# Build a Subgraph (/docs/unichain/guides/subgraph-unichain)

Build and publish a subgraph for Unichain, then query it from your app.

Getting historical data on smart contracts can be frustrating when building a dapp. With [The Graph](https://thegraph.com/) anyone can create or query subgraphs, making the data available to the entire ecosystem.

## Quickstart
A subgraph can be created in just a few minutes by following these steps:

1. Initialize your subgraph
2. Publish your subgraph to The Graph Network
3. Query from your dapp with your unique API key

## Step 1: Initialize Your Subgraph
## Create a subgraph in Subgraph Studio
Go to the [Subgraph Studio](https://thegraph.com/studio/) and connect your
wallet. Once your wallet is connected, you can begin by clicking "Create a
Subgraph". When choosing a name, it's recommended to use Title Case, including
the subgraph and chain name, e.g., "MyDapp Subgraph Unichain".

<img alt="Create Subgraph" src={__img0} placeholder="blur" />

You'll land on your subgraph's page with all CLI commands visible on the right side.

<img alt="Subgraph Commands" src={__img1} placeholder="blur" />

## Install the Graph CLI
```bash
npm install -g @graphprotocol/graph-cli
```

## Initialize your local subgraph
```bash
graph init <SUBGRAPH_SLUG>
```

You'll be prompted to provide information about your subgraph:

<img alt="Initialization Prompts" src={__img2} placeholder="blur" />

Simply verify your contract on the block explorer, and the CLI will
automatically obtain the ABI and set up your subgraph. The default settings will
generate an entity for each event.

## Step 2: Deploy and Publish
## Deploy to Subgraph Studio
First, run these commands:

```bash
$ graph codegen
$ graph build
```

Then, run these to authenticate and deploy your subgraph. You can copy these
commands directly from your subgraph's page in Studio to include your specific
deploy key and subgraph slug:

```bash
$ graph auth <DEPLOY_KEY>
$ graph deploy <SUBGRAPH_SLUG>
```

You will be asked for a version label. You can enter something like v0.0.1, but
you're free to choose the format.

## Test your subgraph
You can test your subgraph by making a sample query in the playground section.
The Details tab will show you an API endpoint. You can use that endpoint to test
from your dapp.

<img alt="Playground Test" src={__img3} placeholder="blur" />

## Publish your subgraph to The Graph's decentralized network
Once your subgraph is ready to be put into production, you can publish it to the
decentralized network. On your subgraph's page in Subgraph Studio, click on the
Publish button:

<img alt="Publish Subgraph" src={__img4} placeholder="blur" />

Before you can query your subgraph, Indexers need to begin serving queries on
it. In order to streamline this process, you can curate your own subgraph using
GRT.

When publishing, you'll see the option to curate your subgraph. As of May 2024,
it is recommended that you curate your own subgraph with at least 3,000 GRT to
ensure that it is indexed and available for querying as soon as possible.

> **Note:** The Graph's smart contracts are all on Arbitrum One, even though
> your subgraph is indexing data from Unichain
> [supported chain](https://thegraph.com/docs/en/developing/supported-networks/).

## Step 3: Query Your Subgraph
Congratulations! You can now query your subgraph on the decentralized network!

To query any subgraph on the decentralized network, pass a GraphQL query into
the subgraph's query URL, which can be found at the top of its Explorer page.

Here's an example from the
[CryptoPunks Ethereum subgraph](https://thegraph.com/explorer/subgraphs/HdVdERFUe8h61vm2fDyycHgxjsde5PbB832NHgJfZNqK)
by Messari:

<img alt="CryptoPunks Example" src={__img5} placeholder="blur" />

The query URL for this subgraph is:

```text
https://gateway-arbitrum.network.thegraph.com/api/[api-key]/subgraphs/id/HdVdERFUe8h61vm2fDyycHgxjsde5PbB832NHgJfZNqK
```

Now, you simply need to fill in your own API Key to start sending GraphQL
queries to this endpoint.

## Get your own API key
In Subgraph Studio, you'll see the "API Keys" menu at the top of the page. Here,
you can create API Keys.

<img alt="API Keys" src={__img6} placeholder="blur" />

## Appendix
## Sample query
This query shows the most expensive CryptoPunks sold.

```graphql
{
  trades(orderBy: priceETH, orderDirection: desc) {
    priceETH
    tokenId
  }
}
```

Passing this into the query URL returns this result:

```json
{
  "data": {
    "trades": [
      {
        "priceETH": "124457.067524886018255505",
        "tokenId": "9998"
      },
      {
        "priceETH": "8000",
        "tokenId": "5822"
      },
//      ...
```

## Sample code
```jsx
const axios = require("axios");

const graphqlQuery = `{
  trades(orderBy: priceETH, orderDirection: desc) {
    priceETH
    tokenId
  }
}`;
const queryUrl =
  "https://gateway-arbitrum.network.thegraph.com/api/[api-key]/subgraphs/id/HdVdERFUe8h61vm2fDyycHgxjsde5PbB832NHgJfZNqK";

const graphQLRequest = {
  method: "post",
  url: queryUrl,
  data: {
    query: graphqlQuery,
  },
};

// Send the GraphQL query
axios(graphQLRequest)
  .then((response) => {
    // Handle the response here
    const data = response.data.data;
    console.log(data);
  })
  .catch((error) => {
    // Handle any errors
    console.error(error);
  });
```

## Additional resources
* To explore all the ways you can optimize and customize your subgraph for better
  performance, read more about
  [creating a subgraph here](https://thegraph.com/docs/en/developing/creating-a-subgraph/).
* To learn more about [querying data from Unichain with your subgraph](https://thegraph.com/docs/en/querying/querying-the-graph/).
* [Subgraph Studio](https://thegraph.com/studio/).