diff --git a/pkg/agent/turn_state.go b/pkg/agent/turn_state.go
index 4318dd28d..4bc8f2ee4 100644
--- a/pkg/agent/turn_state.go
+++ b/pkg/agent/turn_state.go
@@ -686,10 +686,25 @@ func (ts *turnState) restoreSession(agent *AgentInstance) error {
return agent.Sessions.Save(ts.sessionKey)
}
+// messagesContentEqual compares two message slices by content only, ignoring CreatedAt.
+// JSON roundtrip loses the monotonic clock portion of time.Time, so direct
+// reflect.DeepEqual would always differ on messages that roundtripped through
+// the JSONL store.
+func messagesContentEqual(a, b []providers.Message) bool {
+ for i := range a {
+ aCopy, bCopy := a[i], b[i]
+ aCopy.CreatedAt, bCopy.CreatedAt = nil, nil
+ if !reflect.DeepEqual(aCopy, bCopy) {
+ return false
+ }
+ }
+ return true
+}
+
func matchingTurnMessageTail(history, persisted []providers.Message) int {
maxMatch := min(len(history), len(persisted))
for size := maxMatch; size > 0; size-- {
- if reflect.DeepEqual(history[len(history)-size:], persisted[len(persisted)-size:]) {
+ if messagesContentEqual(history[len(history)-size:], persisted[len(persisted)-size:]) {
return size
}
}
diff --git a/pkg/memory/jsonl.go b/pkg/memory/jsonl.go
index 492205114..a63598f4e 100644
--- a/pkg/memory/jsonl.go
+++ b/pkg/memory/jsonl.go
@@ -561,6 +561,12 @@ func (s *JSONLStore) addMsg(sessionKey string, msg providers.Message) error {
l.Lock()
defer l.Unlock()
+ now := time.Now()
+
+ if msg.CreatedAt == nil {
+ msg.CreatedAt = &now
+ }
+
// Append the message as a single JSON line.
line, err := json.Marshal(msg)
if err != nil {
@@ -598,7 +604,6 @@ func (s *JSONLStore) addMsg(sessionKey string, msg providers.Message) error {
if err != nil {
return err
}
- now := time.Now()
if meta.Count == 0 && meta.CreatedAt.IsZero() {
meta.CreatedAt = now
}
@@ -726,6 +731,12 @@ func (s *JSONLStore) SetHistory(
meta.Count = len(history)
meta.UpdatedAt = now
+ for i := range history {
+ if history[i].CreatedAt == nil {
+ history[i].CreatedAt = &now
+ }
+ }
+
// Write meta BEFORE rewriting the JSONL file. If we crash between
// the two writes, meta has Skip=0 and the old file is still intact,
// so GetHistory reads from line 1 — returning "too many" messages
diff --git a/pkg/memory/jsonl_test.go b/pkg/memory/jsonl_test.go
index c77a4393e..219f4e3ee 100644
--- a/pkg/memory/jsonl_test.go
+++ b/pkg/memory/jsonl_test.go
@@ -1058,6 +1058,137 @@ func TestMultipleSessions_Isolation(t *testing.T) {
}
}
+func TestStore_SetsCreatedAtWhenNil(t *testing.T) {
+ type writeOp struct {
+ name string
+ fn func(store *JSONLStore, key string) (expectedCount int)
+ }
+
+ ops := []writeOp{
+ {
+ name: "AddMessage",
+ fn: func(store *JSONLStore, key string) int {
+ if err := store.AddMessage(context.Background(), key, "user", "hello"); err != nil {
+ t.Fatalf("AddMessage: %v", err)
+ }
+ return 1
+ },
+ },
+ {
+ name: "AddFullMessage",
+ fn: func(store *JSONLStore, key string) int {
+ if err := store.AddFullMessage(context.Background(), key, providers.Message{
+ Role: "user",
+ Content: "hello from full",
+ }); err != nil {
+ t.Fatalf("AddFullMessage: %v", err)
+ }
+ return 1
+ },
+ },
+ {
+ name: "SetHistory",
+ fn: func(store *JSONLStore, key string) int {
+ if err := store.SetHistory(context.Background(), key, []providers.Message{
+ {Role: "user", Content: "msg1"},
+ {Role: "assistant", Content: "msg2"},
+ }); err != nil {
+ t.Fatalf("SetHistory: %v", err)
+ }
+ return 2
+ },
+ },
+ }
+
+ for _, op := range ops {
+ t.Run(op.name, func(t *testing.T) {
+ store := newTestStore(t)
+ key := "s1"
+
+ before := time.Now().Add(-time.Second)
+ expectedCount := op.fn(store, key)
+ after := time.Now().Add(time.Second)
+
+ history, err := store.GetHistory(context.Background(), key)
+ if err != nil {
+ t.Fatalf("GetHistory: %v", err)
+ }
+ if len(history) != expectedCount {
+ t.Fatalf("expected %d messages, got %d", expectedCount, len(history))
+ }
+ for i := range history {
+ if history[i].CreatedAt == nil || history[i].CreatedAt.IsZero() {
+ t.Errorf("message %d CreatedAt is zero — not set by %s", i, op.name)
+ }
+ if history[i].CreatedAt.Before(before) || history[i].CreatedAt.After(after) {
+ t.Errorf("message %d CreatedAt %v outside expected window [%v, %v]", i, history[i].CreatedAt, before, after)
+ }
+ }
+ })
+ }
+}
+
+func TestStore_PreservesExistingCreatedAt(t *testing.T) {
+ t1 := time.Date(2026, 1, 1, 10, 0, 0, 0, time.UTC)
+ t2 := time.Date(2026, 1, 1, 11, 0, 0, 0, time.UTC)
+
+ type writeOp struct {
+ name string
+ fn func(store *JSONLStore, key string)
+ wantTimes []time.Time
+ }
+
+ ops := []writeOp{
+ {
+ name: "AddFullMessage",
+ fn: func(store *JSONLStore, key string) {
+ if err := store.AddFullMessage(context.Background(), key, providers.Message{
+ Role: "user",
+ Content: "custom time",
+ CreatedAt: &t1,
+ }); err != nil {
+ t.Fatalf("AddFullMessage: %v", err)
+ }
+ },
+ wantTimes: []time.Time{t1},
+ },
+ {
+ name: "SetHistory",
+ fn: func(store *JSONLStore, key string) {
+ if err := store.SetHistory(context.Background(), key, []providers.Message{
+ {Role: "user", Content: "msg1", CreatedAt: &t1},
+ {Role: "assistant", Content: "msg2", CreatedAt: &t2},
+ }); err != nil {
+ t.Fatalf("SetHistory: %v", err)
+ }
+ },
+ wantTimes: []time.Time{t1, t2},
+ },
+ }
+
+ for _, op := range ops {
+ t.Run(op.name, func(t *testing.T) {
+ store := newTestStore(t)
+ key := "s1"
+
+ op.fn(store, key)
+
+ history, err := store.GetHistory(context.Background(), key)
+ if err != nil {
+ t.Fatalf("GetHistory: %v", err)
+ }
+ if len(history) != len(op.wantTimes) {
+ t.Fatalf("expected %d messages, got %d", len(op.wantTimes), len(history))
+ }
+ for i, want := range op.wantTimes {
+ if history[i].CreatedAt == nil || !history[i].CreatedAt.Equal(want) {
+ t.Errorf("message %d CreatedAt = %v, want %v (should preserve caller-provided time)", i, history[i].CreatedAt, want)
+ }
+ }
+ })
+ }
+}
+
func BenchmarkAddMessage(b *testing.B) {
dir := b.TempDir()
store, err := NewJSONLStore(dir)
diff --git a/pkg/providers/protocoltypes/types.go b/pkg/providers/protocoltypes/types.go
index 650bcb287..b60c46701 100644
--- a/pkg/providers/protocoltypes/types.go
+++ b/pkg/providers/protocoltypes/types.go
@@ -1,5 +1,7 @@
package protocoltypes
+import "time"
+
type ToolCall struct {
ID string `json:"id"`
Type string `json:"type,omitempty"`
@@ -87,6 +89,7 @@ type Message struct {
Role string `json:"role"`
Content string `json:"content"`
ModelName string `json:"model_name,omitempty"`
+ CreatedAt *time.Time `json:"created_at,omitempty"`
Media []string `json:"media,omitempty"`
Attachments []Attachment `json:"attachments,omitempty"`
ReasoningContent string `json:"reasoning_content,omitempty"`
diff --git a/web/backend/api/session.go b/web/backend/api/session.go
index e221386ca..7375216ee 100644
--- a/web/backend/api/session.go
+++ b/web/backend/api/session.go
@@ -51,6 +51,7 @@ type sessionChatMessage struct {
Content string `json:"content"`
Kind string `json:"kind,omitempty"`
ModelName string `json:"model_name,omitempty"`
+ CreatedAt *time.Time `json:"created_at,omitempty"`
Media []string `json:"media,omitempty"`
Attachments []sessionChatAttachment `json:"attachments,omitempty"`
ToolCalls []utils.VisibleToolCall `json:"tool_calls,omitempty"`
@@ -512,6 +513,7 @@ func sessionTranscriptMessages(
Role: "user",
Content: msg.Content,
ModelName: msg.ModelName,
+ CreatedAt: msg.CreatedAt,
Media: append([]string(nil), msg.Media...),
Attachments: attachments,
}
@@ -533,8 +535,9 @@ func sessionTranscriptMessages(
msg.ToolCalls,
msg.ModelName,
toolFeedbackMaxArgsLength,
+ msg.CreatedAt,
)
- visibleToolMessages := visibleAssistantToolMessages(msg.ToolCalls, msg.ModelName)
+ visibleToolMessages := visibleAssistantToolMessages(msg.ToolCalls, msg.ModelName, msg.CreatedAt)
// Pico web chat can persist both visible `message` tool output and a
// later plain assistant reply in the same turn. Hide only the fixed
@@ -560,6 +563,7 @@ func sessionTranscriptMessages(
Role: "assistant",
Content: content,
ModelName: msg.ModelName,
+ CreatedAt: msg.CreatedAt,
Media: append([]string(nil), msg.Media...),
Attachments: attachments,
}
@@ -690,6 +694,7 @@ func assistantThoughtMessage(msg providers.Message) (sessionChatMessage, bool) {
Content: reasoning,
Kind: "thought",
ModelName: msg.ModelName,
+ CreatedAt: msg.CreatedAt,
}, true
}
@@ -697,6 +702,7 @@ func assistantToolCallsMessage(
toolCalls []providers.ToolCall,
modelName string,
toolFeedbackMaxArgsLength int,
+ createdAt *time.Time,
) (sessionChatMessage, bool) {
if len(toolCalls) == 0 {
return sessionChatMessage{}, false
@@ -714,6 +720,7 @@ func assistantToolCallsMessage(
Role: "assistant",
Kind: "tool_calls",
ModelName: modelName,
+ CreatedAt: createdAt,
ToolCalls: visibleToolCalls,
}, true
}
@@ -725,7 +732,7 @@ func visibleAssistantToolArgsPreview(
return utils.VisibleToolCallArgumentsPreview(tc, toolFeedbackMaxArgsLength)
}
-func visibleAssistantToolMessages(toolCalls []providers.ToolCall, modelName string) []sessionChatMessage {
+func visibleAssistantToolMessages(toolCalls []providers.ToolCall, modelName string, createdAt *time.Time) []sessionChatMessage {
if len(toolCalls) == 0 {
return nil
}
@@ -744,6 +751,7 @@ func visibleAssistantToolMessages(toolCalls []providers.ToolCall, modelName stri
Role: "assistant",
Content: content,
ModelName: modelName,
+ CreatedAt: createdAt,
})
}
@@ -926,6 +934,11 @@ func (h *Handler) handleGetSession(w http.ResponseWriter, r *http.Request) {
}
}
+ for i := range sess.Messages {
+ if sess.Messages[i].CreatedAt == nil {
+ sess.Messages[i].CreatedAt = &sess.Updated
+ }
+ }
messages := detailSessionMessages(sess.Messages, toolFeedbackMaxArgsLength)
w.Header().Set("Content-Type", "application/json")
diff --git a/web/frontend/src/api/sessions.ts b/web/frontend/src/api/sessions.ts
index 002a3c5d7..8c0c5e90c 100644
--- a/web/frontend/src/api/sessions.ts
+++ b/web/frontend/src/api/sessions.ts
@@ -14,6 +14,7 @@ export interface SessionDetail {
messages: {
role: "user" | "assistant"
content: string
+ created_at?: string
kind?: "normal" | "thought" | "tool_calls"
model_name?: string
media?: string[]
diff --git a/web/frontend/src/components/chat/assistant-message.tsx b/web/frontend/src/components/chat/assistant-message.tsx
index c8d0480f0..6527562fe 100644
--- a/web/frontend/src/components/chat/assistant-message.tsx
+++ b/web/frontend/src/components/chat/assistant-message.tsx
@@ -117,12 +117,17 @@ export function AssistantMessage({
{trimmedModelName}
)}
-
+ {formattedTimestamp && (
+ {formattedTimestamp}
)}
- />
+
+
)}
{(!isCollapsedBlock || isExpanded) && isToolCalls && hasToolCalls && (
diff --git a/web/frontend/src/components/chat/chat-page.tsx b/web/frontend/src/components/chat/chat-page.tsx
index 3b4cac730..3b158843c 100644
--- a/web/frontend/src/components/chat/chat-page.tsx
+++ b/web/frontend/src/components/chat/chat-page.tsx
@@ -384,6 +384,7 @@ export function ChatPage() {
)}
diff --git a/web/frontend/src/components/chat/user-message.tsx b/web/frontend/src/components/chat/user-message.tsx
index 44b873aac..80ebc7ca0 100644
--- a/web/frontend/src/components/chat/user-message.tsx
+++ b/web/frontend/src/components/chat/user-message.tsx
@@ -1,17 +1,23 @@
import { IconCheck, IconCopy } from "@tabler/icons-react"
+import { useTranslation } from "react-i18next"
import { Button } from "@/components/ui/button"
import { useCopyToClipboard } from "@/hooks/use-copy-to-clipboard"
+import { formatMessageTime } from "@/hooks/use-pico-chat"
import { cn } from "@/lib/utils"
import type { ChatAttachment } from "@/store/chat"
-import { useTranslation } from "react-i18next"
interface UserMessageProps {
content: string
attachments?: ChatAttachment[]
+ timestamp?: string | number
}
-export function UserMessage({ content, attachments = [] }: UserMessageProps) {
+export function UserMessage({
+ content,
+ attachments = [],
+ timestamp = "",
+}: UserMessageProps) {
const { t } = useTranslation()
const { copy, isCopied } = useCopyToClipboard()
const hasText = content.trim().length > 0
@@ -22,6 +28,8 @@ export function UserMessage({ content, attachments = [] }: UserMessageProps) {
const copyMessageLabel = isCopied
? t("chat.copiedLabel")
: t("chat.copyMessage")
+ const formattedTimestamp =
+ timestamp !== "" ? formatMessageTime(timestamp) : ""
return (
@@ -81,6 +89,12 @@ export function UserMessage({ content, attachments = [] }: UserMessageProps) {
)}
+
+ {formattedTimestamp && (
+
+ {formattedTimestamp}
+
+ )}
)
}
diff --git a/web/frontend/src/features/chat/history.ts b/web/frontend/src/features/chat/history.ts
index 72e9ff332..fffae5060 100644
--- a/web/frontend/src/features/chat/history.ts
+++ b/web/frontend/src/features/chat/history.ts
@@ -43,8 +43,6 @@ export async function loadSessionMessages(
sessionId: string,
): Promise {
const detail = await getSessionHistory(sessionId)
- const fallbackTime = detail.updated
-
return detail.messages.map((message, index) => ({
id: `hist-${index}-${Date.now()}`,
role: message.role,
@@ -59,7 +57,7 @@ export async function loadSessionMessages(
media: message.media,
attachments: message.attachments,
}),
- timestamp: fallbackTime,
+ timestamp: message.created_at ?? detail.updated,
}))
}