Overview

ChronDB provides native bindings for multiple programming languages, all generated from a single Rust SDK.

Architecture: One Codebase, Many Languages

Instead of maintaining separate implementations for each language, ChronDB uses the Rust SDK as the single source of truth. All complex logic — worker thread management, GraalVM isolate lifecycle, idle timeout, lock cleanup, shared registry — lives exclusively in Rust. Other language bindings are thin, auto-generated wrappers.

libchrondb.so (GraalVM/Clojure — core database engine)
└── Rust SDK (crate chrondb — all logic lives here)
    │
    ├── UniFFI  → Python, Ruby, Kotlin, Swift
    ├── NAPI-RS → Node.js
    └── Native  → Rust (direct crate dependency)

Why this approach?

Every feature or bug fix is implemented once in Rust and automatically available in all languages. No more reimplementing idle timeout logic in Python, Ruby, and Node.js separately.

UniFFI (Mozilla)

UniFFI is an open-source tool created by Mozilla for generating multi-language bindings from Rust. It powers production components in Firefox — the same tool that generates Kotlin/Swift bindings for Firefox's Rust networking, cryptography, and sync engines is what generates ChronDB's Python and Ruby bindings.

Key references:

• UniFFI repository

• UniFFI user guide

• Mozilla's blog on shipping Rust in Firefox

• Application Services — Mozilla's production project using UniFFI to ship Rust code to Kotlin, Swift, and Python

NAPI-RS

NAPI-RS generates native Node.js addons from Rust. Used in production by projects like SWC (the JavaScript/TypeScript compiler), Rspack, and Biome.

Key references:

• NAPI-RS repository

• NAPI-RS documentation

Available Bindings

Language	Tool	Status	Package
Rust	Native crate	Stable	chrondb on crates.io
Python	UniFFI	Stable	chrondb on PyPI
Ruby	UniFFI	Stable	chrondb gem
Node.js	NAPI-RS	Stable	chrondb on npm
Kotlin	UniFFI	Stable	Maven artifact
Swift	UniFFI	Stable	Swift package

API Consistency

All bindings expose the same core API:

Operation	Description
open_path(db_path)	Open a database connection (preferred)
open(data_path, index_path)	Open with separate paths (deprecated)
open_with_idle_timeout(data_path, index_path, secs)	Open with idle timeout
put(id, doc, branch?)	Save a document
get(id, branch?)	Get a document by ID
delete(id, branch?)	Delete a document
list_by_prefix(prefix, branch?)	List documents by ID prefix
list_by_table(table, branch?)	List documents by table
history(id, branch?)	Get change history
query(query, branch?)	Execute a Lucene query
execute_sql(sql, branch?)	Execute a SQL query directly (no server needed)

Each language wrapper adds idiomatic conveniences (context managers in Python, keyword arguments in Ruby, TypeScript types in Node.js) while the core behavior is identical.

Building Bindings from Source

All bindings require the libchrondb native library (GraalVM native-image) and the Rust toolchain.

# 1. Build the GraalVM native library
clojure -M:shared-lib
native-image @target/shared-image-args

# 2. Build the Rust SDK
cd bindings/rust && cargo build --release

# 3. Generate UniFFI bindings (Python, Ruby, Kotlin, Swift)
cd bindings/uniffi && cargo build --release
cargo run --bin uniffi-bindgen generate \
  --library target/release/libchrondb_uniffi.dylib \
  --language python --language ruby --language kotlin --language swift \
  --out-dir generated/

# 4. Build Node.js binding
cd bindings/node && npm run build