Overview

Concepts

High level Mechanism

• add schedule using governance proposals [Permissioned - Main DAO];

• remove schedule using governance proposals [Permissioned - Main DAO or Security subDAO];

• every given block period execute cosmwasm msgs for added schedules.

General Mechanics

The module allows to receive MsgAddSchedule and MsgRemoveSchedule governance messages.

It also contains permissions:

• MsgAddSchedule can only be executed as main dao governance proposal

• MsgRemoveSchedule can only be executed as main dao governance proposal OR security subdao proposal

In BeginBlocker and EndBlocker module searches for all schedules (with limit by Params.Limit) that are ready to be executed, using last_execute_height.

That way after the schedule was added it will be executed every period of blocks (or more than period if too many schedules ready to execute).

Example

Adding schedule

To add schedule we need to send governance proposal:

{
  "messages": [
    {
      "@type": "/secret.cron.MsgAddSchedule",
      "authority": "secret10d07y265gmmuvt4z0w9aw880jnsr700jc88vt0",
      "name": "custom",
      "period": "2",
      "msgs": [
        {
          "contract": "secret1mfk7n6mc2cg6lznujmeckdh4x0a5ezf6hx6y8q",
          "msg": "7fc422718d9ba824726425866666f408aa66c0d4413803dc064e4ec115bbbbf7{\"increment\":{}}"
        }
      ]
    }
  ],
  "metadata": "ipfs://CID",
  "deposit": "10000000000uscrt",
  "title": "increase counter",
  "summary": "increase counter",
  "expedited": false
}

Removing schedule

To remove schedule we need to send governance proposal:

{
  "messages": [
    {
      "@type": "/secret.cron.MsgRemoveSchedule",
      "authority": "secret10d07y265gmmuvt4z0w9aw880jnsr700jc88vt0",
      "name": "custom"
    }
  ],
  "metadata": "ipfs://CID",
  "deposit": "10000000000uscrt",
  "title": "remove schedule",
  "summary": "summary",
  "expedited": false
}

Key Innovation: Implicit Hash Consensus

The core breakthrough is the addition of an implicit_hash field to Tendermint block headers, enabling deterministic consensus on scheduled execution.

Header Extension: Tendermint block headers now include implicit_hash - a SHA-256 hash of scheduled messages for the next round.

Two-Phase Execution:

1. Commitment Phase (Block N-1 EndBlock): Calculate hash of scheduled messages → store in tm-secret-enclave

2. Execution Phase (Block N BeginBlock): Retrieve hash → include in header → verify and execute

Architecture

The implementation requires coordinated changes across five repositories:

Repository	Role	Key Changes
SecretNetwork	Application Logic	Cron scheduling, message encryption, hash calculation
tm-secret-enclave	Secure State Bridge	Cross-block hash storage
tendermint-go	Consensus Integration	Header creation with implicit hash
cosmos-sdk	ABCI Coordination	Header propagation across ABCI methods
tendermint-rs	Rust Validation	Header structure validation

Execution Flow

Message Types

The formats are as follows:

MsgAddSchedule - adds new schedule to the cron module:

message MsgAddSchedule {
  string authority = 1;                    // Governance account address
  string name = 2;                         // Schedule identifier
  uint64 period = 3;                       // Execution interval in blocks
  repeated MsgExecuteContract msgs = 4;    // Messages to execute
}

MsgRemoveSchedule - removes schedule from the cron module:

message MsgRemoveSchedule {
  string authority = 1;                    // Governance account address
  string name = 2;                         // Schedule identifier to remove
}

MsgExecuteContract - contract execution specification:

message MsgExecuteContract {
  string contract = 1;                     // Smart contract address
  string msg = 2;                          // JSON-encoded message
}

After collecting all schedules ready for execution, we execute them in order.

For each schedule, every stored msg is complemented with more necessary fields to form wasmtypes.MsgExecuteContract:

// wasmtypes.MsgExecuteContract
msg := types.MsgExecuteContract{
    Sender:    senderAddr,        // Cron module account
    Contract:  contractAddr,      // Passed with Schedule.Msgs
    Msg:       encryptedMsg,      // Encrypted message content
    SentFunds: sdk.NewCoins(),    // Empty Coins
}

Then it's executed using wasmd WasmMsgServer implementation within the secure enclave.

For state to be modified, all messages in a given schedule should return successful result. If any cosmwasm msg fails to execute for any reason, all messages in a given schedule will be rolled back.