diff --git a/src/utils/spec-parser.ts b/src/utils/spec-parser.ts
new file mode 100644
index 0000000..d65c9d4
--- /dev/null
+++ b/src/utils/spec-parser.ts
@@ -0,0 +1,122 @@
+import * as fs from 'fs';
+import * as yaml from 'js-yaml';
+import { CLISpec } from '../types/spec.js';
+import { validateSpec } from '../validators/schema.js';
+
+export interface ParseOptions {
+  filePath?: string;
+  content?: string;
+  format?: 'auto' | 'json' | 'yaml';
+}
+
+export interface ParseResult {
+  success: boolean;
+  spec?: CLISpec;
+  errors?: string[];
+  source?: string;
+}
+
+function detectFormat(content: string): 'json' | 'yaml' {
+  const trimmed = content.trim();
+  if (trimmed.startsWith('{') || trimmed.startsWith('[')) {
+    return 'json';
+  }
+  return 'yaml';
+}
+
+function parseJSON(content: string): unknown {
+  return JSON.parse(content);
+}
+
+function parseYAML(content: string): unknown {
+  return yaml.load(content);
+}
+
+export function parseSpec(options: ParseOptions): ParseResult {
+  let content: string;
+  let source: string;
+
+  if (options.content) {
+    content = options.content;
+    source = 'input';
+  } else if (options.filePath) {
+    if (!fs.existsSync(options.filePath)) {
+      return {
+        success: false,
+        errors: [`File not found: ${options.filePath}`],
+        source: options.filePath,
+      };
+    }
+    content = fs.readFileSync(options.filePath, 'utf-8');
+    source = options.filePath;
+  } else {
+    return {
+      success: false,
+      errors: ['Either filePath or content must be provided'],
+      source: undefined,
+    };
+  }
+
+  let parsed: unknown;
+  try {
+    const format = options.format === 'auto' || !options.format ? detectFormat(content) : options.format;
+
+    if (format === 'json') {
+      parsed = parseJSON(content);
+    } else {
+      parsed = parseYAML(content);
+    }
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Unknown parsing error';
+    return {
+      success: false,
+      errors: [`Failed to parse ${source}: ${message}`],
+      source,
+    };
+  }
+
+  if (!parsed || typeof parsed !== 'object') {
+    return {
+      success: false,
+      errors: [`Invalid spec format in ${source}: expected object`],
+      source,
+    };
+  }
+
+  const validation = validateSpec(parsed);
+  if (!validation.success) {
+    return {
+      success: false,
+      errors: validation.errors,
+      source,
+    };
+  }
+
+  return {
+    success: true,
+    spec: validation.data,
+    source,
+  };
+}
+
+export function loadSpec(filePath: string): ParseResult {
+  return parseSpec({ filePath });
+}
+
+export function loadSpecFromStdin(): Promise<ParseResult> {
+  return new Promise((resolve) => {
+    let content = '';
+    process.stdin.setEncoding('utf-8');
+
+    process.stdin.on('readable', () => {
+      let chunk;
+      while ((chunk = process.stdin.read()) !== null) {
+        content += chunk;
+      }
+    });
+
+    process.stdin.on('end', () => {
+      resolve(parseSpec({ content }));
+    });
+  });
+}