cr-sqlite

Decentralized Data Protocol

cr-sqlite is a run-time loadable extension for SQLite (and libSQL) that lets separate copies of a database, each of which has taken independent writes while offline, be merged without conflict. A table is upgraded into a 'conflict-free replicated relation' with one function call; the extension then exposes a virtual table of changes that one peer can read and another can apply, and applies column-level conflict resolution so every replica converges. The project calls this 'like Git, for your data'. It does not include networking: the application moves change sets between devices or a server by whatever means it likes. It is one component of the broader Vulcan project from Vulcan Labs, which also lists a reactive-query engine and a web stack built on SQLite as a collaborative application file format .

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License Permissive (MIT). https://github.com/vlcn-io/cr-sqlite (C extension with Rust and Python tooling)
Dev Status 🟢 Active
Owner Vulcan Labs, the home of the vlcn.io site, whose footer names One Law LLC; the repository is owned by the vlcn-io organisation and the account that created the project (GitHub handle tantaman) is still the committer of recent merges
Governing Body Vulcan Labs (One Law LLC named in the site footer); no external governance body is described
Country Not stated by the project.
Start Year 2022
Stack C extension for SQLite and libSQL, with Rust and Python components, WebAssembly builds for the browser through the vlcn.io tooling, and loadable builds for macOS, Linux, Windows, Android and iOS
Funding Sponsorships: the README and site list company sponsors (including a database company, a hosting provider and an app platform) and individual sponsors
Last Investigated Oct 29, 2026

Use Case Domains

Platform Evolution & Sovereignty Co-Creation & Knowledge

Affordances

Local-first storage Conflict-free editing Data portability

Decentralized Data Protocol Attributes

Origins Local-first and offline-first application development: bring multi-master replication and partition tolerance to SQLite using CRDTs and causally ordered event logs, so application developers need no custom merge code for offline editing, device sync and real-time collaboration
Database SQLite (and libSQL): cr-sqlite is an extension to an existing SQLite database rather than a database of its own; upgraded tables add clock tables and the crsql_changes virtual table
Query Language SQL: changes are read and applied with ordinary SELECT and INSERT against the crsql_changes virtual table, and tables are upgraded with a crsql_as_crr function call
Data Formats SQLite database files; change sets as rows of (table, primary key, column id, value, column version, database version, site id, causal length, sequence) returned by crsql_changes
Collaborative Live Editing Partial: the extension merges independent edits to SQL tables without conflict and supports real-time collaboration when an application sends changes continuously; it has no text-editing algorithm in its core README, but lists sequence CRDTs in its documentation
Rich Text Editing Not stated by the project.
Mobile Support Yes: loadable extension builds for Android and iOS are produced by the project, with build fixes merged in 2026
Web Support Yes: the project's documentation covers use in the browser through WebAssembly and browser persistence
Native Apps Yes: run-time loadable extension for desktop and mobile native applications
Terms Free and open source (MIT)
Funds Not stated by the project.
Based On SQLite and libSQL, and CRDT research; the README cites causally ordered event logs and CRDTs as its two approaches to conflict resolution
P2P Architecture Transport-agnostic replication: peers or a server exchange change sets read from and written to the crsql_changes virtual table by application code; the documentation describes whole-database and partial sync patterns but the project ships no network layer
Overlay Network None: no network is defined; replicas sync through whatever transport the application provides
Content Addressing No: rows are identified by table and primary key with per-site identifiers and version counters
Local-First Local-First: each replica is a normal local SQLite database that can be read and written offline and merged later
E2EE No: the extension does not encrypt data; encryption is left to the application or storage layer
CRDTs Lib cr-sqlite: this entry is itself the CRDT layer for SQLite; its documentation describes table, column and sequence CRDTs
Byzantine Fault Tolerance No: change sets are applied as presented; the README describes no defence against malicious peers
Signature N/A: change rows carry a site identifier but are not signed
Permissions N/A: no access-control model; any peer that can write the change table can apply changes
Semantic Web Compatibility N/A: relational model with no RDF or linked-data layer
Smart Contract N/A: no ledger or contract component
Protocol Stack Position Application-layer: an in-process database extension, independent of the transport
Asset / Value Embedding None: no token or value-transfer mechanism
Protocol Maturity / Standardization Pre-1.0 (v0.16.3) extension; the change-set format is documented in the README but has no formal specification or standards-body involvement