How to Connect OpenCode to NinjaTrader 8 with CrossTrade MCP

OpenCode is an open-source AI coding agent for the terminal, IDE, and desktop. It routes to 75+ providers via Models.dev. The MCP config uses type: 'remote' (NOT 'http' or 'streamable-http') and supports native OAuth with Dynamic Client Registration.

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`
Install command	`curl -fsSL https://opencode.ai/install \| bash`
Config file	`~/.config/opencode/opencode.json (global) or opencode.json (project root)`

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 OpenCode for NinjaTrader work

OpenCode decouples the harness from the model. You configure CrossTrade MCP once, then swap between Claude (strong NinjaScript), GPT (good tool calling), Gemini (long context for journal review), or DeepSeek (cheap iteration) without re-authenticating. For traders this matters: NinjaScript drafts benefit from Claude or GPT, while overnight journal reviews and backtest sweeps can run on a cheaper model.

Step 1: Install OpenCode

curl -fsSL https://opencode.ai/install | bash
# Or:
npm i -g opencode-ai@latest
brew install opencode
choco install opencode      # Windows

Verify with opencode --version. The CLI launches the agent in your terminal; the desktop and IDE entry points use the same config.

Step 2: Add the CrossTrade MCP server

Edit ~/.config/opencode/opencode.json (global) or opencode.json (project root, found upward from cwd to the nearest git root):

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "crosstrade": {
      "type": "remote",
      "url": "https://app.crosstrade.io/v1/api/mcp",
      "enabled": true
    }
  }
}

With OAuth client credentials (if CrossTrade's MCP requires pre-registered OAuth):

{
  "mcp": {
    "crosstrade": {
      "type": "remote",
      "url": "https://app.crosstrade.io/v1/api/mcp",
      "enabled": true,
      "oauth": {
        "scope": "mcp:trade"
      }
    }
  }
}

With a static bearer token:

{
  "mcp": {
    "crosstrade": {
      "type": "remote",
      "url": "https://app.crosstrade.io/v1/api/mcp",
      "enabled": true,
      "headers": {
        "Authorization": "Bearer {env:CROSSTRADE_API_KEY}"
      }
    }
  }
}

OpenCode uses type: "remote"

Most other tools use "http" or "streamable-http". OpenCode uses "remote". The counterpart is "local" (for stdio servers). Pick from those two only.

Restart OpenCode. On the first tool call, OAuth runs in your browser. Approve mcp:trade.

Step 3: Pick the model for the run

OpenCode lets you switch models mid-session with /model. For initial NinjaScript work, Claude or GPT-4.1 both work well. For cost-sensitive backtest sweeps or large journal reviews, DeepSeek V3 is solid. See the model rail below for guidance.

Step 4: First workflow

Use read-only tools only. Confirm CrossTrade MCP is connected. Call ListAccounts,
GetConnections, ListPositions, ListOrders. Report add-on version, NT8 version,
and a one-line status for each account.

If you authorized mcp:trade, also run a Sim101 NinjaScript compile loop. See Vibe Code a NinjaScript Strategy.

Multi-model patterns

A typical OpenCode workflow:

Inspect with DeepSeek (cheap): "What does my journal say about Tuesday morning trades?"
Draft NinjaScript with Claude (best at NinjaScript syntax): "Write me a strategy following these specs."
Compile and repair with whatever model you have available (the agent just runs CompileNinjaScript and reads errors).
Backtest sweep with DeepSeek again to run many parameter combinations cheaply.

FAQ

Does OpenCode need API keys for every provider?

No, only for the providers you actually use. OpenCode reads keys from environment variables or its config. You can route everything through OpenRouter if you want a single key.

Can OpenCode run against a local Llama or Qwen?

Yes, via Ollama or LM Studio. The MCP setup is identical; only the model provider changes.

Why use OpenCode instead of Cursor or Cline?

OpenCode runs in the terminal (and now desktop/IDE), which is what most traders want for a quick agent session that doesn't require opening a full IDE. Cline is similar but VS Code-locked; OpenCode is more portable.

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: "http" or "streamable-http" rejected	OpenCode uses type: "remote" — different from Crush, Cline, Roo Code, etc.	Set "type": "remote" exactly; OpenCode infers Streamable HTTP from this
${env:VAR} expands to literal string	Env var not exported when OpenCode launched	Add the export to your shell rc (.bashrc / .zshrc) and restart OpenCode
Tool calls hang on slower models	Model is reasoning but not surfacing progress	Switch via /model to a faster provider for setup

Prerequisites

Why OpenCode for NinjaTrader work​

Step 1: Install OpenCode​

Step 2: Add the CrossTrade MCP server​

Step 3: Pick the model for the run​

Step 4: First workflow​

Multi-model patterns​

FAQ​

Does OpenCode need API keys for every provider?​

Can OpenCode run against a local Llama or Qwen?​

Why use OpenCode instead of Cursor or Cline?​