mcp-github

Instructions

Implementation Reference

• src/operations/branches.ts:85-103 (handler)

  Core handler function that implements the branch creation logic by resolving the source SHA and calling the low-level createBranch API.

  export async function createBranchFromRef(
    github_pat: string,
    owner: string,
    repo: string,
    newBranch: string,
    fromBranch?: string
  ): Promise<z.infer<typeof GitHubReferenceSchema>> {
    let sha: string;
    if (fromBranch) {
      sha = await getBranchSHA(github_pat, owner, repo, fromBranch);
    } else {
      sha = await getDefaultBranchSHA(github_pat, owner, repo);
    }
  
    return createBranch(github_pat, owner, repo, {
      ref: newBranch,
      sha,
    });
  }

• src/index.ts:118-122 (registration)

  Tool registration in the ListTools response, defining name, description, and input schema.

  {
    name: "create_branch",
    description: "Create a new branch in a GitHub repository",
    inputSchema: zodToJsonSchema(branches.CreateBranchSchema),
  },

• src/index.ts:339-351 (handler)

  Tool dispatch handler in the CallToolRequest switch statement that validates input and invokes the core createBranchFromRef function.

  case "create_branch": {
    const args = branches._CreateBranchSchema.parse(params.arguments);
    const branch = await branches.createBranchFromRef(
      args.github_pat,
      args.owner,
      args.repo,
      args.branch,
      args.from_branch
    );
    return {
      content: [{ type: "text", text: JSON.stringify(branch, null, 2) }],
    };
  }

• src/operations/branches.ts:11-16 (schema)

  Primary input schema definition for the create_branch tool, referenced in registration.

  export const CreateBranchSchema = z.object({
    owner: z.string().describe("Repository owner (username or organization)"),
    repo: z.string().describe("Repository name"),
    branch: z.string().describe("Name for the new branch"),
    from_branch: z.string().optional().describe("Optional: source branch to create from (defaults to the repository's default branch)"),
  });

• src/operations/branches.ts:47-68 (helper)

  Low-level helper function that performs the actual GitHub API call to create a branch ref.

  export async function createBranch(
    github_pat: string,
    owner: string,
    repo: string,
    options: CreateBranchOptions
  ): Promise<z.infer<typeof GitHubReferenceSchema>> {
    const fullRef = `refs/heads/${options.ref}`;
  
    const response = await githubRequest(
      github_pat,
      `https://api.github.com/repos/${owner}/${repo}/git/refs`,
      {
        method: "POST",
        body: {
          ref: fullRef,
          sha: options.sha,
        },
      }
    );
  
    return GitHubReferenceSchema.parse(response);
  }