{"record":{"id":"b4f88257d9ecb929","repo":"alibaba/spring-ai-alibaba","slug":"chatclient-error","errorCode":null,"errorMessage":"ChatClient error","messagePattern":"ChatClient error","errorType":"exception","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"spring-ai-alibaba-admin/spring-ai-alibaba-admin-server-start/src/main/java/com/alibaba/cloud/ai/studio/admin/builder/generator/service/generator/workflow/sections/LLMNodeSection.java","lineNumber":114,"sourceCode":"\t\t\t\t\t\t            memories = \"This is the user's first request without context\";\n\t\t\t\t\t\t        }\n\t\t\t\t\t\t        else {\n\t\t\t\t\t\t            memories = String.format(\"This is the history of previous requests:\\\\n %%s\",\n\t\t\t\t\t\t                    state.value(memoryKey, List.of()).toString());\n\t\t\t\t\t\t        }\n\n\t\t\t\t\t\t        // call chatClient\n\t\t\t\t\t\t        int retryCount = Optional.ofNullable(maxRetryCount).orElse(1);\n\t\t\t\t\t\t        int retryInterval = Optional.ofNullable(retryIntervalMs).orElse(1000);\n\t\t\t\t\t\t        while (retryCount-- > 0) {\n\t\t\t\t\t\t            try {\n\t\t\t\t\t\t                // build messages\n\t\t\t\t\t\t                List<Message> messages = messageTemplates.stream()\n\t\t\t\t\t\t                    .map(messageTemplate -> messageTemplate.render(state))\n\t\t\t\t\t\t                    .toList();\n\t\t\t\t\t\t                String content = chatClient.prompt().system(memories).messages(messages).call().content();\n\t\t\t\t\t\t                if (content == null) {\n\t\t\t\t\t\t                    throw new RuntimeException(\"ChatClient error\");\n\t\t\t\t\t\t                }\n\t\t\t\t\t\t                Map<String, Object> map = new HashMap<>(%s);\n\t\t\t\t\t\t                if (memoryKey != null) {\n\t\t\t\t\t\t                    map.put(memoryKey, content);\n\t\t\t\t\t\t                }\n\t\t\t\t\t\t                return map;\n\t\t\t\t\t\t            }\n\t\t\t\t\t\t            catch (Exception e) {\n\t\t\t\t\t\t                try {\n\t\t\t\t\t\t                    Thread.sleep(retryInterval);\n\t\t\t\t\t\t                } catch (InterruptedException ie) {\n\t\t\t\t\t\t                    Thread.currentThread().interrupt();\n\t\t\t\t\t\t                    break;\n\t\t\t\t\t\t                }\n\t\t\t\t\t\t            }\n\t\t\t\t\t\t        }\n\n\t\t\t\t\t\t        // error handling","sourceCodeStart":96,"sourceCodeEnd":132,"githubUrl":"https://github.com/alibaba/spring-ai-alibaba/blob/f82da0b50f35744c13968191be2b1cd2452ef550/spring-ai-alibaba-admin/spring-ai-alibaba-admin-server-start/src/main/java/com/alibaba/cloud/ai/studio/admin/builder/generator/service/generator/workflow/sections/LLMNodeSection.java#L96-L132","documentation":"The generated LLM node code calls chatClient.prompt()...call().content() and throws RuntimeException(\"ChatClient error\") when the model returns a null content. It signals the ChatClient call completed without producing usable text.","triggerScenarios":"At runtime of the generated workflow: the ChatClient call returns null content — typically empty/failed model completion, misconfigured model or API key, or the model returning only reasoning with no content.","commonSituations":"Missing or invalid DashScope/OpenAI API key; model name not available in the region; max-tokens set too low so response is empty; network issues returning empty body.","solutions":["Verify the ChatModel/API key and model name configuration for the workspace","Check provider-side response (logs/observability) for empty completions and adjust maxTokens/prompt","Wrap the node with an error edge (errorNextNode) so failures route to an error branch instead of aborting"],"exampleFix":"// before\nString content = chatClient.prompt().system(memories).messages(messages).call().content();\n// after\nString content = chatClient.prompt().system(memories).messages(messages)\n    .call().content();\nif (content == null || content.isBlank()) {\n    content = \"\"; // or route to error node\n}","handlingStrategy":"try-catch","validationCode":"if (chatModelConfig.getApiKey() == null || chatModelConfig.getApiKey().isBlank()) { throw new IllegalStateException(\"Model API key not configured\"); }","typeGuard":"null","tryCatchPattern":"try { String content = chatClient.prompt()...call().content(); } catch (RuntimeException e) { log.error(\"LLM call failed\", e); routeToErrorNode(); }","preventionTips":["Configure and rotate model API keys properly","Set sane maxTokens so responses are not truncated to empty","Monitor model completions via observability tooling","Wire an errorNextNode for every LLM node"],"tags":["java","spring-ai","chatclient","null-response"],"backgroundTag":"empty-api-response","analyzedSha":"f82da0b50f35744c13968191be2b1cd2452ef550","analyzedAt":"2026-09-09T15:32:42.421Z","contentChangedAt":"2026-09-09T15:32:42.421Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}