. The generation response includes total_pages_generated and slide_results — use those to determine the correct output position for each chart.

Errors

Error	Status	Meaning
Slide index out of range	`400`	`slide_index` exceeds the number of slides
No chart found	`400`	No chart exists at that `chart_index` on the slide
Presentation not found	`404`	The `presentation_id` does not exist in storage

{
  "detail": "slide_index 7 out of range. Presentation has 7 slides (valid: 0-6)."
}

Introduction

Template management

Generation

AI Agents

Security & Operations

When to use chart updates vs. regeneration

Endpoint

JSON body (presentation already in storage)

Multipart form (upload a .pptx and update it)

Response

Update fields

`chart_data` fields

Errors

​When to use chart updates vs. regeneration

​Endpoint

​JSON body (presentation already in storage)

​Multipart form (upload a .pptx and update it)

​Response

​Update fields

​chart_data fields

​Slide index after pagination

​Errors

When to use chart updates vs. regeneration

Endpoint

JSON body (presentation already in storage)

Multipart form (upload a .pptx and update it)

Response

Update fields

`chart_data` fields

Slide index after pagination

Errors