How Sebtember works

Sebtember is a universal AI assistant platform. You bring your own material — documents, images, spreadsheets, notes, catalogues, manuals, price lists — and Sebtember reads it and answers your questions from that material. It's also an ecosystem: people share trusted content with each other and get answers from personal AI assistants that draw only on that shared, trusted knowledge — never the open web. The AI acts like a senior colleague: it reads the relevant material for your question and gives a grounded answer, plus a little more when it genuinely helps.

Three things make it different from a general chatbot:

• It answers from yoursources, not the public internet. If something isn't in the accessible material, it tells you so instead of inventing an answer.
• Every factual claim is checked and cited, so you can trace it back to the source.
• You can share your knowledge with teammates or clients, and they can use it for free — you only pay for the answers you generate.

Create your account.Go to sebtember.app, click Sign in (top-right) or Get started, and sign in with your Google account. That's it — there's no setup wizard. You land directly in the chat. Your country and preferred language are detected from your browser; you can change either later on the Profiles page.

Joining via an invitation.If someone sent you an invite link — to a Catalogue (shared content) or a token share (shared balance) — just open the link and sign in with Google. You'll be connected to the shared content or balance immediately.

What you get on day one:a free starting balance of tokens (Sebtember's usage currency), an empty chat workspace, and access to the public Marketplace of knowledge libraries shared by other creators.

The account menu. Your avatar and name sit at the bottom of the left sidebar. Click that row to open Profiles, Usage, and Sign out.

Open the account menu → Profiles. There are three tabs. Profilecovers identity (photo, display name, read-only email), localisation (country and preferred language — the AI replies in your preferred language regardless of the source document's language), appearance (light/dark theme plus which sidebar sections show), and account deletion. Companyholds company details and VAT (tick "VAT registered", enter your number, and Verify — Sebtember checks it against EU VIES / UK HMRC). AI Profile shows what the AI has learned about you (read-only) and your own free-form Self-Description.

Your Self-Description is the single biggest lever on answer quality, and it always overrides the auto-learned profile. Examples that work well:

• "I'm a procurement manager. I care about prices and lead times — keep technical detail minimal unless I ask."
• "I'm a lawyer. Always cite the exact clause and section. Reply in formal English."
• "Reply in Lithuanian. I prefer short, direct answers with the key number first."

Profile and Company tabs save automatically as you type; the AI Profile tab has explicit Save / Cancel.

Click + New chat in the sidebar. Each conversation is its own chat room, listed in the sidebar. The AI remembers the current conversation and keeps a rolling summary of older messages so long chats stay coherent. Its only knowledge sources are the Catalogues you have access to and platform-wide system catalogues (like this help guide) — it does not use the open web, and will tell you when something is outside your sources rather than guess.

What you'll see in a reply:

• Cited answer — claims are grounded in your sources, and a verifier labels them (traceable to a source / reasonably derived / unsupported).
• Sources + downloads — the files behind the answer, with download links where the file owner allowed downloads.
• Creators row — the people whose content contributed; click one to see which of their files were used.
• A clarifying question — if your request is genuinely ambiguous, the AI asks a short question with tappable options instead of guessing.
• Action row — Copy, Copy for another AI (bundles your question + answer + citations for handoff), Regenerate.

A Catalogue is a folder of material the AI is allowed to read. To create one: sidebar → hover CATALOGUES → + New, name it, and open it. Inside a catalogue you'll find a Files tab (documents grouped into Collections), a Users tab (people you've shared with), an Output tab (catalogue-wide rules for how the AI presents answers), and — on Library catalogues — a Marketplace tab.

Uploading files. Click + Add file on a Collection card. There are four types:

• Document (PDF, TXT, CSV, JSON, DOCX, XLS, XLSX, max 25 MB) — extracted and indexed.
• Note (max 10,000 chars) — free text you type yourself; visible to the AI but never shown as a citation or download.
• Image (JPG, PNG, WebP, GIF, max 5 MB) — the AI reads text and content from the image.
• Attachment (max 25 MB) — any file you want downloadable from chat without indexing.

Up to 10 files per upload; drag-and-drop works. Each file shows a live status badge (Pending → Processing → Complete). Per-file settings (the kebab menu) let you add a description, toggle Allow download, or delete. Per-collection settings let you rename, set output guidance, or delete.

Output guidanceshapes the AI's voice. Catalogue-wide rules (Output tab, max 1500 chars) might be "Reply in formal English; show prices including VAT." Per-collection rules (max 800 chars) might be "Price lists: model number first, then trade price, then RRP." Both are optional — without them the AI uses sensible defaults.

A Catalogue invitation shares access to your knowledge so others can ask questions of it. From the sidebar, open the kebab (...) on a catalogue → Invite to this Catalogue, pick a duration (30 min / 1 hour / 24 hours / Unlimited), and send the link. The recipient opens it, signs in, and is added.

Invitees do notsee your catalogue in their sidebar — they only encounter its content as answers in their own chats. Manage everyone on the catalogue's Users tab (pause access or remove). One link can be reused by many people until it expires or you revoke it. Sharing content is separate from sharing tokens (see Tokens & billing): content sharing gives someone the right to ask; token sharing gives them the balance to pay for it.

The Marketplace is a public exchange of knowledge libraries. One creator publishes a catalogue; other creators subscribe to use it in their own chats. To browse, enable Show MARKETPLACE in Profiles → Appearance, then click Marketplace in the sidebar — each card shows the publisher, description, and subscriber count. Subscribe (free during launch) and the content is available in your chats immediately.

To publish, enable Show LIBRARY in Profiles → Appearance, then sidebar → hover LIBRARY → + New (this creates a catalogue in Library mode). Upload files, then write a description on the Marketplace tab and Save — that makes the listing public and subscribable. While the description is empty it stays a private draft, visible only to you.

Sebtember runs on tokens. Every AI answer you generate consumes some; you top up to refill. You pay for the answers you generate — the cost is debited when the AI replies. Reading old messages is free; asking is what costs. Content shared with you is free to read from. Platform-wide system content is always free.

You can have two balances: My balance (tokens you bought) and a Shared balance (tokens someone else shared with you). When you have a shared balance, a source selector chip appears in the chat header so you can choose which balance a conversation spends from.

Topping up:account menu → Usage → Billing. Pick a quantity (millions of tokens); the price updates live with VAT for your country. Tick the country-match consent and pay via Stripe's secure checkout — your balance updates within seconds and a VAT invoice PDF is generated automatically. Your card's issuing country must match your profile country; if they differ the charge is voided automatically (no money moves).

Sharing tokens:you can fund someone else's usage up to a monthly cap. On Usage → Billing, click the share icon on your balance card → Create share, choose a monthly cap, and send the link. The recipient accepts and is seeded with the cap from your balance; each month the share tops them back up to the cap, and you pay only for what they actually used. Manage shares under Usage → Analytics → Tokens Users (pause, resume, change the cap, or delete).

The single most important rule: garbage in, garbage out. The AI reads your documents exactly as you provide them. A blurry scan stays blurry, and a wrong price list produces wrong quotes — confidently. Two minutes of prep per file pays back for as long as that file lives in Sebtember.

Maximize accuracy:

• English first. Upload the English version where you have one — it processes faster and avoids double-translation drift on part numbers and unit conversions.
• No blurry scans. Sebtember reads PDFs visually, page by page. Skewed, watermarked, or photocopied-of-a-photocopy pages produce garbled codes and missed columns. If a human has to squint, the AI will misread.
• Tables: Excel and CSV beat PDFs. A native spreadsheet is read as structured data — every cell, every row. The same table inside a PDF is read as a picture.
• One topic per file. A focused 20-page manual is indexed better than a 500-page combined-everything PDF, and yields more precise citations.

Save tokens.Uploading a file is a one-time extraction cost; then every answer is paid for at chat-time by whoever asks. Native files (DOCX, XLSX, CSV, JSON, TXT) cost dramatically less than PDFs, which are processed page-by-page through Vision AI. Delete junk pages (disclaimers, blank pages, repeated glossaries), don't upload duplicates, and keep files lean — bloated files make every answer slower, costlier, and less accurate for everyone you share with.

What not to upload: image-heavy marketing brochures (mostly cost, little signal), password-protected or encrypted PDFs (extraction will fail — unlock first), pure CAD drawings or blueprints with no text labels (attach them as downloadable Attachments instead), and fax-quality scans you can barely read yourself.

Images & photos. Use the Image type for error-code screens, data plates, nameplate stickers, gauge readings — anything with visible text. Clear text is mandatory; glare, motion blur, and oblique angles produce garbage extraction. Diagrams are only useful if components are labelled in text. Skip the marketing shot; upload the close-up of the rating label. Resize anything over 5 MB.

Attachmentsbypass AI extraction entirely (zero processing tokens) and simply create a secure download link — use them for software updates, large CAD files, installer packages, and anything you want downloadable but don't need the AI to read. Noteslet you type up to 10,000 characters of tribal knowledge, context, or errata directly into a Collection; they're free to write, visible to the AI, and hidden from your chat users.

File descriptions give the AI a map. A file named sc-99-v2.pdftells the AI almost nothing. The same file described as "2026 maintenance manual and error-code reference for the Durst Water Pump Series 5 — covers SC-99 and SC-100 variants" gets indexed against every term in that sentence. Always include the product/model/brand, the document type, and the year or revision. Write in your native language — Sebtember translates descriptions to English behind the scenes.

Organize with Collectionsby content type ("Price Lists", "Service Manuals", "Datasheets"). The AI uses Collection structure to retrieve faster, and you can apply per-Collection output guidance that doesn't bleed into other answers. Finally, the Allow Downloadtoggle: ON lets the AI offer a download link; OFF lets it quote from the file but not hand over the original — use OFF for content you license but don't own.

• A file says Error / Fatal error— usually encrypted, password-protected, or corrupt (unlock and re-upload), over the size limit (image > 5 MB or other > 25 MB — resize/split), or a blocked type (executables/scripts).
• The AI can't find something in your files — the file may still be processing, may be in a Catalogue you no longer access, or scanned poorly (re-scan at 300dpi+). Rephrase with terms from the document.
• You ran out of tokens — top up on Usage → Billing, or ask whoever shares a balance with you to resume or raise your cap.
• Stripe declined / country mismatch— your card's issuing country must match your profile country. Fix one and retry; no charge happens until they match.
• Your VAT number won't verify — type the full number with the country prefix (e.g. LT123456789), click Verify, and refresh after a minute. Both the number and the company name must match the official record.
• Where are your receipts — account menu → Usage → Billing → Receipts. Each completed top-up produces a downloadable VAT PDF within a minute.

The account menu is your avatar and name at the bottom of the left sidebar.

Your data stays yours. Files are stored privately, encrypted, EU-hosted on Google's enterprise infrastructure, and never used to train AI models. Sebtember never uses the open web to answer, and deleted data is permanently wiped. For the full picture, see the Security page, the Privacy Policy, and the Terms. Questions: hello@sebtember.app.