omapdf

Preview.app for Linux — but your agent can drive it.

omapdf is an agent-native PDF tool: a fast GTK4 editor for reading, annotating, and signing; a scriptable CLI; an MCP server for AI agents; and an Omarchy integration that ties them all to the operating system. One op engine underneath — anything a human can do by hand, an agent can do by instruction, and vice versa.

omapdf edit lease.pdf                       # the editor
omapdf sign lease.pdf --page 4 --at 120,540 --date -o signed.pdf
# …or just tell your agent: "fill out this lease, highlight anything
#  unusual, and get it ready for my signature"

Why

The "someone emailed me a PDF, I need to highlight two things, sign it, and send it back" workflow is macOS Preview's killer feature — and Linux has no lightweight equivalent. And nobody anywhere treats AI agents as first-class PDF users. omapdf does both, with one architecture:

Related MCP server: PDF Reader MCP Server

One operations API, every client is thin

Every action — highlight, comment, fill a field, stamp a signature, draw ink — is a small JSON operation. A document edit is a list of them. The editor, the CLI, and the MCP server all funnel through the same engine:

     human                            agent
       │                                │
 ┌─────┴─────┐                 ┌────────┴────────┐
 │  editor   │                 │  MCP server /   │
 │  (GTK4)   │                 │  Claude skill   │
 └─────┬─────┘                 └────────┬────────┘
       │          ops (JSON)            │
       └──────────────┬─────────────────┘
              ┌───────┴───────┐
              │   op engine   │  validate → resolve → apply → report
              │   (PyMuPDF)   │
              └───────┬───────┘
                 document.pdf

Every applied op echoes back its resolved geometry, so either side can show the other exactly what changed and where. Everything written is a standard PDF annotation — Acrobat, Preview, and Evince users see your notes and highlights as normal comments.

The editor (omapdf edit)

A native GTK4 editor, Preview-fast, designed for Omarchy but plain-GTK portable:

• Tools (hand-drawn vector icon set): select/drag, pen with a tap-again color palette, highlighter, text, sticky notes, signature placement, green-check and red-cross stamps

• Ghost model: everything you place is a draggable, nudgeable pending item until Save bakes it through the op engine — and undo crosses the save boundary: Ctrl+Z after saving reverts the file and resurrects the saved items as editable ghosts

• Reading comforts: thumbnail sidebar (F9), fit-width zoom that tracks the live viewport, zoom presets + Ctrl+scroll, full-document search (Ctrl+F) with match cycling, page navigation by Up/Down, PgUp/PgDn, Home/End, Ctrl+G go-to-page

• Comments open on click: click any saved annotation to read its text — including comments left by agents or by other people's PDF apps

• Agent proposals as ghosts: omapdf edit doc.pdf --ops proposal.json loads an agent's dry-run ops as selected, draggable overlays — nudge, then Save. Agent proposes, human confirms.

• Ask your agent (✦): type a question, it opens your OS default agent (omarchy agent prompt) with the document attached. The editor watches the file and reloads itself when the agent saves changes.

• Share (native, no fake share sheet): email attach, LocalSend, copy the file (or a zip of it) straight onto the clipboard, show in folder — with an optional flatten-copy-first toggle

• Save celebration included. You'll see.

The CLI

omapdf read doc.pdf                  # structured JSON: text+bboxes, fields, annots
omapdf read doc.pdf --text-only      # just the words
omapdf fields form.pdf               # fillable fields with names and rects
omapdf snapshot doc.pdf --page 2 --grid 50   # page PNG with a labeled
                                     # coordinate grid — agents read placement
                                     # coordinates straight off the image

omapdf annotate doc.pdf --page 2 --match "termination clause"
omapdf note doc.pdf --page 2 --at 400,300 --text "negotiate this"
omapdf fill form.pdf --field tenant_name "Peter Bergin" --field rent "1800"
omapdf apply doc.pdf --ops edits.json        # atomic batch of ops

omapdf sig draw                      # draw your signature once (GTK window)
omapdf sig add ~/sig.png --name work # …or import an image
omapdf sign doc.pdf --page 4 --at 120,540 --date -o signed.pdf
omapdf flatten doc.pdf -o final.pdf  # bake everything in for any viewer
omapdf open doc.pdf                  # opens the omapdf editor

Every edit command takes -o (default: in place), --dry-run, and --json (each op returns its resolved geometry). Coordinates are PDF points, origin top-left, 1-based pages — identical to what read reports. The ops vocabulary is specified in docs/ops.md.

Agents

claude mcp add omapdf -- omapdf-mcp

MCP tools: read_pdf, list_form_fields, apply_ops, highlight, add_note, fill_field, place_signature (dry-run by default — confirm-before-ink), list_signatures, flatten_pdf.

The Claude Code skill in skill/ is a full PDF-assistant playbook: recipes for review-and-highlight, form filling, signing, redlining, checklists, extraction with page citations — built around a precision ladder: text anchors → grid snapshot (look at the page) → dry-run → verify the written result visually → hand a draggable ghost to the human when taste matters.

Install

git clone https://github.com/pbergin11/omapdf && cd omapdf
python -m venv --system-site-packages .venv    # system gi for the GTK editor
.venv/bin/pip install -e '.[mcp]'
ln -s "$PWD/.venv/bin/omapdf" ~/.local/bin/omapdf
ln -s "$PWD/.venv/bin/omapdf-mcp" ~/.local/bin/omapdf-mcp
ln -s "$PWD/bin/omapdf-pick" ~/.local/bin/omapdf-pick

Requires Python ≥ 3.11, PyMuPDF, and (for the editor and sig draw) PyGObject + GTK4 from your distro. Arch packaging in packaging/PKGBUILD.

Make omapdf your system PDF handler:

cp share/omapdf.desktop ~/.local/share/applications/
xdg-mime default omapdf.desktop application/pdf

Omarchy integration

• Top-bar widget (shell-plugin/): a PDF pill — click for a recent-PDFs menu, pick one, it opens in the editor (ln -s .../shell-plugin/omapdf.bar ~/.config/omarchy/plugins/omapdf.bar, then omarchy bar put omapdf.bar --section right)

• Ask-agent uses omarchy agent prompt, so it launches whatever default agent the user picked (omarchy default agent), in Omarchy's native agent window; Voxtype dictation works in the ask box like any text field

• Packaged in the spirit of omasnap: a focused, single-purpose native tool

Status & roadmap

Working today: op engine, CLI, MCP server + skill, signature store and drawing window, the full editor, bar widget, agent ask/watch loop, tests. See docs/roadmap.md for what's next — headlines: signature-line auto-detection (sign --auto), annotation deletion/editing of saved items, comments summary page, cryptographic (PAdES) signing via pyHanko.

License

AGPL-3.0-or-later (matching our PyMuPDF dependency). See LICENSE.