GitHub MCP Server

Instructions

Implementation Reference

• operations/pulls.ts:251-264 (handler)

  The core handler function that executes the GitHub API request to update the pull request branch with the latest changes.

  export async function updatePullRequestBranch(
    owner: string,
    repo: string,
    pullNumber: number,
    expectedHeadSha?: string
  ): Promise<void> {
    await githubRequest(
      `https://api.github.com/repos/${owner}/${repo}/pulls/${pullNumber}/update-branch`,
      {
        method: "PUT",
        body: expectedHeadSha ? { expected_head_sha: expectedHeadSha } : undefined,
      }
    );
  }

• operations/pulls.ts:143-148 (schema)

  Zod input schema defining parameters for the tool: owner, repo, pull_number, and optional expected_head_sha.

  export const UpdatePullRequestBranchSchema = 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"),
    expected_head_sha: z.string().optional().describe("The expected SHA of the pull request's HEAD ref")
  });

• index.ts:185-189 (registration)

  Tool registration in the listTools response, including name, description, and input schema reference.

  {
    name: "update_pull_request_branch",
    description: "Update a pull request branch with the latest changes from the base branch",
    inputSchema: zodToJsonSchema(pulls.UpdatePullRequestBranchSchema)
  },

• index.ts:549-556 (handler)

  Dispatcher case in the central CallToolRequest handler that parses args and invokes the specific updatePullRequestBranch function.

  case "update_pull_request_branch": {
    const args = pulls.UpdatePullRequestBranchSchema.parse(request.params.arguments);
    const { owner, repo, pull_number, expected_head_sha } = args;
    await pulls.updatePullRequestBranch(owner, repo, pull_number, expected_head_sha);
    return {
      content: [{ type: "text", text: JSON.stringify({ success: true }, null, 2) }],
    };
  }