Crate pallet_messages

Stores messages for IPFS and OnChain Schema payload locations

Quick Links

• Configuration: Config
• Extrinsics: Call
• Runtime API: MessagesRuntimeApi
• Custom RPC API: MessagesApiServer
• Event Enum: Event
• Error Enum: Error

Messages Pallet

Stores block-indexed data for a Schema using OnChain or IPFS payload location.

Summary

messages stores metadata and message payload data for a set Schema. Message payloads are meant for streaming data, where when the message was sent is the focus. Discovery is via the MessagesInBlock on new blocks or requesting messages from a block. Retrieval is via a custom runtime API.

Metadata vs Payload

Messages have both metadata and payloads. The payload should always match the data structure or the message is considered invalid. The metadata is the Block Number, Intent Id, and other data useful for discovering and organizing the payload information.

Payload Options

• IPFS: Storage of the CID and length of the file on IPFS
• OnChain: Storage of the entire payload data, usually for sub-256 byte payloads

Message Ordering

Messages are ordered by block number and IntentId, and within each block, they follow a specific order based on their transaction sequence within that block. This order is immutable.

Actions

The Messages pallet provides for:

• Adding messages for a given Intent
• Enabling the retrieval of messages for a given Intent

Interactions

Extrinsics

Name/Description	Caller	Payment	Key Events	Runtime Added
add_ipfs_message Add a message to a Schema with an IPFS payload location	Provider	Capacity or Tokens	MessagesInBlock*	1
add_onchain_message Add a message to a Schema with an ON_CHAIN payload location	Provider	Capacity or Tokens	MessagesInBlock*	1

* The MessagesInBlock may occur at most once per block and does not indicate which Intent(s) received messages.

See Rust Docs for more details.

State Queries

Name	Description	Query	Runtime Added
MessagesV3	Suggested: Use custom runtime API instead of querying this storage directly. Storage for the messages by Block Number, IntentId, and MessageIndex	messagesV3	?
MessagesV2	Removed in Runtime ??	messagesV2	61
Messages	Removed in Runtime 60	messages	1-60

See the Rust Docs for additional state queries and details.

RPCs

Note: May be restricted based on node settings and configuration.

Name	Description	Call	Node Version
Get Messages by Schema Id (deprecated)	Fetch paginated messages for a specific Schema Id in the given block range for a given Schema Id Deprecated in v1.17.?. Use custom Runtime API get_messages_by_intent_id instead	getBySchemaId	v1.0.0+

See Rust Docs for more details.

Runtime API

Name	Description	Call	API Version Added	Runtime Added
Get Schema by Id (deprecated)	Retrieves the schema for the given Schema Id	getBySchemaId	1	1
Get Messages by Schema and Block (deprecated)	Retrieve the messages for a particular schema and block number	getMessagesBySchemaAndBlock	1	1
Get Messages by Intent and Block	Retrieve the messages for a particular intent and block range (paginated)	getMessagesByIntentId	2	?

See Rust Docs for more details.

Re-exports

pub use pallet::*;

pub use weights::*;

Modules

migration

Storage migrations

pallet

The pallet module in each FRAME pallet hosts the most important items needed to construct this pallet.

weights

Autogenerated weights for pallet_messages

Structs

Message

A single message type definition.

Traits

MapToResponse

Trait for converting message storage to response type

Type Aliases

MessageIndex

Index of message in the block

OffchainPayloadType

Payloads stored offchain contain a tuple of (bytes(the payload reference), payload length).