webui: preserve partial response on streaming error (#23090)

diff --git a/tools/server/webui/src/lib/constants/agentic.ts b/tools/server/webui/src/lib/constants/agentic.ts
index 4fe6da61c3837a287d11aaa7bc3b79cc4051de80..c0575163efca9644b188d5dec31a340fa0fc4381 100644 (file)
--- a/tools/server/webui/src/lib/constants/agentic.ts
+++ b/tools/server/webui/src/lib/constants/agentic.ts
@@ -4,9 +4,6 @@ export const ATTACHMENT_SAVED_REGEX = /\[Attachment saved: ([^\]]+)\]/;
 
 export const NEWLINE_SEPARATOR = '\n';
 
-export const LLM_ERROR_BLOCK_START = '\n\n```\nUpstream LLM error:\n';
-export const LLM_ERROR_BLOCK_END = '\n```\n';
-
 export const DEFAULT_AGENTIC_CONFIG: AgenticConfig = {
        enabled: true,
        maxTurns: 100,

diff --git a/tools/server/webui/src/lib/stores/agentic.svelte.ts b/tools/server/webui/src/lib/stores/agentic.svelte.ts
index 3334f6c111a9362d9efb8499f0e758358e07072e..1f1f05c453998093eded33f6522066c4627cdffb 100644 (file)
--- a/tools/server/webui/src/lib/stores/agentic.svelte.ts
+++ b/tools/server/webui/src/lib/stores/agentic.svelte.ts
@@ -30,12 +30,7 @@ import { ToolSource, ToolPermissionDecision } from '$lib/enums';
 import { SvelteMap } from 'svelte/reactivity';
 import { ToolsService } from '$lib/services/tools.service';
 import { isAbortError } from '$lib/utils';
-import {
-       DEFAULT_AGENTIC_CONFIG,
-       NEWLINE_SEPARATOR,
-       LLM_ERROR_BLOCK_START,
-       LLM_ERROR_BLOCK_END
-} from '$lib/constants';
+import { DEFAULT_AGENTIC_CONFIG, NEWLINE_SEPARATOR } from '$lib/constants';
 import {
        IMAGE_MIME_TO_EXTENSION,
        DATA_URI_BASE64_REGEX,
@@ -640,10 +635,9 @@ class AgenticStore {
                                        return;
                                }
                                const normalizedError = error instanceof Error ? error : new Error('LLM stream error');
-                               // Save error as content in the current turn
-                               onChunk?.(`${LLM_ERROR_BLOCK_START}${normalizedError.message}${LLM_ERROR_BLOCK_END}`);
+                               // preserve partial output as is, the outer error dialog informs the user separately
                                await onAssistantTurnComplete?.(
-                                       turnContent + `${LLM_ERROR_BLOCK_START}${normalizedError.message}${LLM_ERROR_BLOCK_END}`,
+                                       turnContent,
                                        turnReasoningContent || undefined,
                                        this.buildFinalTimings(capturedTimings, agenticTimings),
                                        undefined

diff --git a/tools/server/webui/src/lib/stores/chat.svelte.ts b/tools/server/webui/src/lib/stores/chat.svelte.ts
index 7c34579ca564e6a0dd6eaaac6df197e7d7cf9b56..04a735eec91b9f6a28d96ef8732262f37eaee5e7 100644 (file)
--- a/tools/server/webui/src/lib/stores/chat.svelte.ts
+++ b/tools/server/webui/src/lib/stores/chat.svelte.ts
@@ -814,7 +814,7 @@ class ChatStore {
                                        );
                                }
                        },
-                       onError: (error: Error) => {
+                       onError: async (error: Error) => {
                                this.setStreamingActive(false);
                                if (isAbortError(error)) {
                                        cleanupStreamingState();
@@ -826,13 +826,10 @@ class ChatStore {
                                        return;
                                }
                                console.error('Streaming error:', error);
+                               // keep whatever was streamed so far, the message stays in memory and in DB
+                               await this.savePartialResponseIfNeeded(convId);
                                cleanupStreamingState();
                                this.clearPendingMessage(convId);
-                               const idx = conversationsStore.findMessageIndex(assistantMessage.id);
-                               if (idx !== -1) {
-                                       const failedMessage = conversationsStore.removeMessageAtIndex(idx);
-                                       if (failedMessage) DatabaseService.deleteMessage(failedMessage.id).catch(console.error);
-                               }
                                const contextInfo = (
                                        error as Error & { contextInfo?: { n_prompt_tokens: number; n_ctx: number } }
                                ).contextInfo;
@@ -1389,9 +1386,17 @@ class ChatStore {
                                                }
 
                                                console.error('Continue generation error:', error);
-                                               conversationsStore.updateMessageAtIndex(idx, { content: originalContent });
-
-                                               await DatabaseService.updateMessage(msg.id, { content: originalContent });
+                                               // keep whatever was appended so far, the message stays in memory and in DB
+                                               await DatabaseService.updateMessage(msg.id, {
+                                                       content: originalContent + appendedContent,
+                                                       reasoningContent: originalReasoning + appendedReasoning || undefined,
+                                                       timestamp: Date.now()
+                                               });
+                                               conversationsStore.updateMessageAtIndex(idx, {
+                                                       content: originalContent + appendedContent,
+                                                       reasoningContent: originalReasoning + appendedReasoning || undefined,
+                                                       timestamp: Date.now()
+                                               });
 
                                                this.setChatLoading(msg.convId, false);
                                                this.clearChatStreaming(msg.convId);