list_markets

Instructions

Implementation Reference

• mcp-server.ts:81-125 (handler)

  The handler function for the 'list_markets' tool. It fetches outcome metadata (questions + outcomes) and all mid prices from the Hyperliquid API, groups outcomes by their parent question, and returns a formatted text listing all prediction markets with current prices for each side.

  // --- list_markets ---
  server.tool(
    'list_markets',
    'List all prediction markets with current prices',
    {},
    async () => {
      const [meta, mids] = await Promise.all([
        hlInfo<OutcomeMeta>({ type: 'outcomeMeta' }),
        hlInfo<Record<string, string>>({ type: 'allMids' }),
      ]);
  
      const questionMap = new Map<number, QuestionRaw>();
      for (const q of meta.questions) {
        questionMap.set(q.question, q);
      }
  
      const lines: string[] = [];
      // Group outcomes by question
      const grouped = new Map<number | null, OutcomeRaw[]>();
      for (const o of meta.outcomes) {
        const qId = [...questionMap.entries()].find(([, q]) =>
          q.namedOutcomes.includes(o.outcome)
        )?.[0] ?? null;
        if (!grouped.has(qId)) grouped.set(qId, []);
        grouped.get(qId)!.push(o);
      }
  
      for (const [qId, outcomes] of grouped) {
        const q = qId !== null ? questionMap.get(qId) : null;
        if (q) lines.push(`\n## ${q.name}`);
  
        for (const o of outcomes) {
          const sides = o.sideSpecs.map((s, i) => {
            const coin = outcomeToCoin(o.outcome, i);
            const mid = mids[coin] ? (parseFloat(mids[coin]) * 100).toFixed(1) + '%' : '?';
            return `${s.name}: ${mid}`;
          });
          const label = q ? `  [${o.outcome}] ${o.name}` : `\n[${o.outcome}] ${o.name}`;
          lines.push(`${label} — ${sides.join(' | ')}`);
        }
      }
  
      return { content: [{ type: 'text', text: lines.join('\n') }] };
    },
  );

• mcp-server.ts:82-83 (registration)

  Registration of the 'list_markets' tool using the MCP server.tool() method with an empty schema (no input parameters).

  server.tool(
    'list_markets',

• mcp-server.ts:63-65 (helper)

  Helper function outcomeToCoin, used to convert an outcome ID and side index into a coin identifier string (e.g., '#90') for fetching mid prices from the API.

  function outcomeToCoin(outcomeId: number, side: number): string {
    return `#${10 * outcomeId + side}`;
  }

• mcp-server.ts:31-45 (schema)

  Type definitions for OutcomeRaw, QuestionRaw, and OutcomeMeta, which define the shape of data used by the list_markets handler to structure markets and questions.

  interface OutcomeRaw {
    outcome: number;
    name: string;
    description: string;
    sideSpecs: { name: string }[];
  }
  interface QuestionRaw {
    question: number;
    name: string;
    description: string;
    fallbackOutcome: number;
    namedOutcomes: number[];
    settledNamedOutcomes: number[];
  }
  interface OutcomeMeta { outcomes: OutcomeRaw[]; questions: QuestionRaw[] }