Actually - What Markets Really Think

A Chrome extension and an MCP server that put prediction-market odds on top of the news you are already reading.

News tells you that "experts are concerned" or that "odds are rising". It rarely tells you a number. The number exists - on a prediction market, where people are betting their own money on the outcome. It just lives in another tab, and finding it means knowing such a market exists in the first place.

Actually closes that gap. Open an article, click the toolbar icon, and the extension matches the text against live Polymarket markets and shows the market's own probability. No account, no wallet, no signup.

Add it to Chrome from the Chrome Web Store - free.

What it does

• Matches an article to a market. A local embedding model (Xenova/all-MiniLM-L12-v2, ~33 MB) scores the article text against the cached market set, boosted by keyword and number overlap - numbers matter because the encoder is nearly blind to them, and "dip to $57,500" embeds almost identically to "reach $120,000".

• Runs on your device. Model and WASM runtime are bundled at build time - nothing is fetched from a CDN at install or runtime, and on the default settings the article text never leaves the machine.

• Reads non-English pages. They are translated to English before matching, using Chrome's own built-in Translator API (local, no network). Every Polymarket question is written in English, and the local model holds 86 Cyrillic tokens out of 30522 - an untranslated Russian headline embeds to noise. Translated, the same headline scores 0.53-0.71 against the market it is actually about, against a 0.35 floor.

  

• Trades, optionally. Connect any WalletConnect v2 wallet for limit and market orders, selling, cancelling resting orders, and a positions panel with cost basis and P&L. Keys and funds are never held by us.

• Serves agents too. The same capabilities are exposed over the Model Context Protocol: check_news, get_market, place_order, sell_order, cancel_order, get_positions.

Using the MCP server

The MCP server is published, so it needs no clone and no build. Add it to any MCP client (Claude Desktop, Cursor, and anything else that speaks the protocol):

{
  "mcpServers": {
    "actually": {
      "command": "npx",
      "args": ["actually-mcp-server"]
    }
  }
}

That gives an agent the signal tools - check_news and get_market - with no key and no wallet. Ask it "what do markets think about this?" with a headline and it answers with the market's own price.

The very first launch downloads the package and its local model runtime (about 170 MB), and the first check_news then fetches the 34 MB model. On a slow connection that can take longer than a client waits for a server to start; if yours reports a timeout, run npx -y actually-mcp-server once in a terminal, let it finish, and restart the client. Later launches start in a few seconds.

Trading tools appear only if you supply a key of your own:

"env": {
  "POLYMARKET_PRIVATE_KEY": "0x...",
  "ACTUALLY_MAX_ORDER_USD": "100",
  "ACTUALLY_DAILY_LIMIT_USD": "500"
}

Both caps are enforced server-side against a persisted spend ledger, so an agent cannot talk its way past them by claiming a different price. redeem_position needs a further explicit opt-in (ACTUALLY_ENABLE_REDEEM=true) because it submits a real on-chain transaction and is still in testing.

Full documentation, including every environment variable and the reasoning behind the guards: packages/mcp-server/README.md.

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... View full README on GitHub