streamed function name does not match the terminal response

Error message

streamed function name does not match the terminal response

What it means

The adapter compares the function name accumulated from stream deltas (current.Function.Name) with the terminal item.Name whenever both are non-empty. A mismatch means the streamed deltas and the final response disagree about which function to call, so dispatching on either value alone is unsafe and the stream fails.

Source

Thrown at kernel/util/openai_completion.go:524

		}
	}
	output, err := MarshalOpenAIResponseOutput(response.Output)
	if err != nil {
		return err
	}
	stream.responseOutput = output

	for index, raw := range response.Output {
		item, ok := responseOutputItem(raw)
		if !ok || item.Type != "function_call" {
			continue
		}
		current := stream.responseToolCalls[index]
		if current.ID != "" && item.CallID != "" && current.ID != item.CallID {
			return errors.New("streamed function call ID does not match the terminal response")
		}
		if current.Function.Name != "" && item.Name != "" && current.Function.Name != item.Name {
			return errors.New("streamed function name does not match the terminal response")
		}
		if current.Function.Arguments != item.Arguments &&
			!strings.HasPrefix(item.Arguments, current.Function.Arguments) {
			return errors.New("streamed function arguments do not match the terminal response")
		}
		delta := openai.ToolCall{Type: openai.ToolTypeFunction}
		deltaIndex := index
		delta.Index = &deltaIndex
		changed := false
		if current.ID == "" && item.CallID != "" {
			delta.ID = item.CallID
			changed = true
		}
		if current.Function.Name == "" && item.Name != "" {
			delta.Function.Name = item.Name
			changed = true
		}
		if current.Function.Arguments != item.Arguments && strings.HasPrefix(item.Arguments, current.Function.Arguments) {

View on GitHub (pinned to afa823b6b4)

Solutions

Retry the request once — transient inconsistencies often clear.
Reproduce against the official OpenAI endpoint; if clean there, upgrade or replace the gateway.
Disable streaming for tool calls on the affected provider.
Capture an SSE trace and report the name divergence.

Defensive patterns

Strategy: retry

Try / catch

Drop the partial stream state and re-issue the request; if the same function name keeps diverging, route that provider's tool calls through non-streaming requests.

Prevention

Verify gateway tool-schema handling before enabling streaming tools
Keep gateway and SDK versions aligned
Alert on repeated stream-versus-terminal mismatches

When it happens

Trigger: Gateways that rename or alias functions between streaming and finalization; parallel calls with server-side index swaps pairing the wrong name with accumulated state; event middleware rewriting function names.

Common situations: OpenAI-compatible gateways with tool-name normalization; mid-stream failover to a backend with a different tool schema.

Related errors

AI-assisted analysis of siyuan-note/siyuan@afa823b6b4 (2026-08-18). Data as JSON: /api/errors/fa1bf43a2858f411. Report an issue: GitHub.