v0.3.7

Extract pages and selected text as Markdown for agents.

Click Mantis in the browser toolbar. It reads the page already rendered in the active tab, converts it locally, shows a preview, and copies the Markdown to your clipboard.

Page or selection → Markdown → clipboard.

This browser tool is built using Mantis, a small extraction library. Read more →

Field Notes Guides About

A practical guide to local-first tools

Mara Chen · 28 July 2026 · 6 min read

Local-first software keeps the working copy on your device, so the useful part remains available without a network connection.

Look for readable exports, explicit permissions, and a clear account boundary.

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# A practical guide to local-first tools

Local-first software keeps the working copy on your device.

## What to look for
- readable exports
- explicit permissions

page · article · 0.91 confidence · ~480 tokens

Fig. 1 — click Mantis on a rendered page; the Markdown appears and is copied.

Install

Chrome Web Store — not published

Deferred

The Manifest V3 build passes local tests. A public install link will be added after store submission.

Before / after

Browser copy unstructured

FIELD NOTES   Guides   About

A practical guide to local-first tools
Mara Chen  6 min read

Local-first software keeps the working
copy on your device.

Share   Subscribe   Cookie settings

Mantis Markdown

---
title: "A practical guide"
url: "https://fieldnotes.example/..."
confidence: 0.91
---

# A practical guide to local-first tools

Local-first software keeps the working
copy on your device.

Fig. 2 — page chrome is removed; useful structure and source details remain.

Capabilities

Selection first

A useful text selection takes priority over the full page.

Structure kept

Headings, links, lists, code, images, and tables stay in reading order.

Capture details

Source, mode, confidence, warnings, and token estimate remain visible.

Clipboard ready

Copies automatically, with a manual control when the browser blocks it.

Permissions

No persistent site access.

activeTab	Read the tab you click Mantis on.
scripting	Run the packaged extractor in that tab.
clipboardWrite	Copy the Markdown result.

No external page fallback. Page URLs and content are not sent to a proxy service.

Limits

Known browser and extraction boundaries.

Restricted URLs	Browser-internal pages, add-on stores, and other protected URLs cannot be captured.
Page state	Hidden, unloaded, or inaccessible frame content is outside the rendered DOM snapshot.
Extraction	Unusual layouts can produce partial or low-confidence output. Mantis is not a verbatim archive.
Images	Image references and alt text are kept. Mantis does not run OCR or image analysis.