One Slack thread — the diagram, the source, the reasoning.

All seven produce the same thing: a root message in the channel with a PNG preview, an interactive .html file, and History, Branch and Export controls. Open Show source from Export. Later versions appear in the thread; Decision ledger publication is a separate background operation. On Slack Free it stays in the board thread without taking over the channel Canvas tab.

• @mention + describe
  BIS</>

  @Arialine create a checkout funnel with a retry queue and a DLQ after 3 tries

  +
  Address Aria, Arialine, or @arialine: create a checkout funnel with a retry queue and DLQ after 3 tries
• Mention after discussion
  DO

  Dana Okafor10:52 AM

  @Arialine turn this into a diagram

  PNSM14 repliesLast reply today at 10:51 AM
  @arialine turn this into a diagram — uses the relevant discussion from the last 72 hours and asks which topic you mean when two are equally plausible
• Paste Mermaid
  PN

  Priya Nair9:14 AM

  @Arialine render this

  flowchart LR
    A[Checkout] --> B{Paid?}
    B -->|yes| C[Ship]

  @arialine followed by pasted Mermaid — Arialine validates and renders it
• Attach a .mmd file
  SM

  Sam Moreau2:03 PM

  @Arialine make this a boardMMDpayments.mmdMermaid
  @arialine with a .mmd/.mermaid attachment
• Just share a .mmd file
  SM

  Sam Moreau2:03 PM

  MMDpayments.mmdMermaid

  

  ArialineAPP2:03 PM

  🟢 payments · v1 · built from payments.mmd
  Drop the file into a channel — Arialine auto-builds a board (toggleable)
• ‘Render as diagram’ shortcut
  PN

  Priya Nair9:20 AM

  Order service writes to Postgres, then publishes OrderCreated to Kafka.

  Arialine

  Render as diagram

  Render as canvas

  Hover/long-press a message → More actions → Render as diagram
• /arialine or ‘New diagram’
  New diagram✕

  Post in channel

  # architecture

  Paste Mermaid or describe the diagram

  flowchart LR
    API --> Queue --> Worker

  CancelCreate
  Type /arialine (or ⚡ menu → New diagram), then paste Mermaid or describe the diagram — valid Mermaid renders without AI

Arialine posts two files together — an interactive .html and a .png. The .png is the preview you see in Slack on every device. Open the .html in a browser for pan and zoom plus the Decisions, Source and History panels.

The root message is the anchor: its files are swapped to the newest render on every change, so scrolling to the top of a thread always shows the current diagram. The version replies below it hold every historical .png + .html once they've been superseded — nothing is ever lost.

Address Aria, Arialine, or @arialine and say “add a caching layer between the gateway and the database” or “drop the SMS step”. Arialine rewrites the Mermaid, renders it, replaces the artifacts on the root message, and posts a one-line version reply: v2 — added Redis caching layer — by @you, with ↩︎ Undo this change and ⏪ Rewind to here buttons.

You can also react 📌 on any message to propose it as a change. Arialine reads the pinned message in context of the surrounding conversation, then posts a card with Apply, Edit proposal, and Dismiss.

History is additive. Undoing a single change or rewinding to an earlier version is itself a new tracked version. Nothing is ever overwritten, so audits and retrospectives always match reality.

Ask “why is there a dead-letter queue?” in the thread and Arialine answers from the decision log — quoting the message, naming who said it, and linking back to the original Slack post.

Click Branch on the root message (or say @arialine branch this at v3 called experiment) to fork any version into a brand-new board. The branch has its own thread and decision ledger, and links back to the source version.

Mention @arialine brainstorm …, or explicitly ask Arialine to help with ideas. It produces 2–3 alternative takes on the current diagram — each rendered as a preview with two buttons: Adopt to this board (replaces the current diagram as a new version) or Branch to new board (keeps the original untouched).

Where Slack permits, each board gets a ledger Canvas with two sections. Timeline lists every version newest-first, with the rendered diagram for that version. Decisions is the log: what changed, who decided, and a link back to each source message. On Slack Free the same ledger is kept as a message in the board thread.

The ledger is the archive; the HTML file is the diagram you explore. Together they answer both “what does this look like today?” and “how did we get here?” for anyone joining the team six months from now.

Slack doesn't render Markdown in messages, and uploaded .md files show as plain snippets. Arialine converts a shared .md into a proper Slack Canvas — headings, lists, tables — and every mermaid code block inside becomes an embedded diagram image. One doc, fully readable in Slack.

Ask Arialine to append the current version of a board to any Slack canvas it can access — a project doc, a channel canvas, a meeting canvas. Arialine renders the latest, uploads it, and embeds it at the end of the canvas.

Arialine exposes a Model Context Protocol server, so Slackbot can create, edit, branch, and query your boards on your behalf. Ask “turn this discussion into a diagram with Arialine” — Slackbot calls the right tool, Arialine posts the board, and the ledger records who asked.