Arena Predictions
Paper trade prediction markets at live prices from your AI agent, and score every trade.
The current version, v0.5.0, was published to the official MCP registry on 2026-09-29. It is distributed as arena-mcp-server on npm, filed under Other by this index, and declares 3 environment variables. Removals and unreachable sources are measured across every server this index tracks, contract drift across the servers that answer in consecutive snapshots; the index's current counts put this record in context.
Using Arena Predictions in Claude, Cursor, Gemini CLI, Cline, or Zed?
MCP tool contracts can change remotely with no version bump. The mcpindex gate pins each contract and HOLDs the call when it drifts-before your agent acts. Zero credentials. This is not the package install for this server itself (use Install this server for that).
Rewrites your MCP host config so each server launches behind the gate. Inspect first: curl -fsSL https://mcpindex.ai/install.sh | less
uv tool install mcpindex-gate && mcpindex-config-wireVerdict not yet evaluated for this tool. The semantic screen takes adversarial cases first; coverage rolls out as the corpus expands (15/150 labels to graduation). The deterministic conformance probe is built but has not yet run on the public corpus, so a recorded verdict here is REVIEW or UNVERIFIED, never a clearing ALLOW. Until a verdict is recorded, an agent should treat this tool as not-yet-cleared and fall back to its own checks. Method: the eval, four-state verdict, honest limits.
Own this server? Screen its description →
That verdict was true at screening time (snapshot 2026-09-29).
Contracts can change after screening, with no version bump. The gate pins Arena Predictions’s tool contracts on first sight and holds any silent change before your agent acts - the check that keeps being true on Tuesday.
See your first HOLD in 2 minutes →
Related: how to trust an MCP server · screen before install · silent contract drift
ARENA_MCP_ALLOW_TRADESet to 1 to register the paper-trade tools (place_trade, sell_trade, get_orders, cancel_order, settle_open). Any other value leaves trading off.
ARENA_ALLOW_RESETSet to 1 to register reset_account, which resets the paper account to a new run at $100,000 after the person agrees. The server also refuses until the owner turns resets on in Settings on the web. Any other value leaves it out.
ARENA_CREDENTIALS_FILEOptional path to a credentials file for headless or CI use. By default the server reads the credentials that `arena login` stored.
Hosted MCP for Clip Studio public products — same plan as the website.
Financial data and research MCP for US/CN/JP equities: filings, statements, ownership, signals.
Unexpected questions and lateral thinking prompts to break through mental blocks. 86 strategies.