# NexusTrade Financial MCP [Health: Active]

**Category:** 💰 Finance & Fintech  
**Repository:** https://github.com/austin-starks/nexustrade-ts  
**GitHub Stars:** 6  
**Views:** 0  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/nexustrade-financial-mcp

## Description
Quant research, backtesting, walk-forward validation, managed compute, and trading workflows.

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "nexustrade-financial-mcp": {
    "command": "npx",
    "args": ["-y","mcp-remote@latest","https://nexustrade.io/api/mcp","--transport","http-only"]
  }
}
```

## Documentation & README

<div align="center">

<img src="https://nexustrade.io/logo192.jpeg" alt="NexusTrade" width="88" height="88">

# NexusTrade TypeScript SDK

**Author trading strategies in typed TypeScript. Backtest them on the engine that runs them live.**

[![npm](https://img.shields.io/npm/v/nexustrade.svg)](https://www.npmjs.com/package/nexustrade)
[![Node](https://img.shields.io/node/v/nexustrade.svg)](https://www.npmjs.com/package/nexustrade)
[![License](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
[![Deps](https://img.shields.io/badge/dependencies-0-brightgreen.svg)](package.json)

[Quickstart](#quickstart) · [Authoring](#authoring-strategies) · [Polling](#jobs-run-on-the-engine--you-poll) · [Agents](#agent-runs) · [Lake SQL](#lake-sql) · [Auth](#authentication) · [Errors](#errors)

</div>

---

```bash
npm install nexustrade
```

**Zero runtime dependencies.** ESM and CommonJS builds ship together, with types.

## MCP server

NexusTrade also exposes the platform as a hosted, remote Model Context Protocol
server. Modern MCP clients connect directly to the production Streamable HTTP
endpoint and discover NexusTrade OAuth automatically:

```bash
claude mcp add --transport http nexustrade https://nexustrade.io/api/mcp
```

Cursor and other remote-capable clients use:

```json
{
  "mcpServers": {
    "nexustrade": {
      "url": "https://nexustrade.io/api/mcp"
    }
  }
}
```

For Claude Desktop and other stdio-only clients, use the established
`mcp-remote` bridge—no clone or local NexusTrade server is required:

```json
{
  "mcpServers": {
    "nexustrade": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote@latest",
        "https://nexustrade.io/api/mcp",
        "--transport",
        "http-only"
      ]
    }
  }
}
```

The live server exposes more than 120 tools across market research, portfolio
construction, backtesting, optimization, walk-forward validation, managed
compute, Aurora agents, paper trading, and controlled brokerage operations.
Its creator-marketplace tools cover the full strategy adoption path:

- `search_creators` discovers public creators and their marketplace portfolios.
- `subscribe_portfolio` validates a monetized listing and returns a safe
  checkout preview; the user completes payment in NexusTrade, never through the
  MCP tool.
- `fork_shared_portfolio` creates a one-time editable copy of a marketplace
  strategy in a new or existing portfolio.
- `copy_trade_shared` continuously mirrors an accessible strategy into a paper
  or live portfolio at an explicit allocation.

See the [developer guide](https://nexustrade.io/developers), the
[utility tool reference](https://nexustrade.io/docs/api-reference/mcp-tools-utility),
and the [Aurora tool reference](https://nexustrade.io/docs/api-reference/mcp-tools-aurora).

Research and historical results are not investment advice and do not guarantee
future performance. Keep paper and live modes explicit. Tools that can affect
portfolios, schedules, or brokerage orders remain subject to the authenticated
account's NexusTrade permissions and approval controls.

## Quickstart

```ts
import {
  NexusTradeClient,
  always,
  backtest,
  buy,
  portfolio,
  stockAsset,
  strategy,
} from "nexustrade";

const client = new NexusTradeClient();

const book = portfolio("Example", [
  strategy("Buy SPY", always(), buy(stockAsset("SPY"), 100)),
]);

const operation = await client.createBacktest(
  backtest(book, { startDate: "2024-01-01", endDate: "2024-12-31" }),
  { idempotencyKey: "example-v1" }
);
const result = await client.waitForBacktest(operation.id as string);
console.log(result.result);
```

Backtest operations may include `warnings: string[]` immediately after
submission and again in the terminal `result`. Treat them as material caveats;
they do not change a successful operation into a failure.

### Collateral at risk

A terminal operation's `result.statistics` answers how much capital the run had
on the line, not only what it returned. Two fields carry it, typed as
`BacktestCollateralStatistics`:

| Field                       | Meaning                                                     |
| --------------------------- | ----------------------------------------------------------- |
| `peakReservedCollateral`    | Largest collateral locked at any tick, in account currency  |
| `medianReservedCollateral`  | Median across the ticks that held at least one position     |

Both are optional and may be `null`, and that absence is a real answer: a
backtest run before the engine reported collateral has no value, which is not
the same as a book that locked nothing. Display "not recorded" rather than `$0`
— a zero here reads as "this strategy risks nothing", the opposite of what an
unpopulated field means. Do not substitute the portfolio's value either: a book
risking a few thousand dollars would be reported as risking all of it.

Never reconstruct either number from `cash - buyingPower`. Buying power is
clamped at both ends and carries an open credit-spread premium term, so the
inversion breaks precisely on the heavily collateralised books this measures.

## Authoring strategies

Every builder is generated from the same indicator specification the NexusTrade
engine runs, so a book is **valid by construction** rather than by convention.

TypeScript cannot overload comparison operators, so indicators compose through
`gt` / `gte` / `lt` / `lte` / `eq` / `neq` and `and` / `or`:

```ts
import * as nt from "nexustrade";

const book = nt.portfolio(
  "Momentum",
  [
    nt.strategy(
      "Rotate into strength",
      nt.always(),
      nt.dynamicRebalance({
        universe: nt.universe("SP500"),
        pipeline: [
          nt.filter(nt.gt(nt.Price(nt.CANDIDATE), nt.SMA(nt.CANDIDATE, 200))),
          nt.selectTop(nt.RSI(nt.CANDIDATE, 14), 10),
        ],
        weightIndicator: nt.RSI(nt.CANDIDATE, 14),
        limit: 10,
        deploymentPercent: 80,
      })
    ),
  ],
  { initialValue: 100_000 }
);
```

Order execution belongs to the strategy. Omit it for the backward-compatible
Market default, use a fixed unit price for Buy/Sell, or set an option strategy's
maximum net debit / minimum net credit:

```ts
nt.strategy("Buy SPY at my price", nt.always(), nt.buy(nt.stockAsset("SPY"), 10), {
  orderExecution: nt.limitOrder({
    price: nt.unitPriceLimit(500),
    workingTime: nt.goodForDay(),
  }),
});

nt.strategy("Sell the spread for $1.50 or better", nt.always(), optionAction, {
  orderExecution: nt.limitOrder({
    price: nt.minimumNetCredit(1.5),
    workingTime: nt.goodForMinutes(30),
  }),
});
```

`currentLimit()` creates a quote-relative Limit for dynamic rebalance strategies.
It keeps the no-worse-than-current-quote protection, but it is not a resting
price target. Live option strategies must choose an explicit Limit policy.

<details>
<summary><b>What you can build</b> — 170+ generated builders</summary>

| Group               | Examples                                                                                     |
| ------------------- | -------------------------------------------------------------------------------------------- |
| **Price & volume**  | `Price` `OpeningPrice` `HighOfDay` `VWAP` `Volume` `GapPercentage`                           |
| **Technicals**      | `SMA` `EMA` `RSI` `BollingerBand` `AverageTrueRange` `CrossAbove`                            |
| **Position state**  | `PositionValue` `PositionPercentChange` `PositionMaxDrawdown`                                |
| **Portfolio state** | `PortfolioValue` `BuyingPower` `MaxDrawdown` `InitialValue`                                  |
| **Fundamentals**    | `Fundamental` `Economic` `DaysUntilEarnings` `IsIndexMember` `IsIndustry`                    |
| **Options**         | `OptionDaysToExpiration` `OptionCollateral` `OptionUnrealizedPnL` `openOption` `closeOption` |
| **Actions**         | `buy` `sell` `alert` `dynamicRebalance` `rebalanceOption`                                    |
| **Selection**       | `filter` `selectTop` `selectPercentile` `universe`                                           |
| **Logic**           | `always` `atLeast` `atMost` `exactly` `fewerThan` `multi` `and` `or` `sequence`              |
| **Anchored levels** | `IndicatorAtEntry` `LastOrderPrice` `IndicatorAtMinutesAfterOpen` `IndicatorWindowAgo`       |

Every builder is fully typed — your editor completes the whole surface.

</details>

## Jobs run on the engine — you poll

`create*` enqueues work and returns immediately. It does **not** resolve when
results exist. There are no webhooks today.

```mermaid
sequenceDiagram
    participant You
    participant SDK
    participant Engine

    You->>SDK: createBacktest(book)
    SDK->>Engine: POST (enqueue)
    Engine-->>SDK: id, status=queued
    SDK-->>You: operation (returns immediately)

    loop waitForBacktest — backoff 2s→15s
        SDK->>Engine: GET /operations/{id}
        Engine-->>SDK: status update
    end

    SDK-->>You: result (when completed)

    Note over You,Engine: Poll timeout throws operation_timeout.<br/>The job keeps running — call wait again with the same id.
```

Every job kind reports the same envelope, so one poller serves all of them:

```ts
{
  id: "op_...",
  kind: "backtest",          // backtest | optimization | walk_forward
  status: "queued",          // queued | running | completed | failed | cancelled
  result: {...},             // present only once terminal
  error: { code, message, retryable },
}
```

```ts
const finished = await client.waitForBacktest(operation.id as string);
```

| Option                   | Default | Meaning                                            |
| ------------------------ | ------- | -------------------------------------------------- |
| `timeoutSeconds`         | `900`   | Give up waiting (the job keeps running)            |
| `pollIntervalSeconds`    | `2`     | First interval; backs off 1.5×                     |
| `maxPollIntervalSeconds` | `15`    | Interval ceiling                                   |
| `throwOnFailure`         | `true`  | Throw on `failed`/`cancelled` instead of returning |

A timeout throws `operation_timeout` and does **not** cancel the job — call the
waiter again with the same id rather than resubmitting.

**Batches.** `createBacktests` submits many in one request and returns one
operation each; `waitForBacktests(operations)` waits on all of them. Prefer it
over a loop: one request, one idempotency key, one rate-limit slot.

**Optimization and walk-forward** follow the identical shape:

```ts
const study = await client.createWalkForward(
  nt.walkForward(book, {
    globalStartDate: "2022-01-01",
    globalEndDate: "2024-12-31",
    foldCount: 4,
  }),
  { idempotencyKey: "wf-v1" }
);
await client.waitForWalkForward(study.id as string);
```

## Deploying a portfolio

Authoring and backtesting a book does not persist it. `save` writes it to your
account; `deploy` starts running it.

```ts
const book = nt.portfolio("Momentum", [
  /* … */
]);

await book.save({ idempotencyKey: "momentum-v1" }); // persists; sets book.id
const deployment = await book.deploy(); // starts paper trading
await book.undeploy(); // stops it
```

**`save` and `deploy` produce different ids, and the distinction matters.**
`save` persists a _draft_ and sets `book.id` to it. `deploy` mints the real
paper portfolio and returns its own `portfolioId` — deploying creates a
portfolio rather than converting the draft into one, so the two ids coexist.
Hold on to `deployment.portfolioId` for anything that reads live state;
`book.id` addresses the draft.

```ts
deployment.portfolioId; // the running portfolio
deployment.deploymentType; // paper, unless you deployed an existing live one
deployment.outcome; // created | reactivated
```

Handle methods accept an optional `transport`; omitted, they resolve one from
the environment. The same operations exist on the client — `client.deploy(id)`,
`client.undeploy(id)` — when you have an id rather than a handle.

```ts
await client.listPortfolios({ includePaper: true, includePositions: true });
await client.getPortfolio(portfolioId);
```

### Editing a saved portfolio

`updatePortfolio` applies deterministic edits with no LLM in the path. The
`operations` array is a typed union, so the compiler knows which fields each
edit needs.

```ts
import type { PortfolioEditOperation } from "nexustrade";

const operations: PortfolioEditOperation[] = [
  { type: "rename", name: "AAPL Income" },
  {
    type: "replaceStrategy",
    targetStrategyId: strategyId, // or targetStrategyName
    strategyObject: nt.strategy(
      "Buy AAPL",
      nt.always(),
      nt.buy(nt.stockAsset("AAPL"), 25, "percent of portfolio"),
      {
        orderExecution: nt.limitOrder({
          price: nt.unitPriceLimit(150),
          workingTime: nt.goodForDay(),
        }),
      },
    ),
  },
];

await client.updatePortfolio(portfolioId, operations, {
  idempotencyKey: "aapl-limit-v1",
});
```

The five edits are `rename`, `addStrategies`, `removeStrategies`,
`replaceStrategy`, and `replaceStrategies`. Deploy, undeploy, delete,
scheduling, and trading-policy operations are not reachable on this route.

**`replaceStrategies` replaces the whole set**, so a strategy left out of the
array is deleted. Carry unchanged strategies through verbatim, including the
`orderExecution` each already has, or a working Limit silently reverts to
Market. `removeStrategies` takes strategy ids from a fetched portfolio; removal
by name is rejected.

Fetched portfolio handles include a typed, read-only `policy` snapshot. Trading
policy changes are intentionally unavailable through the SDK; edit them in
Portfolio Settings. `PortfolioHandle.toJSON()` omits the snapshot so a fetched
portfolio cannot accidentally submit policy changes through an authoring call.

`listPortfolios` filters with `includePaper`, `includeLive`, `includeInactive`,
`includeChatPortfolios`, `search`, `limit`, and `page`. `includePositions`
defaults off when `search` is set.

**A portfolio you create here is always paper**, and minting a _live_ one still
happens in the web app. Orders and brokerage status are reachable from here;
see [Live trading](#live-trading).

**But `deploy` can start live trading.** Given the id of a portfolio that is
already deployed, it reactivates that portfolio as whatever it already is — so
`client.deploy(id)` on a paused live portfolio resumes live trading against the connected
brokerage, and `includeLive: true` above will hand you such an id. Check `deployment.deploymentType` before
treating a deploy as simulated.

## Live trading

Live trading needs a brokerage linked to your account. Linking is an OAuth
redirect, so an API key cannot complete it — a human opens the URL.

```ts
await client.listBrokerages();
// [{ brokerage: "Alpaca", connected: false,
//    connectUrl: "https://nexustrade.io/live-trading" }, ...]

await client.connectBrokerage("Alpaca"); // logs the URL, waits until connected
```

`connectBrokerage` waits by default **only when stdout is a TTY**. In CI, cron,
or `run_compute` it rejects with `brokerage_not_connected` immediately, with the
URL in the message, rather than stalling for five minutes in front of nobody.
Pass `{ wait: true }` or `{ wait: false }` to force either.

A live-only listing that comes back empty rejects with the same error rather
than an empty array, since an empty array says nothing about why:

```ts
await client.listPortfolios({ includeLive: true, includePaper: false });
// NexusTradeApiError: brokerage_not_connected: No live portfolios, and no
// brokerage is connected. Connect one at https://nexustrade.io/live-trading
```

### Orders

```ts
const result = await client.createOrders(
  portfolioId,
  [
    {
      asset: { name: "SPY", type: "STOCK", symbol: "SPY" },
      side: "BUY",
      quantity: 10,
      orderType: "MARKET",
    },
  ],
  { idempotencyKey: "rebalance-2024-04-01" }
);

// Dollar notional (stock/crypto only — options require contract quantity):
await client.createOrders(
  portfolioId,
  [
    {
      asset: { name: "AAPL", type: "STOCK", symbol: "AAPL" },
      side: "BUY",
      amount: 500,
      orderType: "MARKET",
    },
  ],
  { idempotencyKey: "buy-aapl-500" }
);
```

**Paper orders are accepted immediately. Live orders are staged for approval
and are never sent to a broker by this call.**

```ts
if (result.requiresApproval) {
  console.log("nothing has traded yet — approve at", result.approvalUrl);
}
```

There is no argument, scope, or flag that submits a live order without
approval. The brokerage boundary refuses an unapproved live order regardless of
what any caller asks for, so this is a property of the system rather than a
promise made by this method. At most 50 orders per request.

## Your own data

A custom data source is a time series you own — sentiment counts, a proprietary
factor, anything the platform does not already carry. Create one, then reference
it from a strategy with `CustomIndicator`.

```ts
const series = await client.createCustomIndicator(
  {
    name: "WSB NVDA Mentions",
    scope: "asset",
    description: "Daily r/wallstreetbets mentions",
    pointKind: "observation",
    points: [
      { timestamp: "2024-04-01", value: 152, ticker: "NVDA" },
      { timestamp: "2024-04-02", value: 90, ticker: "NVDA" },
    ],
  },
  { idempotencyKey: "wsb-mentions-v1" }
);

const busy = nt.gt(
  nt.CustomIndicator(nt.stockAsset("NVDA"), String(series.customIndicatorId)),
  100
);
const book = nt.portfolio("Attention", [
  nt.strategy("Buy the buzz", busy, nt.buy(nt.stockAsset("NVDA"), 25)),
]);
```

`scope` is `"global"` (one series) or `"asset"` (one series per ticker, so every
point needs a `ticker`). It cannot be changed after creation.

Declare `pointKind` whenever the time semantics are known: `observation` for
point-in-time samples, `period_aggregate` plus `aggregatePeriod` (`1d`, `1w`,
`1mo`, or `1q`) for closed-period values, and `disclosed` for values with an
explicit publication time on every row. The SDK applies this contract before
both inline and large-upload writes. A same-day date-only observation becomes
an explicit same-day UTC instant instead of shifting to the next calendar day.

**Size is not a constraint.** `points` is unlimited. A batch that fits the
request goes with it; a larger one is uploaded to storage and validated before
the call resolves. Either way the returned indicator reflects what actually
landed, and an upload that fails validation rejects rather than reporting
success.

**Growing a series.** Append to the same id every run:

```ts
await client.appendCustomIndicatorPoints(
  String(series.customIndicatorId),
  [{ timestamp: "2024-04-03", value: 118, ticker: "NVDA" }],
  { idempotencyKey: "wsb-mentions-2024-04-03" }
);
```

Creating a fresh series per run splits the history into fragments no strategy
can read. Re-sending an identical batch is safe — the duplicate is not written
twice.

| Call                                                          | Purpose                   |
| ------------------------------------------------------------- | ------------------------- |
| `createCustomIndicator(spec, { idempotencyKey })`             | Create, optionally seeded |
| `appendCustomIndicatorPoints(id, points, { idempotencyKey })` | Add points                |
| `replaceCustomIndicatorPoints(id, points, { idempotencyKey })` | Replace points, retain id |
| `archiveCustomIndicator(id)` / `restoreCustomIndicator(id)`   | Reversible lifecycle      |
| `listCustomIndicators()` / `getCustomIndicator(id)`           | Discover ids and coverage |

Points accept `timestamp`, `value`, `ticker`, `assetType`, and `availableAt`
— camelCase or snake_case, with `Date` objects allowed. Set `availableAt` when a
value became knowable later than it is dated: an earnings figure stamped to
quarter-end but published weeks after. An unrecognized field throws rather than
being silently dropped.

To hand over a file you already have on disk, `createCustomIndicatorUpload` /
`completeCustomIndicatorUpload` / `waitForCustomIndicatorUpload` expose the
three steps directly. CSV, JSON, and JSONL up to 100 MB.

## Agent runs

Every other job is fire-and-poll. **Agents are not** — three states
(`pending_plan_approval`, `pending_action_approval`, `awaiting_user_input`)
cannot advance without you. Iterate the run and answer when it blocks:

```mermaid
sequenceDiagram
    participant You
    participant Run as AgentRun
    participant Engine

    You->>Run: createAgent(prompt)
    Run->>Engine: POST /agents
    Engine-->>Run: run id

    loop for await (const event of run)
        Run->>Engine: GET events (cursor)
        Engine-->>Run: new events

        alt event.needsApproval
            Run-->>You: plan or action awaiting approval
            You->>Run: approve() or reject()
            Run->>Engine: POST approval
        else event.needsInput
            Run-->>You: awaiting user input
            You->>Run: say("...")
            Run->>Engine: POST message
        else
            Run-->>You: event.text
        end
    end

    Run-->>You: terminal

    Note over You,Engine: Without approve/say, the run stalls and bills.<br/>Reattach later with attachAgent(run.id).
```

```ts
const run = await client.createAgent("Find momentum names in the S&P 500", {
  idempotencyKey: "momentum-scan-v1",
  costCeilingUsd: 20,
});
for await (const event of run) {
  console.log(event.text);
  if (event.needsApproval) await run.approve();
  if (event.needsInput) await run.say("Focus on tech");
}
```

## Lake SQL

Read-only SQL over the NexusTrade market-data lake, against the server-resolved
`lake.*` catalog. Results are durable Parquet parts rather than an implicitly
materialized in-memory array.

```mermaid
flowchart LR
    A[createLakeQuery] --> B[waitForLakeQuery]
    B --> C[getLakeQueryManifest]
    C --> D[downloadLakeQueryPart]
    D --> E[Stream Parquet within your memory budget]
```

```ts
const query = await client.createLakeQuery(
  {
    query:
      "SELECT ticker, date, closingPrice FROM lake.daily_ohlc WHERE ticker = ?",
    params: ["AAPL"],
    limits: { maxRows: 10_000 },
  },
  { idempotencyKey: "aapl-daily-v1" }
);
const finished = await client.waitForLakeQuery(query.id as string);
const manifest = await client.getLakeQueryManifest(finished.id as string);
```

## Natural language

Describe the screen instead of writing the SQL. The server generates it,
validates it against the same `lake.*` catalog the engine reads, executes it,
and hands back both the rows and the statement.

```ts
const screen = await client.createNlScreen(
  "technology stocks with a market cap over 100 billion and a PE under 30"
);
const done = await client.waitForNlScreen(screen.id as string);

const result = done.result as Record<string, unknown>;
console.log(result.rows);
console.log(result.sql); // always check the SQL — it is model-generated
```

`returnQuery` defaults to `true` because the SQL is the audit trail: without it
the rows are a number you cannot re-derive. It is returned on failure whatever
you pass, since a rejected query is the most useful thing to read.

Branch on `result.outcome`, not on status alone:

| `outcome`           | Meaning                                                   |
| ------------------- | --------------------------------------------------------- |
| `ROWS`              | Matches found                                              |
| `EMPTY`             | Every filter ran and nothing cleared them all — an answer  |
| `CLARIFICATION`     | The question was ambiguous; `result.clarification` asks    |
| `GENERATION_FAILED` | The retry budget was spent — the only case worth retrying  |

This method spends LLM credits. The structured `lake` API below does not.

Use the manifest plus `downloadLakeQueryPart` to stream results within your own
memory budget. NexusTrade picks a compatible backing engine for the referenced
tables; your SQL does not change when it does.

> The Python SDK additionally ships `nt.lake.sql(...)`, a DuckDB/pandas
> convenience layer over these same endpoints.

## Complete method reference

Every public method on `NexusTradeClient`. A test in this package fails if one
is missing here, so this list cannot drift from the code.

**Live trading and orders**

| Method                                                  | Purpose                                              |
| ------------------------------------------------------- | ---------------------------------------------------- |
| `listBrokerages()`                                      | Every connectable brokerage and whether it is linked |
| `getBrokerage(brokerage)`                               | Whether one brokerage is linked                      |
| `connectBrokerage(brokerage, { wait })`                 | Log the connect URL and wait for the link            |
| `createOrders(portfolioId, orders, { idempotencyKey })` | Stage orders; live ones need approval                |

**Portfolios**

| Method                                      | Purpose                                      |
| ------------------------------------------- | -------------------------------------------- |
| `createPortfolio(book, { idempotencyKey })` | Persist a portfolio definition               |
| `listPortfolios(options)`                   | List portfolios, with filters and pagination |
| `getPortfolio(portfolioId)`                 | Read one portfolio                           |
| `updatePortfolio(id, operations, { idempotencyKey })` | Rename or edit strategies deterministically |
| `forkPublicPortfolio(sharedId, { idempotencyKey })` | Fork a public portfolio into the workspace |
| `deploy(portfolioId, { frequency })`        | Start paper trading it                       |
| `undeploy(portfolioId)`                     | Stop it                                      |

**Backtests**

| Method                                         | Purpose                    |
| ---------------------------------------------- | -------------------------- |
| `createBacktest(handle, { idempotencyKey })`   | Submit one backtest        |
| `createBacktests(handles, { idempotencyKey })` | Submit many in one request |
| `getBacktest(backtestId)`                      | Read the operation         |
| `waitForBacktest(backtestId, options)`         | Block until terminal       |
| `waitForBacktests(operations, options)`        | Block on a whole batch     |

**Optimization and walk-forward**

| Method                                           | Purpose                     |
| ------------------------------------------------ | --------------------------- |
| `createOptimization(handle, { idempotencyKey })` | Submit an optimization      |
| `getOptimization(optimizationId)`                | Read the operation          |
| `waitForOptimization(optimizationId, options)`   | Block until terminal        |
| `createSystematicSweep(handle, { idempotencyKey })` | Submit an explicit-gene sweep |
| `getSystematicSweep(optimizationId)`             | Read the sweep operation      |
| `waitForSystematicSweep(optimizationId, options)` | Block until terminal         |
| `createWalkForward(handle, { idempotencyKey })`  | Submit a walk-forward study |
| `getWalkForward(studyId)`                        | Read the operation          |
| `waitForWalkForward(studyId, options)`           | Block until terminal        |

**Custom data sources**

| Method                                                                      | Purpose                                            |
| --------------------------------------------------------------------------- | -------------------------------------------------- |
| `createCustomIndicator(spec, { idempotencyKey })`                           | Create a series, optionally seeded                 |
| `listCustomIndicators(options)`                                             | List owned series                                  |
| `getCustomIndicator(id)`                                                    | Read one, with its point count and range           |
| `appendCustomIndicatorPoints(id, points, { idempotencyKey })`               | Add points                                         |
| `replaceCustomIndicatorPoints(id, points, { idempotencyKey, allowShrink })` | Replace the complete series while retaining its id |
| `archiveCustomIndicator(id, { confirm })`                                   | Soft-archive a series                              |
| `restoreCustomIndicator(id)`                                                | Restore an archived series                         |
| `createCustomIndicatorUpload(id, options)`                                  | Open an upload slot (CSV/JSON/JSONL)               |
| `completeCustomIndicatorUpload(id, jobId)`                                  | Start validating uploaded bytes                    |
| `getCustomIndicatorUpload(id, jobId)`                                       | Read the upload operation                          |
| `waitForCustomIndicatorUpload(id, jobId, options)`                          | Block until validated                              |

**Agent runs**

| Method                                    | Purpose                             |
| ----------------------------------------- | ----------------------------------- |
| `createAgent(prompt, { idempotencyKey })` | Start a run                         |
| `getAgent(agentId)`                       | Read its status                     |
| `attachAgent(agentId, { cursor })`        | Reattach to a run already in flight |

**Lake SQL**

| Method                                          | Purpose                              |
| ----------------------------------------------- | ------------------------------------ |
| `createLakeQuery(request, { idempotencyKey })`  | Submit read-only SQL                 |
| `getLakeQuery(queryId)`                         | Read the operation                   |
| `waitForLakeQuery(queryId, options)`            | Block until terminal                 |
| `cancelLakeQuery(queryId)`                      | Cancel an owned query                |
| `createLakeAsk(question)`                       | Ask the lake in plain language       |
| `getLakeAsk(askId)`                             | Read the operation                   |
| `waitForLakeAsk(askId, options)`                | Block until terminal                 |
| `cancelLakeAsk(askId)`                          | Cancel an owned ask                  |
| `getLakeQueryManifest(queryId)`                 | Schema, checksums, and part metadata |
| `downloadLakeQueryPart(queryId, part, options)` | Download one Parquet part            |
| `getLakeCatalog()`                              | List queryable tables                |
| `describeLakeTable(table)`                      | Columns and types for one table      |

**Natural language**

| Method                                      | Purpose                                     |
| ------------------------------------------- | ------------------------------------------- |
| `createNlScreen(question, { returnQuery })` | Screen stocks from a plain-language question |
| `getNlScreen(screenId)`                     | Read the operation                          |
| `waitForNlScreen(screenId, options)`        | Block until terminal                        |
| `cancelNlScreen(screenId)`                  | Cancel an owned screen                      |

**Client construction**

| Method                                      | Purpose                                  |
| ------------------------------------------- | ---------------------------------------- |
| `new NexusTradeClient({ apiKey, baseUrl })` | Explicit credentials                     |
| `new NexusTradeClient()`                    | Lazy anonymous workspace with strict limits |
| `NexusTradeClient.fromEnvironment()`        | Read them from the environment or `.env` |
| `exportWorkspaceSession()`                  | Export an anonymous workspace for later use |
| `importWorkspaceSession(token)`             | Resume an existing anonymous workspace      |

**PortfolioHandle** — returned by the `portfolio(...)` builder and by
`getPortfolio` / `listPortfolios`.

| Method                                             | Purpose                                |
| -------------------------------------------------- | -------------------------------------- |
| `save({ idempotencyKey })`                         | Persist it as a draft, setting `.id`   |
| `backtest({ startDate, endDate, idempotencyKey })` | Backtest it, preferring the saved id   |
| `deploy({ frequency })`                            | Mint the real paper portfolio (new id) |
| `undeploy()`                                       | Deactivate its deployment              |

## Authentication

An API key is optional. With no key, the first API operation lazily creates a
real unregistered NexusTrade workspace and applies stricter request, backtest,
and AI limits. Anonymous workspaces can create, edit, and fork portfolios,
launch backtests, and use the programmatic agent/chat surface. Every optimization
operation—including genetic and systematic sweep launches, result reads,
reruns, promotion, and out-of-sample workflows—requires a registered API key.
Export the workspace's opaque token if the work must survive a new process:

```ts
const guest = new NexusTradeClient();
await guest.listPortfolios();
const token = guest.exportWorkspaceSession();

const resumed = new NexusTradeClient({ workspaceSession: token });
```

An expired explicit workspace token raises
`NexusTradeWorkspaceSessionExpiredError`; the SDK never creates a replacement
workspace that would make saved work appear deleted.

Registered users can create a key at
**[nexustrade.io/developers](https://nexustrade.io/developers)** (Profile → API
Keys). Keys start with `sk-` and are shown once. When both credentials are
provided, registered `Authorization` takes precedence and the workspace header
is not sent.

```ts
const client = new NexusTradeClient({
  apiKey: "sk-...",
  baseUrl: "https://nexustrade.io/api/v1",
});
// or set NEXUSTRADE_API_KEY / NEXUSTRADE_API_BASE_URL and:
const fromEnv = new NexusTradeClient();
```

Both variables are also read from a **`.env` file** at or above the current
directory, so a local project works with no exports, no `dotenv` dependency, and
no `--env-file` flag:

```bash
# .env
NEXUSTRADE_API_KEY=sk-...
NEXUSTRADE_API_BASE_URL=https://nexustrade.io/api/v1
```

The real environment always wins — a `.env` value is used only when the variable
is absent, so a stale file can never override what you exported. Nothing is
written back to `process.env`. Opt out with `NEXUSTRADE_DISABLE_DOTENV=1`.

| Scope   | Grants                                                                            |
| ------- | --------------------------------------------------------------------------------- |
| `read`  | Portfolio, backtest, genetic, sweep, and walk-forward reads                       |
| `write` | Portfolio create/edit/fork, backtests, genetic/sweep, and walk-forward launches   |
| `lake`  | Lake catalog, query lifecycle, manifests, result parts                            |

A key missing the scope gets `403 insufficient_scope`.

> **OAuth is not accepted here.** NexusTrade's OAuth flow serves the MCP server.
> These endpoints take `sk-` API keys only; a bearer JWT is rejected with
> `401 invalid_token`.

**Transport hardening.** HTTPS is required (except loopback). The client refuses
cross-origin redirects, so the credential cannot be replayed to another host, and
refuses to follow a redirect on any non-GET request, so a redirect can never
re-submit a paid job. The key is held in a `#private` field and never appears in
a stringified client.

## Idempotency

Every mutation takes a key. Reusing the same key with the same request returns
the original resource instead of launching a second paid job — so a retry after
a network failure is free.

```ts
await client.createBacktest(handle, { idempotencyKey: "momentum-2024-v1" });
```

## Errors

```ts
import { NexusTradeApiError } from "nexustrade";

try {
  await client.createBacktest(handle, { idempotencyKey: "run-1" });
} catch (error) {
  if (
    error instanceof NexusTradeApiError &&
    error.code === "rate_limit_exceeded"
  ) {
    // back off
  }
  throw error;
}
```

| Status | Code                                   | Meaning                                                      |
| ------ | -------------------------------------- | ------------------------------------------------------------ |
| 401    | `invalid_token`                        | Missing, malformed, or expired key (or an OAuth JWT)         |
| 403    | `insufficient_scope`                   | Key lacks `read`, `write`, or `lake`                         |
| 400    | `invalid_request`, `invalid_portfolio` | Malformed input                                              |
| 400    | `invalid_idempotency_key`              | Must match `[A-Za-z0-9._:-]{1,160}`                          |
| 409    | `idempotency_conflict`                 | Key reused with a different payload                          |
| 409    | `idempotency_in_progress`              | Same key, first call still running. Re-poll, do not resubmit |
| 404    | `not_found`, `operation_not_found`     | Unknown or not yours                                         |
| 429    | `rate_limit_exceeded`                  | Back off and retry                                           |

`status` is `0` when no HTTP status describes the failure: `transport_error`
(never reached the API), `unsafe_redirect`, or an `invalid_response` envelope
check on an otherwise-successful reply.

## Timeouts

`new HttpTransport({ timeoutSeconds })` (default 30) is a total wall-clock
deadline for one request. Neither it nor the poll timeout bounds how long a
_job_ takes.

## Scope

Portfolio drafting, backtesting, optimization, walk-forward studies, and
read-only SQL over the market-data lake, versioned under `/api/v1/nexustrade`.
The full surface requires a registered API key; anonymous workspaces are limited
to portfolio authoring/forking, backtests, and programmatic agent/chat calls.
The screener and creating a live deployment remain outside this surface.
Orders are reachable, but a live order is only ever staged for human approval —
never submitted. `deploy` and `undeploy` act on whatever an existing id already
is, live included.

## Requirements

Node 18+ (uses the global `fetch`). Contributing: the test suite runs TypeScript
directly via `node --test`, which needs Node 22.6+ for type stripping. The
published `dist/` is plain JavaScript and has no such requirement.

## Using this SDK with a coding agent

See **[AGENTS.md](https://github.com/austin-starks/nexustrade-ts/blob/HEAD/AGENTS.md)** — the conventions, invariants, and recipes an
agent needs to write correct NexusTrade strategies on the first pass.

## License

MIT