Cast url doesn’t contain all the full cast hash value, it usually looks like this: https://farcaster.xyz/dwr.eth/0x029f7cce. This guide demonstrates how to fetch cast information from cast url. Check out this Getting started guide to learn how to set up your environment and get an API key. First, initialize the client: 
// 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);
Then fetch the cast: 
// @dwr.eth AMA with @balajis.eth on Farcaster
const url = "https://farcaster.xyz/dwr.eth/0x029f7cce";
const cast = await client.lookupCastByHashOrUrl({
  identifier: url,
  type: CastParamType.Url,
});
console.log(cast);
Example output: 
{
  cast: {
    object: "cast_hydrated",
    hash: "0x029f7cceef2f0078f34949d6e339070fc6eb47b4",
    thread_hash: "0x029f7cceef2f0078f34949d6e339070fc6eb47b4",
    parent_hash: null,
    parent_url: "https://thenetworkstate.com",
    parent_author: {
      fid: null
    },
    author: {
      object: "user",
      fid: 3,
      custody_address: "0x6b0bda3f2ffed5efc83fa8c024acff1dd45793f1",
      username: "dwr.eth",
      display_name: "Dan Romero",
      pfp_url: "https://res.cloudinary.com/merkle-manufactory/image/fetch/c_fill,f_png,w_256/https://lh3.googleusercontent.com/MyUBL0xHzMeBu7DXQAqv0bM9y6s4i4qjnhcXz5fxZKS3gwWgtamxxmxzCJX7m2cuYeGalyseCA2Y6OBKDMR06TWg2uwknnhdkDA1AA",
      profile: [Object ...],
      follower_count: 19381,
      following_count: 2703,
      verifications: [ "0xd7029bdea1c17493893aafe29aad69ef892b8ff2",
        "0xa14b4c95b5247199d74c5578531b4887ca5e4909",
        "0xb877f7bb52d28f06e60f557c00a56225124b357f",
        "0x8fc5d6afe572fefc4ec153587b63ce543f6fa2ea"
      ],
      active_status: "active"
    },
    text: "Welcome to @balajis.eth!\n\nHe’s kindly agreed to do an AMA. Reply with your questions. :)",
    timestamp: "2023-11-28T14:44:32.000Z",
    embeds: [],
    reactions: {
      likes: [
        [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...],
        [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...],
        [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...],
        [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...]
      ],
      recasts: [
        [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...], [Object ...]
      ]
    },
    replies: {
      count: 180
    },
    mentioned_profiles: [
      [Object ...]
    ]
  }
}
Obviously, you can also fetch cast by hash: 
// full hash of the warpcast.com/dwr.eth/0x029f7cce
const hash = "0x029f7cceef2f0078f34949d6e339070fc6eb47b4";
const cast = (await client.lookUpCastByHashOrUrl({
  identifier: hash,
  type: CastParamType.Hash,
}));
console.log(cast);
Which will return the same result as above.

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