SubmitMessage API ​

The SubmitMessage API lets you submit signed Farcaster protocol messages to the Hub. Note that the message has to be sent as the encoded bytestream of the protobuf (Message.enocde(msg).finish() in typescript), as POST data to the endpoint.

The encoding of the POST data has to be set to application/octet-stream. The endpoint returns the Message object as JSON if it was successfully submitted

submitMessage ​

Submit a signed protobuf-serialized message to the Hub

Query Parameters

Example

curl -X POST "http://127.0.0.1:2281/v1/submitMessage" \
     -H "Content-Type: application/octet-stream" \
     --data-binary "@message.encoded.protobuf"

Response

{
  "data": {
    "type": "MESSAGE_TYPE_CAST_ADD",
    "fid": 2,
    "timestamp": 48994466,
    "network": "FARCASTER_NETWORK_MAINNET",
    "castAddBody": {
      "embedsDeprecated": [],
      "mentions": [],
      "parentCastId": {
        "fid": 226,
        "hash": "0xa48dd46161d8e57725f5e26e34ec19c13ff7f3b9"
      },
      "text": "Cast Text",
      "mentionsPositions": [],
      "embeds": []
    }
  },
  "hash": "0xd2b1ddc6c88e865a33cb1a565e0058d757042974",
  "hashScheme": "HASH_SCHEME_BLAKE3",
  "signature": "3msLXzxB4eEYe...dHrY1vkxcPAA==",
  "signatureScheme": "SIGNATURE_SCHEME_ED25519",
  "signer": "0x78ff9a...58c"
}

Auth ​

If the rpc auth has been enabled on the server (using --rpc-auth username:password), you will need to also pass in the username and password while calling submitMessage using HTTP Basic Auth.

Example

curl -X POST "http://127.0.0.1:2281/v1/submitMessage" \
     -u "username:password" \
     -H "Content-Type: application/octet-stream" \
     --data-binary "@message.encoded.protobuf"

JS Example

import axios from "axios";

const url = `http://127.0.0.1:2281/v1/submitMessage`;

const postConfig = {
    headers: { "Content-Type": "application/octet-stream" },
    auth: { username: "username", password: "password" },
};

// Encode the message into a Buffer (of bytes)
const messageBytes = Buffer.from(Message.encode(castAdd).finish());

try {
    const response = await axios.post(url, messageBytes, postConfig);
} catch (e) {
    // handle errors...
}