> For the complete documentation index, see [llms.txt](https://docs.blockrazor.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.blockrazor.io/streams/node-stream/robinhood-chain/sequencer-feed.md).

# Sequencer Feed

### What is Sequencer Feed?

The Sequencer Feed is a real-time data stream pushed by the Robinhood Chain Sequencer. Nodes subscribe to the Feed via WebSocket to quickly receive block data and keep track of the latest on-chain status.

For node operators, e.g. searchers, the transmission speed and stability of the Sequencer Feed directly impact the speed at which nodes catch up with blocks and update their state. When the official Feed endpoint experiences issues such as network latency, network jitter, or unstable connections, nodes may fail to receive the latest data in a timely manner, resulting in node height lag and data update delays.

### Why BlockRazor Sequencer Feed

BlockRazor Sequencer Feed provides Robinhood Chain nodes with a more stable and efficient Sequencer Feed access service.

Compared to directly connecting to the official feed endpoint, BlockRazor Sequencer Feed reduces latency caused by network jitter and connection interruptions during feed synchronization by using the nearest access point and optimizing the transmission path.

Furthermore, the BlockRazor Sequencer Feed is compatible with the official standard access method. Nodes only need to replace the Feed URL to receive the latest data faster and more stably, reducing block tracking latency and keeping the on-chain state synchronized in real time.

### Benchmark

We established WSS connections with both the Robinhood Chain Sequencer Feed and the BlockRazor Sequencer Feed using the same test client, comparing the relative latency of receiving blocks from both. The Sequencer Feed that received the block first had a relative latency of 0ms, while the Sequencer Feed that received the block later had a relative latency equal to the difference in timestamps between the received blocks. Specific data is as follows:

<table><thead><tr><th width="299.70703125">Sequencer Feed</th><th>Win rate</th><th>P50</th><th>P90</th></tr></thead><tbody><tr><td>BlockRazor Sequencer Feed</td><td><strong>88.40%</strong></td><td><strong>0.000 ms</strong></td><td><strong>0.293 ms</strong></td></tr><tr><td>Robinhood Chain Sequencer Feed</td><td><strong>11.60%</strong></td><td><strong>6.520 ms</strong></td><td><strong>14.579 ms</strong></td></tr></tbody></table>

In terms of latency distribution, BlockRazor not only arrives first on most blocks, but this lead is also highly consistent; in contrast, Robinhood Chain Sequencer Feed is more often in a lagging position and has more pronounced latency fluctuations.

In summary, BlockRazor Sequencer Feed demonstrates significant advantages in block transmission speed, first-to-delivery rate, and latency stability, providing a more reliable first-to-delivery window for latency-sensitive transactions.

### Price

The price is $80 per unit per day and $800 per unit per month.

### Endpoint

wss\://us.robinhood-feeder.blockrazor.io/ws/{authToken}

### Usage Instructions

{% stepper %}
{% step %}
**Subscribe BlockRazor Sequencer Feed**
{% endstep %}

{% step %}
**Retrieve the auth from the portal and append it as the URI to the WSS URL.**

wss\://us.robinhood-feeder.blockrazor.io/ws/{authToken}
{% endstep %}

{% step %}
**Stop the running Robinhood Chain node**

The specific command depends on the current deployment method, such as Docker, Docker Compose, or systemd. Before stopping, it is recommended to ensure that the node data directory is correctly mounted to avoid losing existing synchronized data after restarting.
{% endstep %}

{% step %}
**Add Feed URL**

The following configuration can be found in the node startup command:

```bash
--node.feed.input.url=wss://feed.mainnet.chain.robinhood.com
```

replace it with BlockRazor Sequencer Feed：

```bash
--node.feed.input.url=wss://feed.mainnet.chain.robinhood.com
--node.feed.input.url=wss://us.robinhood-feeder.blockrazor.io/ws/{authToken}
```

The complete mainnet startup example is as follows:

```bash
DATA_DIR="$HOME/rh/robinhood-nitro-data"

docker run --rm -it \
  -v "$DATA_DIR":/home/nitro/.arbitrum \
  -v "$HOME/rh/config":/home/nitro/config \
  -p 8547:8547 \
  -p 8548:8548 \
  offchainlabs/nitro-node:v3.11.2-3599aca \
    --chain.info-files=/home/nitro/config/robinhood-chain-info.json \
    --parent-chain.connection.url=<L1_EXECUTION_RPC_URL> \
    --parent-chain.blob-client.beacon-url=<L1_BEACON_URL> \
    --init.genesis-json-file=/home/nitro/config/robinhood-genesis.json \
    --node.feed.input.url=wss://<BLOCKRAZOR_FEED_URL> \
    --http.addr=0.0.0.0 \
    --http.port=8547 \
    --http.api=net,web3,eth
```

{% endstep %}

{% step %}
**Restart the node**

After saving the configuration and restarting the node, the node will receive Robinhood Sequencer data via the BlockRazor Sequencer Feed.

Check the node logs to confirm:

* BlockRazor Feed connection successful
* No persistent reconnection, timeout, or WebSocket error.
* The node continuously receives the latest Sequencer data.
* Node height is keeping up with Robinhood Chain
  {% endstep %}

{% step %}
**Verify node status**

Check synchronization status:

```bash
curl -d '{"id":0,"jsonrpc":"2.0","method":"eth_syncing","params":[]}' \
  -H "Content-Type: application/json" \
  http://localhost:8547
```

After full synchronization, eth\_syncing should return:

```bash
false
```

{% endstep %}
{% endstepper %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.blockrazor.io/streams/node-stream/robinhood-chain/sequencer-feed.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.