The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Prediction Market Signal MCP listing page.
Live Polymarket + Kalshi prediction-market odds, movers, price history, cross-platform gaps, watch, and X/Twitter sentiment inside Claude, Cursor, or any MCP client — no API key, no subscription, no monthly minimum. Your agent pays a fraction of a cent per call in USDC on Base using x402.
Facts only — not investment advice. Every answer is implied probability, volume, and price
history from the markets themselves (plus, for pm_sentiment, a plain read of what X/Twitter is
saying). Nothing here is a buy/sell/hold signal, a trade recommendation, or financial advice.
Prediction markets (Polymarket, Kalshi) already price real-world questions — elections, Fed decisions, macro events — as crowd-forecast odds. Reading them across two platforms usually means two different SDKs, two rate limits, and no cross-platform comparison. This server does both in one call, charges per request instead of a subscription, and there is nothing to cancel.
pm_search — $0.01Markets on Polymarket + Kalshi matching a question or topic, ranked by relevance, each with
probability, 24h change, volume, close date, URL, and id (use the id with pm_history or
pm_watch). Inputs: q (required), limit (optional, 1-50, default 20).
pm_odds — $0.02"What do the markets say" for one question — the headline market per platform, the cross-platform probability gap, 7-day history, and a one-line summary:
Input: q (required). Use pm_search instead when you want the full ranked list.
pm_movers — $0.02Biggest 24h/7d probability swings among liquid Polymarket markets — what's newly hot. Inputs:
window (optional, 24h default or 7d), limit (optional, 1-50, default 20).
pm_history — $0.02One market's probability series over time, first/last/high/low. Inputs: id (required — a
Polymarket condition id/slug/numeric id, or a Kalshi ticker, from pm_search), interval
(optional, 1d/1w/1m/max, default 1w).
pm_ticker_events — $0.01Open Polymarket + Kalshi markets mentioning a US stock ticker or company (a bare ticker like
TSLA is also matched against the company name, Tesla). Facts only — implied probability, 24h
change, volume — never a trade signal. Inputs: q (required — ticker or company/topic), limit
(optional, 1-50, default 20).
pm_sentiment — $0.05What the markets say AND what X/Twitter is saying about the SAME question, one call: headline
market probability, an AI read of X chatter's yes/no lean, key themes, driving accounts, notable
post URLs, and an aligned / diverges / no_clear_read verdict comparing the two:
Input: q (required). No market matched on either platform = no charge.
pm_watch — $0.02Monitor 1-20 market ids or a topic, get back only the change since your last check: current
probability, change_since_cursor (probability points), a moved flag, and (for a topic watch)
newly-listed markets. Pass the response's cursor back in next time — it's stateless, so you can
run any number of watches in parallel. Inputs: ids (1-20 comma-separated ids) OR q (a topic) —
provide one, not both; cursor (optional, omit on the first call); min_move (optional,
probability points, default 3). Nothing moved and nothing new = no charge — the fresh cursor
still comes back so your monitor keeps its place.
pm_gaps — $0.02Biggest Polymarket-vs-Kalshi disagreements on the SAME question — matched by topic, close date,
and shared numbers, with a match_confidence score and a polarity check so opposite-side matches
never show as a misleading gap. Served from a snapshot rebuilt every 30 minutes. Inputs: limit
(optional, 1-50, default 20), min_gap (optional, probability points, default 5), q (optional
topic filter). No matches at that gap size = no charge; snapshot not built yet after a cold start
= free, retry shortly.
pm_closing — $0.01Markets on both platforms closing within 24h or 7d, sorted by volume. Inputs: window (optional,
24h default or 7d), limit (optional, 1-50, default 20), q (optional topic filter).
pm_resolved — $0.01Markets on both platforms that settled within 24h or 7d, with the final outcome and last price —
for grading a forecast against reality. Same inputs as pm_closing.
pm_example — freeA real pm_odds result for a fixed question ("fed rate cut"), capped to 5 markets and 12 history
points, refreshed every 6 hours. No wallet, no payment, no x402 needed — use it to see the
answer shape before spending on any paid tool. No inputs.
You need a Coinbase CDP wallet funded with a little USDC on Base — that wallet pays per call.
Create one at portal.cdp.coinbase.com (API key + wallet secret).
pm_example works without any of this — it's free.
Claude Desktop / Claude Code — add to claude_desktop_config.json (or .mcp.json for Claude
Code):
Cursor — Settings → MCP → Add new MCP server, same command/args/env as above.
X402_MAX_PRICE is a hard per-call ceiling in USD. If the endpoint ever quotes more than this,
the request is refused before anything is signed — no charge. The default 0.05 already
covers every paid tool above (the priciest is pm_sentiment at $0.05) — you don't need to raise it.
x402, bring-your-own-wallet. Every paid tool pays from the wallet you configure — your own Coinbase CDP account, funded with USDC on Base. There is no server-side wallet and no shared account: each call signs its own USDC authorization, and the endpoint's facilitator settles it on Base. Gas is covered by the facilitator; you spend USDC only.
pm_search / pm_ticker_events / pm_gaps /
pm_closing / pm_resolved / pm_sentiment comes back as no_results with charged: false —
the payment is never settled.pm_watch only charges when something moved or something new appeared. A check that finds
nothing new is free — poll it on a schedule without worry.pm_gaps before its 30-minute background snapshot has finished its first build answers free
(503) instead of charging for an incomplete answer.error and logs
the call for refund rather than pretending it worked.Protocol: x402 v2 (CAIP-2 networks, PAYMENT-REQUIRED challenge header).
MIT