Customize
Taskpane builder
Design the taskpane your add-in's users open from the ribbon — drag blocks into tabs, brand it with your own colors and logo, and publish changes to every open workbook without a re-deploy.
7 min read
The taskpane isn't fixed. Under Resources → Taskpane for each environment, a drag-and-drop builder lets you arrange it into tabs, fill each tab with blocks, and brand the whole pane to match your product — directly in a live preview that renders exactly what Excel will show. Everything you build here rides the same live config channel as your functions and connections: save it, and it's live in every open workbook without a re-deploy.
Tabs
A layout is one or more tabs, each holding an ordered list of blocks. Add a tab, drag to reorder it, give it a label, and pick an icon — either a curated glyph or an uploaded image. With a single tab, Excel shows no tab bar at all; add a second tab and a tab strip appears automatically.
Blocks
Build each tab by dragging blocks from the palette into the live preview, or click to append one. Every block is editable in place — double-click a text block to edit its copy directly on the canvas.
| Field | Type | Description |
|---|---|---|
headingOptional | Heading | A section title. Choose the level, alignment, and an optional color override. |
textOptional | Text | A paragraph with alignment, a curated font size, and an optional color. |
imageOptional | Image | An image from your organization's asset library, with alt text, alignment, and width. |
calloutOptional | Callout | A tinted note box in one of four tones — info, success, warning, or danger. |
linkOptional | Link button | A button that opens an external URL, styled as primary, outline, or subtle — or displayed as a compact icon tile for quick-action rows. |
dividerOptional | Divider | A plain horizontal rule. |
spacerOptional | Spacer | Vertical breathing room — small, medium, or large. |
signinOptional | Sign-in | The sign-in card bound to your add-in's authentication provider — inert when your add-in is open access. |
functionListOptional | Function list | A titled list of your published functions; the user clicks one to insert it. |
functionButtonOptional | Function button | One button that inserts a single function in one click — only functions with no required parameters can be assigned. A function that needs input belongs behind an Open dialog button instead. Can also display as a compact icon tile; place tiles side by side in a columns block (2–4 columns) for a quick-actions row. |
uploadRangeOptional | Upload range | A button that reads the user's selected range — or the whole table around it — and uploads it through one of your write functions. The first row becomes the column names by default, and large ranges are sent in retry-safe chunks, so re-clicking after a partial failure replaces rather than duplicates. |
functionResultOptional | Function result | Runs a read function as the signed-in user and renders the result as a table inside the pane, never in the grid — "My uploads", "Shared with me", and other per-user views when the connection uses a user-token authentication mode. It runs on its own when the pane opens, offers a refresh control, and takes a function, an optional title, and fixed argument values. |
templateListOptional | Template list | A titled list of your workbook templates; one click inserts every sheet. |
gridViewListOptional | Table / PivotTable list | The Tables and PivotTables configured for this environment; each entry spills its source function and turns the result into a real Excel Table or PivotTable. |
sectionOptional | Section | A card that groups other blocks together, one level deep — a section can hold any block except another section. |
The starter layout uses a few more blocks
The built-in starter template reproduces the agent's default four-tab pane, so it also uses a function-explorer block, a live status block, and an endpoints block. You won't need to add these yourself unless you're building a layout from scratch — they exist to make the starter a faithful copy of the agent's built-in UI. The function explorer can alternatively render as a flat list — every function as one row with its own colored icon badge — instead of collapsible module groups.
Sections
A section is a card that groups blocks together — put a heading, some text, and a button inside one to set it visually apart from the rest of the tab. Sections are one level deep: a section can hold any other block except another section.
Branding and theme
The Brand panel controls the whole taskpane's look, applied consistently across every tab:
| Field | Type | Description |
|---|---|---|
accentOptional | color | Brand accent used for buttons, links, and highlights. |
fontOptional | system | sans | serif | mono | Base font family for the pane. |
corner radiusOptional | sharp | rounded | round | Corner roundness of cards, buttons, and inputs. |
densityOptional | compact | cozy | roomy | Spacing between blocks. |
modeOptional | light | dark | inherit | Color scheme; light is the default so the preview always matches Excel, and inherit follows the Excel host's own theme. |
backgroundOptional | color | gradient | image | A solid color, a two-color gradient at a curated angle, or an uploaded image. |
headerOptional | title, subtitle, logo, status | An optional branded bar above the tabs, with a title, subtitle, a live connection-status dot, and a logo — a curated mark, an uploaded image, or a monogram of the title. |
Starter templates and the built-in fallback
When an environment's taskpane has never been saved, the builder opens on a ready-made starter layout that reproduces the agent's built-in four-tab pane (Functions, Templates, Status, Resources) — so you start editing a real, working taskpane, not a blank canvas. Use "Start from template" to reset to a starter, or copy another environment's saved layout as your draft.
No saved layout, no missing pane
If you never save a layout in an environment, its agent falls back to the same built-in four-tab pane it has always had — your users are never left with a blank taskpane.
Publishing
Save your layout and it rides the next agent config snapshot — the same live channel functions and connections use. There is no manifest change and no re-deploy: every taskpane a user has open picks up the new layout the next time they open it.
Mutual TLS (mTLS)
The agent authenticates to this backend by enrolling for its own mTLS client certificate — there is no API key, no bearer token to configure at runtime, and no alternative auth mode. You never have to create or handle the certificate yourself; the agent generates its own key and gets it signed during enrollment.
Ribbon buttons
Add custom buttons to the Excel ribbon that open your taskpane, run one of your functions, or launch a dialog — placed on a built-in tab or your own branded tab.