init

utils/tempfile.ts

@@ -0,0 +1,31 @@
+import { createHash, randomUUID } from 'crypto'
+import { tmpdir } from 'os'
+import { join } from 'path'
+
+/**
+ * Generate a temporary file path.
+ *
+ * @param prefix Optional prefix for the temp file name
+ * @param extension Optional file extension (defaults to '.md')
+ * @param options.contentHash When provided, the identifier is derived from a
+ *   SHA-256 hash of this string (first 16 hex chars). This produces a path
+ *   that is stable across process boundaries — any process with the same
+ *   content will get the same path. Use this when the path ends up in content
+ *   sent to the Anthropic API (e.g., sandbox deny lists in tool descriptions),
+ *   because a random UUID would change on every subprocess spawn and
+ *   invalidate the prompt cache prefix.
+ * @returns Temp file path
+ */
+export function generateTempFilePath(
+  prefix: string = 'claude-prompt',
+  extension: string = '.md',
+  options?: { contentHash?: string },
+): string {
+  const id = options?.contentHash
+    ? createHash('sha256')
+        .update(options.contentHash)
+        .digest('hex')
+        .slice(0, 16)
+    : randomUUID()
+  return join(tmpdir(), `${prefix}-${id}${extension}`)
+}