How to Connect Cline to NinjaTrader 8 with CrossTrade MCP

Cline is an open-source AI coding assistant for VS Code with MCP support. The UI flow (Cline panel → MCP Servers → Remote Servers tab) is easier than the JSON file for first-time setup. Note that Cline uses streamableHttp (camelCase) as the type value — different from Roo Code and Continue which use streamable-http kebab-case.

OAuth scope: mcp:tradeMulti-model harness

Prerequisites

Requirement	Detail
CrossTrade subscription	Elite
CrossTrade Add-On	v1.13.0 or higher
NinjaTrader 8	Running, broker connected
Account	Sim101 for first runs
OAuth scope	`mcp:trade`
Config file	`Cline panel → MCP Servers → Remote Servers tab (or cline_mcp_settings.json in VS Code globalStorage)`

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.

Step 1 (recommended): Add CrossTrade through the Cline UI

Open VS Code.
Open the Cline panel.
Click the MCP Servers icon.
Switch to the Remote Servers tab.
Click Add Server.
Fill in:
- Server Name: crosstrade
- Server URL: https://app.crosstrade.io/v1/api/mcp
- Transport Type: Streamable HTTP (SSE is marked Legacy)
Save.

On first tool call, Cline displays an OAuth2 URL. Click to open in browser. Approve mcp:trade. Re-authorization is automatic after the initial setup.

Step 1 (alternative): Edit cline_mcp_settings.json

If you prefer the JSON file (for sync across machines):

{
  "mcpServers": {
    "crosstrade": {
      "type": "streamableHttp",
      "url": "https://app.crosstrade.io/v1/api/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN"
      },
      "disabled": false,
      "autoApprove": []
    }
  }
}

File location (VS Code globalStorage):

macOS: ~/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
Linux: ~/.config/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
Windows: %APPDATA%\Code\User\globalStorage\saoudrizwan.claude-dev\settings\cline_mcp_settings.json

Casing matters

Cline expects "type": "streamableHttp" in camelCase. Continue and Roo Code use "streamable-http" in kebab-case. Copy-pasting between them silently fails.

Step 2: First read-only workflow

Pull the last 20 closed trades on Sim101. Group by instrument and side. Report
win rate, average win, average loss, and the three biggest losers.

Step 3: NinjaScript compile loop (mcp:trade)

If you reauthorize at mcp:trade, Cline can run the full compile loop:

GetNinjaScriptHelp on every NT8 type and method you plan to use.
Draft the source.
CompileNinjaScript(in_memory: true).
On failure, LookupNinjaScriptSymbol and repair.
WriteNinjaScriptFile after confirmation.
RunStrategyBacktest on Sim101 with realistic commission and slippage.

See Vibe Code a NinjaScript Strategy for the full sequence.

Model choice

Cline routes to whatever LLM you've configured in its settings. For NinjaScript work, Claude and GPT both produce strong code; DeepSeek is a cheaper option for iteration-heavy work. See the model rail below.

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 add-on (v1.13.0+) is installed
type: "streamable-http" rejected	Wrong transport-key casing	Cline uses type: "streamableHttp" (camelCase). Roo Code and Continue use the kebab-case form; do not copy between them
Re-auth fails with "missing stored state"	Known bug after token expiry (GitHub issue #7964)	Remove the server entry and re-add it; OAuth flow restarts cleanly

Prerequisites

Step 1 (recommended): Add CrossTrade through the Cline UI​

Step 1 (alternative): Edit cline_mcp_settings.json​

Step 2: First read-only workflow​

Step 3: NinjaScript compile loop (mcp:trade)​

Model choice​