* Studio: wire OpenAI image_generation tool
OpenAI's Responses API exposes server-side image generation as a
tool entry (`{type: "image_generation"}`); the result comes back as
an `image_generation_call` output item with the base64 image on
`result`, the actual prompt used on `revised_prompt`, plus `size`,
`quality`, `output_format`, `background`. The model decides when to
call the tool based on the user's request; rendering uses one of
the gpt-image-* backbones server-side.
Available on every gpt-5.x family member plus gpt-4.1, gpt-4o, o3,
o4-mini per the docs.
Changes:
- Append `{type:"image_generation"}` to the Responses request tools
array when `enabled_tools` carries `image_generation` AND the base
URL points at cloud OpenAI. Non-cloud bases (ollama, llama.cpp,
"custom" presets that collapse to provider="openai") silently drop
the tool to avoid 400s.
- Mirror the same logic in `_build_body` (the post-expiry retry
builder) so retries carry the same tool set as the original
attempt.
- Handle `image_generation_call` items in
`response.output_item.done`: emit `tool_start` with
`arguments:{kind:"image", prompt:<revised_prompt>}` and `tool_end`
with `image_b64`, `image_mime`, `size`, `quality`, `background`
so the chat adapter can render an inline preview. Image bytes go
on the tool_end chunk; no extra fields on the chat-completions
envelope so the OpenAI SDK shape stays clean.
- Add `import time` (used for synthesised tool_call_id fallback).
- Add `test_openai_image_generation.py` with 5 cases: tool entry on
cloud OpenAI, combined with web_search + code_execution
(verifies all three coexist), non-cloud drop, omitted pill leaves
body untouched, output item translation produces the expected
tool_start + tool_end chunks.
Live verified end-to-end: `gpt-5.4-mini` with `image_generation`
tool returned an `image_generation_call` carrying ~1MB of base64
PNG plus the gpt-image backbone's revised prompt.
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* Use time.time_ns() for synthesised image_generation tool_call_id
Gemini medium on PR #5688: `int(time.time() * 1000)` has 1ms
resolution; two image generations resolving in the same millisecond
would collide on the synthesised id. Bump to nanoseconds.
(In practice the upstream `image_generation_call` item always carries
its own `id`; the synthesised fallback only fires when OpenAI omits
it -- rare, but cheap to harden.)
---------
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
5b41872e8b