The Nuclino API exposes item content as Markdown. It adheres to the CommonMark spec and uses GFM extensions to add support for strikethrough, task lists and simple tables. Tables that contain cells with multiple lines use the grid table format. Additionally, it uses HTML comments to add metadata that is specific to Nuclino. Inline nodes like internal links, mentions, and file uploads are represented as Markdown links and are recognized based on their URL.
Example of Nuclino item content formatted as Markdown:
# Large heading
## Medium heading
### Small heading
---
- List item 1
- Nested list item
- List item 2
1. Ordered list item 1
1. Nested ordered list item
2. Ordered list item 2
- [ ] Task item
- [ ] Nested task item
- [x] Task item checked
# Inline nodes
Simple paragraph with *emphasized* and **bold** text.
Inline `code` can also be used. And they can be ***`combined`***.
~~Strikethrough~~ and ==text highlights== are also supported.
Highlights can also have a color: <mark color="green">green highlight</mark>.
External link: [Nuclino](https://www.nuclino.com "Nuclino | Your team’s collective brain")
Internal link: [Other item](https://app.nuclino.com/t/b/b85028d7-9251-45aa-9f96-51c2ea1bae87?n)
Internal link with custom text: [Read the other item](https://app.nuclino.com/t/b/b85028d7-9251-45aa-9f96-51c2ea1bae87)
User mention: [Jonathan Kienzle](https://app.nuclino.com/users/2e96f3bb-c742-4164-af2c-151ab2fd346b?mId=LTh3VS5u)
Group mention: [Developers](https://app.nuclino.com/groups/1f78f7ae-e34f-4c7e-88cb-76e042a1d1f9?mId=hDMIfnLV)
File upload: [Example.txt](https://files.nuclino.com/files/aaf815d8-017a-404c-95f8-d485d6228021/Example.txt)
Inline equation: $$2+2=4$$
Inline date: <2024-01-20>
Inline comment: [commented text]<!-- comment id=a7ab12fd-2669-4a53-885a-49df3c327b2c -->
# Image
# Image with comment
<!-- image comment=a7ab12fd-2669-4a53-885a-49df3c327b2c -->
# Image with caption
<!-- caption -->
The *settings* page
# Video with caption
<!-- video -->
[recording.mp4](https://files.nuclino.com/files/e4df99a6-6bde-48c8-b970-bfa91f134ddc/recording.mp4)
<!-- caption -->
A short walkthrough
# Audio
<!-- audio -->
[standup.mp3](https://files.nuclino.com/files/5b2f9c1e-7a4d-4e0b-9c3a-2d8e6f1a4b7c/standup.mp3)
# Image grid
<!-- image-grid -->
<!-- video -->
[recording.mp4](https://files.nuclino.com/files/e4df99a6-6bde-48c8-b970-bfa91f134ddc/recording.mp4)
# Quote
> This is a blockquote.
# Callout
> [!note]
> This is a callout.
# Table
| top left | top right |
| ----------- | ------------ |
| bottom left | bottom right |
# Table with multi-line cells and header
+-----------------+------------------+
| header top left | header top right |
+=================+==================+
| cell 1 | cell 2 |
+-----------------+------------------+
| line 1 | bottom right |
| | |
| line 2 | |
+-----------------+------------------+
# Code block
```javascript
function sum(a, b) {
return a + b;
}
```
# Embed
<!-- embed -->
[](https://www.youtube.com/watch?v=wvL2SFjpoVo)
# Equation block
```math
E=mc^2
```
# Mermaid diagram
```mermaid
flowchart
A --> B
```Internal links point to https://app.nuclino.com/t/b/ITEM_ID. The ?n suffix marks a native link whose displayed text always follows the title of the linked item. Without the suffix, the link keeps its own text.
Mentions are links to https://app.nuclino.com/users/USER_ID or https://app.nuclino.com/groups/GROUP_ID. The mId parameter identifies the mention and should be preserved when editing.
Files are links to https://files.nuclino.com/files/FILE_ID/FILE_NAME, the url of a file object (see Files). A regular link shows the file as an attachment, an image link () embeds an image or video, and a link preceded by an <!-- audio --> comment shows an audio player (e.g. for MP3, M4A, WAV or FLAC files). Files are uploaded through the Files endpoints of the API or the MCP file tools; referencing a file that does not exist or is not accessible removes the link.
Comments are anchored either inline, by wrapping the commented Markdown in [...]<!-- comment id=COMMENT_ID -->, or on a block through the comment attribute of the block's metadata comment (e.g. <!-- image comment=COMMENT_ID -->). Blocks that support metadata comments are image, video, audio, embed, diagram, equation and mermaid. Images can carry additional attributes such as display and align.
Captions can be added to images, videos, audio blocks and Canvases (diagram) by placing a <!-- caption --> comment directly after the block, followed by the caption text on the next line.
Image grids start with an <!-- image-grid --> comment followed by the images, videos and Canvases of the grid (at least two, optionally with captions). <!-- image-grid display=large --> shows a maximized grid.
Heading anchors are stored as <!-- heading id=ANCHOR_ID --> in front of a heading and allow linking to the heading via #ANCHOR_ID.
Highlights use ==text== for the default color (purple). Colored highlights use an HTML mark tag with a color attribute, e.g. <mark color="red">text</mark>. Supported colors are red, orange, yellow, green and blue. A mark tag without a supported color creates a default highlight.
Metadata comments and special URLs should be preserved when updating content, otherwise the associated comments, anchors and links are lost.