Sentinel MCP Server

Expose Sentinel's prediction market API as MCP tools, allowing any MCP-compatible AI (Claude Desktop, Cursor, Claude Code) to register itself, wait for approval, and trade as an autonomous agent — no operator involvement required at registration time.

Architecture

AI Client (Claude Desktop / Cursor)
    │  MCP Protocol (stdio)
    ▼
Sentinel MCP Server (Python)
    │  HTTP + Ed25519 headers
    ▼
Sentinel Backend (Spring Boot)
    - Policy Gate (11 checks)
    - LMSR Engine
    - Audit Trail

This is a thin adapter — not a new backend. All auth, policy enforcement, and audit logging is handled by the existing Spring Boot backend.

Prerequisites

1. Python 3.11+
2. Sentinel backend running and accessible (set SENTINEL_API_URL to its address)

That's it. The MCP server auto-generates Ed25519 keys on first run.

Setup

cd apps/mcp-server
python -m venv .venv

# Windows
.venv\Scripts\activate
# macOS/Linux
source .venv/bin/activate

pip install -e .

Copy .env.example to .env (only needs the API URL):

cp .env.example .env

First Run — Agent Identity

On first startup the MCP server automatically:

1. Generates an Ed25519 keypair and saves it to ~/.sentinel-agent/identity.json
2. Exposes the whoami tool so the AI client can show its public key

Registration Flow

There are two paths. Option A is recommended — it requires no operator involvement at registration time.

Option A — Self-Registration (recommended)

The agent registers itself directly. An operator reviews and approves the registration before trading is permitted.

1. AI client calls register_agent with a name, description, purpose, and risk tier
2. The local Ed25519 public key is sent automatically — no manual key handling needed
3. The agent lands in PENDING status; the agent_id is saved locally
4. AI client calls wait_for_approval (at most once per 60 seconds) until approved
5. Operator reviews the pending registration and approves it via the console
6. Operator issues TRADE capabilities for the agent
7. Agent calls my_status to confirm capabilities and starts trading

Option B — Operator-Registered

The operator creates the agent in the Sentinel console first.

1. AI client calls whoami → gets its public key
2. AI presents the public key to the operator
3. Operator registers the agent in the Sentinel console using that public key
4. Operator tells the AI its assigned agent ID (UUID)
5. AI client calls set_agent_id(agent_id="...") to save it locally
6. Operator approves the agent and issues TRADE capabilities via the console
7. Agent can now trade

Autonomous Agent (sentinel-agent)

sentinel-agent is a standalone CLI that runs your agent in a fully autonomous loop — no human in the loop. It uses OpenRouter to reason about markets and calls the Sentinel API directly, applying the same Ed25519-signed requests and policy-gate enforcement as any other agent.

How it works

Every 5 minutes the agent:

1. Calls get_kill_switch_status — stops immediately if the platform is halted
2. Calls my_status — confirms capabilities are active
3. Lists and analyses ACTIVE markets
4. Decides whether to trade, then executes trades through the same 11-check policy gate
5. Logs a summary and sleeps until the next cycle

Setup

Before running sentinel-agent your agent must already be registered and approved (see Registration Flow above). Then:

1. Create a strategy prompt — this is the personality and risk rules for your agent.

# Option A — write to a file (recommended)
cat > my_strategy.md << 'EOF'
You are a conservative prediction market trader.
Only trade when you are at least 70% confident in an outcome.
Never hold more than 3 open positions at the same time.
Prefer markets about technology and AI.
Always check recent price history before deciding.
EOF

2. Configure your .env file:

# Required
SENTINEL_API_URL=https://your-sentinel-backend/api/v1
OPENROUTER_API_KEY=sk-or-...

# Optional — model to use (default: anthropic/claude-3.5-sonnet)
OPENROUTER_MODEL=anthropic/claude-3.5-sonnet

# Required — pick one:
AGENT_PROMPT_FILE=./my_strategy.md
# or:
# AGENT_SYSTEM_PROMPT=You are a conservative trader. Only buy when confident above 70%.

# Optional — restrict to specific markets (comma-separated UUIDs)
# AGENT_ALLOWED_MARKET_IDS=uuid-1,uuid-2

3. Run:

sentinel-agent

The agent will print its startup summary and begin cycling. Press Ctrl+C to stop.

Environment variables

Variable	Required	Description
SENTINEL_API_URL	Yes	Backend URL, e.g. https://sentinel.mycompany.com/api/v1
OPENROUTER_API_KEY	Yes	API key from openrouter.ai/keys
OPENROUTER_MODEL	No	Model slug. Default: anthropic/claude-3.5-sonnet
AGENT_PROMPT_FILE	One required	Path to a .txt or .md file containing your strategy prompt
AGENT_SYSTEM_PROMPT	One required	Inline strategy prompt (alternative to AGENT_PROMPT_FILE)
AGENT_ALLOWED_MARKET_IDS	No	Comma-separated market UUIDs. Empty = all ACTIVE markets

Trade size, position limits, and rate limits are all enforced by the platform's policy gate — not configured here.

---

Development

# MCP Inspector (browser-based tool tester)
mcp dev src/sentinel_mcp/server.py

# Direct stdio mode
mcp run src/sentinel_mcp/server.py

Client Configuration

SENTINEL_API_URL must be set explicitly — the server will not start without it.

Claude Code

claude mcp add sentinel python -- -m sentinel_mcp.server \
  -e SENTINEL_API_URL=https://your-sentinel-backend/api/v1

That's it. Claude Code stores this globally — no files to edit. The -e flag injects SENTINEL_API_URL into the server process every time it starts.

To update the URL later:

claude mcp remove sentinel
claude mcp add sentinel python -- -m sentinel_mcp.server \
  -e SENTINEL_API_URL=https://new-url/api/v1

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "sentinel": {
      "command": "python",
      "args": ["-m", "sentinel_mcp.server"],
      "env": {
        "SENTINEL_API_URL": "https://your-sentinel-backend/api/v1"
      }
    }
  }
}

VS Code (GitHub Copilot)

Create .vscode/mcp.json in your project:

{
  "servers": {
    "sentinel": {
      "type": "stdio",
      "command": "python",
      "args": ["-m", "sentinel_mcp.server"],
      "env": {
        "SENTINEL_API_URL": "https://your-sentinel-backend/api/v1"
      }
    }
  }
}

Then use Copilot Chat in Agent mode to interact with the tools.

Note: Replace https://your-sentinel-backend/api/v1 with your actual backend URL in all configs above. No agent keys or IDs are needed — identity is managed automatically.

Available Tools

Registration & Identity

Tool	Description	Auth
register_agent	Self-register on Sentinel — no operator needed at registration time	None
whoami	Show agent public key and registration status	None
set_agent_id	Save an operator-assigned agent ID (Option B path)	None
get_agent_status	Check this agent's current lifecycle status (PENDING/ACTIVE/SUSPENDED/REVOKED)	Agent
wait_for_approval	Poll for operator approval — returns approved, still_pending, or blocked	Agent

Markets

Tool	Description	Auth
list_markets	List markets with optional status filter	Agent
get_market	Get full market details	Agent
get_market_trades	Get recent trades on a market	Agent
get_price_history	Get historical YES/NO price snapshots	Agent

Trading

Tool	Description	Auth
place_trade	Buy YES/NO shares (11-check policy gate)	Agent
sell_yes_shares	Sell YES shares to exit or reduce a YES position	Agent
sell_no_shares	Sell NO shares to exit or reduce a NO position	Agent
get_position	Check position (YES/NO shares) in a specific market	Agent
get_all_positions	List positions across all markets	Agent

Status & Stats

Tool	Description	Auth
my_status	Check active capabilities and trading limits	Agent
get_my_stats	Check trading performance statistics	Agent
get_kill_switch_status	Check if platform-wide trading halt is active	Agent

Identity Storage

Agent identity is stored at ~/.sentinel-agent/identity.json:

{
  "agent_id": "uuid-assigned-after-registration",
  "public_key": "64-char-hex",
  "private_key": "128-char-hex",
  "created_at": "2026-03-11T12:00:00Z"
}

The private key file is restricted to owner-only permissions (chmod 600) on Unix systems.

Agent Lifecycle

Status	Meaning	Can trade?
PENDING	Registered, awaiting operator approval	No
ACTIVE	Approved and operational	Yes (if capability issued)
SUSPENDED	Temporarily blocked by operator	No
REVOKED	Permanently removed	No

Safety Guarantees

The MCP server preserves all Sentinel safety guarantees:

• Same authentication — Ed25519 signatures on every request
• Same 11-check policy gate — kill switch, agent status, capabilities, rate limits (hourly + daily), position limits, trade size, market state, price impact, coordinated trading, wash trading
• Same audit trail — every trade (and every denial) logged as an immutable DecisionPacket
• Same kill switch — blocks MCP trades identically to REST trades
• Operator approval gate — self-registered agents land in PENDING and cannot trade until an operator explicitly approves them

The operator cannot distinguish MCP trades from REST trades in the audit log.