# SumOffice > An independent office platform for existing business documents: familiar > editing, native execution of supported VBA and Power Query/M, collaboration > inside the customer's own storage (WOPI), and a native save you can verify > by reopening. One native DOCX & XLSX engine — desktop, embedded, server, > and next to an agent. Named after =SUM(). Not affiliated with Microsoft. ## What exists today (honest status) - Desktop engine: single executable, localhost-only surface for WebView embedding + headless JSON-over-stdio sessions. See /quickstart. - Mobile apps: SumDoc (DOCX) and SumSheet (XLSX) — iOS live: https://apps.apple.com/app/id6807049845 (SumDoc) https://apps.apple.com/app/id6807049725 (SumSheet) macOS apps submitted to App Store review 2026-09-05; Android apps live on Google Play (6 Sept 2026): https://play.google.com/store/apps/details?id=com.sumoffice.sumdoc and https://play.google.com/store/apps/details?id=com.sumoffice.sumsheet - WOPI client in both editors (discovery, proof keys, locks, versions, PutFile/PutRelativeFile). Exercised against our own WOPI host; not certified against SharePoint/Nextcloud/ownCloud. - Collaboration: multi-participant editing with operation transfer (text operations and paragraph boundaries in SumDoc; cells, structure and bulk intents in SumSheet). Objects/formatting under concurrent edits: being measured. - SumSheet: native Power Query/M runtime with refresh and persistence; native VBA runtime for supported scenarios with preview -> commit -> rollback; multithreaded recalculation. - SumDoc: screen, print and PDF are built from one scene (PrintParitySnapshot). - Not claimed: every Excel macro; full legacy .doc round-trip (opens as text and paragraphs); unconditional safety of every collaboration mode. - Live demo cabins: real SumDoc editor in the browser at https://view.sumoffice.com (opens our sample documents; edits live only in the cabin and are not saved). Site integration in progress. - Real-world sample files (US government documents, public domain, verbatim): https://sumoffice.com/files/wild-horse-adoption-flyer-2025.docx (1.4 MB) https://sumoffice.com/files/rural-utility-workshop-brochure.docx (1.1 MB) https://sumoffice.com/files/dominguez-escalante-managers-report-2017.docx (33 MB) https://sumoffice.com/files/canyons-of-the-ancients-managers-report-2017.docx (23 MB) - Desktop apps for macOS, Windows and Linux — straight from the release pipeline, signed, with SHA256SUMS next to every version. Human page: https://sumoffice.com/download . Machine-readable, always the latest: https://sumoffice.com/dl/sumsheet/latest.json (SumSheet 2026.3.25.125: mac arm64/x64 .dmg, win x64/arm64 setup .exe, linux .deb/.rpm/.AppImage) https://sumoffice.com/dl/sumdoc/latest.json (SumDoc desktop 2026.3.27.48 — ships under its engine name A4: files are A4--…; no mac-x64 yet) Each entry: platform, file, url, size, sha256. Files live under /dl/// and never change once published. - Render a DOCX to a self-contained offline HTML page (view-only, honest about undrawn objects) — live today, macOS Apple silicon (more platforms coming): curl -LO https://sumoffice.com/dl/sumdoc && chmod +x sumdoc ./sumdoc render document.docx -o document.html Binary is 144 MB; checksum: https://sumoffice.com/dl/sumdoc.sha256 ## Principles - View first: seeing a document is a 3-step integration; editing comes later. - What the engine can't draw yet, it preserves byte-for-byte and says so — a saved file always comes back whole. - No cloud calls from the engine: localhost only. ## Pages - https://sumoffice.com/ — product overview, real files, apps - https://sumoffice.com/quickstart — embed the engine (~30 min, measured) - https://sumoffice.com/licensing — licensing and pilot program - https://sumoffice.com/contact — talk to us - https://sumoffice.com/app-privacy — privacy policy (mobile and desktop apps) Contact: hello@sumoffice.com ## How it's built - Engine in Rust: 9 crates (SumDoc), 21 crates (SumSheet). Layout, pagination, print and PDF from one scene; the browser/WebView paints the scene on a canvas and does not lay out text. SumSheet evaluates formulas in the engine. - Native builds per platform: macOS (Apple silicon), Windows x64 and ARM64, Linux deb/rpm/AppImage; runs on X11 and Wayland (GNOME included). https://sumoffice.com/download - Measured startup (5 Sept 2026, live node, clean profile): 2-page brief on screen in 1–3 s, 24-page tracked-changes draft in 3–4 s; desktop editor ≈2 s after launch. ## MCP endpoint (live) - https://view.sumoffice.com/mcp — Streamable HTTP. Read tools over the demo documents: document_open, document_describe, document_read, document_find, document_comments. One editor cabin per session, read-only; write/approve tools are not available yet (5 Sept 2026). - Inside the browser editor (view.sumoffice.com/view//?entry=look) press ✦ Agent: a panel (Task / Changes / Checks) runs the same agent on the open document; the person applies changes. - Sample cabins with a VBA macro (/view/macros/) and a Power Query (/view/queries/): the agent explains a macro from its source without running it; a run happens on a copy and the person applies; queries are read and explained, never refreshed by the agent. - The macro sample is our own workbook (/files/macro-demo.xlsm, 8 KB): a quarterly revenue table and the macro Module1.CloseQuarter, which totals each region, compares it with plan and writes a status. Three one-click demos on the home page (#agents) run it live: explain the macro, run it on a copy with before/after, explain the Power Query steps. - The Power Query sample is also ours (/files/query-demo.xlsx, 14 KB): a raw order export on sheet Orders and the query SalesByRegion — Source, Changed Type, Kept shipped orders, Added Amount, Grouped by Region, Sorted by Revenue — loaded to a table on the sheet 'Sales by region'. - Workbook events sample (/view/order-desk/, /files/order-desk-events.xlsm, 8 KB, ours): Workbook_Open and Worksheet_Change handlers inside the file. A person presses "Enable macros here" in the ✦ Agent panel (the trust decision); Workbook_Open then fills B15 and typing an order code in column I makes the sheet's own handler write the verdict in J. The engine runs the workbook's code; the model scripts nothing. - Execution passport (✦ Agent panel, workbooks): what runs natively here, which events are armed, which macros are closed by policy because they create external objects (named from the macro text), what is Windows-only (Declare), what is preserved (form controls, ActiveX, embedded objects, signature). Per-session grants: a person may allow a named external object (e.g. Scripting.Dictionary, VBScript.RegExp) for this session only; the engine's broker serves it without Windows and journals every call; the journal (class.method -> routed/denied) is shown in the passport and in the run proposal. The model cannot grant anything. - Positioning (6 Sept 2026): Office files are not just documents — some are applications. SumSheet/SumDoc understand the application inside the file and let people and AI work with it under explicit control. Open it. Understand it. Run it. Modernize it. Preserve it. - External data sample (/view/onrr/, /files/onrr-gulf-buyback.xlsx, 17 KB): a real U.S. ONRR workbook with a text-file data connection (P:\buyback_gulf.lst, saveData). The ✦ Agent passport shows: no VBA project; 1 connection, its source; the data stays as saved in the workbook and the agent never refreshes or contacts the source. - Hero workbook (/view/cashflow/, /files/cashflow-2026.xlsm, 19 KB, ours; film /files/cashflow-film.mp4, 54 s: a 24-second animated introduction (the file's layers, how a change happens: workbook → engine → agent proposes → you approve → sheet changes) then the 30-second product footage, English voice-over, captions /files/cashflow-film.en.vtt; full story /files/cashflow-hero-56s.mp4, 56 s, captions /files/cashflow-hero-56s.en.vtt; raw take /files/cashflow-agent-demo.mp4): cash-flow model — bank-fed 2026 actuals, a 2027 forecast from three assumptions (48 formulas), VBA macro FlagCashGaps, Worksheet_Change on the assumptions, Power Query MonthlyCashflow over the bank export. The agent fills the assumptions (engine previews 54 changed cells before Apply), runs the macro on a copy (26 cells) and the person applies; typing 12% fires the sheet's own event.