Xudanu Documentation

A hypertext document store built on the Udanax-Gold foundation with modern enhancements: BLAKE3 content addressing, CRDT collaborative editing, cryptographic author attribution, real-time transclusion queries, trails, document map, and content similarity.

Xudanu at a Glance CLICK ANY REGION

🌐 Browser — React + CRDT collaborative editor WebSocket / WSS SERVER CORE (Rust) Editions & Works versioned documents O-Tree order / positions GrandMap content dedup Transclusion Engine links · quotes · canopy Attribution Ed25519 signed authors Identity / Clubs auth · permissions BLAKE3 content-addressed chunk store + manifest ⇄ Federation I/O & storage core data structures transclusion attribution / identity

The fundamental pieces, end to end. Click any region to open its deep-dive page.

Getting Started START HERE

Start here if you're new to Xudanu.

User Guide (v0.7.0)

Complete guide to the web UI: editing, stars, trails, document map, transclusion, attribution, revisions, and persistence.

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README

Quick Start guide, prerequisites, CLI reference, security notes, and macOS Gatekeeper instructions.

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User Manual

Complete manual covering server setup, web UI guide, command bar, document operations, and troubleshooting.

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TLS Setup Guide

Configure HTTPS and WSS for encrypted connections. Self-signed certs, Caddy reverse proxy, and Safari compatibility.

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Stars / Favorites

Star documents to mark them as favorites. Starred docs appear in a dedicated sidebar section and as amber nodes in the Document Map.

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Xudanu in One Page

Content and performance architecture diagram on a single page. The complete system at a glance: O-tree, chunk store, WAL, CRDT, federation, and the wire protocol.

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Collaborative Editing

Real-time multi-user editing with O-tree CRDT, Ed25519-signed author attribution, awareness state (cursors/selections), three-way merge fallback, and LLM-assisted change narration.

8 sections · 1 diagram

Notification System

Real-time notification and event system for collaborative editing sessions.

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Documents & Storage CORE

How content is stored, versioned, and managed. A Xudanu document is an edition — an immutable snapshot of text and structure. Editions are organized into works, persisted in chunks, and tracked through a version DAG.

Editions & Works

How documents are structured as versioned editions with per-line attribution, three-way merge, and the O-tree data model. Essential reading for understanding Xudanu's core abstractions.

10 sections · 10 diagrams

Storage System

BLAKE3 content-addressed chunk store, incremental checkpoints, garbage collection, and integrity verification.

13 sections · 11 diagrams

Ent, DagWood & Trace DAG

The versioning spine adapted from Udanax-Gold C++: partial-order TracePositions, Root/Tree/Dag branch topologies, the navigation cache (max-over-paths), assertion-based content with 13 payload types, conflict-preserving AlternativeSet materialization, the H-Tree, and the bridge to the Edition model — with code examples and SVG diagrams.

18 sections · 7 diagrams

Manifest & Chunk Architecture

How manifest.json uses hash pointers to reference document content in the chunk store: WorkChunkRef, EditionChunkRef, EntryChunk, ProvenanceChunk, and the three-layer link persistence model.

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Garbage Collector

How the GC reclaims disk space: mark-and-sweep algorithm, chunk write path, WAL journaling, and the v0.7.5 safety fix.

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Storage System

Content-addressed BLAKE3 chunk store, incremental checkpoints, garbage collection, and integrity verification. 13 sections with SVG diagrams.

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Hardened Persistence

Three-layer data protection: Write-Ahead Log, dual manifest slots (A/B), and atomic fsync+rename checkpoints every 5 seconds.

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Paths, Snapshots, Endorsements

Label sequences through nested editions, snapshot persistence, and the endorsement system.

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Connections & Reuse HYPERTEXT

How documents link to, reference, and include each other. Xudanu's core innovation is visible, typed connections between specific passages — combined with transclusion (live content reuse) that tracks provenance back to the original source.

Links & Backlinks

Nelson's typed, bidirectional, unbreakable connections between passages. The five link types (Comment, Reference, Disagreement, Quotation, See Also), the two-part creation flow, backlinks, span migration, and profuse overlapping links — with code examples and canvas-render diagrams.

14 sections · 9 diagrams

Transclusion Engine

How content reuse is detected, indexed, and queried across documents: BLAKE3 fingerprinting, Bert Canopy tree, Recorder pub/sub, Hoist propagation, and Backfollow queries. The core intellectual property of Xanadu.

9 sections · 3 diagrams

Provenance & Cryptographic Attribution

How Xudanu answers "who wrote this?" at the character level. Ed25519 span signing, content fingerprints, domain separation, the materialization pipeline, transclusion attribution, historical attestation for imported texts, the tamper-evident SHA-256-chained attribution log, provenance ancestry walks, exportable attestation reports, and federation cluster consensus with W3C PROV-JSON export.

23 sections · 7 diagrams

Compound Documents

How live transclusion works: inline RangeElement::Transclusion in the O-tree, recursive resolution, attribution propagation, span migration, and the visual Compound Builder for assembling passages from multiple sources into one editable view.

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Compound Builder Guide

Visual builder for assembling compound documents from transcluded passages. Drag, drop, and rearrange live content from multiple sources into a single editable view.

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Compound Tutorial

Step-by-step user guide for compound documents: creating transclusions, seeing colour-coded source regions, the compound panel, and the legal brief assembly example. Includes comparison with Udanax-Gold.

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Links Tutorial

Step-by-step user guide for creating links and backlinks: using the Link Creator wizard, choosing link types, creating transclusions, managing existing links, and understanding the visual markers.

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Document Map

Force-directed graph showing all documents, transclusion links (solid lines), and content similarity (dashed lines). Click nodes to navigate.

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Trails

Create ordered reading paths through your documents — Nelson's original concept of guided sequences through hypertext.

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Content Similarity

Documents with overlapping vocabulary (>15% Jaccard similarity) are connected with dashed lines and drift together in the Document Map.

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PROV-JSON Validator

Interactive W3C PROV-JSON validator for Xudanu's attribution export. Paste a report, see the provenance graph, verify signatures and timestamps.

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Storage & Rendering Architecture

How Xudanu stores documents, revisions, and images — and how they flow through the system to appear on your screen. Diagrams the 5-layer stack, disk layout, image upload flow, and revision persistence across restarts.

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Transclusion Plan

Plan for connecting BackfollowEngine, canopy, recorder, and ENT into a working transclusion detection pipeline.

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Mathematical Foundations MATH

The position algebra and tree structures that make precise content addressing possible. These power span migration (links survive edits), intercomparison (finding shared passages), and efficient tree traversal.

The Space Algebra

The mathematical foundation underlying every position, region, span, mapping, and address in Xudanu. The four core traits (Space, Position, Region, Dsp), the transition-set representation, the seven concrete spaces (Integer, Real, Sequence/Tumbler, CrossSpace2, CrossSpaceN, FilterSpace), span migration, shared-content detection, and tumbler addressing for federation — explained from the ground up for developers.

20 sections · 9 diagrams

Canopy (Bert Tree)

The hierarchical property tree that indexes content for fast transclusion queries. Built atop the Space Algebra, the Canopy maps regions to properties and powers backfollow lookup — the structural heart of content reuse and intercomparison.

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Identity & Security SECURITY

Who you are, what you can access, and how content is verified. Xudanu uses cryptographic signatures (Ed25519), Argon2id password hashing, and a club-based permission system inherited from Udanax-Gold.

Identity & Authentication

Clubs (the Udanax-Gold identity model), the lock hierarchy (Boo/Wall/Challenge/Match/Multi), KeyMaster authority tracking, Ed25519 provenance, and per-session security monitoring.

8 sections · 1 diagram

Cryptography & Security

Production-grade crypto stack: Ed25519 signatures, X25519 key exchange, ChaCha20-Poly1305 AEAD, HKDF-SHA256 domain separation, and Argon2id password hashing.

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Network & Federation FEDERATION

Connecting Xudanu servers across the internet. Tumblers provide stable hierarchical addresses for content on any server. Cross-server backlinks, BLAKE3 hash verification, and the federation protocol let documents span multiple independent servers.

The Xanadu Network Guide

Verified end-to-end: two servers sharing content via tumblers, automatic bidirectional backlinks, click-to-resolve content fetch with BLAKE3 verification. Includes setup guide, tumbler format, security model, and Gold heritage comparison.

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The Xanadu Network & the Docuverse

How independent Xudanu servers form a connected literature. The tumbler address space, content sharing without replication, transclusion across server boundaries, BLAKE3 content addressing, three-layer verification (tumbler + hash + Ed25519), server operator responsibilities, scaling to hundreds of servers, and the risks and mitigations of hostile machines in the network.

12 sections · 6 diagrams

Federation Trust Boundary Analysis

A security audit of the multi-server federation layer. Maps seven trust boundaries from connection admission through governance, catalogs 14 authorization gaps by severity (CRITICAL/HIGH/MEDIUM/LOW), and provides a phased remediation roadmap to align federation access control with the single-server club model. Includes safe deployment patterns for current-state operation.

13 sections · 3 diagrams · 14 gaps catalogued

FR-6: Linked Independent Servers

Lightweight multi-server model using tumbler resolution instead of data-replicating clusters. Each server is sovereign; cross-server content references via tumbler addresses with BLAKE3-verified caching. Handles hundreds of servers, offline machines, and hostile actors. Replaces FR-3 as the default multi-server architecture.

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FR-6 Implementation Stories

10 ordered user stories for building the linked independent server model. Covers server identity, directory, public content API, reference manifests, cross-server resolution, offline caching, provenance chains, trust management, referral discovery, and mothballing the FR-3 cluster.

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Federation Activation

How to enable and operate the optional cluster federation: the outbound dialer, PeerPool, periodic sync and heartbeat, and PBFT broadcast. Operational guide for running federated nodes behind the --enable-cluster flag.

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Micropayments & Cost Model

Ted Nelson's micropayment vision, storage cost accounting, the utility meter, and per-use billing — the economic layer for a federated docuverse.

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Developer Guide BUILD

For contributors building on Xudanu. Technical architecture deep-dives, wire protocol specifications, test documentation, and phase-by-phase development history.

Technical Architecture

15-section deep dive with 9 SVG diagrams, worked examples, and Big-O analysis of every data structure.

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Wire Protocol

The complete 140+ operation WebSocket API: message framing, JSON and binary codecs, connection lifecycle, real-time subscriptions, and security features. The integration surface for building clients.

8 sections · 1 diagram

Architecture & Design

System Overview

Xanadu Gold as a Rust library compiling to WebAssembly. High-level component map and design philosophy.

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Three-Layer Architecture

Separation of the core hypertext engine from the applications and clients built on top of it.

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Content Model

The Udanax-Gold content model where content is identity — bytes are their own addressing key.

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The 17 Rules of Xanadu

Nelson's original 17 rules for Xanadu systems with xudanu's compliance status for each rule.

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Rule 8: Publication Model

How Xudanu's publication model compares to the original Udanax-Gold and Nelson's specifications.

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Architecture Diagram

Full system architecture diagram showing the relationship between O-tree, chunk store, WAL, CRDT sync, wire protocol, and federation layers.

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API, Protocol & Testing

API Reference

Wire protocol API reference (v2). WebSocket JSON message format, all operations, request/response schemas.

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Protocol & Audit

WebSocket protocol details, session lifecycle, and server-side audit/logging capabilities.

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Integration Guide

How to integrate Xanadu Gold into a JavaScript or TypeScript application.

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Custom Frontend Guide

Building custom frontends that connect to the xudanu server over its WebSocket JSON API.

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Test Registry

Index of the test suite: backend library tests, integration tests, and frontend Vitest specs, with what each covers and how to run them.

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Gold Heritage & Comparison

30 Years of Innovation

Presentation: Xanadu history, migration story, architecture, performance, and live demo. Arrow keys to navigate.

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30 Years of Hypertext Innovation

The history of Xanadu from Nelson's 1960 vision through Udanax-Gold to Xudanu. Timelines, key people, and how the concepts evolved over six decades.

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Udanax Gold Heritage

Side-by-side concept mapping: every Gold type, module, and subsystem traced to its Rust descendant, with SVG diagrams and status badges.

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Xanadu Gold Foundations

Progressive implementation of Udanax-Gold: transclusion with provenance, content addressing, clubs/permissions, cryptographic attribution, and trails.

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What's New Since Gold

New features beyond Gold: cryptographic provenance, CRDT editing, BLAKE3 content addressing, OAuth, federation, and more.

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Gold vs. Xudanu Complexity

Subsystem-by-subsystem complexity comparison between Udanax-Gold and Xudanu: lines of code, data-structure footprint, and where modern Rust simplifies the original C++ design.

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Udanax-Gold vs. OpenXanadu vs. Xudanu

Comparative analysis across three Xanadu lineages: feature coverage, architectural choices, and implementation maturity.

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Xudanu: What's New Since Udanax Gold

Markdown comparison of what Xudanu adds, changes, and drops relative to the original Udanax-Gold codebase.

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Migration Notes

Tracking the port from Udanax-Gold C++ to Rust. Edition, XnRegion, RangeElement, and connected components.

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Implementation Phases

Design documents for each phase of the Rust implementation, from core data structures through federation.

Phases 4–6: Mapping, FeText, Wrappers, Clubs

Mapping algebra, text manipulation, type wrappers with certification, and the club-based permission hierarchy.

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Phase 7: Label & Identity Unification

Label system and identity unification — two critical features from the Udanax-Gold model.

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Phase 8: Bundle Retrieval & Storage Cost

Reading content from the document store and storage cost accounting for editions.

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Phase 9: Shared Content Mapping

Content-fingerprint-based shared detection and proper mapping types beyond positional matching.

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Phase 10: Full Transclusion Queries

Range-based transclusion queries and an ordered bundle stepper with merge-sort for the O-tree.

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Phase 11: Recorder, Fossil, Agenda

Persistent queries that accumulate results over time, plus admin health monitoring.

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Phase 12: Modern Encryption

Production-grade cryptography: Ed25519, X25519, ChaCha20-Poly1305, HKDF-SHA256, Argon2id.

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Phase 13: Endorsement Authority

Endorsement system wired into the server API with authority validation.

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Phase 14: Federation Foundation

Types, identity, and addressing for multi-server federation.

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Phase 15: Server-to-Server Transport

Mutual authentication and encrypted channels between federated servers.

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Phase 16: Content Replication

G-Set CRDT with BLAKE3 verification for cross-server content replication.

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Phase 18: DagWood Reconciliation

The Reconciliation Plane — mutable state via DagWood for concurrent edit resolution.

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Phase 19a: Trust & Membership

Web-of-trust join protocol and membership management for federated servers.

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Phase 19b: Governance (PBFT)

Governance Plane using lightweight PBFT consensus for federation-wide decisions.

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