This week on Nexus 07.06.26

This edition covers new market-data streams, more detail in the account and position APIs, finer control over isolated margin, and a broad pass on the correctness and durability of the parts of the Exchange that handle your money — margin, liquidations, price feeds, and settlement.

Trading

• Isolated margin controls. You can now add and remove margin on an isolated position directly through the API. Each market also enforces a minimum isolated-margin floor, so a position cannot be left under-collateralized by a withdrawal.
• Per-market open-interest limits. Every market now tracks open interest and enforces a ceiling on it, keeping any single market within its risk budget.

Account history and market data

• Public market-data streams. Real-time order book, trades, and candlestick (OHLC) data now stream over public WebSocket channels — no account required to consume them.
• Position P&L breakdown. A new endpoint returns per-position profit-and-loss decomposed into its components, so you can see exactly where a position’s gains and losses come from.
• Per-market risk parameters. You can now read the risk parameters for each market directly from the API.
• Friendlier account routes. Account-scoped routes accept self as an alias for the calling account, and the /account response now echoes the resolved owner.
• Clearer errors. Order error responses now carry a stable, machine-readable code alongside the human-readable message, so clients can branch on failures reliably.
• Tiered subscription limits. WebSocket connections are now bounded by subscription count per tier, keeping streams responsive under load.

Price feeds

• Fail closed on stale prices. If a price feed’s value freezes, the Exchange now stops trusting that feed rather than acting on a stale number.
• Feed-quality evaluation. We added tooling to run candidate price-feed sources side by side against production, so feed changes are measured before they go live.

Command line and installers

• Signed CLI installs. The Nexus CLI now ships a signed install path: the published binary is verified with minisign against the release key before it runs, so a tampered download is rejected rather than executed.
• Renamed compute CLI. The compute CLI is now published as nexus-compute-cli and served from the /compute install route, so the install script pulls the renamed tool by default.

Safety and reliability

• Margin and liquidation correctness. Cross-margin collateral is now consumed exactly once across markets, liquidations on isolated positions are scoped to that position’s own margin, and insurance-fund draws and auto-deleveraging now behave deterministically when a fund is depleted.
• Durable settlement. The matching and risk engines now write to a write-ahead log with crash recovery, deposits are processed idempotently, and a reconciliation loop continuously checks that vault and Exchange balances agree.
• Fail closed under lag. Risk checks now fail closed if the fill stream falls behind, rather than continuing on incomplete data.
• Access protection. Pre-authentication rate limiting protects public routes, and internal administrative routes fail closed if their auth is not configured.

Behind the scenes

Most of this window went into the machinery that keeps the above honest and fast — none of it changes how the Exchange looks, but it is why the numbers you see are trustworthy.

• Expanded automated coverage across order types, account and position lifecycles, and market-making flows, plus stabilized stress and end-to-end suites.
• New instrumentation and dashboards for matching-engine latency, order-book depth, settlement, and funding, with benchmark regression gates to catch performance drift before it ships.
• Health probes, typed halt reasons, and metrics ingestion wiring to make operations more observable and recovery more predictable.