Arc day-1 open-listen tool: pre-wire Factory subs

On Arc mainnet day-1, fill the endpoint into env and you are live. This post pre-wires the launchpad Factory / PairCreated eth_subscribe recipe—browser keeps ARC_HTTPS / ARC_WSS placeholders; swap real BlockReq public values the moment they ship.

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

Use	Endpoint (day-1 placeholder)
HTTPS	process.env.ARC_HTTPS (fill BlockReq Arc public HTTPS when live)
WSS	process.env.ARC_WSS (fill BlockReq Arc public WSS when live)
Private	Trailing public → {API_KEY} (keys stay local)

Chain: Arc Mainnet EVM (chainId per official release table). Public endpoints · eth_subscribe · Plans · Register.

1. Hook: day-1 opens start at the Factory

Tape feel	On-chain signal	Watch
Open lands	Factory PairCreated / equivalent Create	pair / token0 / token1
Launchpad cluster	multi-Factory same-window pushes	pad tag + factoryTx
Sniper hear-first	Create hit → outbound	Dedupe = txHash / pair
Day-1 endpoint swap	env swap → keep listening	fill ARC_WSS and run

Same shape as Base / RH open-listen: narrow Factory logs → decode → open card. Related: Base new-pool sniper · OpenLaunch one-shot open.

2. Event: pre-wire PairCreated eth_subscribe

Keep ARC_HTTPS / ARC_WSS / LAUNCHPAD_FACTORY / PAIR_CREATED_TOPIC0 in env. When the public endpoint ships, change env only—the subscribe body stays the same.

Step A · Subscribe Factory PairCreated

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

• address = process.env.LAUNCHPAD_FACTORY (fill from day-1 address table).
• topics[0]: Uniswap V2-style PairCreated (confirm against Factory ABI; swap only this item across pads).
• Decode token0 / token1 / pair → write launchState.

Step B · Open-card fields

{ pad: "arc-day1", pair, token0, token1, factory, factoryTx, blockNumber, ts }

Dedupe on txHash / pair; merge repeat pushes for the same pool inside a short window.

Step C · Optional stack: first-window Swap

After Create, feed pair into a second narrow subscribe (Swap). First in-window prints → stack firstSwap / earlyDensity.

3. Browser demo

Connect ARC_WSS placeholder (local mock until live, then real value), fill Factory + topic0, hit Start, stream open cards.

:::pages-demo https://blockreq.com/demos1/arc-mainnet-day1-listen/en/ title: Arc day-1 Factory listen height: 520 :::

env  → ARC_HTTPS · ARC_WSS · LAUNCHPAD_FACTORY · PAIR_CREATED_TOPIC0
WSS  → process.env.ARC_WSS
HTTPS→ process.env.ARC_HTTPS

Paths: /demos1/arc-mainnet-day1-listen/zh/ · /demos1/arc-mainnet-day1-listen/en/. For keyed: swap trailing public for {API_KEY}.

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

4. Alert rhythm

1. Create arrives → decode pair / token0 / token1.
2. Outbound → Arc day-1 open · pair=… · t0=… · t1=… · blk=….
3. Optional → same-window Swap density as a second chip.
4. Dedupe → one push per txHash / pair.

On disconnect: reconnect and re-subscribe; gap-fill with HTTPS eth_getLogs on the same Factory. POST → process.env.ARC_HTTPS.

5. Summary + CTA

1. Grain: day-1 open = Factory PairCreated / Create.
2. Recipe: ARC_WSS + LAUNCHPAD_FACTORY + PairCreated topic + optional Swap stack → open card.
3. Runnable: browser pre-wired with placeholders; day-1 swap to the real endpoint and keep listening.
4. Start: Public endpoints + blockreq.com register for 3M free requests monthly.

Next: pin Factory / topic → webhook → stack with a multi-pad address table. Docs · Pricing · Register.