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TRC-1009 - Offline Conflict-Free Task Reconciliation

3 min read

Living Document Notice
Published 2026-09-17. The evolving architecture, revisions, and connected notes for this dispatch live in the Stax Digital Garden.

Offline Conflict-Free Task Reconciliation

Offline Conflict-Free Task Reconciliation: Dual-trace Phosphor P20 safety amber and P22R ruby red vector CRT macro showing three-way CRDT state merge lattices and join-semilattice advancement curves

Summary

Updating task statuses across disconnected phones and workstations inevitably triggers Git merge conflicts. Trice introduces monotonic state advancement and three-way checklist merges that guarantee conflict-free convergence across devices.

The Chaos of Concurrent Task Edits

Consider an operator marking a task as completed on their mobile device while simultaneously editing the task’s technical checklist on their workstation. When synchronization occurs, traditional line-based file mergers fail:

<<<<<<< HEAD
task_state: "completed"
=======
  * [ ] Add regression test for boundary overflow
>>>>>>> incoming-mobile

Corrupted task files lock up automated dispatchers and require manual Git conflict resolution.

Trice implements specialized Conflict-Free Replicated Data Type (CRDT) merge semantics for task notes.

+-------------------------------------------------------------+
|             Trice Three-Way Task Reconciliation             |
|                                                             |
|   Base Task: v1.0 (State: Active, Checkboxes: 2/3)          |
|         │                                │                  |
|         ▼                                ▼                  |
|   Node A: Mark Completed          Node B: Add Checkbox Item |
|   (State: Completed)              (+ Regression Test Item)  |
|         │                                │                  |
|         └────────────────┬───────────────┘                  |
|                          │                                  |
|                          v                                  |
|   Merged Task: v2.0                                         |
|   - State: Completed (Monotonic Advancement Wins)           |
|   - Checkboxes: 3 Items Preserved, 2 Checked                |
+-------------------------------------------------------------+

Monotonic State Advancement Lattice

Trice models task states as a partially ordered set (poset) forming a join-semilattice:

Pending (0) < Active (1) < Blocked (2) < Completed (3) < Archived (4)

When two nodes report differing states for the same task without an intervening rollback, the engine computes the least upper bound (join):

pub fn merge_states(local: TaskState, remote: TaskState) -> TaskState {
    match (local, remote) {
        (TaskState::Archived, _) | (_, TaskState::Archived) => TaskState::Archived,
        (TaskState::Completed, _) | (_, TaskState::Completed) => TaskState::Completed,
        (TaskState::Blocked, TaskState::Active) => TaskState::Blocked,
        (TaskState::Active, TaskState::Pending) => TaskState::Active,
        _ => remote,
    }
}

A task marked completed on one device cannot be accidentally reverted to active by a concurrent edit from another device.

Checkbox Set Union

For action checklists within note bodies, Trice uses an Observed-Remove Set (OR-Set) algorithm keyed on the hash of each checklist line:

  1. Checked boxes remain checked across merges.
  2. Newly added checklist items on either branch are unioned into the final list.
  3. Whitespace and indentation are preserved exactly according to CST trivia rules.

This guarantees that operators can toggle tasks freely on mobile devices without fear of corrupting vault notes.

  • Directus Target: trice
  • Garden Source Reference: MOC - Bosun PKM Tools, MOC - Fleet Operations
  • Garden Source Reference: [TRC-1009 - Offline Conflict-Free Task Reconciliation](TRC-1009 - Offline Conflict-Free Task Reconciliation)

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