Base new-pool sniper tool: nail those first hits

Those first minutes of a celebrity-meme launch — pump then dump. You want a runnable recipe now: the second a Base pool lands, count Swaps in the first blocks; cross the threshold → push a card. Browser on BlockReq public is enough.

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

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

Chain: Base Mainnet EVM chainId = 0x2105 (8453). Public endpoints · eth_subscribe · Plans · Register.

1. Hook: first-15m spike — what is listenable on-chain

Tape feel	On-chain signal	Listen focus
Launch spike	Swap cluster right after new pair/pool	First N blocks / M seconds
Sniper density	Many addresses buying in a short window	Unique-buyer threshold
Celebrity-meme rhythm	Social blast ↔ on-chain first cluster	Open card + spike chip
Hear first	PairCreated fires; spike stacks next	Two-stage subscribe

Spike = new pool lands + first-window trade density clears a threshold. This post only teaches the recipe and how to alert.

2. Listen: PairCreated / PoolCreated + first-N-block density

One public WSS: subscribe Factory open logs first, then stack Swap / Transfer on the hit pair/pool; drive the first-window counter with newHeads.

Step A · Subscribe V2 PairCreated

{
  "jsonrpc": "2.0", "id": 1, "method": "eth_subscribe",
  "params": ["logs", {
    "address": "${V2_FACTORY}",
    "topics": ["0x0d3648bd0f6ba80134a33ba9275ac585d9d315f0ad8355cddefde31afa28d0e9"]
  }]
}

Step B · Subscribe V3 PoolCreated (can run in parallel)

{
  "jsonrpc": "2.0", "id": 2, "method": "eth_subscribe",
  "params": ["logs", {
    "address": "${V3_FACTORY}",
    "topics": ["0x783cca1c0412dd0d695e784568c96da2e9c22ff989357a2e8b1d9b2b4e6b7118"]
  }]
}

• Keep V2_FACTORY / V3_FACTORY in env (use Base official Factory tables).
• Decode token0 / token1 / pair or pool → write launchState and start the first-window timer.

Step C · First-window density (Swap / Transfer)

Metric	How to count	Use
Swap count	Swap logs in first N blocks / M seconds	Spike strength
Unique buyers	Dedupe from/to on Transfer / Swap	Sniper density
Early volume hint	Rough sum of amountIn / amountOut	Second chip

Narrow listen: feed the pair/pool address into a second logs subscribe; full-chain Swap scans burn quota fast—first-window narrow address stays lean.

3. StackBlitz / browser: BlockReq Base public logs + newHeads

In the browser, connect Base public WSS, fill Factory + topic0, hit Start: new-pool cards stream, then stack newHeads to advance the counter. Compact StackBlitz / demos1-friendly UI:

:::pages-demo https://blockreq.com/demos1/base-launch-spike-listen/en/ title: Base launch-spike listen height: 520 :::

WSS  → wss://base-rpc.blockreq.com/v1/rpc/public
HTTPS→ https://base-rpc.blockreq.com/v1/rpc/public
env  → V2_FACTORY · V3_FACTORY · SPIKE_WINDOW_SEC · SWAP_THRESHOLD · BUYER_THRESHOLD

Path hint: /demos1/base-launch-spike-listen/zh/ · /demos1/base-launch-spike-listen/en/. For keyed: swap trailing public for {API_KEY}.

Quota to start: blockreq.com register for 3M free requests monthly (public endpoint connects as-is).

4. Alert recipe: new pool → M-sec Swap / unique buyers → “spike”

on PairCreated|PoolCreated:
  start window(M sec or N blocks)
  count swaps, uniqueBuyers
  if swaps >= SWAP_THRESHOLD and uniqueBuyers >= BUYER_THRESHOLD:
    emit spikeCard

Spike-card fields

{ pairOrPool, token0, token1, factoryTx, windowSec, swapCount, uniqueBuyers, earlyVolume?, ts }

Dedupe on pair / pool; demo thresholds are knobs (e.g. M=60, swaps≥8, buyers≥5). Optionally also subscribe newHeads to align on block height:

{
  "jsonrpc": "2.0", "id": 3, "method": "eth_subscribe",
  "params": ["newHeads"]
}

On disconnect: reconnect and re-subscribe; gap-fill with HTTPS eth_getLogs on Factory + pair addresses. POST → https://base-rpc.blockreq.com/v1/rpc/public.

5. Summary + CTA

1. Launch spike = new pool lands + first-window Swap / unique-buyer density clears a threshold.
2. Recipe: V2/V3 Factory logs → first-window narrow Swap/Transfer → threshold hit → spike card.
3. Runnable: browser / StackBlitz on BlockReq Base public WSS + newHeads.
4. Start: Public endpoints + blockreq.com register for 3M free requests monthly.

Positive tech only: hear signals, push alert cards; sizing stays in your own strategy layer. Next: pin Factory / threshold JSON → wire spike cards to webhooks → stack beside OpenLaunch one-tx opens. Docs · Pricing · Register.