fix(providers): scope Z.ai schema guidance to the response_format call only

- schemaGuidance now falls back to the bare responseFormat object when
  .schema is absent, matching the schema-or-format fallback used
  elsewhere in the codebase (was silently injecting nothing for callers
  that pass a bare JSON schema)
- guidance is now only appended to the messages sent alongside an
  actual response_format (the immediate call, or whichever pass
  deferResponseFormat applies it to) instead of every turn of an
  active tool loop, where it wrongly told the model to return final
  JSON instead of continuing to call tools

Author: waleedlatif1

apps/sim/providers/zai/index.ts

@@ -29,6 +29,22 @@ const logger = createLogger('ZaiProvider')
 
 const ZAI_BASE_URL = 'https://api.z.ai/api/paas/v4'
 
+function buildSchemaGuidance(responseFormat: ProviderRequest['responseFormat']): string {
+  if (!responseFormat) return ''
+  const schema = responseFormat.schema || responseFormat
+  return `\n\nYour response must be valid JSON matching this schema${
+    responseFormat.name ? ` ("${responseFormat.name}")` : ''
+  }:\n${JSON.stringify(schema, null, 2)}`
+}
+
+function withSchemaGuidance(messages: any[], guidance: string): any[] {
+  if (!guidance) return messages
+  if (messages[0]?.role === 'system') {
+    return [{ ...messages[0], content: `${messages[0].content}${guidance}` }, ...messages.slice(1)]
+  }
+  return [{ role: 'system', content: guidance.trimStart() }, ...messages]
+}
+
 /**
  * Z.ai's GLM models via an OpenAI-compatible chat-completions API (`api.z.ai`), with these
  * documented deviations from a standard OpenAI-compatible adapter:
@@ -68,16 +84,10 @@ export const zaiProvider: ProviderConfig = {
 
       const allMessages = []
 
-      const schemaGuidance = request.responseFormat
-        ? `\n\nYour response must be valid JSON matching this schema${
-            request.responseFormat.name ? ` ("${request.responseFormat.name}")` : ''
-          }:\n${JSON.stringify(request.responseFormat.schema, null, 2)}`
-        : ''
-
-      if (request.systemPrompt || schemaGuidance) {
+      if (request.systemPrompt) {
         allMessages.push({
           role: 'system',
-          content: `${request.systemPrompt || ''}${schemaGuidance}`,
+          content: request.systemPrompt,
         })
       }
 
@@ -147,6 +157,10 @@ export const zaiProvider: ProviderConfig = {
       const deferResponseFormat = !!responseFormatPayload && hasActiveTools
       if (responseFormatPayload && !deferResponseFormat) {
         payload.response_format = responseFormatPayload
+        payload.messages = withSchemaGuidance(
+          payload.messages,
+          buildSchemaGuidance(request.responseFormat)
+        )
       }
 
       if (request.stream && (!tools || tools.length === 0 || !hasActiveTools)) {
@@ -489,6 +503,10 @@ export const zaiProvider: ProviderConfig = {
         streamingPayload.tool_choice = undefined
         if (deferResponseFormat && responseFormatPayload) {
           streamingPayload.response_format = responseFormatPayload
+          streamingPayload.messages = withSchemaGuidance(
+            streamingPayload.messages,
+            buildSchemaGuidance(request.responseFormat)
+          )
         }
 
         const streamResponse = await zai.chat.completions.create(
@@ -562,7 +580,10 @@ export const zaiProvider: ProviderConfig = {
         const finalFormatStartTime = Date.now()
         const finalPayload: any = {
           ...payload,
-          messages: currentMessages,
+          messages: withSchemaGuidance(
+            currentMessages,
+            buildSchemaGuidance(request.responseFormat)
+          ),
           response_format: responseFormatPayload,
         }
         finalPayload.tools = undefined