Tracking the Delta: How an AI Agent Watches Tokenized Stocks Drift From Their Underlyings

A delta tracker that computes the real-time price divergence between tokenized stocks and their underlying equities now serves AI agents over MCP, with a free tier of 1 request per minute and an HTTP 402 x402 paywall charging 5 USDC on Arc Testnet for 30 days of access. The tracker, built on Binance token prices with Finnhub and Alpaca equity data, exposes five MCP tools (get_delta, list_deltas, get_quote, get_events, get_digest) and flags stale feeds after 15 seconds without updates and alerts when the delta crosses a configurable 0.5% threshold. The system matters because tokenized stocks trade 24/7 while their underlyings are closed, letting an agent capture convergence when a token drifts, such as a −2% gap on a Saturday night.

Tracking the Delta: How an AI Agent Watches Tokenized Stocks Drift From Their Underlyings Tokenized stocks trade 24/7 while their underlyings sleep. We built a real-time delta tracker and exposed it to AI agents over MCP — with a 402 paywall on Arc. A delta tracker computes the price divergence between a tokenized stock and its underlying in real time and serves it to AI agents over MCP — free tier 1 req/min, then HTTP 402 with an x402 payment on Arc Testnet. Picture this: Apple trades at $336.45 on Nasdaq. Tokenized Apple AAPLB on Binance trades at $336.44 at the same moment. A penny apart — noise. But on a Saturday night, with Nasdaq asleep, AAPLB can drift to −2%. That is not noise anymore. That is a signal. The delta — the gap between a tokenized stock’s price and its underlying — is where the opportunities live. Humans cannot watch 20+ tokens around the clock. A machine can. So we built a tracker that computes the delta in real time and handed it to AI agents. Binance streams token prices around the clock; Finnhub/Alpaca supply the equity prices. DeltaEngine computes the delta, the market phase O/C/P and the stale flag 15s without updates . The MCP server exposes it to the agent through five tools, and Telegram receives an alert the moment a delta crosses the 0.5% threshold. What the tracker computes For every bStock the tracker keeps two prices: - bStockPrice — the token’s price on Binance, where tokenized stocks trade 24/7; - underlyingPrice — the real stock’s price from market data providers Finnhub, with an Alpaca fallback . Delta in percent: tokenPrice − stockPrice / stockPrice × 100 . Alongside it, three flags a trader actually needs: - phase — is the stock market open O , closed C , or in pre-market P ; - stale — the price feed went quiet for more than 15 seconds, so treat the number with care; - inAlert — the delta crossed the 0.5% threshold configurable . A live response looks like this: {"symbol":"AAPLB","underlying":"AAPL","multiplier":1.0006, "bStockPrice":336.44,"underlyingPrice":336.45, "deltaPct":-0.064,"phase":"O","stale":false,"inAlert":false} How an agent uses it An AI agent is a program — Claude, a GPT-based bot, your own script — that calls services on its own. Agents talk to services over MCP , an open protocol where a service lists its tools and the agent calls them like functions. The tracker is an MCP server with these tools: - get delta — delta for one symbol; - list deltas — all symbols at once; - get quote — current quote; - get events — event history threshold crossings, stale feeds ; - get digest — the day’s summary. curl -X POST https://agentbadge.xyz/mcp/bstock/tools/get delta -H "Authorization: Bearer $TOKEN" -d '{"symbol": "AAPLB"}' There is also Telegram: subscribe telegram registers the agent’s operator, and the tracker pushes a message whenever a delta crosses 0.5%. No polling needed — the signal finds you. Freemium: a snapshot for free, the stream for a fee The first request each minute is free. After that the server answers with HTTP 402 Payment Required — not an error, an invoice: “want real-time? pay”. The x402 standard lets the agent pay automatically: 5 USDC on the Arc network buys 30 days of access. No signup, no card, one on-chain transaction — gas paid in USDC too, an Arc specialty. The server verifies the transaction on-chain and opens the door. The same payment cannot be replayed — replay protection is built in. Why a trader should care A −0.06% delta is noise. A −2% delta on a closed exchange means “the token was sold off and the equity has not woken up yet”. Whoever sees it first captures the convergence. A person cannot monitor every token every second — an agent can, and it pays for its own data feed without a human in the loop. Next: inside the 402 paywall — how freemium works when the customer is a machine. Links - Agent guide endpoints, limits, examples : agentbadge.xyz/bstock-guide https://agentbadge.xyz/bstock-guide - All articles in the series: agentbadge.xyz/blog https://agentbadge.xyz/blog - MCP endpoint: https://agentbadge.xyz/mcp/bstock/tools/get delta