Artifacts

An artifact is a piece of finished work your project keeps: a report, a chart, a file someone needs. Each one has versions that never change once published, and a page in your app where its owner reads it.

Kinds

Publish an artifact

Store the files first, then publish them under their paths in the artifact:

const markdown = await sixb.blobs.put({
  body: new TextEncoder().encode(report),
  fileName: "document.md",
  mediaType: "text/markdown",
})
const chart = await sixb.blobs.put({ body: png, fileName: "revenue.png", mediaType: "image/png" })

const { artifact } = await sixb.artifacts.create({
  kind: "document",
  title: "Q3 operating review",
  files: [
    { path: "document.md", file: markdown },
    { path: "figures/revenue.png", file: chart },
  ],
})

sixb.artifacts.publish(artifact.id, input) adds the next version. Publishing checks the whole version first: a document's images must be files in that version or another artifact's address, so it reads the same wherever it opens.

From outside the server, use POST /api/artifacts and POST /api/artifacts/{artifactId}/versions with files uploaded through POST /api/files.

The Agent publishes

In a conversation, the Agent publishes what you ask it to make, such as a report, a brief, a table of data, or a file in a format you name, as an artifact. Each new artifact gets a card under the reply. The first one a reply publishes opens beside the conversation as soon as it is published, while the Agent is still working; on a phone, where it would open over the conversation, it waits on its card instead.

Ask for a change and the Agent publishes the next version of the same artifact. The reply shows it as a line with the version number and what changed, such as a sheet or section added, and the version menu keeps the earlier versions. The conversation's header lists every artifact it published.

A cancelled reply keeps what it already published. Retrying a reply that failed removes what it published along with what it said.

The Agent learns the formats from a built-in skill, sixb-artifacts.

A file one of your tools returns stays with that tool's step in the conversation. The Agent publishes it when it is what you asked for.

Write a document

A document is Markdown with tables, footnotes, and task lists. A few conventions shape its page:

• The first # heading is the title, and the paragraph after it is the lede.
• ## and ### headings form the outline beside the page.
• A quote that starts with [!NOTE], [!TIP], [!IMPORTANT], [!WARNING], or [!CAUTION] becomes a callout.
• An image with a title alone in its paragraph becomes a figure, and the title becomes its caption: ![Revenue by region](figures/revenue.png "Revenue by region, Q3").
• Table columns of figures align right.

Write a sheet

A sheet is workbook.json and one CSV per sheet under sheets/. The CSV holds raw values; the workbook says how to read them:

{
  "sheets": [
    {
      "name": "Regions",
      "frozenColumns": 1,
      "columns": {
        "Visits": "number",
        "Within SLA": { "type": "percent", "decimals": 1 },
        "Parts cost": { "type": "currency", "currency": "USD" }
      }
    }
  ],
  "charts": [{ "name": "sla", "type": "bar", "sheet": "Regions", "x": "Region", "y": "Within SLA" }]
}

sheets/Regions.csv
Region,Visits,Within SLA,Parts cost
North,1284,0.961,182400
Central,962,0.934,141950

• A column is text unless the workbook gives it a type: number, currency, percent (written as a fraction, 0.961), date (2026-09-30), link (a full https:// or http:// address), or image (the path of an image file in the artifact).
• Values are formatted in the reader's locale, so write them without symbols or separators.
• frozenRows (default 1, the header) and frozenColumns (default 0) stay in view while the sheet scrolls; widths sets columns' widths in pixels.
• A chart is a bar, line, area, or pie chart of up to five y columns against an x column. Its name is its address, so keep it across versions and rename it by its title. Bar and area charts can be stacked; a pie has one y column and at most five rows.

Publishing reads every typed cell and every chart against its sheet and refuses the version with the file, row, and column to fix. A sheet holds at most 200 columns and 100,000 rows, and a workbook 20 sheets and 10 charts.

Readers sort columns, select a range to see its sum, average, and count, copy cells, and download each sheet as CSV. A CSV or TSV file artifact opens in the same grid.

Write slides

A deck is index.html with one <section class="slide"> per 1280×720 slide, and the CSS and images it loads beside it by relative path. Sixb adds a kit and a small runtime to the page: they scale the slides to fit, number them, apply your app's theme and dark mode, and give the reader previous and next, an overview of every slide, and present, where the slide fills the page.

<section class="slide title">
  <p class="eyebrow">Q3 2026</p>
  <h1>Restorations within SLA reached 94%</h1>
  <p>Up from 88% in Q2</p>
</section>
<section class="slide stat">
  <h2>Revenue grew 9.6%</h2>
  <div class="value">$2.14M</div>
  <div class="label">Service revenue, Q3</div>
  <p class="source">Field service records</p>
</section>

• A slide picks a layout by class: title, section, stat, split, chart, table, quote, or image. .eyebrow sits above a heading and .source at a slide's foot.
• The kit reads your theme's tokens as CSS variables (--foreground, --primary, --chart-1 to --chart-5, --font-sans, …). A deck's own CSS overrides the kit and the theme.
• Slides open in a sandboxed frame from a short-lived link. A deck runs its own scripts, but it can't read the app's cookies or call the API as the reader, and it loads only its own files and a few public CDNs (jsDelivr, cdnjs, unpkg, and Google Fonts).
• A link to another artifact (<a href="artifact:…">) opens it where the reader is. <sixb-embed src="artifact:…#chart=revenue"> shows another artifact on a slide: a chart, a range, a section, or a slide of another deck, drawn by the app over the slide at the size the deck gives the box, as documents show it. <img src="artifact:…/figure.png"> shows an image file of another artifact. Either shows only what its reader can open; anything else is an empty box. Thumbnails and the overview show each box empty, with its title.
• ?part=4 opens a deck at slide 4, and ![…](artifact:…#4) shows that slide in a document.
• When the Agent publishes a deck, it lays the deck out in its sandbox's headless browser and gets a warning for each slide with content past its edge or over the footer, overlapping or cut off text, text under 18px or under WCAG AA contrast in light or dark mode (only the mode a deck's theme.json pins, with its tokens), or a broken image, with a screenshot of every slide to look at before it revises. This needs the agent image (or a sandbox with Playwright for Node at /opt/sixb/js/node_modules/playwright); without a browser the deck still publishes, unchecked, and the Agent is told.

Reference another artifact

A document, a sheet, or an agent's reply can show another artifact, or a part of it, by its address. A report that shows a sheet's chart stays current when the sheet changes. The Agent is told to pin the version a reply describes (@2), so that what the reply shows matches its words; an address it writes without a version follows the latest one.

artifact:<id>[@<version>][/<file>][#<part>]

In Markdown, an image alone in its paragraph shows the target in place, with the image's alt text as its caption; a link opens it:

![Revenue by quarter](artifact:art_k3m9q2x7tp#chart=revenue)

The [regional numbers](artifact:art_k3m9q2x7tp#Regions) explain the gap.

A range shows as a table formatted the way its sheet formats it, a chart as the chart, a section as its text, an image file as the image, and a whole artifact as a card. Under each, a line names the source and whether it follows the latest version or a fixed one. Something shown inside a shown artifact appears as a link. In a sheet, a link or image column cell can hold an address.

Publishing resolves every address in a version against what its author can read, and refuses one that names nothing, saying what the target has instead. When a new version renames or removes something another artifact shows, it publishes with a warning naming that artifact. A reader who can't open a target sees it as unavailable.

Open an artifact

Every artifact has a page at /artifacts/{artifactId} that fills the window, over your app's navigation. Add ?v=2 for a version and ?part=revenue to open at a document's section, a sheet (?part=Regions), or a chart (?part=chart=sla). In an agent conversation, artifacts open beside the chat.

/artifacts lists every artifact you can open, most recently updated first, each with a preview of its latest version: a sheet's first chart, a document's title and lede, a deck's first slide, an image. Filter it by kind with ?kind=document, sheet, slides, or file; the list API takes the same kind. The user menu, search (⌘K), and a conversation's artifact menu link to it.

The link button in an artifact's header copies a link to its page, and the one beside a heading a link to that section. A link to the latest version keeps following the artifact as new versions are published; a link copied from an earlier version stays on it.

Only the artifact's owner can open it. Server code that runs as the system, outside any user's request, reaches every artifact in the project.

Theme an artifact

Artifacts use your app's theme, including dark mode. To style artifacts apart from the rest of the app, scope token overrides in app/globals.css:

[data-sixb-artifact] {
  --font-serif: "Source Serif 4", serif;
}

A document, a sheet, or a deck can carry its own theme.json at its root to pin a mode or override tokens:

{ "mode": "light", "tokens": { "--primary": "#0f766e", "--radius": "6px" } }

It can set colors (--background, --foreground, --border, --chart-1 to --chart-5, and --card, --muted, --primary, and --accent with their -foreground pairs), fonts (--font-sans, --font-serif, --font-mono), and --radius. A file artifact holds one file, so a theme.json there is that file, not a theme.