[yoruuuchan]

Summary

• A streamed Codex tool call goes out with an empty function.name. The Responses stream puts the name on response.output_item.added's item; the function_call_arguments.* events that follow carry only item_id. sse.go parsed the item for type/status only, so the chunk that announces the call sent name: "".
• Consequence for a client: it cannot dispatch a call whose name is empty (DSH reports unknown tool ""), and once that empty name is replayed in the request history the upstream rejects every later turn with Invalid 'input[6].name': empty string. Expected a string with minimum length 1, but got an empty string instead.
• Fix: record item.name / item.call_id per output_index when the item is a function_call (or custom_tool_call), and use them when the call is announced. Non-tool items are skipped, so a reasoning item neither takes a tool-call index nor emits a chunk.

Reproduction

Same request, one field differs:

mode	returned tool call
stream: false	{"id":"call_…","type":"function","function":{"name":"get_weather","arguments":"{\"city\":\"Tokyo\"}"}}
stream: true	{"index":0,"id":"fc_…","type":"function","function":{"name":"","arguments":"{\"city\":\"Tokyo\"}"}}

Test plan

• go test ./internal/providers/codex/ -count=1 — green
• go vet ./... — green
• go test ./... — not green in this environment, on origin/main as well: internal/api, internal/executor, internal/providers/qoder, internal/runtime, internal/store fail on a clean f16d802 worktree (Windows path handling and a missing qodercli in PATH). internal/providers/codex passes both before and after this diff.
• cd worker && npm test — no worker changes in this diff
• cd frontend && npm run build && npm run lint — no frontend changes in this diff
• Added changelog/unreleased/codex-stream-tool-name.md
• No tokens, auth blobs, raw captures, or host details in the diff

New tests in internal/providers/codex/sse_test.go:

• TestRewriteStreamKeepsToolNameFromOutputItem — fails before the change with "name":"" in the announcing chunk, passes after.
• TestRewriteStreamIgnoresNonToolOutputItems — a reasoning item must not consume tool-call index 0 or emit a chunk.

[caigee-cmd]

The empty function.name on streamed Codex tool calls is a real client-breaking bug: the name lives on response.output_item.added, and the argument events that follow only carry item_id. Recording name / call_id there, skipping non-tool items so a reasoning item cannot steal index 0, and covering both with tests is the right fix.

Changelog fragment is bilingual. Approving.