Use Claude API to generate branch names from prompts, falling back to a local slugify function

src/cli.ts

@@ -70,16 +70,55 @@ async function saveChanges(worktree: string, message?: string): Promise<boolean>
 
 // ── sandlot new <branch> ──────────────────────────────────────────────
 
-function branchFromPrompt(text: string): string {
+function fallbackBranchName(text: string): string {
   return text
     .toLowerCase()
     .replace(/[^a-z0-9\s-]/g, "")
     .trim()
     .split(/\s+/)
-    .slice(0, 2)
+    .slice(0, 5)
     .join("-")
 }
 
+async function branchFromPrompt(text: string): Promise<string> {
+  // Read API key from ~/.env
+  const envFile = Bun.file(join(homedir(), ".env"))
+  if (!(await envFile.exists())) return fallbackBranchName(text)
+
+  const envContent = await envFile.text()
+  const apiKey = envContent.match(/^(?:export\s+)?ANTHROPIC_API_KEY=["']?([^"'\s]+)["']?/m)?.[1]
+  if (!apiKey) return fallbackBranchName(text)
+
+  try {
+    const res = await fetch("https://api.anthropic.com/v1/messages", {
+      method: "POST",
+      headers: {
+        "content-type": "application/json",
+        "x-api-key": apiKey,
+        "anthropic-version": "2023-06-01",
+      },
+      body: JSON.stringify({
+        model: "claude-haiku-4-5-20251001",
+        max_tokens: 30,
+        messages: [{ role: "user", content: `Generate a short git branch name (2-4 lowercase words, hyphen-separated, no slashes) for this task:\n\n${text}\n\nOutput ONLY the branch name, nothing else.` }],
+      }),
+    })
+
+    if (!res.ok) return fallbackBranchName(text)
+
+    const body = await res.json() as any
+    const name = body.content?.[0]?.text?.trim()
+      .toLowerCase()
+      .replace(/[^a-z0-9-]/g, "-")
+      .replace(/-+/g, "-")
+      .replace(/^-|-$/g, "")
+
+    return name && name.length > 0 && name.length <= 50 ? name : fallbackBranchName(text)
+  } catch {
+    return fallbackBranchName(text)
+  }
+}
+
 program
   .command("new")
   .argument("[branch]", "branch name or prompt (if it contains spaces)")
@@ -90,14 +129,14 @@ program
   .action(async (branch: string | undefined, prompt: string | undefined, opts: { print?: string; save?: boolean }) => {
     // No branch given — derive from -p prompt
     if (!branch && opts.print) {
-      branch = branchFromPrompt(opts.print)
+      branch = await branchFromPrompt(opts.print)
     } else if (!branch) {
       console.error("✖ Branch name or prompt is required.")
       process.exit(1)
     } else if (branch.includes(" ")) {
       // If the "branch" contains spaces, it's actually a prompt — derive the branch name
       prompt = branch
-      branch = branchFromPrompt(branch)
+      branch = await branchFromPrompt(branch)
     }
     const root = await git.repoRoot()
     const worktreeAbs = join(homedir(), '.sandlot', basename(root), branch)