dbc-stream

Decoded, ready-to-use events for Meteora Dynamic Bonding Curve (DBC). Plain JavaScript.

DBC events are hard to read from raw transactions (inner instructions, duplicate swap events, BN values). dbc-stream does that for you and gives you clean events for one launchpad.

const { DbcStream } = require("dbc-stream");

const stream = new DbcStream({
  rpcUrl: process.env.RPC_URL,
  configs: ["YourLaunchpadConfigAddress"],   // follow only your launchpad
  cursorFile: "./cursor.json",               // optional: resume after a restart
});

stream.on("pool_created", (e) => console.log("new token", e.data.base_mint));
stream.on("swap", (e) => console.log(e.derived.side, e.derived.price, e.derived.progress_pct + "%"));
stream.start();

Event shape

{
  "id": "<signature>:<index>",
  "type": "swap",
  "name": "EvtSwap2",
  "signature": "...", "slot": 454532498, "blockTime": 1791459205,
  "data": { "...": "all fields from the program, as strings" },
  "derived": { "side": "sell", "price": 2.6e-7, "base_amount": "...", "quote_amount": "...", "progress_pct": 83.67 }
}

| type | events it covers | meaning | |---|---|---| | pool_created | EvtInitializePool, ...WithTransferHook | a token launched on the curve | | swap | EvtSwap2, EvtSwap2WithTransferHook, legacy EvtSwap | a buy or sell (counted once) | | curve_complete | EvtCurveComplete, ...WithTransferHook | curve filled up, pool is ready to graduate | | fee_claim | EvtClaim*Fee* | creator, partner or protocol claimed fees | | withdraw | Evt*Withdraw* | surplus, leftover or migration-fee withdrawal | | config_created | EvtCreateConfig* | a launchpad config was created | | metadata | EvtPartnerMetadata, EvtVirtualPoolMetadata | token or partner metadata | | other | everything else | raw name in event.name |

DBC has no "migrated" event. curve_complete is the last DBC signal before graduation.

derived is only set on swaps. price is quote per whole base token (set baseDecimals / quoteDecimals if not 6 / 9). progress_pct is how close the pool is to graduating.

Options

| option | default | what it does | |---|---|---| | rpcUrl | required | Solana RPC (http) | | wsUrl | rpc default | RPC websocket | | configs | none | only follow these launchpad config addresses | | cursorFile | none | save progress; replay missed events on restart | | idl | bundled | DBC IDL | | maxRequestsPerSecond | 5 | RPC rate cap | | maxQueue | 500 | max waiting transactions |

stream.backfill({ limit }) replays history. stream.stats() returns live counters. Delivery is at-least-once: after a restart an event can repeat, so dedupe on event.id.

Serve it over WebSocket

The package itself has no server and no ws dependency. A ready-made server lives in examples/server.js: run it, copy it, or build your own with stream.on("event", ...) (see examples/custom-server.js).

npm i ws          # the example server needs it
npm run server    # ws://localhost:8080

Clients choose what they get with a query string (all optional, lists are comma separated):

| URL | gives you | |---|---| | ws://host:8080 | every event | | ws://host:8080?types=swap,pool_created | only those event types | | ws://host:8080?pool=<pool address> | only events for those pools | | ws://host:8080?config=<config address> | only events for those launchpads | | ws://host:8080?types=swap&pool=A,B&replay=20 | combine filters; replay=20 sends the last 20 matching events first | | http://host:8080/health | { ok, clients, ...stream.stats() } |

pool and config match event.data.pool / event.data.config; events without that field are skipped when you filter on it. The server pings clients (drops dead connections), keeps the last 200 events for replay, and limits clients (maxClients, default 500). For a public wss:// endpoint, put it behind a TLS proxy such as Caddy or nginx.

Try it with no RPC at all: npm run demo:fake in one terminal, npm run ws-client in another.

Docker

docker build -t dbc-stream .
docker run -p 8080:8080 -e RPC_URL=... -e CONFIG_KEYS=... dbc-stream

Setup from source

npm install
cp .env.example .env      # set RPC_URL and CONFIG_KEYS
npm run events            # list event names in the IDL
npm run find-config -- <token mint>   # find the config behind a launched token
npm run example
npm test

Tip: a partner PoolConfig is not the same as the DAMM v2 migration fee config keys in the Meteora docs.

Notes

• Without configs, the stream follows the entire DBC program. That is very busy and will hit free RPC limits.
• The bundled IDL is constant/idl.json. Replace it, or pass idl, if Meteora updates the program.

MIT licensed.

DbcStream