Code runs inside the DB
Deploy a WebAssembly module; OriginDB runs it in a wasmtime sandbox with epoch CPU deadlines and a memory limiter.
connecting…this is a live OriginDB board — move your cursor, double-click to pin a note
OPEN SOURCEMIT LICENSESELF-HOSTED
Lightweight real-time app server.
Database & business logic, all in one.
OriginDB is an open-source realtime database where your application logic lives inside the engine — as sandboxed WebAssembly reducers. Every write is transactional, logged to a durable WAL, and streamed to each client over a SQL-filtered changefeed.
THE MODEL
One write. A whole pipeline.
A client calls a reducer. Your WebAssembly code runs in a wasmtime sandbox against a staged overlay, commits atomically, hits the WAL, and emits exactly one changefeed event — delivered only to subscribers whose WHERE clause matches.
01
Call a reducer
A client invokes a function you deployed. Args arrive as JSON; the host freezes the clock for determinism.
gRPC · your .wasm
02
Commit + WAL
Staged writes apply through one transaction, or roll back entirely on a trap or abort. Durable before you hear “ok”.
ACID · group-commit fsync
03
Filtered changefeed
Each commit emits one ordered event. Subscribers get only rows matching their SQL — no client sees the firehose.
websocket · SQL WHERE
EVERYTHING YOU NEED
Your backend, compiled in.
A small, readable engine — the whole thing is roughly 15k lines — with the primitives a realtime app actually needs.
SQL-filtered changefeed
Subscribe with SELECT … WHERE … and receive only matching changes, in order. The predicate runs server-side.
Durable by default
A writer thread batches commits behind one fdatasync. Power-loss safe; throughput rises with concurrency.
Live module hot-swap
Redeploy a new version and the rules change instantly — no migration, no downtime, against a running world.
ACID transactions
Reducer writes stage in an overlay and apply as one atomic commit, or the entire call rolls back. No partial state.
SQL engine
Query and subscribe with real SQL — WHERE, comparisons, LIKE, and boolean logic over your tables.
Write in your language
First-class SDKs for AssemblyScript and C#, with Rust and C++ in the tree.
Crash-recoverable
The WAL is the canonical world. Replay on boot rebuilds exactly the set of acknowledged commits — fast, compact binary.
BUILT ON IT
Whole apps, authoritative in WASM.
Each demo's entire simulation is a reducer. The browser is a pure subscriber — it renders what the changefeed streams and holds no authority of its own.
01COLLAB
NIGHTBOARD
A shared realtime wall — live cursors, pinned notes, an activity tape. Every twitch travels through a reducer, a commit, the WAL, and a filtered changefeed before it lands.
Open live board02GAME
cube.io
An agar-style arena whose authoritative tick is a WASM reducer. Server-authoritative rewards mean a hot-swap re-values the whole arena instantly.
Play cube.io03PHYSICS
Marble Clash
A 60 Hz physics sumo whose whole simulation is a reducer, ticked natively across cores. Roll, ram, and shove rivals off the rim — hundreds of players per server.
Play Marble Clash04STRATEGY
Territories
A persistent region-control RTS — thousands of tiles, region-sharded ticks, and area-of-interest subscriptions so each client streams only the map it can see.
Play TerritoriesMEASURED, NOT MARKETED
Honest numbers.
From the repo's benchmark suite on a dev Mac — deliberately the worst realistic case (F_FULLFSYNC ≈ 21 ms). On Linux with fdatasync, the absolute figures climb.
4.0×
durable-commit throughput at 8 concurrent writers vs 1 — group commit working
−57%
WAL size after moving to a compact binary record format
~15k LOC
the entire engine — storage, WAL, changefeed, SQL, WASM host
1event
exactly one ordered changefeed event per committed write
FROM DEV TO PRODUCTION
From clone to changefeed in minutes.
# build, then run the server
$ origindb_server -d ./data -p 8787 -g 50051
✓ listening — ws :8787 grpc :50051
# deploy your reducer module
$ origindb deploy chat chat.wasm 1.0.0
# call it — the write commits and streams
$ origindb call chat sendMsg '["general","hi"]'// a browser is a pure subscriber
const ws = new WebSocket("ws://localhost:8787");
ws.onopen = () => ws.send(JSON.stringify({
type: "sql_subscribe",
sql: "SELECT * FROM msgs WHERE room='general'"
}));
// initial snapshot + live matching commits
ws.onmessage = (e) => render(JSON.parse(e.data));Ready to build something realtime?
OriginDB is MIT-licensed and self-hosted. No seats, no metered egress, no proprietary runtime between you and your data. Read the source, run it on your box, ship on top of it.