# HermesOffice: Open-Source AI Office Suite for Word, Excel, PowerPoint, and PDF

> HermesOffice is a free, Apache-2.0-licensed Electron app for macOS, Windows, and Linux that opens and saves real Microsoft Office formats with byte-preserving fidelity, and lets the Hermes AI agent edit documents block by block with snapshot and diff tracking.

**criptogus/HermesOffice** — AI-native office suite (Docs, Sheets, Slides, PDF) where the Hermes Agent is the brain — open standards, byte-preserving round-trip, 100% local.

- Repository: https://github.com/criptogus/HermesOffice
- Stars: 596 · Forks: 81
- Language: TypeScript
- License: Apache-2.0
- Published: 2026-09-10 · Updated: 2026-09-10 · Language: en
- Canonical page: https://hysenlabs.com/projects/criptogus-hermesoffice

## What HermesOffice Is and Who It Serves

HermesOffice is an Electron-based office suite that runs on macOS, Windows, and Linux. It opens, edits, and saves the real Microsoft Office formats: .docx, .xlsx, and .pptx. It also handles PDF and Markdown. The core distinction from LibreOffice and similar alternatives is twofold: it uses in-house document engines designed to produce byte-preserving round-trips (only what you change is different, so Word or Excel do not treat the file as modified in unexpected ways), and it integrates a Hermes AI agent as a first-class editing workflow rather than an optional chat sidebar.

The README positions HermesOffice for macOS users immediately, since the only published binary artifact is a .dmg for Apple Silicon. Windows and Linux users who want to run the app without building from source are not yet served by official releases. This is a real adoption barrier for teams beyond the Apple Silicon base.

The project is licensed under Apache-2.0 and published under the organization name genspark-ai in the package.json, though the repository itself is under the criptogus GitHub account.

## The Hermes Agent: Block-Level Edits with Snapshots and Diffs

The Hermes Agent is what separates HermesOffice from a standard office suite with a chatbot attached. According to the README, the agent performs block-level edits on documents, tracking each change with a snapshot and generating a diff. This means the user can see exactly what the agent modified, compare before and after states, and revert specific blocks.

The README describes the AI editing as document-aware: the agent understands the structure of the document being edited rather than treating it as a plain text stream. For a Word document with headings, paragraphs, and tables, the agent can target specific structural elements.

The bring-your-own-key model list is extensive. The README documents support for Claude, OpenAI, Gemini, DeepSeek, Kimi, GLM, Qwen, Doubao, MiniMax, Grok, Mistral, OpenRouter, and any OpenAI-compatible endpoint. Users can also sign in with Genspark to avoid configuring keys entirely. Built-in agent tools include web and image search, image generation, and media analysis.

This is a significant difference from Microsoft Copilot in Microsoft 365, which is a subscription add-on tied to Microsoft's cloud services. HermesOffice lets any engineer point the same editing workflow at whichever model they already pay for, entirely locally.

## Installing HermesOffice on macOS, Linux, and Windows

The macOS Apple Silicon build is the only published artifact. Download the .dmg from the releases page at github.com/criptogus/HermesOffice/releases/latest. The README notes that the bundle is ad-hoc signed but not notarized, so the first launch requires a manual override: right-click the app and select Open, or allow it under System Settings > Privacy and Security.

On Linux, the README documents three package formats. For Debian or Ubuntu:

```bash
sudo apt install ./hermesoffice_<version>_amd64.deb
```

For Fedora or RHEL-family distributions:

```bash
sudo dnf install ./hermesoffice-<version>.x86_64.rpm
```

For the AppImage, which runs in place on any Linux distribution with FUSE 2:

```bash
chmod +x HermesOffice-<version>.AppImage
./HermesOffice-<version>.AppImage
```

On Ubuntu 24.04 the FUSE 2 package has been renamed: install libfuse2t64 rather than libfuse2. Windows builds are not yet published; building from source is required.

## Document Engines: OOXML, PDF, and Local Conversion

The README describes a set of in-house document engines rather than a dependency on Pandoc or a cloud conversion service. The OOXML engine handles .docx editing with Word-faithful pagination, meaning page breaks land where Word would place them. Excel-compatible spreadsheet support uses an in-house engine with a Rust .xlsx sidecar for format handling, and includes charts, pivot tables, and slicers. The PowerPoint engine handles masters, layouts, smart guides, and non-destructive crop for image editing within slides.

PDF editing is more capable than most open-source tools provide. The README states that users can retype text and edit images in the page itself with original fonts preserved. Local PDF-to-Word, PDF-to-PowerPoint, and PDF-to-Excel conversion runs entirely on the user's machine with no upload. On macOS and Windows, scanned PDFs are processed through the system OCR before conversion to editable text. This combination of features addresses a common pain point: taking a PDF from a client or partner and turning it into an editable Office document without trusting a cloud API with the contents.

Markdown-to-Word conversion uses the same OOXML engine and requires neither Pandoc nor a cloud call.

## Six Apps Sharing One Engine Layer

HermesOffice ships as six separate Electron applications sharing a common engine layer. The README's apps table describes the product breakdown: HermesDocs (word processor), HermesSheets (spreadsheet), HermesSlides (presentations), HermesPDF (PDF editor and converter), HermesMarkdown (Markdown editor), and HermesShell (the AI agent hub). Each app is a separate entry point, which means users can install only the applications they need.

The package.json workspaces structure reflects this: apps/* and packages/* are separate workspace entries. The test suite covers the docx-engine, pdf2docx, pptx-engine, pptx-render, ai-search, agent-core, ai-provider, project-store, docs, sheets, shell, slides, pdf, and markdown packages individually. This level of test coverage for individual document engine packages is unusual for an open-source office suite and suggests the engine layer was built with correctness rather than speed of integration in mind.

## Limitations and What the README Does Not Cover

The most immediate limitation is platform coverage for published binaries. Only macOS Apple Silicon has a downloadable artifact. macOS Intel, Windows, and all Linux distributions require building from source, which involves Node.js 22.12.0 or later, npm 10 or later, and Electron tooling. The README includes development setup in the CONTRIBUTING.md but the README itself does not reproduce those steps.

The macOS build is ad-hoc signed but not notarized, meaning macOS's Gatekeeper will block it on first launch. While the workaround (right-click, Open) is a one-time step, it is a deterrent for users who are not comfortable overriding security prompts. There is no Apple Developer ID certificate behind the build.

LibreOffice takes a different architectural approach: it is a single monolithic suite built on a C++ document model with decades of compatibility work. HermesOffice's in-house engines are newer and have fewer years of interoperability testing. The README's byte-preserving claim is specific: "only what you touched changes; Word never notices." How well this holds across complex Word documents with tracked changes, embedded objects, or unusual formatting is not documented.

The repository's most recent release at the time of this writing was ho-v0.8.5, published on 2026-09-28. The project is under active development.

## Conclusion

HermesOffice is the right choice for a developer or power user on macOS who needs to edit Microsoft Office formats locally without a cloud subscription, wants AI editing through their own API keys, or needs local PDF-to-Word conversion without uploading to a third-party service. On Windows and Linux, the only published artifact is for macOS Apple Silicon; other platforms require building from source. The byte-preserving OOXML engine and the bring-your-own-key AI model list make HermesOffice a credible alternative to both LibreOffice and cloud-based office suites, but the self-hosted build process and the absence of notarization on macOS mean it is not a zero-friction install for most users.

## FAQ

### What can the Hermes agent do in HermesOffice?

According to the README, the Hermes agent performs block-level edits on documents, tracks changes with snapshots and diffs, and is document-aware rather than treating the file as plain text. Built-in tools include web and image search, image generation, and media analysis. It works with any supported API key or through a Genspark sign-in.

### Does HermesOffice support Windows and Linux?

Yes in principle, but only the macOS Apple Silicon build has a published binary. Windows and Linux users must build from source. The Linux build supports Debian/Ubuntu .deb packages, Fedora/RHEL .rpm packages, and AppImages for other distributions, but these are built from source rather than downloaded from the releases page.

### Can HermesOffice convert PDFs to Word documents without uploading to a cloud service?

Yes. The README states that local PDF-to-Word, PDF-to-PowerPoint, and PDF-to-Excel conversion runs entirely on the user's machine with no cloud upload. On macOS and Windows, scanned PDFs are processed through the system OCR before conversion. The conversion uses HermesOffice's in-house OOXML engine rather than Pandoc.

## Sources

- [criptogus/HermesOffice on GitHub](https://github.com/criptogus/HermesOffice)
- [Issues](https://github.com/criptogus/HermesOffice/issues)
- [License: Apache-2.0](https://github.com/criptogus/HermesOffice/blob/main/LICENSE)
- [README](https://github.com/criptogus/HermesOffice/blob/main/README.md)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/criptogus-hermesoffice