Native-quality rendering
Renders every page straight from the engine's own image buffer with no intermediate conversion that blurs detail, with zoom, rotation, thumbnails, and high-DPI export.
‹ qOS
Agent Documents· Lector
A document engine that acts, not just views.
Lector is a document engine we built for native-quality rendering, compiled to run inside any browser. It renders pages pixel-perfect with no quality-degrading image conversion, and goes far beyond viewing: it reads text, fills forms, permanently redacts content, and cryptographically signs and encrypts documents. The same engine ships as a drop-in viewer or as headless building blocks.
Native quality direct-to-canvas, no image round-trip
Sign + redact real cryptography, in the browser
4 frameworks: React, Vue, Svelte, HTML
Why Lector
Web PDF tools could show a document, not act on it.
Most web PDF tools wrap aging, second-hand engines: they download the whole file before showing a page, lose quality by turning each page into a compressed image, and can only view. Anything serious, filling a form, redacting sensitive data, or legally signing, pushes you to desktop software or expensive closed SDKs.
Lector collapses all of that into one engine that runs in any browser and can be driven by software or a person, with nothing leaving the page.
Capabilities
What it can do.
Text, search, and selection
Extracts exact text with per-character positioning, click-and-drag selection and copy, and full-document search with case, whole-word, and regex options.
Rich annotations
Sixteen drawing tools, from highlight and ink to shapes, arrows, free text, and sticky notes, with threaded comments, undo and redo, and standard import and export so markup is portable.
Interactive forms
Fills every PDF field type, populates and extracts data in batch, and runs Adobe-style auto-calculations and formatting in a sandboxed engine.
Permanent redaction
A mark-then-apply workflow that does not just draw a black box: it deletes the underlying content and regenerates the page, so redacted text cannot be recovered.
Digital signing and validation
Cryptographically signs documents with a certificate and verifies existing signatures for integrity, certificate, and expiry, with trusted timestamps for long-term validity.
Password protection and encryption
Applies AES-256 encryption with user and owner passwords and granular permission flags for print, modify, copy, and annotate.
Compare and reorganize
Visually diffs two documents down to the word, and inserts, deletes, rotates, reorders, merges, splits, and flattens pages.
Built different
Why it is not just another PDF viewer.
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A modern engine, not a years-old build
Lector runs a current, hardware-accelerated rendering engine, instead of the years-old builds most web PDF libraries carry, with their known rendering bugs.
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No image round-trip
Competitors turn each page into a compressed picture, introducing artifacts and double memory. Lector transfers the raw rendered bitmap with zero copies, preserving exact fidelity.
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Real cryptography, not a stub
Signing, verification, and encryption are implemented over a real crypto library compiled into the engine, producing standards-compliant signatures and AES-256 entirely in the browser, where most viewers either lack this or punt it to a server.
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One engine, every framework
A framework-agnostic core with a thirty-plugin system, plus thin official bindings for React, Vue, Svelte, and Web Components, each shipping a full viewer and headless hooks.
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Private by construction
All engine work runs off the main thread, and everything, including signing and encryption, happens client-side with nothing leaving the browser. Permissions can gate print, export, signing, and redaction per document.
By the numbers
Engineered for fidelity.
498engine functions exposed
16annotation tools
AES-256in-browser encryption
Web Workeroff the main thread
Agent-first
From talking about a contract to acting on it.
A document engine turns an agent from something that can only discuss a contract into something that can act on it. With Lector in a sandbox, an agent can open a contract, read and search its exact text, fill in a form, black out personal data, then sign and return it, all programmatically, with nothing leaving the sandbox.
- Read and extract: pull exact text and field values to reason over.
- Modify safely: fill forms, permanently redact, and annotate, with full undo history.
- Finalize: encrypt with a password or apply a digital signature before sending.
Put Agent Documents to work.
See HQ running in your own Slack or Teams, on the operating system we built for agents.