mcp-server-leetcode

Implementation Reference

• src/tools/problem-tools.ts:54-80 (registration)

  Registers the 'search-problems' MCP tool, including input schema and execution handler.

  // Search problems
  server.tool(
    "search-problems",
    {
      tags: z.string().optional().describe("Tags to filter by, separated by '+' (e.g., 'array+dynamic-programming')"),
      difficulty: z.enum(["EASY", "MEDIUM", "HARD"]).optional().describe("Difficulty level"),
      limit: z.number().min(1).max(100).optional().default(20).describe("Maximum number of problems to return"),
      skip: z.number().optional().default(0).describe("Number of problems to skip")
    },
    async ({ tags, difficulty, limit, skip }) => {
      try {
        const data = await leetcodeService.searchProblems(tags, difficulty, limit, skip);
        return {
          content: [{ 
            type: "text", 
            text: JSON.stringify(data, null, 2)
          }]
        };
      } catch (error: unknown) {
        const errorMessage = error instanceof Error ? error.message : String(error);
        return {
          content: [{ type: "text", text: `Error: ${errorMessage}` }],
          isError: true
        };
      }
    }
  );

• src/tools/problem-tools.ts:63-79 (handler)

  Handler function for the 'search-problems' tool that calls LeetCodeService and formats response.

  async ({ tags, difficulty, limit, skip }) => {
    try {
      const data = await leetcodeService.searchProblems(tags, difficulty, limit, skip);
      return {
        content: [{ 
          type: "text", 
          text: JSON.stringify(data, null, 2)
        }]
      };
    } catch (error: unknown) {
      const errorMessage = error instanceof Error ? error.message : String(error);
      return {
        content: [{ type: "text", text: `Error: ${errorMessage}` }],
        isError: true
      };
    }
  }

• src/services/leetcode-service.ts:83-96 (helper)

  LeetCodeService.searchProblems method that executes the GraphQL search query with filters.

  /**
   * Search for problems matching criteria
   */
  async searchProblems(tags?: string, difficulty?: string, limit: number = 20, skip: number = 0) {
    return this.executeQuery(searchProblemsQuery, { 
      categorySlug: "",
      limit,
      skip,
      filters: {
        tags: tags ? tags.split("+") : [],
        difficulty: difficulty || null
      }
    });
  }

• src/graphql/queries.ts:146-175 (schema)

  GraphQL query definition for searching LeetCode problems used by the tool.

  export const searchProblemsQuery = `
    query problemsetQuestionList($categorySlug: String, $limit: Int, $skip: Int, $filters: QuestionListFilterInput) {
      problemsetQuestionList: questionList(
        categorySlug: $categorySlug
        limit: $limit
        skip: $skip
        filters: $filters
      ) {
        total: totalNum
        questions: data {
          acRate
          difficulty
          freqBar
          frontendQuestionId: questionFrontendId
          isFavor
          paidOnly: isPaidOnly
          status
          title
          titleSlug
          topicTags {
            name
            id
            slug
          }
          hasSolution
          hasVideoSolution
        }
      }
    }
  `;