Hacker News

points by vardhan1237 4 days ago | 0 comments

Hi HN,

I built PaperPilot because I was frustrated by the privacy trade-offs of modern PDF utilities.

Whenever you need to split, merge, compress, or sign a confidential document (tax forms, legal contracts, medical paperwork) using online tools, your files are transmitted to a third-party server. Most "free" tools retain copies or run in closed-source cloud environments.

PaperPilot is a 100% zero-cloud, local-first engine written in pure Rust (built on top of lopdf, pdf-writer, and image). 0 bytes are ever sent to an external server.

Key aspects of the project:

1. Penta-Interface Architecture: Instead of building just another web app or CLI, the same core Rust operations run across 5 surfaces: - Terminal CLI: High-throughput local processing and bash scripting. - Local Desktop App: Native cross-platform GUI built with Tauri 2 and Svelte 5. - Client-Side Web: Runs 100% inside your browser via WebAssembly (https://usepaperpilot.com/). - REST / Gateway API: Standalone local daemon (localhost:7823) for local microservices. - Model Context Protocol (MCP): Connects local AI agents (Claude Desktop, Cursor, OpenCode) directly to local PDF tools so LLMs can inspect, redact, and sign PDFs on disk without cloud upload.

2. Capabilities (75+ Tools): - Standard operations: Merge, split, rotate, reorder, burst, booklet imposition, and N-up grid. - Privacy & Compliance: Local PII regex redaction (SSNs, cards, emails), metadata striping, and digital signature verification. - Document Extraction: PDF to structured Markdown tables (no coordinate loss), PDF to JSON, and pure-Rust layout analysis. - Offline RAG: Embedded vector store (libsql_vector) with an actionable visual citation canvas.

3. Performance & License: - Average operation latency is ~20ms to 130ms. - 100% Free and Open Source under the Apache 2.0 license.

The GitHub repository is at https://github.com/KrushnaVardhanReddy/PaperPilot and the browser-based WASM sandbox is live at https://usepaperpilot.com/.

I’d love to hear your feedback on the architecture, performance benchmarks, and any edge-case PDF formats we should test against!

[–] Shorel 4 days ago

Is there anything in this project that was not already easily available with command line tools?

[–] ligarota 4 days ago

Yes, it's wasm. So you can run it in any browser. Super useful when no cli. Example on friend phone

[–] moooff 4 days ago

I really like the approach with WASM and the browser sandbox. That alone makes this very usable. iam also working on an agent harnes in the browser sandbox called "hermit" using a local inference endpoint. It runs Python in WASM with a virtual file system.

https://moooff.github.io/HermitUI/hermit-agent/

So this Tool comes in very handy and will try to integrate it.

[–] metchio 4 days ago

who doesn't need to merge and compress bunch of pdfs on a friend phone on a saturday morning

[–] Shorel 4 days ago

Yeah, it has to be a friend phone as mine has command line via ssh (and tailscale).

[–] smartbit 4 days ago

Congrats with your product, hope it works out well. Nice competitor analysis & (future) features list at https://github.com/KrushnaVardhanReddy/PaperPilot/blob/main/..., IMHO easier to read than your above list.

Question: seemingly you’re using Antigravity, an harness not many use. Please tell use about the choice of LLM and your experience with it.

[–] vardhan1237 3 days ago

Thanks for checking out the docs! We used a hybrid workflow: Antigravity IDE paired with Jules for asynchronous sub-tasks (like spinning up isolated unit tests and docs in parallel containers).

Having a strict test-first harness where every PR has to run against real PDF byte fixtures (zero mocks) and compile across CLI, WASM, and MCP kept the codebase consistent even when moving fast.

[–] smartbit 2 days ago

Thanks for your reply. Will look into Jules [0] [1].

Are you using Antigravity IDE v2.5.5 that hasn't been updated since 2026-08-13 and that supports 3 legacy models + Gemini Flash 3.8? I assume you're using Gemini Flash 3.8?

[0] https://news.ycombinator.com/item?id=44034918 [1] https://news.ycombinator.com/item?id=44813854

[–] sreekanth850 4 days ago

Is this a port of MuPDF?