SYKES-VCS

CRDT ENGINE

Sykes VCS Engine

The Sykes VCS Engine is the C-based logical core between editors, coding agents, the Application, and Sykes DB. It translates source edits into anchor-based CRDT operations and applies the rules that keep collaborative state deterministic.

STATUS PROTOTYPE
MODEL ANCHOR CRDT
LANGUAGE C
RUNTIME IN-MEM B+TREE
engine component 01 / What it is

The CRDT logic at the center of Sykes VCS

The Engine receives changes from editor plugins, coding-agent interfaces, and application workflows, then turns those changes into CRDT operations that the rest of the system can validate, store, replay, and inspect.

  • Translates raw edits into anchor-based CRDT operations.
  • Enforces operation validity, ordering, and collaboration rules.
  • Provides one operation model to the Application and Sykes DB.
engine component 02 / Engine boundary

Logic is separate from storage and UI

The Engine owns CRDT creation, validation, deterministic ordering, and applying collaborative edits. Sykes DB owns durable storage and recovery, while the Application owns repositories, review, teams, and user-facing workflows.

  • The Engine does not store durable history by itself.
  • Database compression and recovery stay with Sykes DB and its storage components.
  • User intent and review context belong to higher-level workflows.
engine component 03 / CRDT model

Anchor-based source editing

The current model is an anchor-based CRDT for text. It supports keystroke-level edits and larger inputs such as paste events, formatter output, refactors, or generated code.

  • Insert, delete, undo, and redo are the current core operation families.
  • Anchors remain stable as other edits arrive.
  • An in-memory statistical B+ tree supports matching edits to anchors.
engine component 04 / Determinism

Every replica should resolve to the same state

Operations can arrive concurrently or out of order. Replica sequence data, Lamport values, and deterministic tie-breakers let the Engine apply those operations consistently across replicas.

  • Replica sequence numbers identify local operation order.
  • Lamport values help order concurrent operations.
  • Replica identity provides a deterministic same-anchor tie-breaker.
engine component 05 / Current status

Prototype behavior under simulation

The Engine is still in early development. The anchor model, operation types, ordering rules, and editing paths are being shaped through prototypes and simulation before they become a stable public interface.

  • The core operation model is being tested.
  • Simulation is being built to expose convergence and storage edge cases.
  • A stable third-party interface is not defined yet.

NEXT STEP

The Engine turns edits into deterministic CRDT state

Editors and coding agents produce local changes. The Sykes VCS Engine structures and applies those changes, then passes the operation stream to Sykes DB and the Application.

sykes-vcs.com/engine [engine component]

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