Greptile Summary

This PR fixes a serialization issue where an empty name field in a FunctionCall struct was being included in JSON output as \"name\": \"\", which causes some LLM providers to reject the request. The fix adds omitempty to the JSON tag so an empty name is silently omitted from the payload.

• FunctionCall.Name is now tagged json:\"name,omitempty\", preventing \"name\": \"\" from appearing in serialized function call payloads — which is relevant during streaming aggregation where the function name arrives in a later delta chunk.
• No test is added to assert the new serialization behavior, leaving the fix without direct regression coverage.

Confidence Score: 4/5

The change is isolated to one JSON struct tag, only affects marshaling (not unmarshaling), and corrects a real compatibility problem with providers that reject "name":"". Safe to merge.

The one-line tag addition correctly eliminates an empty name field from serialized function call payloads, which is the right behavior for both streaming aggregation and pass-through scenarios. The only gap is the absence of a direct unit test asserting the new serialization behavior, leaving the fix unguarded against future regressions.

llm/transformer/openai/model.go — the only changed file; no new test accompanies the fix.

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant Stream as Streaming Provider
    participant Agg as aggregator.go
    participant Conv as outbound_convert.go (ToolCallFromLLM)
    participant JSON as JSON Serializer
    participant Downstream as Downstream LLM Provider

    Stream->>Agg: "delta chunk (name="", arguments="")"
    Note over Agg: Initialize ToolCall with empty Name
    Agg->>Agg: "delta chunk (name="get_weather", arguments="{}")"
    Note over Agg: Update Name to "get_weather"
    Agg->>Conv: "llm.ToolCall{Name: ""}  [partial/forwarded]"
    Conv->>JSON: "FunctionCall{Name: "", Arguments: "..."}"
    Note over JSON: Before fix: emits name:""<br/>After fix (omitempty): name key omitted
    JSON->>Downstream: "{"function": {"arguments": "..."}}"
    Note over Downstream: Accepts payload without empty name field

_{Reviews (1): Last reviewed commit: "fix: should omit empty name for function..." | Re-trigger Greptile}