Understanding Universal Transactions

Overview

In most blockchain apps today, if a user on Ethereum wants to call a contract on another chain, they need to manually bridge tokens, switch wallets, pay gas on multiple networks, and hope nothing goes wrong between steps.

Universal transactions eliminate all of that. You write one transaction. The SDK handles origin detection, gas orchestration, proof replay, and final execution regardless of which chain the user is on.

Push Chain turns all chains into universal execution environments behind a single transaction interface.

Summary

A universal transaction is a single transaction that executes across chains through Push Chain, without requiring manual bridging, network switching, or multi-step coordination.

Key Account Types

Before diving into routes and lifecycle, it helps to understand the three account types that power this system.

Universal Origin Account (UOA)

The UOA is the user's actual wallet. It can be an Ethereum address, Solana public key, Push address or any chain-native identity. This is where transactions originate and the entity (controller) that authorizes execution. It never changes and requires no setup.

Universal Executor Account (UEA)

The UEA is a smart contract account on Push Chain, deterministically derived from the UOA. It is the entity that actually executes transactions on Push Chain on behalf of the user.

Key properties:

• Deterministic: the same UOA always maps to the same UEA address, across all chains
• Non-custodial: only a valid proof from the UOA can authorize UEA actions
• Lazy-deployed: the UEA is deployed automatically on first use, no setup required

Chain Executor Account (CEA)

The CEA is an executor account deployed on a supported external chain (e.g., Ethereum, BNB Chain). It is deterministically mapped to a user or contract and allows execution on external chains while preserving identity across environments.

CEAs are not limited to users with a UEA. They can also exist for native Push Chain EOAs or smart contracts. Depending on the target chain, a CEA may be implemented as an EOA or a smart contract, while remaining logically bound to its originating account.

CEAs are only used when execution must happen on or originate from an external chain.

Mental Model

• UEA executes transactions on Push Chain for users interacting from external chains
• CEA executes on external chains

Together, they form a unified execution layer across all chains

Transaction Routes

Universal transactions support three routing modes. The route is determined automatically by the tx.to and tx.from fields you supply.

Route	Flow	Description
Route 1	Any Origin → Push	Execute on Push Chain via UEA
Route 2	Any Origin → External via CEA	Execute on external chain via CEA
Route 3	External (via CEA) → Push	Execute on Push Chain with external origin

Route 1: Any Origin to Push Chain

The most common route. The user signs from any supported chain and the transaction executes on Push Chain via their UEA.

When to use: Contract calls, token transfers, multicall batches — anything targeting Push Chain.

// Route 1: plain address target triggers Push Chain execution
await pushChainClient.universal.sendTransaction({
  to: '0xContractOnPushChain',
  data: encodedCalldata,
  value: BigInt(0),
});

Route 2: Any Origin to External Chain via CEA

The user signs from any chain, but execution happens on an external chain through their CEA. Push Chain acts as the coordination layer.

When to use: Calling a contract on Ethereum, BNB Chain, or any supported external chain without the user needing to switch networks.

// Route 2: { address, chain } target routes through CEA on that chain
await pushChainClient.universal.sendTransaction({
  to: {
    address: '0xContractOnEthereum',
    chain: PushChain.CONSTANTS.CHAIN.ETHEREUM_SEPOLIA,
  },
  data: encodedCalldata,
});

Route 3: External CEA Origin to Push Chain

The execution originates from a CEA on an external chain and targets Push Chain. This route is used when a transaction returns from an external chain and needs to preserve the identity established there.

For example, a user can move from Solana to Push Chain via a UEA, interact with Ethereum using a CEA (such as depositing into Aave), and then return to Push Chain. Route 3 ensures the execution reflects their Ethereum identity.

When to use: When execution on Push Chain must reflect an external chain identity, typically after interacting with contracts on that chain.

// Route 3: tx.from forces CEA on specified chain to be the execution origin
await pushChainClient.universal.sendTransaction({
  from: { chain: PushChain.CONSTANTS.CHAIN.ETHEREUM_SEPOLIA },
  to: '0xContractOnPushChain',
  data: encodedCalldata,
});

Transaction Lifecycle

Every call to sendTransaction follows the same execution pipeline. These steps are handled automatically by the SDK.

Step	Stage	Description
1	Origin Detection	Identifies the UOA and source chain
2	Gas Estimation	Estimates total execution cost across chains
3	UEA Resolution	Resolves or deploys the user's UEA on Push Chain
4	User Authorization	Collects signature or verifies on-chain proof
5	Gas Funding	Funds the UEA if required
6	Asset Movement	Moves assets if tx.funds is set
7	Broadcast	Submits the transaction to Push Chain
8	Confirmation	Returns transaction hash and execution receipt

Asset Movement (step 6) only runs when tx.funds is set. For plain Push Chain transactions it is skipped entirely.

Each step emits a SEND-TX-* progress event. You can subscribe via progressHook at the client level or per-call to show live status in your UI.

Why Universal Transactions Matter

Universal transactions fundamentally change how apps are built and used across chains.

• No per-chain deployments
  Developers deploy once and reach users across all supported chains

• No bridging or network switching
  Users interact from their native chain without managing infrastructure

• Unified user identity
  The same user can execute across chains while preserving identity

• Composable cross-chain flows
  Complex multi-chain interactions happen within a single transaction

This enables a new class of applications that are truly chain-agnostic and universal.

Next Steps

• Send your first universal transaction with Send Universal Transaction
• Track and monitor execution with Track Universal Transaction
• Build advanced cross-chain flows with Send Multichain Transactions