> For the complete documentation index, see [llms.txt](https://docs.blinklabs.xyz/blink/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.blinklabs.xyz/blink/bnb-smart-chain-bsc/searchers.md).

# Searchers

Please fill out our [searcher onboarding form](https://forms.gle/q7LLi3rkMVSZkyFYA) or contact [@Adamblink](https://t.me/Adamblink?text=Hi%20I%27m%20interested%20in%20searching%20on%20BSC%0Ahttps%3A%2F%2Fforms.gle%2Fq7LLi3rkMVSZkyFYA) on telegram to get an API key to access the searcher websocket and to bid on transactions. Join our [telegram broadcast channel](https://t.me/+QZC4QzfdvH1jNzRi) for updates and announcements regarding our BSC flow.

By searching on our BSC flow, you agree to our [searcher terms & conditions](/blink/ethereum/searchers/terms.md).

### Requirements

By participating in the Blink BSC auction, searchers agree to the following:

* **No frontrunning of any kind.** Sandwiching or any other form of frontrunning will result in an immediate ban.
* **No self-submission.** Unlike Base, Blink submits the winning bundle to the builder on your behalf. Submitting target transactions or backruns directly to builders or the public mempool will result in a ban.
* **Bid by payment.** Your bid is the total value your bundle transfers to the Blink payout address (provided during onboarding). There is no declared bid — payment inside the bundle *is* the bid.

***

### WebSocket Connection

Connect to Blink's WebSocket endpoint:

```
wss://bscauction.blinklabs.xyz/ws/v1/{$API_KEY}
```

A maximum of 5 concurrent connections per API key is allowed.

**Transaction Subscription**

Send the following message after connecting to begin receiving transaction data:

```json
{
    "method": "eth_subscribe",
    "params": ["blink_partialPendingTransactions"]
}
```

***

### Submitting Bundles

Bundles are submitted with the `eth_sendBundle` RPC call — either as a message over the same WebSocket connection, or over HTTP:

```
https://bscauction.blinklabs.xyz/v1/{$API_KEY}
```

The first element must be the target transaction hash; subsequent elements are your raw backrun transaction(s):

```json
{
    "id": 1,
    "jsonrpc": "2.0",
    "method": "eth_sendBundle",
    "params": [
        {
            "txs": [
                "0xTargetTxHash",  // Target transaction hash (required)
                "0xRawBackrunHex"  // Your backrun transaction in raw hex format (required)
            ]
        }
    ]
}
```

The bundle must contain at least two transactions. The `bidWei` field is parsed for compatibility but has no effect — your bid is determined by simulation.

{% hint style="info" %}
A bundle-hash response acknowledges receipt only. It does not guarantee that your bundle arrived within the auction window or passed simulation.
{% endhint %}

***

### Auction Mechanics

**How it works**

* Blink broadcasts pending transactions to connected searchers via WebSocket. Each broadcast opens a **100ms bidding window** for that transaction.
* Submitted bundles are simulated on arrival. Your bid is the sum of **native BNB and WBNB** your bundle transfers to the Blink payout address. Bundles that revert or transfer nothing are rejected.
* When the window closes, the highest-bidding valid bundle wins and is submitted privately to the block builder by Blink. Losing bundles are dropped — they are never forwarded or exposed.

**Bidding**

* Pay your bid to the Blink payout address **within your backrun transaction**, as a native BNB transfer or a WBNB transfer. Native BNB is preferred.
* The payout address is provided during onboarding.

**Timing and Inclusion**

* Bundles must arrive within the 100ms window that opens at WebSocket broadcast. Late bundles are not entered into the auction.
* We strongly recommend colocating in **AWS us-east-1** for optimal latency.

***

### Blink Monitoring

Blink actively monitors for rule violations and will take action accordingly:

* Frontrunning or sandwiching of Blink transactions
* Self-submission of Blink flow to builders or the public mempool

Violations may result in:

* Reduced flow
* WebSocket delay
* Complete ban