mcp-github

Instructions

Implementation Reference

• src/operations/pulls.ts:410-428 (handler)

  The main handler function that fetches the pull request diff using the GitHub API with a specific 'Accept: application/vnd.github.diff' header to retrieve the raw diff as a string.

  export async function getPullRequestDiff(
    github_pat: string,
    owner: string,
    repo: string,
    pullNumber: number
  ): Promise<string> {
    const response = await githubRequest(
      github_pat,
      `https://api.github.com/repos/${owner}/${repo}/pulls/${pullNumber}`,
      {
        headers: {
          "Accept": "application/vnd.github.diff"
        }
      }
    );
    
    // The response is already a string because the content type is not JSON
    return response as string;
  }

• src/operations/pulls.ts:195-203 (schema)

  Zod input schemas for validating the tool arguments: public schema without PAT and internal schema including the GitHub PAT.

  export const GetPullRequestDiffSchema = z.object({
    owner: z.string().describe("Repository owner (username or organization)"),
    repo: z.string().describe("Repository name"),
    pull_number: z.number().describe("Pull request number")
  });
  
  export const _GetPullRequestDiffSchema = GetPullRequestDiffSchema.extend({
    github_pat: z.string().describe("GitHub Personal Access Token"),
  });

• src/index.ts:306-310 (registration)

  Registration of the tool in the MCP server's listTools handler, specifying name, description, and input schema.

  {
    name: "get_pull_request_diff",
    description: "Get the diff for a pull request",
    inputSchema: zodToJsonSchema(pulls.GetPullRequestDiffSchema),
  },

• src/index.ts:786-793 (registration)

  Dispatch logic in the MCP server's callToolRequest handler that parses arguments and calls the implementation function.

  case "get_pull_request_diff": {
    const args = pulls._GetPullRequestDiffSchema.parse(params.arguments);
    const { github_pat, owner, repo, pull_number } = args;
    const result = await pulls.getPullRequestDiff(github_pat, owner, repo, pull_number);
    return {
      content: [{ type: "text", text: result }],
    };
  }