> ## Documentation Index
> Fetch the complete documentation index at: https://docs.neynar.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add a Verification

> Walkthrough on how to add an ethereum or solana address as a verification to a user's farcaster profile

<Tip>
  * If you want to integrate Farcaster auth for your users, easiest way to start is [Sign in with Neynar](/docs/how-to-let-users-connect-farcaster-accounts-with-write-access-for-free-using-sign-in-with-neynar-siwn) (Neynar pays all onchain fee)
  * If you want dedicated signers for your user or bot, simplest to clone this [example app](https://github.com/neynarxyz/farcaster-examples/tree/main/managed-signers) for quickstart
</Tip>

This guide demonstrates adding an Ethereum address verification with the Neynar SDK.

Check out this [Getting Started Guide](/docs/getting-started-with-neynar) to learn how to set up your environment and get an API key.

First, initialize the client:

<CodeGroup>
  ```javascript Javascript theme={"system"}
  // npm i @neynar/nodejs-sdk
  import { NeynarAPIClient, Configuration } from "@neynar/nodejs-sdk";

  // make sure to set your NEYNAR_API_KEY .env
  // don't have an API key yet? get one at neynar.com
  const config = new Configuration({
    apiKey:process.env.NEYNAR_API_KEY,
  });

  const client = new NeynarAPIClient(config);
  const signer = process.env.NEYNAR_SIGNER;
  ```
</CodeGroup>

Then like a cast:

<CodeGroup>
  ```javascript Javascript theme={"system"}
  const hash = "0x6932a9256f34e18892d498abb6d00ccf9f1c50d6";
  client.publishReaction({ signerUuid: signer, reactionType: "like", target:hash });
  ```
</CodeGroup>

Recasting works the same way, just replace "like" with "recast":

<CodeGroup>
  ```javascript Javascript theme={"system"}
  const hash = "0x6932a9256f34e18892d498abb6d00ccf9f1c50d6";
  client.publishReaction({ signerUuid: signer, reactionType: "like", target:hash });
  ```
</CodeGroup>

The end result should look like this:

<CodeGroup>
  ```javascript Javascript theme={"system"}
  {
    success: true;
  }
  ```
</CodeGroup>

To verify that the reaction was published, you can fetch the cast's reactions:

<CodeGroup>
  ```javascript Javascript theme={"system"}
  const types = ReactionsType.All;
  const reactions = await client.fetchCastReactions({ hash, types: [types] });
  console.log(reactions);
  ```
</CodeGroup>

Which would print out

```json theme={"system"}
{
  "result": {
    "casts": [
      {
        "type": "like",
        "hash": "0x691fabb3fc58bd4022d4358b2bc4f44469ad959a",
        "reactor": {
          "fid": "4640",
          "username": "picture",
          "displayName": "Picture",
          "pfp": {
            "url": "https://lh3.googleusercontent.com/erYudyT5dg9E_esk8I1kqB4bUJjWAmlNu4VRnv9iUuq_by7QjoDtZzj_mjPqel4NYQnvqYr1R54m9Oxp9moHQkierpY8KcYLxyIJ"
          },
          "followerCount": "45",
          "followingCount": "57"
        },
        "timestamp": "2023-12-10T15:26:45.000Z",
        "castHash": "0x6932a9256f34e18892d498abb6d00ccf9f1c50d6"
      }
    ],
    "next": {
      "cursor": null
    }
  }
}
```

That's it! You can now like or recast any cast on Farcaster.

PS - to learn more about how writes technically work on Farcaster, read [Write to Farcaster with Neynar Managed Signers](/docs/write-to-farcaster-with-neynar-managed-signers)

<Info>
  ### Ready to start building?

  Get your subscription at [neynar.com](https://neynar.com) and reach out to us on [Slack](https://neynar.com/slack) with any questions!
</Info>