Neynar Documentation

Authorizations

x-api-key

string

header

default:NEYNAR_API_DOCS

required

API key to authorize requests

Body

application/octet-stream

A Message is a delta operation on the Farcaster network. The message protobuf is an envelope that wraps a MessageData object and contains a hash and signature which can verify its authenticity.

The body is of type file.

Response

A successful response.

A Message is a delta operation on the Farcaster network that represents a state change. Messages are the fundamental unit of data in Farcaster and can represent various actions like:

Creating or removing casts (posts)
Adding or removing reactions
Following or unfollowing users
Updating profile data
Verifying Ethereum addresses

Each message contains:

A MessageData object with the actual content
A hash of the content for integrity verification
A cryptographic signature to prove authenticity
The signer's public key for verification

Messages are immutable once created and form an append-only log of all user actions on the network.

data

object

required

Represents a new cast (post) being created in the Farcaster network. A cast can include text content, mentions of other users, embedded URLs, and references to parent posts for replies.

Show child attributes

data.fid

integer<uint64>

required

The unique identifier (FID) of the user who created this message. FIDs are assigned sequentially when users register on the network and cannot be changed.

Example:

2

data.timestamp

integer<int64>

required

Seconds since Farcaster Epoch (2021-01-01T00:00:00Z). Used to order messages chronologically and determine the most recent state. Must be within 10 minutes of the current time when the message is created.

Example:

48994466

data.network

enum<string>

default:FARCASTER_NETWORK_MAINNET

required

Farcaster network the message is intended for.

FARCASTER_NETWORK_MAINNET: Public primary network
FARCASTER_NETWORK_TESTNET: Public test network
FARCASTER_NETWORK_DEVNET: Private test network

Available options:

FARCASTER_NETWORK_MAINNET,

FARCASTER_NETWORK_TESTNET,

FARCASTER_NETWORK_DEVNET

data.castAddBody

object

required

The content and metadata of the new cast, including the text, mentions, embeds, and any parent references for replies.

Show child attributes

data.castAddBody.embedsDeprecated

string[]

required

data.castAddBody.mentions

integer<uint64>[]

required

data.castAddBody.text

string

required

data.castAddBody.mentionsPositions

integer<int64>[]

required

data.castAddBody.embeds

URLs or cast IDs to be embedded in the cast · object[]

required

Option 1
Option 2

Show child attributes

data.castAddBody.embeds.castId

object

required

A unique identifier for a cast (post) in the Farcaster network, consisting of the creator's FID and a hash of the cast's content. This combination ensures global uniqueness across all casts.

Show child attributes

data.castAddBody.embeds.castId.fid

integer<uint64>

required

The Farcaster ID (FID) of the user who created the cast. Required to uniquely identify the cast's author in the network.

Example:

2

data.castAddBody.embeds.castId.hash

string

required

A unique hash that identifies a specific cast within the creator's posts. Generated using HASH_SCHEME_BLAKE3 of the cast's content.

Example:

"0x03aff391a6eb1772b20b4ead9a89f732be75fe27"

data.castAddBody.parentCastId

object

A unique identifier for a cast (post) in the Farcaster network, consisting of the creator's FID and a hash of the cast's content. This combination ensures global uniqueness across all casts.

Show child attributes

data.castAddBody.parentCastId.fid

integer<uint64>

required

The Farcaster ID (FID) of the user who created the cast. Required to uniquely identify the cast's author in the network.

Example:

2

data.castAddBody.parentCastId.hash

string

required

A unique hash that identifies a specific cast within the creator's posts. Generated using HASH_SCHEME_BLAKE3 of the cast's content.

Example:

"0x03aff391a6eb1772b20b4ead9a89f732be75fe27"

data.castAddBody.parentUrl

string

Example:

"chain://eip155:1/erc721:0x39d89b649ffa044383333d297e325d42d31329b2"

data.type

enum<string>

default:MESSAGE_TYPE_CAST_ADD

Type of the MessageBody.

MESSAGE_TYPE_CAST_ADD: Add a new Cast
MESSAGE_TYPE_CAST_REMOVE: Remove an existing Cast
MESSAGE_TYPE_REACTION_ADD: Add a Reaction to a Cast
MESSAGE_TYPE_REACTION_REMOVE: Remove a Reaction from a Cast
MESSAGE_TYPE_LINK_ADD: Add a new Link
MESSAGE_TYPE_LINK_REMOVE: Remove an existing Link
MESSAGE_TYPE_VERIFICATION_ADD_ETH_ADDRESS: Add a Verification of an Ethereum Address
MESSAGE_TYPE_VERIFICATION_REMOVE: Remove a Verification
MESSAGE_TYPE_USER_DATA_ADD: Add metadata about a user
MESSAGE_TYPE_USERNAME_PROOF: Add or replace a username proof
MESSAGE_TYPE_FRAME_ACTION: A Farcaster Frame action

Available options:

MESSAGE_TYPE_CAST_ADD,

MESSAGE_TYPE_CAST_REMOVE,

MESSAGE_TYPE_REACTION_ADD,

MESSAGE_TYPE_REACTION_REMOVE,

MESSAGE_TYPE_LINK_ADD,

MESSAGE_TYPE_LINK_REMOVE,

MESSAGE_TYPE_VERIFICATION_ADD_ETH_ADDRESS,

MESSAGE_TYPE_VERIFICATION_REMOVE,

MESSAGE_TYPE_USER_DATA_ADD,

MESSAGE_TYPE_USERNAME_PROOF,

MESSAGE_TYPE_FRAME_ACTION

hash

string

required

Example:

"0xd2b1ddc6c88e865a33cb1a565e0058d757042974"

hashScheme

enum<string>

default:HASH_SCHEME_BLAKE3

required

Type of hashing scheme used to produce a digest of MessageData. - HASH_SCHEME_BLAKE3: Default scheme for hashing MessageData

Available options:

HASH_SCHEME_BLAKE3

signature

string<byte>

required

signatureScheme

enum<string>

default:SIGNATURE_SCHEME_ED25519

required

Type of signature scheme used to sign the Message hash

SIGNATURE_SCHEME_ED25519: Ed25519 signature (default)
SIGNATURE_SCHEME_EIP712: ECDSA signature using EIP-712 scheme

Available options:

SIGNATURE_SCHEME_ED25519,

SIGNATURE_SCHEME_EIP712

signer

string

required

Overview

Farcaster

Deploy onchain

Farcaster Hub API

Other SDKs

Github

Submit signed message

Authorizations

Body

Response