Polymarket MCP Server

Instructions

Implementation Reference

• src/api/clob.ts:24-28 (handler)

  The actual implementation of the getMidpoint API call that fetches data from the CLOB endpoint.

  async getMidpoint(tokenId: string): Promise<ClobMidpoint> {
    return this.client.clob<ClobMidpoint>("/midpoint", {
      token_id: tokenId,
    });
  }

• src/tools/clob/prices.ts:26-43 (registration)

  Registration and MCP tool handler for "get_midpoint", which calls the clob.getMidpoint method.

  server.tool(
    "get_midpoint",
    "Get the midpoint price for a Polymarket token (average of best bid and ask).",
    {
      token_id: z.string().describe("CLOB token ID"),
    },
    async (args) => {
      try {
        const data = await clob.getMidpoint(args.token_id);
        return { content: [{ type: "text", text: JSON.stringify(data, null, 2) }] };
      } catch (error) {
        return {
          content: [{ type: "text", text: `Error: ${(error as Error).message}` }],
          isError: true,
        };
      }
    },
  );