Architecture

North Star consists of four core components that work together to enable ephemeral, high-performance execution on top of Sonic SVM.

North Star System Architecture

System Components

Component	Layer	Role
Portal Program	Sonic SVM / L1	Single source of truth — sessions, delegation, deposits, finalization, disputes
Northstar Validator	Off-chain	Watches L1 events, provisions ERs, manages lifecycle, posts checkpoint bonds
Ephemeral Rollup	L2 (ephemeral)	Short-lived SVM runtime for high-speed execution of delegated state
Router	Off-chain	Stateless tx routing — inspects delegation status, routes to ER or L1

Portal Program (L1)

The Portal is a Solana on-chain program and the single source of truth for the entire North Star protocol.

1. Session Management — Creates, tracks, and closes Ephemeral Rollup sessions. Each session has a unique ID, fee deposit, and bounded lifetime.

2. Account Delegation — Transfers ownership of specified accounts to the Portal program. Delegated accounts are locked on L1 — no L1 transaction can modify them until the session closes.

3. Fee Deposits & Withdrawals — Users deposit SOL/tokens to fund ER execution. Fees are released to the sequencer upon successful settlement or returned upon cancellation.

4. State Finalization — Receives committed state from the Validator, updates delegated account data on L1, and transfers ownership back to the original program.

5. Dispute Interface — Accepts challenges, manages the bisection protocol, and enforces slashing.

Northstar Validator

Off-chain software that watches the Portal Program for events and manages ER lifecycle.

• Listens to SessionCreated events → provisions an ER instance

• Listens to AccountDelegated events → marks accounts as writable in the ER

• Bootstraps each ER with the current L1 state of all delegated accounts

• On session close: stashes execution results and submits state commits to the Portal

• Posts Checkpoint Bonds every ~30 seconds with state hashes for the dispute game

Ephemeral Rollup (L2)

A short-lived, dedicated SVM runtime instance. Each ER:

• Runs a full SVM execution environment (same instruction set as Solana L1)

• Has write access only to delegated accounts — non-delegated accounts are rejected

• Can read any L1 account in readonly mode — enables composability with L1 programs, oracles, token balances

• Processes transactions at >1M TPS with <50ms confirmation

• Terminates when the session closes — zero residual infrastructure

Router

A transparent, stateless transaction routing layer:

• If any referenced account is currently delegated → route to the corresponding Ephemeral Rollup

• If no referenced accounts are delegated → route to Solana L1 RPC

• Queries delegation status from the Portal Program — deterministic, no local state

Data Flows

North Star Data Flows

1. Provision — dApp calls createSession() via SDK → Portal opens session on L1, deposits execution fees

2. Delegate — dApp calls delegateAccount(pubkey) → Portal transfers account ownership, Validator marks writable on L2

3. Execute — User sends transactions → Router routes to ER → SVM executes at wire speed → confirmation in ~50ms

4. Checkpoint — Every ~30 seconds, Validator posts a Checkpoint Bond with state hash of all delegated accounts

5. Settle — Session closes → Validator stashes final state → Portal updates L1 accounts → ownership returns to original program

Read Path (L2 → L1)

ERs can read any Solana L1 account in readonly mode, enabling: oracle price feeds (Pyth, Switchboard), SPL token balance checks, and calls to L1 programs that only require readonly access. Read latency is bounded by L1 RPC round-trip (~50-100ms from a co-located validator).

The SDK

The North Star SDK is the primary developer interface. It abstracts sessions, delegation, routing, and settlement into a clean API:

import { NorthStar } from '@northstar/sdk';

// Initialize with standard Solana connection
const ns = new NorthStar({ connection, wallet });

// 1. Open a session (deposits fees, provisions ER)
const session = await ns.createSession({
  accounts: [orderbookState, userPosition],
  maxDuration: 3600,  // 1 hour max
  feeDeposit: 0.01,   // SOL
});

// 2. Send transactions (auto-routed to ER)
const sig = await session.sendTransaction(placeOrderIx);
// Confirmation in ~50ms

// 3. Close session (settles to L1)
await session.close();
// State is now on L1 with full finality

• Session management — create, extend, close sessions

• Automatic delegation — handles account ownership transfer to/from Portal

• Transaction routing — transparently routes to ER or L1 based on delegation status

• Wallet integration — compatible with Phantom, OKX, Backpack, and all wallet-standard adapters

• Fee estimation — calculates required deposits based on expected CU consumption