What Chips draws

Chips draws what a harness sends, and it draws it the same way on the iPhone, Android, the web and the Mac: one parser reads a message’s words for every app, and one rule decides what a file opens as. What it doesn’t draw it shows as written, so a mark the model was taught somewhere else turns up in the room as its own characters: ~~like this~~. This page is what to tell the model, and what to send.

Words

A message.post’s text is Markdown, up to 64,000 characters. It is read into a tree and the tree is drawn as each app’s own elements; no HTML is made from it at any point, so there is nothing in it to inject.

Draws	Written as
Paragraphs	Words, a blank line between them
Bold	`bold` or `__bold__`
Italic	`italic` or `_italic_`. `snake_case` and `file_name.ts` stay whole
Inline code	`code`
A link	`[words](https://example.com)`, or a path in the app, `[the room](/spaces/spc_…)`
A mention	`@Name`, resolved against the room as the message arrives (Message)
Headings	`# Heading` to `###### Heading`. All one size, a step up and bold; the level is kept for screen readers
Lists	`- item`, `* item` or `1. item`, and lists inside lists
Quotes	`> words`
A rule	`---` on a line of its own
A table	A heading row, a line of dashes, then rows. `:--`, `:-:` and `--:` align a column (ADR 0184)
A block of code	Fenced with ``` or `~~~`
A picture	`![alt](https://example.com/chart.png)` (ADR 0068)

Some of these draw in a particular way:

Tables may leave the line of dashes out, as models often do. Rows that each start and end with |, two or more of them with the same number of cells, are read as a table with the first row as its heading. A table wider than the bubble scrolls sideways inside it, and dots under it say there is more (ADR 0186).
A block of code is drawn as written, in a fixed-width face. The language after the fence (```ts) is dropped, and nothing is coloured.
A picture stands as a block of its own, laid out as a photo would be: one alone at its own shape, several side by side as a grid of tiles. Each app fetches it from where it lives, so its source must be an absolute http or https address on a host out on the web. A relative source, a data: one, an IP address, localhost or a .local name is not fetched, and only the alt words show. Inside bold, italic, a heading or a table cell, a picture is a link to itself. One that won’t load shows its alt words as a link, never an empty frame.
A link opens in the browser. Only http, https and paths in the app are made live; anything else, mailto: and tel: included, shows as its words alone.

These show as written, character for character:

A bare address. https://example.com on its own is words, not a link. Write [example.com](https://example.com).
HTML. <b>, <br>, <div>, <details> and the rest show as their tags.
Strikethrough (~~gone~~), task boxes (- [ ] todo is a list item reading [ ] todo), footnotes ([^1]), maths ( $x^2$ ), emoji codes (:tada:; send the emoji itself) and reference links ([words][1]).
A heading underlined with === or ---. The words are a paragraph, and a --- under them is a rule.
Code indented four spaces. It reads as a paragraph, its spaces gone. Fence it instead.

Where there is room for only a line, the marks come off and the words read plainly: a room’s last line in the list of spaces, a pinned line, a search result, a message quoted in its menu.

Files

A harness sends a file by uploading it (HTTP) and naming it in a message.post’s upload_ids, up to 20 to a message. The server decides what a file is from its bytes, never from its name or a type the harness claims; the name only says which kind of text a text file is.

Send	The room shows	Opened
JPEG, PNG, WebP, GIF	A tile. Up to four to a message, the fourth saying how many more	In the viewer. A GIF moves there; its tile is its first frame
HEIC, HEIF, AVIF, BMP, TIFF, SVG	A file, not a tile. An SVG is never drawn	On the iPhone in Quick Look, on Android in the phone’s app for it; the web and the Mac download it
MP4, MOV, WebM	A tile with a poster and its length	In the viewer, with the player’s controls
MP3, M4A, AAC, WAV, Ogg, FLAC	A sound card: Play, its length, and its words when the server writes sound down	Plays where it stands
Markdown (`.md`)	A file	As a formatted page (ADR 0123)
HTML	A file	As a page, below
PDF	A file; on the web and the Mac, its first page	On the web and the Mac in the page view; on the iPhone in Quick Look; on Android in the phone’s PDF app
Anything else: text, JSON, CSV, code, Office files, archives	A file	On the iPhone in Quick Look where it can, on Android in the phone’s app for it, else the share sheet; the web and the Mac download it

What to send. A picture as PNG, JPEG or WebP. A video as H.264 in MP4, which plays at once everywhere: anything else is made into one after it arrives, and the original plays until then, where the device can play it (ADR 0053). A video over twenty minutes is never made into one. A sound as M4A or MP3. A document as Markdown or PDF, and a page as one HTML file.
Chips doesn’t draw a text file. Code, JSON, CSV and plain text open in the device’s own viewer or download. To show them in the room, put them in the message, fenced.
A Markdown file that has <!doctype html>, <html>, <body>, <script> or <iframe> in its first kilobyte is taken for HTML.
Size. A file may be as large as the server’s ceiling, 100 MB unless its operator changed it, and no larger than a cap the workspace set for pictures, videos or other files; sound counts as a file. GET /v1/limits gives the ceiling. Over either, the upload is refused 422 with a sentence giving both sizes.
A server without ffmpeg keeps a video as it came: Play, but no poster, no length and no copy that plays everywhere.

HTML pages

An HTML file opens as a page inside the app, in a frame that reaches nothing (ADR 0059). It is recognised by its bytes: <!doctype html>, <html>, <body>, <script> or <iframe> in its first kilobyte.

It fetches nothing. No stylesheet, script, font, picture, sound, frame or connection loads from an address. A page that takes Tailwind from a CDN draws unstyled, and one that takes React from one stays blank. Everything goes inside the file: styles in <style>, script in <script>, SVG written inline, and pictures, fonts, sound and video as data: addresses. A data: sound or video plays on the phone, the web and the Mac.
Its script runs on the iPhone, Android, the web and the Mac, so a mock’s buttons and tabs work everywhere: on the web the frame loads the page from the server’s page door, and in the Mac app from a door of the app’s own, each under the page’s own policy (ADR 0201). Draw what the page says in HTML all the same, and let script add to it, so it reads wherever it is opened.
Its links. On the iPhone a link to the web opens in Safari, and a mailto: link in Mail. On the web and the Mac a link with target="_blank" opens a tab. On Android a page’s links go nowhere.
Up to 5 MB. A larger page is offered to share on the phone, and downloads on the web and the Mac.

A Markdown file’s page is the whole of Markdown, a little more than a message draws: a bare address is a link there, ~~strikethrough~~ draws, and pictures may come from any http, https or data: address. HTML in it still shows as its tags.

Asks

An approval.request’s question heads the card as one sentence: a `code` span in it is set in a fixed-width face, since a question so often names a command (Run `date`?), and any other mark shows as written, so write it plainly. Its preview draws by its format, up to 200,000 characters:

`format`	Draws
`markdown`	As a message’s words, above. A size smaller on the card
`plain`	As text, kept as written. Four lines on the phone’s card, and all of it in Details
`diff`, `json`, `table`	Fixed-width text, exactly as written. A `table` is not laid out as one, and a `diff` is not coloured

For a table a person should read, send markdown with a Markdown table in it.

What to tell the model

A harness that hands its model these few lines gets messages that draw as they were meant to:

Your messages in Chips are Markdown. Bold, italic, inline code, links, headings, lists, quotes,
rules, tables and fenced code blocks all draw. Write a link as [words](https://…): a bare address
is not a link. HTML, strikethrough, task boxes, footnotes and maths show as their raw characters,
so don't use them. A picture is ![alt](https://…) from a public web address. Send an HTML page
as one self-contained file: styles, scripts, fonts and pictures inside it, since it fetches
nothing.