@cyanheads/git-mcp-server
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An MCP (Model Context Protocol) server enabling LLMs and AI agents to interact with Git repositories. Provides tools for comprehensive Git operations including clone, commit, branch, diff, log, status, push, pull, merge, rebase, worktree, tag management,
145 lines (144 loc) • 6.92 kB
JavaScript
import { execFile } from "child_process";
import { promisify } from "util";
import { z } from "zod";
import { BaseErrorCode, McpError } from "../../../types-global/errors.js"; // Direct import for types-global
import { logger, sanitization } from "../../../utils/index.js"; // logger (./utils/internal/logger.js), RequestContext (./utils/internal/requestContext.js), sanitization (./utils/security/sanitization.js)
const execFileAsync = promisify(execFile);
// Define the input schema for the git_show tool using Zod
// No refinements needed here, so we don't need a separate BaseSchema
export const GitShowInputSchema = z.object({
path: z
.string()
.min(1)
.optional()
.default(".")
.describe("Path to the local Git repository. Defaults to the directory set via `git_set_working_dir` for the session; set 'git_set_working_dir' if not set."),
ref: z
.string()
.min(1)
.describe("The object reference (commit hash, tag name, branch name, HEAD, etc.) to show."),
filePath: z
.string()
.optional()
.describe("Optional specific file path within the ref to show (e.g., show a file's content at a specific commit). If provided, use the format '<ref>:<filePath>'."),
// format: z.string().optional().describe("Optional format string for the output"), // Consider adding later
});
/**
* Executes the 'git show' command for a given reference and optional file path.
*
* @param {GitShowInput} input - The validated input object.
* @param {RequestContext} context - The request context for logging and error handling.
* @returns {Promise<GitShowResult>} A promise that resolves with the structured result.
* @throws {McpError} Throws an McpError for path resolution/validation failures or unexpected errors.
*/
export async function gitShowLogic(input, context) {
const operation = "gitShowLogic";
logger.debug(`Executing ${operation}`, { ...context, input });
let targetPath;
try {
// Resolve and sanitize the target path
const workingDir = context.getWorkingDirectory();
targetPath =
input.path && input.path !== "." ? input.path : (workingDir ?? ".");
if (targetPath === "." && !workingDir) {
logger.warning("Executing git show in server's CWD as no path provided and no session WD set.", { ...context, operation });
targetPath = process.cwd();
}
else if (targetPath === "." && workingDir) {
targetPath = workingDir;
logger.debug(`Using session working directory: ${targetPath}`, {
...context,
operation,
sessionId: context.sessionId,
});
}
else {
logger.debug(`Using provided path: ${targetPath}`, {
...context,
operation,
});
}
targetPath = sanitization.sanitizePath(targetPath, {
allowAbsolute: true,
}).sanitizedPath;
logger.debug("Sanitized path", {
...context,
operation,
sanitizedPath: targetPath,
});
}
catch (error) {
logger.error("Path resolution or sanitization failed", {
...context,
operation,
error,
});
if (error instanceof McpError)
throw error;
throw new McpError(BaseErrorCode.VALIDATION_ERROR, `Invalid path: ${error instanceof Error ? error.message : String(error)}`, { context, operation, originalError: error });
}
// Validate ref format (simple validation)
if (!/^[a-zA-Z0-9_./~^:-]+$/.test(input.ref)) {
// Allow ':' for filePath combination
throw new McpError(BaseErrorCode.VALIDATION_ERROR, `Invalid reference format: ${input.ref}`, { context, operation });
}
// Validate filePath format if provided (basic path chars)
if (input.filePath && !/^[a-zA-Z0-9_./-]+$/.test(input.filePath)) {
throw new McpError(BaseErrorCode.VALIDATION_ERROR, `Invalid file path format: ${input.filePath}`, { context, operation });
}
try {
// Construct the refspec, combining ref and filePath if needed
const refSpec = input.filePath
? `${input.ref}:${input.filePath}`
: input.ref;
// Construct the command
const args = ["-C", targetPath, "show", refSpec];
logger.debug(`Executing command: git ${args.join(" ")}`, {
...context,
operation,
});
// Execute command. Note: git show might write to stderr for non-error info (like commit details before diff)
// We primarily care about stdout for the content. Errors usually have non-zero exit code.
const { stdout, stderr } = await execFileAsync("git", args);
if (stderr) {
// Log stderr as debug info, as it might contain commit details etc.
logger.debug(`Git show command produced stderr (may be informational)`, {
...context,
operation,
stderr,
});
}
logger.info(`git show executed successfully for ref: ${refSpec}`, {
...context,
operation,
path: targetPath,
});
return { success: true, content: stdout }; // Return raw stdout content
}
catch (error) {
const errorMessage = error.stderr || error.message || "";
logger.error(`Failed to execute git show command`, {
...context,
operation,
path: targetPath,
error: errorMessage,
stderr: error.stderr,
stdout: error.stdout,
});
// Specific error handling
if (errorMessage.toLowerCase().includes("not a git repository")) {
throw new McpError(BaseErrorCode.NOT_FOUND, `Path is not a Git repository: ${targetPath}`, { context, operation, originalError: error });
}
if (/unknown revision or path not in the working tree/i.test(errorMessage)) {
const target = input.filePath
? `${input.ref}:${input.filePath}`
: input.ref;
throw new McpError(BaseErrorCode.NOT_FOUND, `Failed to show: Reference or pathspec '${target}' not found. Error: ${errorMessage}`, { context, operation, originalError: error });
}
if (/ambiguous argument/i.test(errorMessage)) {
throw new McpError(BaseErrorCode.VALIDATION_ERROR, `Failed to show: Reference '${input.ref}' is ambiguous. Provide a more specific reference. Error: ${errorMessage}`, { context, operation, originalError: error });
}
// Throw a generic McpError for other failures
throw new McpError(BaseErrorCode.INTERNAL_ERROR, `Git show failed for path: ${targetPath}, ref: ${input.ref}. Error: ${errorMessage}`, { context, operation, originalError: error });
}
}