# Explore your first topic

Connect Studio, produce a message, inspect history, and diagnose a consumer group

Package: @cookiemonsterdev/kafka-studio 1.3.0
Canonical: https://cookiemonsterdev.github.io/kafka/docs/studio/start/getting-started/
Source revision: b44fa31a7bc13327d62e12e4496106792b4c2bf8

This walkthrough uses a local single-broker cluster at `localhost:9092`. Follow
[Your first message](https://cookiemonsterdev.github.io/kafka/docs/core/start/getting-started/) to start it and create `docs-demo-events`.
Install Studio using [Installation](https://cookiemonsterdev.github.io/kafka/docs/studio/start/installation/), then run:

```sh
KAFKA_BROKERS=localhost:9092 kafka-studio
```

Open the full URL printed in the terminal. Its hash contains a session token; do not share
that URL or include it in screenshots. The screenshots below show the local demo, not a production cluster.

## 1. Check the cluster

The overview identifies the connected cluster and displays topic, partition, and broker counts.
Open **Topics**, then select `docs-demo-events`. Confirm the topic name before making changes.

<img src="https://cookiemonsterdev.github.io/kafka/images/studio-overview.png" alt="Studio cluster overview showing the connected demo cluster and navigation" loading="lazy" width="1200" height="800" />

_Overview: the navigation leads to Topics, Messages, Produce, and Consumer groups._

## 2. Produce a record

Open **Produce**, select `docs-demo-events`, and enter key `user-1` and JSON value `{"message":"hello"}`.
Send a single record. Expected: a successful send with partition and offset information.
In read-only mode producing is unavailable and the server rejects write requests.

<img src="https://cookiemonsterdev.github.io/kafka/images/studio-produce.png" alt="Studio producer showing the topic selector and message composer" loading="lazy" width="1200" height="800" />

_Produce: choose the demo topic and send a single record before trying burst mode._

## 3. Read it back

Open **Messages**, choose the same topic, and use **History** to read stored records.
Find `hello`, expand the record, and inspect its key, partition, offset, and headers.
**Live** watches new records; return to History to stop tailing.

<img src="https://cookiemonsterdev.github.io/kafka/images/studio-messages.png" alt="Studio messages view showing records from the demo topic" loading="lazy" width="1200" height="800" />

_Messages: History reads stored records; Live follows newly produced records._

## 4. Inspect consumer progress

Run the Core quickstart consumer, then open **Consumer groups** and `docs-demo-reader`.
Inspect membership and per-partition lag. Stop the consumer before previewing an offset reset.
A reset backward causes redelivery; it does not restore deleted topic data.

For cross-topic correlation and replay, continue with [Debugger](https://cookiemonsterdev.github.io/kafka/docs/studio/guides/debugger/).
If your token is lost after a reload, reopen the original token-bearing URL from the launch terminal.

## Finish

Stop Studio with Ctrl+C. Stop the demo consumer and remove the local demo cluster using the
quickstart's cleanup steps. For remote clusters, use [profiles](https://cookiemonsterdev.github.io/kafka/docs/cli/guides/configuration/#profiles)
and review [Studio security](https://cookiemonsterdev.github.io/kafka/docs/studio/reference/api/#security) before exposing the server.