Neynar Documentation
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A message is the fundamental data type in the Farcaster network. When an account takes an action like casting a public message, changing its profile, or verifying an Ethereum account, it generates a new message.
1. Message
The message is a protobuf that contains the data, its hash and a signature from the author.
| Field | Type | Label | Description |
|---|---|---|---|
| data | MessageData | Contents of the message. Alternatively, you can use the data_bytes to serialize the MessageData |
|
| hash | bytes | Hash digest of data | |
| hash_scheme | HashScheme | Hash scheme that produced the hash digest | |
| signature | bytes | Signature of the hash digest | |
| signature_scheme | SignatureScheme | Signature scheme that produced the signature | |
| signer | bytes | Public key or address of the key pair that produced the signature | |
| data_bytes | bytes | Alternate to the “data” field. If you are constructing the MessageData in a programming language other than Typescript, you can use this field to serialize the MessageData and calculate the hash and signature on these bytes. Optional. |
1.1 MessageData
MessageData is a generic envelope that contains a type, fid, timestamp and network which must be present in all Farcaster messages. It also contains a body whose type is determined by the MessageType.
| Field | Type | Label | Description |
|---|---|---|---|
| type | MessageType | Type of Message contained in the body | |
| fid | uint64 | Farcaster ID of the user producing the message | |
| timestamp | uint32 | Farcaster epoch timestamp in seconds | |
| network | FarcasterNetwork | Farcaster network the message is intended for | |
| body | CastAddBody, CastRemoveBody, ReactionBody, VerificationAddAddressBody, VerificationRemoveBody, UserDataBody, LinkBody, UserNameProof, FrameActionBody, LinkCompactStateBody | oneOf | Properties specific to the MessageType |
1.2 HashScheme
Type of hashing scheme used to produce a digest of MessageData
| Name | Number | Description |
|---|---|---|
| HASH_SCHEME_NONE | 0 | |
| HASH_SCHEME_BLAKE3 | 1 | Default scheme for hashing MessageData |
1.3 Signature Scheme
Type of signature scheme used to sign the Message hash
| Name | Number | Description |
|---|---|---|
| SIGNATURE_SCHEME_NONE | 0 | |
| SIGNATURE_SCHEME_ED25519 | 1 | Ed25519 signature (default) |
| SIGNATURE_SCHEME_EIP712 | 2 | ECDSA signature using EIP-712 scheme |
1.4 Message Type
Type of the MessageBody
| Name | Number | Description |
|---|---|---|
| MESSAGE_TYPE_NONE | 0 | Invalid default value |
| MESSAGE_TYPE_CAST_ADD | 1 | Add a new Cast |
| MESSAGE_TYPE_CAST_REMOVE | 2 | Remove an existing Cast |
| MESSAGE_TYPE_REACTION_ADD | 3 | Add a Reaction to a Cast |
| MESSAGE_TYPE_REACTION_REMOVE | 4 | Remove a Reaction from a Cast |
| MESSAGE_TYPE_LINK_ADD | 5 | Add a Link to a target |
| MESSAGE_TYPE_LINK_REMOVE | 6 | Remove a Link from a target |
| MESSAGE_TYPE_VERIFICATION_ADD_ETH_ADDRESS | 7 | Add a Verification of an Address |
| MESSAGE_TYPE_VERIFICATION_REMOVE | 8 | Remove a Verification |
| MESSAGE_TYPE_USER_DATA_ADD | 11 | Add metadata about a user |
| MESSAGE_TYPE_USERNAME_PROOF | 12 | Add or replace a username proof |
| MESSAGE_TYPE_FRAME_ACTION | 13 | Frame action (not stored) |
| MESSAGE_TYPE_LINK_COMPACT_STATE | 14 | Compact state for links |
1.5 Farcaster Network
Farcaster network the message is intended for
| Name | Number | Description |
|---|---|---|
| FARCASTER_NETWORK_NONE | 0 | |
| FARCASTER_NETWORK_MAINNET | 1 | Public primary network |
| FARCASTER_NETWORK_TESTNET | 2 | Public test network |
| FARCASTER_NETWORK_DEVNET | 3 | Private test network |
2. UserData
A UserData message represents user metadata (e.g. a profile picture url).
2.1 UserDataBody
Body of a UserData message
| Field | Type | Label | Description |
|---|---|---|---|
| type | UserDataType | Type of metadata | |
| value | string | Value of the metadata |
2.2 UserDataType
Type of UserData message
| Name | Number | Description |
|---|---|---|
| USER_DATA_TYPE_NONE | 0 | Invalid default value |
| USER_DATA_TYPE_PFP | 1 | Profile Picture for the user |
| USER_DATA_TYPE_DISPLAY | 2 | Display Name for the user |
| USER_DATA_TYPE_BIO | 3 | Bio for the user |
| USER_DATA_TYPE_URL | 5 | URL of the user |
| USER_DATA_TYPE_USERNAME | 6 | Preferred Farcaster Name for the user |
| USER_DATA_TYPE_LOCATION | 7 | Location for the user |
| USER_DATA_TYPE_TWITTER | 8 | Twitter username for the user |
| USER_DATA_TYPE_GITHUB | 9 | GitHub username for the user |
| USER_DATA_TYPE_BANNER | 10 | Banner image for the user |
| USER_DATA_PRIMARY_ADDRESS_ETHEREUM | 11 | Primary Ethereum address |
| USER_DATA_PRIMARY_ADDRESS_SOLANA | 12 | Primary Solana address |
3. Cast
A Cast message is a public post from a user.
3.1 CastAddBody
Adds a new Cast message.
| Field | Type | Label | Description |
|---|---|---|---|
| embeds_deprecated | string | repeated | URLs to be embedded in the cast |
| mentions | uint64 | repeated | Fids mentioned in the cast |
| parent_cast_id | CastId | oneOf parent | Parent cast of the cast |
| parent_url | string | oneOf parent | Parent URL of the cast |
| text | string | Text of the cast | |
| mentions_positions | uint32 | repeated | Positions of the mentions in the text |
| embeds | Embed | repeated | URLs or cast ids to be embedded in the cast |
| type | CastType | Type of cast (regular, long, etc.) |
Embed
| Field | Type | Label | Description |
|---|---|---|---|
| url | string | ||
| cast_id | CastId |
3.2 CastRemoveBody
Removes an existing Cast message.
| Field | Type | Label | Description |
|---|---|---|---|
| target_hash | bytes | Hash of the cast to remove |
3.3 CastId
Identifier used to look up a Cast
| Field | Type | Label | Description |
|---|---|---|---|
| fid | uint64 | Fid of the user who created the cast | |
| hash | bytes | Hash of the cast |
4. Reaction
A Reaction message creates a relationship between an account and a cast. (e.g. like)
4.1 ReactionBody
Adds or removes a Reaction from a Cast
| Field | Type | Label | Description |
|---|---|---|---|
| type | ReactionType | Type of reaction | |
| target_cast_id | CastId | CastId of the Cast to react to | |
| target_url | string | URL to react to |
4.2 ReactionType
Type of Reaction
| Name | Number | Description |
|---|---|---|
| REACTION_TYPE_NONE | 0 | Invalid default value |
| REACTION_TYPE_LIKE | 1 | Like the target cast |
| REACTION_TYPE_RECAST | 2 | Share target cast to the user’s audience |
5. Link
A Link message creates a relationship between two users (e.g. follow)
5.1 LinkBody
Adds or removes a Link
| Field | Type | Label | Description |
|---|---|---|---|
| type | string | Type of link, <= 8 characters | |
| displayTimestamp | uint32 | optional | User-defined timestamp that preserves original timestamp when message.data.timestamp needs to be updated for compaction |
| target_fid | uint64 | The fid the link relates to |
6. Verification
A Verification message is a proof of ownership of something.
6.1 VerificationAddAddressBody
Adds a bi-directional signature proving that an fid has control over an address (supports multiple protocols).
| Field | Type | Label | Description |
|---|---|---|---|
| address | bytes | Address being verified | |
| claim_signature | bytes | Signature produced by the user’s address | |
| block_hash | bytes | Hash of the latest block when the claim was produced | |
| verification_type | uint32 | Type of verification (0 = EOA, 1 = contract) | |
| chain_id | uint32 | Chain ID of the verification | |
| protocol | Protocol | Protocol of the address (Ethereum, Solana, etc.) |
6.2 VerificationRemoveBody
Removes a Verification of any type
| Field | Type | Label | Description |
|---|---|---|---|
| address | bytes | Address of the Verification to remove |
7. Frame Action
Represents an action performed by a user on a frame. This message is not stored on the nodes and cannot be submitted, only validated.
7.1 FrameActionBody
A user action on a frame
| Field | Type | Label | Description |
|---|---|---|---|
| url | bytes | The original url of the frame as embedded in the cast | |
| button_index | uint32 | The button that was pressed (indexed from 1) | |
| cast_id | CastId | The cast id that hosted the frame | |
| input_text | bytes | Any text the user input as part of the action | |
| state | bytes | Serialized state passed from frame to server | |
| transaction_id | bytes | Transaction ID for transaction frames | |
| address | bytes | Address involved in the frame action |
8. Protocol
Type of protocol for addresses
| Name | Number | Description |
|---|---|---|
| PROTOCOL_ETHEREUM | 0 | Ethereum |
| PROTOCOL_SOLANA | 1 | Solana |
9. CastType
Type of cast
| Name | Number | Description |
|---|---|---|
| CAST | 0 | Regular cast |
| LONG_CAST | 1 | Extended length cast |
| TEN_K_CAST | 2 | Ten thousand character cast |
10. LinkCompactStateBody
Compact state representation for links
| Field | Type | Label | Description |
|---|---|---|---|
| type | string | Type of link | |
| target_fids | uint64 | repeated | Array of target fids |