What causes "no memory service" in Tencent/WeKnora?

Initialize and pass a valid memory service when constructing SearchMemoryTool.

no memory service

Error message

no memory service

What it means

SearchMemoryTool.Execute returns "no memory service" when the tool's memoryService dependency is nil, meaning long-term memory is not wired up. The tool returns ToolResult Success=false with Error="long-term memory is not available" plus this error. It is a dependency-injection guard: the tool exists but its backing store was never configured.

Source

Thrown at internal/agent/tools/search_memory.go:108

	var input SearchMemoryInput
	if err := json.Unmarshal(args, &input); err != nil {
		return &types.ToolResult{
			Success: false,
			Error:   fmt.Sprintf("Failed to parse args: %v", err),
		}, err
	}
	query := strings.TrimSpace(input.Query)
	if query == "" {
		return &types.ToolResult{
			Success: false,
			Error:   "query is required",
		}, fmt.Errorf("missing query")
	}
	if t.memoryService == nil {
		return &types.ToolResult{
			Success: false,
			Error:   "long-term memory is not available",
		}, fmt.Errorf("no memory service")
	}

	limit := input.Limit
	if limit <= 0 {
		limit = types.MemorySearchDefaultItems
	}
	if limit > types.MemorySearchMaxItems {
		limit = types.MemorySearchMaxItems
	}

	result := t.memoryService.SearchMemory(ctx, query, limit)

	// "Switched off" and "nothing stored matches" have to reach the model as
	// different answers. Reporting an empty store to someone who turned memory
	// off would have the agent tell them it knows nothing about them, which is
	// both wrong and the opposite of what disabling memory was meant to do.
	if !result.Available {
		return &types.ToolResult{

View on GitHub (pinned to 988cbb0330)

Solutions

Initialize and pass a valid memory service when constructing SearchMemoryTool.
Unregister or skip registering the search-memory tool when long-term memory is disabled.
Verify memory backend configuration/connection at startup before the agent runs.

Example fix

// before
tool := tools.NewSearchMemoryTool(nil) // nil memoryService
// after
memSvc, err := memory.NewService(cfg.Memory)
if err != nil {
    return fmt.Errorf("init memory service: %w", err)
}
tool := tools.NewSearchMemoryTool(memSvc)

Defensive patterns

Strategy: type-guard

Validate before calling

if memSvc == nil {
    return errors.New("cannot register search-memory tool: memory service not configured")
}

Type guard

func memoryAvailable(t *tools.SearchMemoryTool, svc memory.Service) bool { return svc != nil }

Try / catch

res, err := tool.Execute(ctx, input)
if err != nil && strings.Contains(err.Error(), "no memory service") {
    // degrade gracefully: skip memory search or answer without recall
}

Prevention

Initialize the memory service during startup and fail fast if it is nil
Only register memory tools when the memory backend is enabled
Add a startup health check for the memory backend connection

When it happens

Trigger: Executing SearchMemoryTool after constructing it without a memory service (New... called with nil), or in a build/configuration where long-term memory is disabled but the tool is still registered with the agent.

Common situations: Memory backend (e.g. vector store) not initialized at startup; feature flag disabling long-term memory while tools are registered unconditionally; constructor dependency accidentally passed as nil; config missing memory connection settings.

Related errors

AI-assisted analysis of Tencent/WeKnora@988cbb0330 (2026-09-02). Data as JSON: /api/errors/3b18feffc3bc86a9. Report an issue: GitHub.