#crdt #local-first #data #collaborative #json #collaboration #rich-text

loro

Loro is a high-performance CRDTs framework. Make your app collaborative efforlessly.

19 releases (6 stable)

new 1.4.1 Feb 13, 2025
1.3.2 Jan 30, 2025
1.1.0 Nov 9, 2024
0.16.12 Sep 7, 2024
0.1.0 Aug 7, 2022

#260 in Web programming

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554 downloads per month

MIT license

2.5MB
56K SLoC

Loro

Make your JSON data collaborative and version-controlled

Loro is a high-performance CRDTs framework offering Rust, JavaScript and Swift APIs.

Designed for local-first software, it enables effortless collaboration in app states.

Examples

Map/List/Text

use loro::{LoroDoc, LoroList, LoroText, LoroValue, ToJson};
use serde_json::json;

let doc = LoroDoc::new();
let map = doc.get_map("map");
map.insert("key", "value").unwrap();
map.insert("true", true).unwrap();
map.insert("null", LoroValue::Null).unwrap();
map.insert("deleted", LoroValue::Null).unwrap();
map.delete("deleted").unwrap();
let list = map.insert_container("list", LoroList::new()).unwrap();
list.insert(0, "List").unwrap();
list.insert(1, 9).unwrap();
let text = map.insert_container("text", LoroText::new()).unwrap();
text.insert(0, "Hello world!").unwrap();
assert_eq!(
    doc.get_deep_value().to_json_value(),
    json!({
        "map": {
            "key": "value",
            "true": true,
            "null": null,
            "list": ["List", 9],
            "text": "Hello world!"
        }
    })
);

Rich Text

use loro::{ExpandType, LoroDoc, ToJson};
use serde_json::json;

let doc = LoroDoc::new();
let text = doc.get_text("text");
text.insert(0, "Hello world!").unwrap();
text.mark(0..5, "bold", true).unwrap();
assert_eq!(
    text.get_richtext_value().to_json_value(),
    json!([
        { "insert": "Hello", "attributes": {"bold": true} },
        { "insert": " world!" },
    ])
);
text.unmark(3..5, "bold").unwrap();
assert_eq!(
    text.get_richtext_value().to_json_value(),
    json!([
          { "insert": "Hel", "attributes": {"bold": true} },
          { "insert": "lo world!" },
    ])
);

Sync

use loro::{LoroDoc, ToJson, ExpandType};
use serde_json::json;

let doc = LoroDoc::new();
let text = doc.get_text("text");
text.insert(0, "Hello world!").unwrap();
let bytes = doc.export_from(&Default::default());
let doc_b = LoroDoc::new();
doc_b.import(&bytes).unwrap();
assert_eq!(doc.get_deep_value(), doc_b.get_deep_value());
let text_b = doc_b.get_text("text");
text_b
    .mark(0..5, "bold", true)
    .unwrap();
doc.import(&doc_b.export_from(&doc.oplog_vv())).unwrap();
assert_eq!(
    text.get_richtext_value().to_json_value(),
    json!([
        { "insert": "Hello", "attributes": {"bold": true} },
        { "insert": " world!" },
    ])
);

Save

use loro::LoroDoc;

let doc = LoroDoc::new();
let text = doc.get_text("text");
text.insert(0, "123").unwrap();
let snapshot = doc.export_snapshot();

let new_doc = LoroDoc::new();
new_doc.import(&snapshot).unwrap();
assert_eq!(new_doc.get_deep_value(), doc.get_deep_value());

Dependencies

~7–14MB
~175K SLoC