console: OA-compat stream conversion drops tool_calls when a chunk also has content

Description

fromOaCompatibleChunk splits a single SSE chunk that contains both delta.content and delta.tool_calls into two choices entries. toOaCompatibleChunk and toAnthropicChunk only read choices[0], so the tool call is dropped.

Reproduced on current dev with a one-chunk payload:

{"choices":[{"delta":{"content":"fox","tool_calls":[{"index":0,"id":"call_1","type":"function","function":{"name":"get_time","arguments":"{}"}}]}}]}

After fromOaCompatibleChunk → toOaCompatibleChunk / toAnthropicChunk, only the text "fox" remains. The get_time tool call is gone.

This is the format converter used when Zen translates OA-compat streams to another provider format (and back). Same-format passthrough is unaffected.

Plugins

None

OpenCode version

dev (c7134cb)

Steps to reproduce

1. Import fromOaCompatibleChunk and toOaCompatibleChunk from packages/console/app/src/routes/zen/util/provider/openai-compatible.ts.
2. Feed the chunk above (as data: {...}).
3. Convert back with toOaCompatibleChunk.
4. Observe that tool_calls is missing.

Screenshot and/or share link

No response

Operating System

Linux

Terminal

n/a (unit-level)