How to Connect Cursor to NinjaTrader 8 with CrossTrade MCP

Cursor is a popular AI-coding IDE that supports MCP. With CrossTrade MCP registered, Cursor can draft NinjaScript that compiles against your real NT8 install, run Strategy Analyzer backtests, and keep a strategy in Sim101 until you decide otherwise. Native browser OAuth flow.

OAuth scope: mcp:tradeMulti-model harness

Prerequisites

Requirement	Detail
CrossTrade subscription	Elite
CrossTrade NT8 Add-On	v1.13.0 or higher
NinjaTrader 8	Running, broker connected
Account	Sim101 for first runs
OAuth scope	`mcp:trade`
Config file	`.cursor/mcp.json (project) or ~/.cursor/mcp.json (global)`

CrossTrade MCP server

https://app.crosstrade.io/v1/api/mcp

Transport: streamable-http. Auth: OAuth 2.1 + PKCE. Request scope mcp:trade. Read plus write. Place/cancel orders, deploy strategies, compile NinjaScript.

Why Cursor plus CrossTrade MCP is useful for vibe coding NinjaScript

The connection path from Cursor to a NinjaTrader 8 account. The client speaks the Model Context Protocol to the CrossTrade MCP server, which is hosted rather than local. Authorisation happens once over OAuth and issues a scoped token. From there the server calls through to the CrossTrade NT8 Add-On inside your running NinjaTrader, and results travel back the same way as plain language. — Four hops, authorised once. Read-only is the scope to start with.

Cursor's strength is editor context: it sees your project files and can refactor across them. CrossTrade MCP adds the part Cursor cannot do on its own: it lets the agent look at your actual NT8 install, compile NinjaScript against it, and drive Strategy Analyzer. The pair turns vibe coding into a verified compile-backtest loop.

Step 1: Add the MCP server

Easiest: create .cursor/mcp.json in your workspace (or ~/.cursor/mcp.json for global):

{
  "mcpServers": {
    "crosstrade": {
      "url": "https://app.crosstrade.io/v1/api/mcp"
    }
  }
}

For environment-variable interpolated headers:

{
  "mcpServers": {
    "crosstrade": {
      "url": "https://app.crosstrade.io/v1/api/mcp",
      "headers": {
        "Authorization": "Bearer ${env:CROSSTRADE_TOKEN}"
      }
    }
  }
}

Cursor infers HTTP transport from url. Variable interpolation: ${env:NAME}, ${userHome}, ${workspaceFolder}.

Step 2: Complete OAuth

Reload the MCP servers list (Settings → Features → MCP, or open the chat panel which auto-discovers). On the next tool call, Cursor opens a browser tab. Approve mcp:trade. The token caches locally.

Cursor's OAuth callback URL is cursor://anysphere.cursor-mcp/oauth/callback. You do not configure this yourself. CrossTrade's OAuth server accepts Cursor's fixed callback during dynamic client registration, so the bare url config above is all you need.

Step 3: Confirm tools are available

List the CrossTrade MCP tools you can call. Then GetMcpCapabilities and
McpSelfTest. Report the add-on version, NT8 version, and feature flags.

Step 4: Create a workspace for strategy drafts

mkdir -p ~/crosstrade-strategies/SampleEmaCross
cd ~/crosstrade-strategies/SampleEmaCross

Open the folder in Cursor. The advantage of using Cursor over a chat-only setup is that drafts and notes live alongside the code.

Step 5: Ask Cursor to inspect NinjaScript symbols before writing code

For an MES 5-minute EMA crossover strategy with an ATR-based trailing stop,
call GetNinjaScriptHelp on EMA, ATR, CrossAbove, and SetTrailStop. Restate the
chosen overloads. Do not draft yet.

Step 6: Generate a strategy

Draft SampleEmaCross.cs into this workspace. Long when 9-EMA crosses above
21-EMA. ATR-based trailing stop, multiplier 2.0. One contract. Max two trades
per session. Time filter 09:30 to 11:00 ET. Account Sim101. Do not compile yet.

Step 7: Compile through CrossTrade MCP

CompileNinjaScript(in_memory: true) using the source in SampleEmaCross.cs.
If compile fails, for each error LookupNinjaScriptSymbol on the unresolved
identifier and rewrite the offending line. Recompile until green. Do not call
WriteNinjaScriptFile yet; we will do that explicitly.

Step 8: Backtest and iterate

WriteNinjaScriptFile to Strategies/SampleEmaCross.cs. Then RunStrategyBacktest
on Sim101, last 30 trading days, 5-minute bars, commission $1.27 per round-trip,
slippage 1 tick. Show the metrics block.

Apply your gates: minimum profit factor, max drawdown cap, minimum trade count. If the gates fail, iterate the prompt.

FAQ

Is Cursor required?

No. Claude Desktop, Claude Code, or any MCP client works. Cursor is well-suited to multi-file workspaces.

Does this need `mcp:trade`?

Yes. Compile, write, and backtest are write-capable tools that require mcp:trade.

What if I need a static Bearer token instead of OAuth?

Put it in headers.Authorization (mint a token at My Account, AI Clients tab). Do not use the auth object for a bearer token. That object is for OAuth client credentials (CLIENT_ID, CLIENT_SECRET, scopes), not a static token.

OAuth handshake

The first tool call surfaces an authorization URL. Open it in a browser, approve mcp:trade, and return to the harness. The access token is stored by the harness (keychain, config file, or memory depending on the client).

See CrossTrade MCP OAuth for the full flow, and 403/408 troubleshooting if the handshake fails.

Verify the connection

Smoke-test before doing anything stateful:

Call GetMcpCapabilities and McpSelfTest. Then ListAccounts and GetConnections.
Report add-on version, NT8 version, and which accounts are linked.

If you authorized mcp:trade, also confirm Sim101 is the default account before any order placement.

Funded-account safety

The mcp:trade scope grants order placement. The scope does not protect a funded account; your prompt and account selection do. Default to Sim101 during setup. For funded accounts, verify the firm's automation policy first.

Troubleshooting

Symptom	Likely cause	Fix
403 insufficient_scope	Token authorized at mcp:read but tool requires mcp:trade	Reauthorize the connection and select mcp:trade
OAuth callback fails	System browser blocked the redirect or popup	Copy the auth URL manually, complete it, paste the code back
Tools list is empty after connect	Server registered but session did not refresh	Restart the harness or trigger a tool list refresh
Add-on offline error	NT8 not running, or add-on not loaded	Confirm NT8 is open and the CrossTrade NT8 add-on (v1.13.0+) is installed
Compile keeps failing the same way	Agent not calling LookupNinjaScriptSymbol	Force a fresh lookup before each retry
OAuth callback fails with redirect mismatch	auth or redirectUri fields added to mcp.json	Cursor uses a fixed callback (cursor://anysphere.cursor-mcp/oauth/callback) you cannot change, and CrossTrade accepts it automatically. Leave auth, redirectUri, and transport out of mcp.json; only url is needed.
Transport falls back to SSE and fails	Cursor's auto-fallback from Streamable HTTP to SSE has known bugs	Stick with the streamable HTTP endpoint; CrossTrade exposes Streamable HTTP natively

Prerequisites

Why Cursor plus CrossTrade MCP is useful for vibe coding NinjaScript​

Step 1: Add the MCP server​

Step 2: Complete OAuth​

Step 3: Confirm tools are available​

Step 4: Create a workspace for strategy drafts​

Step 5: Ask Cursor to inspect NinjaScript symbols before writing code​

Step 6: Generate a strategy​

Step 7: Compile through CrossTrade MCP​

Step 8: Backtest and iterate​

FAQ​

Is Cursor required?​

Does this need mcp:trade?​

What if I need a static Bearer token instead of OAuth?​