diff --git a/otohttp/templates/client.ts.plush b/otohttp/templates/client.ts.plush
index 9c24d47..d8cdedb 100644
--- a/otohttp/templates/client.ts.plush
+++ b/otohttp/templates/client.ts.plush
@@ -1,87 +1,99 @@
 // Code generated by oto; DO NOT EDIT.
 
-// HeadersFunc allows you to mutate headers for each request.
-// Useful for adding authorization into the client.
-interface HeadersFunc {
-	(headers: Headers): void;
-}
+import { z } from 'zod';
+import type { Schema, ZodTypeDef, ZodError } from 'zod';
 
-// Client provides access to remote services.
-export class Client {
-	// basepath is the path prefix for the requests.
-	// This may be a path, or an absolute URL.
-	public basepath: String = '/oto/'
-	// headers allows calling code to mutate the HTTP
-	// headers of the underlying HTTP requests.
-	public headers?: HeadersFunc
-}
+type JsonPrimitive = string | number | boolean | undefined;
+export type Json = JsonPrimitive | JsonObject | JsonArray;
+type JsonObject = { [member: string]: Json } | {};
+interface JsonArray extends ReadonlyArray<Json> {}
 
-<%= for (service) in def.Services { %>
-<%= format_comment_text(service.Comment) %>export class <%= service.Name %> {
-	constructor(readonly client: Client) {}
-	<%= for (method) in service.Methods { %>
-	<%= format_comment_text(method.Comment) %>	async <%= method.NameLowerCamel %>(<%= camelize_down(method.InputObject.TSType) %>?: <%= method.InputObject.TSType %>, modifyHeaders?: HeadersFunc): Promise<<%= method.OutputObject.TSType %>> {
-		if (<%= camelize_down(method.InputObject.TSType) %> == null) {
-			<%= camelize_down(method.InputObject.TSType) %> = new <%= method.InputObject.TSType %>();
-		}
-		const headers: Headers = new Headers();
-		headers.set('Accept', 'application/json');
-		headers.set('Content-Type', 'application/json');
-		if (this.client.headers) {
-			await this.client.headers(headers);
-		}
-		if (modifyHeaders) {
-			await modifyHeaders(headers)
-		}
-		const response = await fetch(this.client.basepath + '<%= service.Name %>.<%= method.Name %>', {
-			method: 'POST',
-			headers: headers,
-			body: JSON.stringify(<%= camelize_down(method.InputObject.TSType) %>),
-		})
-		if (response.status !== 200) {
-			throw new Error(`<%= service.Name %>.<%= method.Name %>: ${response.status} ${response.statusText}`);
-		}
-		return response.json().then((json) => {
-			if (json.error) {
-				throw new Error(json.error);
-			}
-			return new <%= method.OutputObject.TSType %>(json);
-		})
-	}
-	<% } %>
+export type ClientResponse =
+  | {
+      success: false;
+      error: { status: number; statusText: string; message: string };
+    }
+  | { success: true; payload: Json };
+
+export type Client = {
+  fetch: (path: string, payload: Json) => Promise<ClientResponse>;
+};
+
+/**
+ * Decode json to a zod schema
+ */
+export async function decodeJson<T extends { error?: string }>(
+  something: Json,
+  schema: Schema<T, ZodTypeDef, Json>
+): Promise<APIResponse<T>> {
+  const result = await schema.safeParseAsync(something);
+  if (result.success) {
+    const { error } = result.data;
+    if (error !== undefined && error?.length > 0) {
+      return {
+        success: false,
+        error: {
+          status: 400,
+          statusText: 'API error',
+          message: error,
+        },
+      };
+    }
+  }
+  return result;
 }
-<% } %>
+
+export type APIResponse<T> =
+  | {
+      success: false;
+      error: ZodError<Json> | { status: number; statusText: string; message: string };
+    }
+  | { success: true; data: Omit<T, 'error'> };
 
 <%= for (object) in def.Objects { %>
-<%= format_comment_text(object.Comment) %>export class <%= object.Name %> {
-	constructor(data?: any) {
-		if (data) {
-		<%= for (field) in object.Fields { %>
-			<%= if (field.Type.IsObject) { %>
-				<%= if (field.Type.Multiple) { %>
-					if (data.<%= field.NameLowerCamel %>) {
-						this.<%= field.NameLowerCamel %> = []
-						for (let i = 0; i < data.<%= field.NameLowerCamel %>.length; i++) {
-							this.<%= field.NameLowerCamel %>.push(new <%= field.Type.TSType %>(data.<%= field.NameLowerCamel %>[i]));
-						}
-					}
-				<% } else { %>
-					this.<%= field.NameLowerCamel %> = new <%= field.Type.TSType %>(data.<%= field.NameLowerCamel %>);
-				<% } %>
-			<% } else { %>
-			this.<%= field.NameLowerCamel %> = data.<%= field.NameLowerCamel %>;
-			<% } %>
-		<% } %>
-		}
-	}
-<%= for (field) in object.Fields { %>
-	<%= format_comment_text(field.Comment) %>	<%= field.NameLowerCamel %><%= if (field.Type.IsObject || field.Type.Multiple) { %>?<% } %>: <%= if (field.Type.IsObject) { %><%= field.Type.TSType %><%= if (field.Type.Multiple) { %>[]<% } %><% } else { %><%= field.Type.JSType %><%= if (field.Type.Multiple) { %>[]<% } %><%= if (!field.Type.Multiple) { %> = <%= field.Type.JSType %>Default<% } %><% } %>;
+<%= format_comment_text(object.Comment) %>export function <%= object.Name %>Schema() { return z.object({
+    <%= for (field) in object.Fields { %>
+     <%= field.NameLowerCamel %>: <%= if (field.Type.IsObject) { %>
+        <%= field.Type.TSType %>Schema()
+      <% } else if (field.Metadata["options"]) { %>
+z.enum([<%= for (option) in field.Metadata["options"] { %>'<%= option %>',<% } %> ""])
+      <% } else if (field.Type.JSType == "object") { %>
+        z.record(z.unknown())
+      <% } else { %> z.<%= field.Type.JSType %>() <% } %><%= if (field.Type.Multiple) { %>.array()<% } %><%= if (field.Metadata["optional"]) {%>.optional()<%}%> ,<% } %>
+  });
+}
+
+  export type <%= object.Name %> = z.infer<ReturnType<typeof <%= object.Name %>Schema>>;
+
+
 <% } %>
+
+
+<%= for (service) in def.Services { %>
+<%= if (service.Metadata["deprecated"]) { %>
+    /**
+    * @deprecated  <%= service.Metadata["deprecated"] %>
+    */
+<% } else { %><%= format_comment_text(service.Comment) } %>export class <%= service.Name %> {
+  private readonly _client: Client;
+  public constructor(client: Client) {
+    this._client = client;
+  }
+  <%= for (method) in service.Methods { %>
+  <%= if (method.Metadata["deprecated"]) { %>
+    /**
+    * @deprecated  <%= method.Metadata["deprecated"] %>
+    */
+  <% } else { %><%= format_comment_text(method.Comment) } %>public async <%= method.NameLowerCamel %>(<%= camelize_down(method.InputObject.TSType) %>: <%= method.InputObject.TSType %>): Promise<
+ APIResponse<<%= method.OutputObject.TSType %>> 
+  > {
+    const response = await this._client.fetch('<%= service.Name %>.<%= method.Name %>', <%= camelize_down(method.InputObject.TSType) %>);
+    if (!response.success) {
+      return response;
+    }
+    return decodeJson(response.payload, <%= method.OutputObject.TSType %>Schema());
+  }
+  <% } %>
 }
 <% } %>
 
-// these defaults make the template easier to write.
-const stringDefault = ''
-const numberDefault = 0
-const booleanDefault = false 
-const anyDefault = null