Messaging

What you can send

Anything iMessage carries. Sauna reads text, voice notes, images, screenshots, PDFs, and spreadsheets. It picks up tapback reactions on its own messages, and it tracks which message you were replying to when you swipe-reply.

• Text. No inbound length limit. Sauna gets the message verbatim.
• Attachments. Up to 25 MB per file. Images (PNG, JPEG, GIF, WebP, HEIC, HEIF), audio (MP3, M4A, WAV, AAC, CAF, AMR, AIFF), PDFs, Excel, and common office formats. iPhone HEIC photos convert to JPEG automatically so Sauna can actually read them. Files over the cap come back with a rejection note.
• Voice notes. Sauna transcribes your voice notes before reading them, and tags them so it knows they came from audio. Talk to it the way you'd talk to a person.
• Reactions. Tapback one of Sauna's messages (like, dislike, love, laugh, emphasize, question) and Sauna treats it as a quoted reaction. There's no built-in shortcut like "thumbs-up equals approve", Sauna decides what it means in context.
• Swipe-reply. Reply to one of Sauna's earlier messages with the iMessage reply gesture and your message routes back to that original thread's session, even if your current session pointer has moved on.
• Commands. Two only:
  • /new starts a fresh session. Sauna replies "New session started." and forgets the earlier context for future messages.
  • /unlink disconnects your phone from Sauna.

What you get back

Sauna replies in plain text, renders long outputs as PDFs, sends images and voice memos natively, and drops in connection links when it needs an app it doesn't have yet.

• Plain text, one thought per bubble. Each part of Sauna's reply is a separate iMessage bubble. Short replies stay inline; anything over about 1,000 characters comes back as a PDF, with a preview text in the bubble above it.
• Images inline. PNG, JPEG, WebP, HEIC all render in the thread.
• Docs as PDFs. If Sauna writes a Markdown artifact, it renders to PDF before sending, so you can read it on your phone without a Markdown viewer.
• Voice memos as voice memos. Native iMessage voice memo with the waveform and play button, not a generic audio attachment.
• Connection prompts. If Sauna needs an app you haven't wired up, it texts you a link like Connect Gmail: https://.... Open it, finish the handshake in the browser, and Sauna picks up where it left off when you text next. This works for Pipedream-native integrations and for any MCP server or API connection, so you can bring in apps Sauna doesn't natively ship with, right from the thread.