BoundaryML/baml · error

failed to get SSE chunks

Error message

failed to get SSE chunks: %w

What it means

llmStreamCall.SSEChunks() calls the native "sse_chunks" method; any error from that FFI invocation is wrapped as "failed to get SSE chunks: %w". It signals the runtime could not return the chunk list for this stream call handle.

Solutions

1. Read the wrapped cause to identify the FFI failure
2. Collect SSEChunks() while the stream/runtime is still alive
3. Re-run the stream and read chunks from the new stream call
4. Match generated client and native runtime versions

Example fix

// before
chunks, err := streamCall.SSEChunks()
// after
chunks, err := streamCall.SSEChunks()
if err != nil {
    return fmt.Errorf("sse chunks unavailable: %w", err)
}

// Go
chunks, err := streamCall.SSEChunks()
if err != nil {
    return fmt.Errorf("sse chunks unavailable: %w", err)
}

When it happens

Trigger: Calling SSEChunks() on an llmStreamCall whose native object was invalidated, after stream teardown, or when the runtime errors internally while collecting chunks.

Common situations: Reading chunks after the BAML runtime shut down; using a stream call from an aborted/failed stream; native library and generated client version mismatch.

Related errors

• failed to get text
• unexpected type for SSE chunks: %T
• __class_getitem__ for streaming
• decodeLiteralValue: valueLiteral is nil
• destructor returned unexpected result

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/fa49d5ae643e3d2d. Report an issue: GitHub.

Appendix: source

Thrown at engine/language_client_go/pkg/rawobjects_llm_stream_call.go:26

	"github.com/boundaryml/baml/engine/language_client_go/pkg/cffi"
)

type llmStreamCall struct {
	*llmCall
}

func newLLMStreamCall(ptr int64, rt unsafe.Pointer) LLMStreamCall {
	return &llmStreamCall{&llmCall{raw_objects.FromPointer(ptr, rt)}}
}

func (l *llmStreamCall) ObjectType() cffi.BamlObjectType {
	return cffi.BamlObjectType_OBJECT_LLM_STREAM_CALL
}

func (l *llmStreamCall) SSEChunks() ([]SSEResponse, error) {
	result, err := raw_objects.CallMethod(l, "sse_chunks", nil)
	if err != nil {
		return nil, fmt.Errorf("failed to get SSE chunks: %w", err)
	}

	casted, ok := result.([]raw_objects.RawPointer)
	if !ok {
		return nil, fmt.Errorf("unexpected type for SSE chunks: %T", result)
	}

	chunks := make([]SSEResponse, len(casted))
	for i, chunk := range casted {
		chunks[i] = chunk.(SSEResponse)
	}

	return chunks, nil
}

View on GitHub (pinned to bd85ce9dee)