1. Account/Contract Merge

• Merge Overview:
  • Casper currently contains separate Accounts and Contracts. These record types are similar but contain small differences. Condor merges these into one record called AddressableEntity.
  • All existing Account and Contract records will migrate upon on-chain interaction (e.g., sending transactions, native transfers).
  • All new “accounts” and “contracts” created on the system will result in an AddressableEntity record being created.
  • PublicKeys and AccountHashes for existing Account records remain in place and continue to function with the corresponding AddressableEntity record.
• Changes to Named Keys:
  • Named keys are now a top-level concern and stored directly in global state.
  • Entry points for smart contracts are now a top-level concern, with each entry point being stored directly in global state rather than embedded within an AddressableEntity record.
• Action Items:
  • Any off-chain logic that retrieves Account or Contract records from the blockchain (e.g., processing, storage, indexing) must be modified to retrieve and use the AddressableEntity record structure.

2. Fee Elimination

• New Support Features:
  • Condor introduces support for configurable fee, refund, and pricing strategies. The initial rollout will be in “NoFee” mode, where tokens are placed on hold instead of transferred from a paying purse.
  • There is a configurable interval that determines how long a balance hold remains. The available balance of a purse equals its actual balance minus all non-expired holds.
  • Off-chain logic can use the existing query_balance endpoint for the available balance or the new query_balance_details RPC endpoint for detailed balance information.
• Action Items:
  • Placing holds rather than taking fees is beneficial as gas costs return over time.
  • Existing implementations should generally not need changes.
  • Advanced platforms with automated funding should consider the new behavior for optimal scheduling strategies.

3. Dynamic Pricing

• Gas Price Changes:
  • Current gas price is 1 mote per unit of gas. Condor introduces a configurable gas price multiplier.
  • Gas price adjusts based on block usage in the current era, increasing or decreasing by 1 within set thresholds.
  • Minimum and maximum gas prices and adjustment thresholds are configurable.
  • The gas price is included in the block header for easy discovery.
• Action Items:
  • Plan for potential cost increases during high network usage.
  • Transactions can specify the maximum gas price they are willing to pay using the gas_tolerance field.

4. Transaction Types

• Transition to Transaction Model:
  • The Deploy structure is deprecated; Condor introduces a Transaction model.
  • Condor supports native / Wasm-less user-land mint and stake management actions.
• Action Items:
  • Verify compatibility with the legacy Deploy model.
  • Consider upgrading to the Transaction model to leverage new features and efficiencies.

5. Block Restructure

• Changes to Block Structure:
  • Block records are modified. New blocks post-Condor will use the new format; historical blocks retain their original format.
• Action Items:
  • Upgrade client software to parse new blocks while retaining the ability to handle historical blocks.

6. Contract Level Events

• New Feature:
  • Smart contracts can define message topics and emit messages as contract level events.
• Action Items:
  • Existing systems do not need changes.
  • Consider migrating from dictionaries for events to the new system for better security and support.

7. Zug Consensus Protocol

• New Consensus Protocol:
  • Zug Consensus Protocol replaces Highway on the Casper network.
  • Private/hybrid networks can choose between Highway or Zug.
• Action Items: None.

8. Server-Sent Event (SSE) Endpoint Changes

• Event Stream Changes:
  • Due to the structural changes in certain record kinds (notably the Block record structure and the transition from the Deploy model to the Transaction model), and the addition of contract-level events in the form of Messages, there are breaking changes to the contents of the event stream.
  • Changes include:
    • Instead of a DeployProcessed event, there is now a TransactionProcessed event.
    • Instead of a DeployExpired event, there is now a TransactionExpired event.
    • Other similar changes in event naming and content.
• Action Items:
  • Existing software (including SDKs) that deserializes the JSON produced by the SSE event stream will require updating to continue to follow the event stream post-Condor.
  • Software that does not follow the event stream is unaffected by these changes.

For further details, you can refer to the updated documentation available at the provided links:

• Contract-level Messages
• Zug Consensus Protocol Design
• Zug Consensus Protocol Theory

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