feat(batch_commit): sequential multi-commit tool

First mutating tool in the server. Accepts an array of {message, files}
entries, stages and commits each in order, stops on first failure.
Validates all file paths against the git toplevel before staging.

Returns per-commit results with SHA, or error details including which
commits succeeded before the failure.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: AlbinoGeek

src/server/batch-commit-tool.ts

@@ -0,0 +1,166 @@
+import type { FastMCP } from "fastmcp";
+import { z } from "zod";
+
+import { isStrictlyUnderGitTop, resolvePathForRepo } from "../repo-paths.js";
+import { gitTopLevel, spawnGitAsync } from "./git.js";
+import { jsonRespond, spreadDefined } from "./json.js";
+import { requireGitAndRoots } from "./roots.js";
+import { WorkspacePickSchema } from "./schemas.js";
+
+const CommitEntrySchema = z.object({
+  message: z.string().min(1).describe("Commit message."),
+  files: z.array(z.string().min(1)).min(1).describe("Paths to stage, relative to the git root."),
+});
+
+interface CommitResult {
+  index: number;
+  ok: boolean;
+  sha?: string;
+  message: string;
+  files: string[];
+  error?: string;
+  detail?: string;
+}
+
+export function registerBatchCommitTool(server: FastMCP): void {
+  server.addTool({
+    name: "batch_commit",
+    description:
+      "Create multiple sequential git commits in a single call. " +
+      "Each entry stages the listed files then commits with the given message. " +
+      "Stops on first failure. See docs/mcp-tools.md.",
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: false,
+      idempotentHint: false,
+    },
+    parameters: WorkspacePickSchema.extend({
+      commits: z
+        .array(CommitEntrySchema)
+        .min(1)
+        .max(50)
+        .describe("Commits to create, applied in order."),
+    }),
+    execute: async (args) => {
+      const pre = requireGitAndRoots(server, args, undefined);
+      if (!pre.ok) return jsonRespond(pre.error);
+
+      const rootInput = pre.roots[0];
+      if (!rootInput) {
+        return jsonRespond({ error: "no_workspace_root" });
+      }
+
+      const gitTop = gitTopLevel(rootInput);
+      if (!gitTop) {
+        return jsonRespond({ error: "not_a_git_repository", path: rootInput });
+      }
+
+      const results: CommitResult[] = [];
+
+      for (let i = 0; i < args.commits.length; i++) {
+        const entry = args.commits[i];
+        if (!entry) break;
+
+        // --- Validate all paths are under the git toplevel ---
+        const escapedPaths: string[] = [];
+        for (const rel of entry.files) {
+          const abs = resolvePathForRepo(rel, gitTop);
+          if (!isStrictlyUnderGitTop(abs, gitTop)) {
+            escapedPaths.push(rel);
+          }
+        }
+        if (escapedPaths.length > 0) {
+          results.push({
+            index: i,
+            ok: false,
+            message: entry.message,
+            files: entry.files,
+            error: "path_escapes_repository",
+            detail: escapedPaths.join(", "),
+          });
+          break;
+        }
+
+        // --- Stage files ---
+        const addResult = await spawnGitAsync(gitTop, ["add", "--", ...entry.files]);
+        if (!addResult.ok) {
+          results.push({
+            index: i,
+            ok: false,
+            message: entry.message,
+            files: entry.files,
+            error: "stage_failed",
+            detail: (addResult.stderr || addResult.stdout).trim(),
+          });
+          break;
+        }
+
+        // --- Commit ---
+        const commitResult = await spawnGitAsync(gitTop, ["commit", "-m", entry.message]);
+        if (!commitResult.ok) {
+          results.push({
+            index: i,
+            ok: false,
+            message: entry.message,
+            files: entry.files,
+            error: "commit_failed",
+            detail: (commitResult.stderr || commitResult.stdout).trim(),
+          });
+          break;
+        }
+
+        // --- Extract SHA from commit output ---
+        const shaMatch = /\[[\w/.-]+\s+([0-9a-f]+)\]/.exec(commitResult.stdout);
+        results.push({
+          index: i,
+          ok: true,
+          sha: shaMatch?.[1],
+          message: entry.message,
+          files: entry.files,
+        });
+      }
+
+      const allOk = results.length === args.commits.length && results.every((r) => r.ok);
+
+      if (args.format === "json") {
+        return jsonRespond({
+          ok: allOk,
+          committed: results.filter((r) => r.ok).length,
+          total: args.commits.length,
+          results: results.map((r) => ({
+            index: r.index,
+            ok: r.ok,
+            ...spreadDefined("sha", r.sha),
+            message: r.message,
+            files: r.files,
+            ...spreadDefined("error", r.error),
+            ...spreadDefined("detail", r.detail),
+          })),
+        });
+      }
+
+      // --- Markdown ---
+      const lines: string[] = [];
+      const header = allOk
+        ? `# Batch commit: ${results.length}/${args.commits.length} committed`
+        : `# Batch commit: ${results.filter((r) => r.ok).length}/${args.commits.length} committed (stopped on error)`;
+      lines.push(header, "");
+
+      for (const r of results) {
+        const icon = r.ok ? "✓" : "✗";
+        const sha = r.sha ? ` \`${r.sha}\`` : "";
+        lines.push(`${icon}${sha} ${r.message}`);
+        if (!r.ok && r.detail) {
+          lines.push(`  Error: ${r.error} — ${r.detail}`);
+        }
+      }
+
+      if (!allOk && results.length < args.commits.length) {
+        const skipped = args.commits.length - results.length;
+        lines.push("", `${skipped} remaining commit(s) skipped.`);
+      }
+
+      return lines.join("\n");
+    },
+  });
+}

src/server/tools.ts

@@ -1,5 +1,6 @@
 import type { FastMCP } from "fastmcp";
 
+import { registerBatchCommitTool } from "./batch-commit-tool.js";
 import { registerGitInventoryTool } from "./git-inventory-tool.js";
 import { registerGitParityTool } from "./git-parity-tool.js";
 import { registerGitStatusTool } from "./git-status-tool.js";
@@ -11,5 +12,6 @@ export function registerRethunkGitTools(server: FastMCP): void {
   registerGitInventoryTool(server);
   registerGitParityTool(server);
   registerListPresetsTool(server);
+  registerBatchCommitTool(server);
   registerPresetsResource(server);
 }