Recipes

Flap BSC New Token Alerts: Real-Time TokenCreated via WSS

Catch new Flap tokens on BSC in real time: subscribe to Portal TokenCreated over free public WSS, add LaunchedToDEX for Pancake graduation. Live demo.

BlockReq EngineeringOctober 22, 20265 min read

Flap → Pancake graduation tape keeps printing on BSC—this post converges on Portal TokenCreated: token / creator / nonce / name / symbol / meta in one log; optional LaunchedToDEX for the graduation pool. Brew BNB twin pools watches same-cap PairCreated; here we watch Flap Portal open cards.

Run on the public endpoint · blockreq.com register for 3M free requests monthly.

Use	Endpoint
Public HTTPS	`https://bsc-rpc.blockreq.com/v1/rpc/public`
Public WSS	`wss://bsc-rpc.blockreq.com/v1/rpc/public`
Private	Trailing `public` → `{API_KEY}` (keys stay local)

Chain: BNB Smart Chain EVM chainId = 0x38 (56). Public endpoints · eth_subscribe · Plans · Register.

1. Hook: Portal × TokenCreated

Tape feel	On-chain signal	Watch
Flap open	Portal TokenCreated	token · creator · nonce · name · symbol · meta
Graduate to Pancake	LaunchedToDEX (optional)	token · pool · amount · eth
Sniper tape	hit → outbound	Dedupe = token + launchTx

Same family, different grain: Brew twin pools narrow to PairCreated pairs; Flap narrows to Portal launch open cards.

2. Event: Portal TokenCreated (+ optional LaunchedToDEX)

Local JSON prefills verified addresses (editable):

Key	Value
`PORTAL`	`0xe2cE6ab80874Fa9Fa2aAE65D277Dd6B8e65C9De0`
`TOKEN_CREATED_TOPIC0`	`0x504e7f360b2e5fe33cbaaae4c593bc55305328341bf79009e43e0e3b7f699603`
`LAUNCHED_TO_DEX_TOPIC0` (optional)	`0x6e4f47630b8745b8cacbd44f42a8a33e7eea7cc08ef22fc7630f4f385784ff7d`
`PCS_V2_FACTORY` (hint)	`0xcA143Ce32Fe78f1f7019d7d551a6402fC5350c73`

Signatures (ABI has no indexed fields; topic0 only, decode all from data):

TokenCreated(uint256 ts, address creator, uint256 nonce, address token, string name, string symbol, string meta)
LaunchedToDEX(address token, address pool, uint256 amount, uint256 eth)

Step A · Subscribe Portal TokenCreated

{
  "jsonrpc": "2.0", "id": 1, "method": "eth_subscribe",
  "params": ["logs", {
    "address": "0xe2cE6ab80874Fa9Fa2aAE65D277Dd6B8e65C9De0",
    "topics": ["0x504e7f360b2e5fe33cbaaae4c593bc55305328341bf79009e43e0e3b7f699603"]
  }]
}

topics[0]: TokenCreated topic0 (verified against sample logs).
Decode data → ts / creator / nonce / token / name / symbol / meta.

Step B · Optional LaunchedToDEX

Subscribe 0x6e4f47630b8745b8cacbd44f42a8a33e7eea7cc08ef22fc7630f4f385784ff7d on the same Portal; decode token / pool / amount / eth; merge graduation fields by token.

Step C · Open-card fields

{ chain: "bsc", pad: "flap", token, creator, nonce, name, symbol, meta, ts, launchTx, blockNumber }

Dedupe on token + launchTx; demo knobs: Portal / topic0.

3. Browser demo (StackBlitz)

Default BSC public WSS; Portal + topic0 prefilled; hit Start for open cards. Code lives in StackBlitz — the post only embeds the preview:

Repo: blockreq/blog-demos → examples/flap-bsc-portal-token-created-listen (Vite+React+viem; open repo root in StackBlitz).

Product page: ZH · EN

WSS  → wss://bsc-rpc.blockreq.com/v1/rpc/public
HTTPS→ https://bsc-rpc.blockreq.com/v1/rpc/public
env  → PORTAL · TOKEN_CREATED_TOPIC0 · LAUNCHED_TO_DEX_TOPIC0

Keyed: swap trailing public for {API_KEY}. Quota: blockreq.com register for 3M free requests monthly.

4. Alert rhythm

TokenCreated arrives → decode token / creator / nonce / name / symbol / meta.
Optional graduation → matching LaunchedToDEX → attach pool.
Outbound → Flap BSC · token=… · symbol=… · creator=… · blk=….
Dedupe → one push per token + launchTx.

On disconnect: reconnect and re-subscribe; gap-fill with HTTPS eth_getLogs on the same Portal. POST → https://bsc-rpc.blockreq.com/v1/rpc/public.

5. Summary + CTA

Grain: Flap BSC open = Portal TokenCreated open cards.
Recipe: Portal + TokenCreated topic0 (+ optional LaunchedToDEX) → cards.
Runnable: browser on BlockReq BSC public WSS; demos1 paths above.
Start: public endpoints + blockreq.com register for 3M free requests monthly.

Docs · Pricing · Register.

6. FAQ

How do I get alerts for new Flap tokens on BSC? Subscribe with eth_subscribe (logs) to the Flap Portal 0xe2cE6ab80874Fa9Fa2aAE65D277Dd6B8e65C9De0 filtered by the TokenCreated topic0 0x504e7f360b2e5fe33cbaaae4c593bc55305328341bf79009e43e0e3b7f699603. Each log carries ts, creator, nonce, token, name, symbol and meta.

Why does my topic filter on token or creator return nothing? The ABI has no indexed fields, so only topic0 is usable as a filter. Decode every field from data, then filter client-side.

How can I tell when a Flap token graduates to PancakeSwap? On the same Portal, also subscribe to LaunchedToDEX (topic0 0x6e4f47630b8745b8cacbd44f42a8a33e7eea7cc08ef22fc7630f4f385784ff7d) and decode token / pool / amount / eth; merge it into the token's card by token.

Which endpoint can I use for free? The BlockReq BSC public WSS wss://bsc-rpc.blockreq.com/v1/rpc/public (HTTPS on the same path). For a private endpoint, replace the trailing public with your API key; registering gives 3M free requests per month.

What if the WebSocket disconnects? Reconnect and re-subscribe, then backfill the gap with HTTPS eth_getLogs on the same Portal and dedupe on token + launchTx.