get_price_history

Instructions

Implementation Reference

• src/index.ts:1206-1243 (registration)

  Tool 28 'get_price_history' registration in the MCP server. Defined with inputSchema requiring tokenId, interval (1m/5m/1h/6h/1d/1w/max), and fidelity (1-500). Handler calls getClobPriceHistory() and transforms the response.

  server.registerTool(
    "get_price_history",
    {
      description:
        "Get historical price data for a Polymarket outcome token. Returns time-series price points for charting and trend analysis.",
      inputSchema: {
        tokenId: z.string().describe("CLOB token ID"),
        interval: z
          .enum(["1m", "5m", "1h", "6h", "1d", "1w", "max"])
          .default("1d")
          .describe("Time interval: 1m, 5m, 1h, 6h, 1d, 1w, or max"),
        fidelity: z
          .number()
          .min(1)
          .max(500)
          .default(60)
          .describe("Number of data points to return (1-500)"),
      },
    },
    async ({ tokenId, interval, fidelity }) => {
      try {
        const data = await getClobPriceHistory(tokenId, interval, fidelity);
        const history = (data.history ?? []).map((p) => ({
          timestamp: p.t,
          date: new Date(p.t * 1000).toISOString(),
          price: p.p,
        }));
        return textResult({
          tokenId,
          interval,
          pointCount: history.length,
          history,
        });
      } catch (error) {
        return errorResult(error);
      }
    }
  );

• src/polymarketApi.ts:201-209 (handler)

  getClobPriceHistory() — the actual implementation function that calls the Polymarket CLOB API at /prices-history endpoint. Takes tokenId, interval, and fidelity; returns { history: Array<{ t: number, p: number }> }.

  export async function getClobPriceHistory(
    tokenId: string,
    interval: string = "1d",
    fidelity: number = 60
  ): Promise<{ history: Array<{ t: number; p: number }> }> {
    return fetchJson<{ history: Array<{ t: number; p: number }> }>(
      `${CLOB_BASE}/prices-history?market=${encodeURIComponent(tokenId)}&interval=${interval}&fidelity=${fidelity}`
    );
  }

• src/index.ts:1211-1224 (schema)

  Input schema for get_price_history: tokenId (string), interval (enum: 1m/5m/1h/6h/1d/1w/max, default 1d), fidelity (number 1-500, default 60).

    inputSchema: {
      tokenId: z.string().describe("CLOB token ID"),
      interval: z
        .enum(["1m", "5m", "1h", "6h", "1d", "1w", "max"])
        .default("1d")
        .describe("Time interval: 1m, 5m, 1h, 6h, 1d, 1w, or max"),
      fidelity: z
        .number()
        .min(1)
        .max(500)
        .default(60)
        .describe("Number of data points to return (1-500)"),
    },
  },

• src/polymarketApi.ts:19-31 (helper)

  fetchJson<T>() — generic HTTP helper used by getClobPriceHistory to make requests to the CLOB API with JSON parsing and error handling.

  async function fetchJson<T>(url: string): Promise<T> {
    const response = await fetch(url, {
      headers: { Accept: "application/json" },
    });
    if (!response.ok) {
      throw new PolymarketApiError(
        `HTTP ${response.status}: ${response.statusText}`,
        response.status,
        url
      );
    }
    return response.json() as Promise<T>;
  }