diff --git a/src/browser.ts b/src/browser.ts
index 36898b3..fcf4e14 100644
--- a/src/browser.ts
+++ b/src/browser.ts
@@ -1,5 +1,5 @@
 // Browser-compatible exports
-export * from "./schemas/latest.js";
 export * from "./schemas/index.js";
+export * from "./schemas/validate.js";
 export * from "./shared/config.js";
 export * from "./types.js";
diff --git a/src/schemas/index.ts b/src/schemas/index.ts
index 06ad45c..3afe1b1 100644
--- a/src/schemas/index.ts
+++ b/src/schemas/index.ts
@@ -10,6 +10,7 @@ export * as vLatest from "./latest.js";
 export {
   MANIFEST_VERSION as LATEST_MANIFEST_VERSION,
   McpbManifestSchema as LatestMcpbManifestSchema,
+  McpbManifestSchema, // backwards compatibility - exports latest schema
 } from "./latest.js";
 
 /**
diff --git a/src/schemas/validate.ts b/src/schemas/validate.ts
new file mode 100644
index 0000000..89063f7
--- /dev/null
+++ b/src/schemas/validate.ts
@@ -0,0 +1,100 @@
+import type * as z from "zod";
+
+import * as v0_1 from "./0.1.js";
+import * as v0_2 from "./0.2.js";
+import * as v0_3 from "./0.3.js";
+
+type McpbManifestV0_1 = z.infer<typeof v0_1.McpbManifestSchema>;
+type McpbManifestV0_2 = z.infer<typeof v0_2.McpbManifestSchema>;
+type McpbManifestV0_3 = z.infer<typeof v0_3.McpbManifestSchema>;
+
+/**
+ * Union type representing any supported manifest version.
+ * This is the return type of validateManifest.
+ */
+type ValidatedManifest = McpbManifestV0_1 | McpbManifestV0_2 | McpbManifestV0_3;
+
+/**
+ * Validates a manifest using the appropriate schema based on its manifest_version.
+ *
+ * This function automatically detects the manifest version from the data and applies
+ * the correct schema. This avoids TypeScript "excessively deep" errors that can occur
+ * when using union schemas across package boundaries.
+ *
+ * @param data - The manifest data to validate
+ * @returns The validated manifest with the correct type
+ * @throws ZodError if validation fails
+ *
+ * @example
+ * ```typescript
+ * import { validateManifest } from '@anthropic-ai/mcpb/browser';
+ *
+ * const manifest = validateManifest(unknownData);
+ * // manifest is typed as McpbManifestAny (union of all versions)
+ * ```
+ */
+export function validateManifest(data: unknown): ValidatedManifest {
+  // Read manifest_version or dxt_version from data
+  const version = (data as any)?.manifest_version || (data as any)?.dxt_version;
+
+  // Use appropriate schema based on version
+  if (version === "0.1") {
+    return v0_1.McpbManifestSchema.parse(data);
+  }
+
+  if (version === "0.2") {
+    return v0_2.McpbManifestSchema.parse(data);
+  }
+
+  // Default to latest version (0.3) if not specified or if version is "0.3"
+  return v0_3.McpbManifestSchema.parse(data);
+}
+
+/**
+ * Validates a manifest using the appropriate schema, returning a Result-style object.
+ *
+ * @param data - The manifest data to validate
+ * @returns An object with either { success: true, data } or { success: false, error }
+ *
+ * @example
+ * ```typescript
+ * import { validateManifestSafe } from '@anthropic-ai/mcpb/browser';
+ *
+ * const result = validateManifestSafe(unknownData);
+ * if (result.success) {
+ *   console.log(result.data);
+ * } else {
+ *   console.error(result.error);
+ * }
+ * ```
+ */
+export function validateManifestSafe(data: unknown):
+  | { success: true; data: ValidatedManifest }
+  | { success: false; error: unknown } {
+  try {
+    return { success: true, data: validateManifest(data) };
+  } catch (error) {
+    return { success: false, error };
+  }
+}
+
+/**
+ * Get the appropriate schema for a given manifest version.
+ * Useful when you need to work with the schema directly.
+ *
+ * @param version - The manifest version (e.g., "0.1", "0.2", "0.3")
+ * @returns The schema for that version
+ *
+ * @example
+ * ```typescript
+ * import { getSchemaForVersion } from '@anthropic-ai/mcpb/browser';
+ *
+ * const schema = getSchemaForVersion("0.2");
+ * const result = schema.safeParse(data);
+ * ```
+ */
+export function getSchemaForVersion(version: "0.1" | "0.2" | "0.3") {
+  if (version === "0.1") return v0_1.McpbManifestSchema;
+  if (version === "0.2") return v0_2.McpbManifestSchema;
+  return v0_3.McpbManifestSchema;
+}
diff --git a/src/shared/config.ts b/src/shared/config.ts
index 20e4262..bf8391c 100644
--- a/src/shared/config.ts
+++ b/src/shared/config.ts
@@ -1,6 +1,7 @@
 import type {
   Logger,
   McpbManifest,
+  McpbManifestAny,
   McpbUserConfigValues,
   McpServerConfig,
 } from "../types.js";
@@ -85,7 +86,7 @@ export function replaceVariables(
 }
 
 interface GetMcpConfigForManifestOptions {
-  manifest: McpbManifest;
+  manifest: McpbManifestAny;
   extensionPath: string;
   systemDirs: Record<string, string>;
   userConfig: McpbUserConfigValues;
@@ -179,7 +180,7 @@ export async function getMcpConfigForManifest(
 }
 
 interface HasRequiredConfigMissingOptions {
-  manifest: McpbManifest;
+  manifest: McpbManifestAny;
   userConfig?: McpbUserConfigValues;
 }