OfficeCLI is a cross-platform CLI application written in C#/.NET that creates, reads, and mutates OOXML Office documents (Word .docx, Excel .xlsx, PowerPoint .pptx) without requiring Microsoft Office. It is explicitly engineered as an agent-facing tool: every document element is addressable through a uniform path syntax (e.g. /slide[1]/shape[2]), all commands emit structured JSON with error codes and suggestions, and it ships AI-skill files for Claude/Copilot/Cursor/Codex, an MCP server, plus Python and Node SDKs. The core operation model is a batch command language: documents are mutated by replayable JSON items (add/set/remove/get) executed atomically through the CLI or over a named pipe to a resident process. Architecturally the repo is a single .NET binary (embedded runtime) with a CommandBuilder layer, a DocumentHandlerFactory dispatching to three large partial-class handlers (WordHandler, ExcelHandler, PowerPointHandler), and a shared Core layer containing chart-to-SVG rendering, a formula evaluator implementing 350+ Excel functions with statistical distributions, pivot table construction, Mermaid diagram parsing, OOXML theme/table-style resolution, HTML/PNG/SVG preview rendering, and a plugin protocol for foreign-format dump-readers and exporters. Security is taken seriously: SsrfGuard validates remote fetch targets, HyperlinkUriValidator allowlists URI schemes, XmlTextValidator and DocumentLimits guard against decompression bombs and DOM sprawl, and AtomicPackageWriter prevents torn file writes. Quality is strong but carries real maintenance debt. The code demonstrates deep OOXML craftsmanship - schema-order-correct XML insertion, exact EMU unit round-trips, Lanczos-based gamma functions, and curated chart-style galleries. However, handlers are split across dozens of partial-class files that evolved from former god methods, the property API is stringly-typed (props dictionaries parsed per key), examples must be maintained in parallel shell and Python twins, and the tool deliberately tolerates 'UNSUPPORTED props' warnings (exit code 2), which can mask incomplete feature coverage. The best reuse targets are the self-contained Core utilities rather than the format handlers. The project is actively maintained with multi-platform CI publishing to npm and PyPI.