I use mostly typst for pdf generating today i have written different frontends and connectors to transform everything into typ files and templates. I eben use it with sphinx as a backend
How do you use it with i18n and theming and templates? Do you define all of these outside of typst and (e.g.) add a shadow file to the typst compiler?
Asking because I've recenly been doing something similar, but since my typst files are templates, which with the same inputs can differ and may need different translations as well, I've written a small i18n library in typst (but I guess you could require a set of translations to be present with a given typst file as well).
Is this PDF engine vibe-coded and derived from reading the MuPDF source code? (Written from C to Rust) I see some slight references to MuPDF in certain places.
If it is you should disclose it and the license should be AGPLv3 instead of Apache.
Unless they meant vaguely similar code (which I can't judge), the only mentions of mupdf are in the AI instructions:
> **The Opportunity:** Capturing the high-growth enterprise AI engineering market by replacing bloated, slow Python extraction pipelines (`Unstructured.io`, `Docling`, `Marker`, `LlamaParse`, `PyMuPDF4LLM`) with a pure-Rust, sub-10ms, multi-format ingestion kernel.
- This structure guarantees that if we ever swap the PDF engine to `pdfium` or `mupdf`, not a single line of business logic in `paperpilot-core` or CLI tools will need to be rewritten.
> Directly captures the high-growth AI Engineering & RAG pipeline market (displacing bloated Python stacks like Docling, Marker, PyMuPDF4LLM, and Camelot) with sub-10ms, pure-Rust, on-device parsing.
| A.2.5 | `MuPdfBackend` adapter (Future) | Use MuPDF for OCR-heavy workflows via FFI |
I think there's a difference between a standard PDF viewer and basic functionality, vs a full PDF authoring suite like Adobe. For some of the basic features in one of the comments, I'm not quite sure how tried and tested tools that are simple like Foxit PDF don't fit the bill for most things. Unless you're trying to process gobs of PDFs in headless mode or do some sort of analysis... eh.
Is there a real use case for manually authoring a PDF directly? I assumed everyone would either use a word processor or some other tool that exports as pdf rather than editing a pdf as if it was a word doc.
Love the web interface! But can it be done better?
First, how do you "sign" a PDF using this tool?
If you're going to build this, can you find a small, even tiny model that has decent tool calling and, effectively turn that in combination with this tool into a single HTML page that I can use everywhere?
Literally something I could save on a work laptop or cloud desktop and would actually work (even if it would be slow, it'd still be a great improvement)
In case you don't have showdead on, the OP writes:
"""
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.
> Native cross-platform GUI built with Tauri 2 and Svelte 5
That's not native, and if you pointed it out to the LLM that wrote this, it would agree. It's just dumb so it didn't think of the fact that that's entirely the wrong term.
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.
I use mostly typst for pdf generating today i have written different frontends and connectors to transform everything into typ files and templates. I eben use it with sphinx as a backend
How do you use it with i18n and theming and templates? Do you define all of these outside of typst and (e.g.) add a shadow file to the typst compiler?
Asking because I've recenly been doing something similar, but since my typst files are templates, which with the same inputs can differ and may need different translations as well, I've written a small i18n library in typst (but I guess you could require a set of translations to be present with a given typst file as well).
I started building things like this as browser extensions to make the hosting simpler.
Is this PDF engine vibe-coded and derived from reading the MuPDF source code? (Written from C to Rust) I see some slight references to MuPDF in certain places.
If it is you should disclose it and the license should be AGPLv3 instead of Apache.
It's using hayro in Rust
Licenses are so yesterday. /s
Seriously though, can you list some examples?
Unless they meant vaguely similar code (which I can't judge), the only mentions of mupdf are in the AI instructions:
Would be useful to have a remove password feature (for a known password) and support for adding signatures
Can I use it with Open-Webui instead of Apache Tika?
Great work. But why you are using AI for build such a service, it does not need an AI.
The feature i like about this is privacy focused
Sorry I just realized it is private running in browser only. thats the feature i am looking for
interesting，but will it have official GUI？
I think there's a difference between a standard PDF viewer and basic functionality, vs a full PDF authoring suite like Adobe. For some of the basic features in one of the comments, I'm not quite sure how tried and tested tools that are simple like Foxit PDF don't fit the bill for most things. Unless you're trying to process gobs of PDFs in headless mode or do some sort of analysis... eh.
Is there a real use case for manually authoring a PDF directly? I assumed everyone would either use a word processor or some other tool that exports as pdf rather than editing a pdf as if it was a word doc.
Nice work.
Love the web interface! But can it be done better?
First, how do you "sign" a PDF using this tool?
If you're going to build this, can you find a small, even tiny model that has decent tool calling and, effectively turn that in combination with this tool into a single HTML page that I can use everywhere?
Literally something I could save on a work laptop or cloud desktop and would actually work (even if it would be slow, it'd still be a great improvement)
In case you don't have showdead on, the OP writes:
""" 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! """
Which reads very much LLM produced.
> Native cross-platform GUI built with Tauri 2 and Svelte 5
That's not native, and if you pointed it out to the LLM that wrote this, it would agree. It's just dumb so it didn't think of the fact that that's entirely the wrong term.
It read to me as a case of: "only webpages are software, and I'm afraid of the command line".
Really. All he wants was very easy to do already.
> It read to me as a case of: "only webpages are software, and I'm afraid of the command line".
I think you've missed this part:
> Terminal CLI: High-throughput local processing and bash scripting.
Woah, I certainly did!
I am interested in the following use case: convert the PDF to e-pub, then edit it with Calibre to fix some issues that always happen.
Currently using pandoc.
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!
Is there anything in this project that was not already easily available with command line tools?
Yes, it's wasm. So you can run it in any browser. Super useful when no cli. Example on friend phone
who doesn't need to merge and compress bunch of pdfs on a friend phone on a saturday morning
Yeah, it has to be a friend phone as mine has command line via ssh (and tailscale).
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.
Is this a port of MuPDF?