nanobot/nanobot/providers/image_generation.py
moran 2d302a006e feat(image-generation): add StepFun provider support and StepPlan docs
- Add StepFunImageGenerationClient with step-image-edit-2 / step-1x-medium support
- Map aspect ratios to StepFun size strings (WxH order)
- Add style_reference for step-1x-medium reference-image generation
- Register in image gen provider registry (auto-discovered by nanobot.py)
- Add 7 unit tests: payload, default size, explicit size, style_reference (1x/non-1x), missing key, no-images
- Add StepFun section to docs/image-generation.md with provider config
- Add StepPlan (订阅制) subsection with apiBase override example
2026-05-20 00:08:38 +08:00

891 lines
29 KiB
Python

"""Image generation provider helpers."""
from __future__ import annotations
import base64
import binascii
from abc import ABC, abstractmethod
from dataclasses import dataclass
from pathlib import Path
from typing import Any
import httpx
from loguru import logger
from nanobot.providers.registry import find_by_name
from nanobot.utils.helpers import detect_image_mime
_OPENROUTER_ATTRIBUTION_HEADERS = {
"HTTP-Referer": "https://github.com/HKUDS/nanobot",
"X-OpenRouter-Title": "nanobot",
"X-OpenRouter-Categories": "cli-agent,personal-agent",
}
_DEFAULT_TIMEOUT_S = 120.0
_AIHUBMIX_TIMEOUT_S = 300.0
_AIHUBMIX_ASPECT_RATIO_SIZES = {
"1:1": "1024x1024",
"3:4": "1024x1536",
"9:16": "1024x1536",
"4:3": "1536x1024",
"16:9": "1536x1024",
}
_GEMINI_DEFAULT_TIMEOUT_S = 120.0
_GEMINI_IMAGEN_ASPECT_RATIOS = {"1:1", "9:16", "16:9", "3:4", "4:3"}
class ImageGenerationError(RuntimeError):
"""Raised when the image generation provider cannot return images."""
@dataclass(frozen=True)
class GeneratedImageResponse:
"""Images and optional text returned by the provider."""
images: list[str]
content: str
raw: dict[str, Any]
def _read_image_b64(path: str | Path) -> tuple[str, str]:
"""Return ``(mime, base64)`` for the image at ``path``."""
p = Path(path).expanduser()
raw = p.read_bytes()
mime = detect_image_mime(raw)
if mime is None:
raise ImageGenerationError(f"unsupported reference image: {p}")
return mime, base64.b64encode(raw).decode("ascii")
def image_path_to_data_url(path: str | Path) -> str:
"""Convert a local image path to an image data URL."""
mime, encoded = _read_image_b64(path)
return f"data:{mime};base64,{encoded}"
def image_path_to_inline_data(path: str | Path) -> dict[str, str]:
"""Convert a local image path to a Gemini ``inlineData`` payload dict."""
mime, encoded = _read_image_b64(path)
return {"mimeType": mime, "data": encoded}
def _b64_image_data_url(value: str) -> str:
encoded = "".join(value.split())
try:
raw = base64.b64decode(encoded, validate=True)
except binascii.Error as exc:
raise ImageGenerationError("generated image payload was not valid base64") from exc
mime = detect_image_mime(raw)
if mime is None:
raise ImageGenerationError("generated image payload was not a supported image")
return f"data:{mime};base64,{encoded}"
def _aihubmix_size(aspect_ratio: str | None, image_size: str | None) -> str:
"""Return an OpenAI Images API size string for AIHubMix.
The WebUI emits compact size hints like ``1K`` for OpenRouter. AIHubMix's
Images API expects OpenAI-style dimensions or ``auto``, so only pass
through explicit dimension strings and otherwise derive the closest
supported orientation from aspect ratio.
"""
if image_size and "x" in image_size.lower():
return image_size
if aspect_ratio in _AIHUBMIX_ASPECT_RATIO_SIZES:
return _AIHUBMIX_ASPECT_RATIO_SIZES[aspect_ratio]
return "auto"
def _aihubmix_model_path(model: str) -> str:
if "/" in model:
return model
if model.startswith(("gpt-image-", "dall-e-")):
return f"openai/{model}"
return model
async def _download_image_data_url(
client: httpx.AsyncClient,
url: str,
) -> str:
response = await client.get(url)
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = response.text[:500]
raise ImageGenerationError(f"failed to download generated image: {detail}") from exc
raw = response.content
mime = detect_image_mime(raw)
if mime is None:
raise ImageGenerationError("generated image URL did not return a supported image")
encoded = base64.b64encode(raw).decode("ascii")
return f"data:{mime};base64,{encoded}"
# ---------------------------------------------------------------------------
# Registry
# ---------------------------------------------------------------------------
_IMAGE_GEN_PROVIDERS: dict[str, type[ImageGenerationProvider]] = {}
def register_image_gen_provider(cls: type[ImageGenerationProvider]) -> None:
name = cls.provider_name
if not name:
raise ValueError(f"{cls.__name__} must set provider_name")
_IMAGE_GEN_PROVIDERS[name] = cls
def get_image_gen_provider(name: str) -> type[ImageGenerationProvider] | None:
return _IMAGE_GEN_PROVIDERS.get(name)
def image_gen_provider_names() -> tuple[str, ...]:
"""Return registered image generation provider names in registry order."""
return tuple(_IMAGE_GEN_PROVIDERS)
def image_gen_provider_configs(config: Any) -> dict[str, Any]:
providers_cfg = config.providers
return {
name: pc
for name in _IMAGE_GEN_PROVIDERS
if (pc := getattr(providers_cfg, name, None)) is not None
}
# ---------------------------------------------------------------------------
# Base class
# ---------------------------------------------------------------------------
class ImageGenerationProvider(ABC):
"""Base class for image generation provider clients."""
provider_name: str = ""
missing_key_message: str = ""
default_timeout: float = _DEFAULT_TIMEOUT_S
def __init__(
self,
*,
api_key: str | None,
api_base: str | None = None,
extra_headers: dict[str, str] | None = None,
extra_body: dict[str, Any] | None = None,
timeout: float | None = None,
client: httpx.AsyncClient | None = None,
) -> None:
self.api_key = api_key
self.api_base = self._resolve_base_url(api_base)
self.extra_headers = extra_headers or {}
self.extra_body = extra_body or {}
self.timeout = timeout if timeout is not None else self.default_timeout
self._client = client
def _resolve_base_url(self, api_base: str | None) -> str:
if api_base:
return api_base.rstrip("/")
spec = find_by_name(self.provider_name)
if spec and spec.default_api_base:
return spec.default_api_base.rstrip("/")
return self._default_base_url()
def _default_base_url(self) -> str:
return ""
@abstractmethod
async def generate(
self,
*,
prompt: str,
model: str,
reference_images: list[str] | None = None,
aspect_ratio: str | None = None,
image_size: str | None = None,
) -> GeneratedImageResponse: ...
def _require_images(self, images: list[str], data: dict[str, Any]) -> None:
if images:
return
provider_error = data.get("error") if isinstance(data, dict) else None
label = self.provider_name
if provider_error:
raise ImageGenerationError(f"{label} returned no images: {provider_error}")
raise ImageGenerationError(f"{label} returned no images for this request")
async def _http_post(
self,
url: str,
*,
headers: dict[str, str],
body: dict[str, Any],
) -> httpx.Response:
if self._client is not None:
return await self._client.post(url, headers=headers, json=body)
async with httpx.AsyncClient(timeout=self.timeout) as c:
return await c.post(url, headers=headers, json=body)
class OpenRouterImageGenerationClient(ImageGenerationProvider):
"""Small async client for OpenRouter Chat Completions image generation."""
provider_name = "openrouter"
missing_key_message = (
"OpenRouter API key is not configured. Set providers.openrouter.apiKey."
)
def _default_base_url(self) -> str:
return "https://openrouter.ai/api/v1"
async def generate(
self,
*,
prompt: str,
model: str,
reference_images: list[str] | None = None,
aspect_ratio: str | None = None,
image_size: str | None = None,
) -> GeneratedImageResponse:
if not self.api_key:
raise ImageGenerationError(self.missing_key_message)
content: str | list[dict[str, Any]]
references = list(reference_images or [])
if references:
blocks: list[dict[str, Any]] = [{"type": "text", "text": prompt}]
blocks.extend(
{"type": "image_url", "image_url": {"url": image_path_to_data_url(path)}}
for path in references
)
content = blocks
else:
content = prompt
body: dict[str, Any] = {
"model": model,
"messages": [{"role": "user", "content": content}],
"modalities": ["image", "text"],
"stream": False,
}
image_config: dict[str, str] = {}
if aspect_ratio:
image_config["aspect_ratio"] = aspect_ratio
if image_size:
image_config["image_size"] = image_size
if image_config:
body["image_config"] = image_config
body.update(self.extra_body)
headers = {
"Authorization": f"Bearer {self.api_key}",
"Content-Type": "application/json",
**_OPENROUTER_ATTRIBUTION_HEADERS,
**self.extra_headers,
}
url = f"{self.api_base}/chat/completions"
response = await self._http_post(url, headers=headers, body=body)
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = response.text[:500]
raise ImageGenerationError(f"OpenRouter image generation failed: {detail}") from exc
data = response.json()
images: list[str] = []
text_parts: list[str] = []
for choice in data.get("choices") or []:
if not isinstance(choice, dict):
continue
message = choice.get("message") or {}
if isinstance(message.get("content"), str):
text_parts.append(message["content"])
for image in message.get("images") or []:
if not isinstance(image, dict):
continue
image_url = image.get("image_url") or image.get("imageUrl") or {}
url_value = image_url.get("url") if isinstance(image_url, dict) else None
if isinstance(url_value, str) and url_value.startswith("data:image/"):
images.append(url_value)
self._require_images(images, data)
return GeneratedImageResponse(
images=images,
content="\n".join(part for part in text_parts if part).strip(),
raw=data,
)
class AIHubMixImageGenerationClient(ImageGenerationProvider):
"""Small async client for AIHubMix unified image generation."""
provider_name = "aihubmix"
missing_key_message = (
"AIHubMix API key is not configured. Set providers.aihubmix.apiKey."
)
default_timeout = _AIHUBMIX_TIMEOUT_S
def _default_base_url(self) -> str:
return "https://aihubmix.com/v1"
async def generate(
self,
*,
prompt: str,
model: str,
reference_images: list[str] | None = None,
aspect_ratio: str | None = None,
image_size: str | None = None,
) -> GeneratedImageResponse:
if not self.api_key:
raise ImageGenerationError(self.missing_key_message)
refs = list(reference_images or [])
headers = {
"Authorization": f"Bearer {self.api_key}",
**self.extra_headers,
}
size = _aihubmix_size(aspect_ratio, image_size)
client = self._client or httpx.AsyncClient(timeout=self.timeout)
try:
return await self._generate_with_client(
client,
prompt=prompt,
model=model,
reference_images=refs,
size=size,
headers=headers,
)
finally:
if self._client is None:
await client.aclose()
async def _generate_with_client(
self,
client: httpx.AsyncClient,
*,
prompt: str,
model: str,
reference_images: list[str],
size: str,
headers: dict[str, str],
) -> GeneratedImageResponse:
image_input: str | list[str] | None = None
if reference_images:
image_refs = [image_path_to_data_url(path) for path in reference_images]
image_input = image_refs[0] if len(image_refs) == 1 else image_refs
input_body: dict[str, Any] = {
"prompt": prompt,
"n": 1,
"size": size,
}
if image_input is not None:
input_body["image"] = image_input
input_body.update(self.extra_body)
body = {"input": input_body}
model_path = _aihubmix_model_path(model)
url = f"{self.api_base}/models/{model_path}/predictions"
try:
response = await client.post(
url,
headers={**headers, "Content-Type": "application/json"},
json=body,
)
except httpx.TimeoutException as exc:
raise ImageGenerationError("AIHubMix image generation timed out") from exc
except httpx.RequestError as exc:
raise ImageGenerationError(f"AIHubMix image generation request failed: {exc}") from exc
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = response.text[:500]
raise ImageGenerationError(f"AIHubMix image generation failed: {detail}") from exc
payload = response.json()
images = await _aihubmix_images_from_payload(client, payload)
self._require_images(images, payload)
return GeneratedImageResponse(images=images, content="", raw=payload)
def _http_error_detail(response: httpx.Response) -> str:
"""Extract a readable error message from an HTTP error response."""
try:
data = response.json()
if isinstance(data, dict):
err = data.get("error")
if isinstance(err, dict):
return err.get("message") or str(err)
if err:
return str(err)
except Exception:
pass
return response.text[:500] or "<empty response body>"
class GeminiImageGenerationClient(ImageGenerationProvider):
"""Async client for Gemini/Imagen image generation via the Generative Language API."""
provider_name = "gemini"
missing_key_message = (
"Gemini API key is not configured. Set providers.gemini.apiKey."
)
default_timeout = _GEMINI_DEFAULT_TIMEOUT_S
def _default_base_url(self) -> str:
return "https://generativelanguage.googleapis.com/v1beta"
def _resolve_base_url(self, api_base: str | None) -> str:
# The Gemini provider's registry default_api_base is the OpenAI-compat
# shim (.../v1beta/openai/), which has no image endpoints.
# Skip the registry lookup and use the native API base directly.
if api_base:
return api_base.rstrip("/")
return self._default_base_url()
async def generate(
self,
*,
prompt: str,
model: str,
reference_images: list[str] | None = None,
aspect_ratio: str | None = None,
image_size: str | None = None,
) -> GeneratedImageResponse:
if not self.api_key:
raise ImageGenerationError(self.missing_key_message)
if "imagen" in model.lower():
if reference_images:
logger.warning(
"Imagen models do not support reference images; "
"ignoring {} reference image(s) for {}",
len(reference_images),
model,
)
return await self._generate_imagen(
prompt=prompt, model=model, aspect_ratio=aspect_ratio
)
return await self._generate_gemini_flash(
prompt=prompt, model=model, reference_images=reference_images or []
)
async def _generate_imagen(
self,
*,
prompt: str,
model: str,
aspect_ratio: str | None,
) -> GeneratedImageResponse:
parameters: dict[str, Any] = {"sampleCount": 1}
if aspect_ratio in _GEMINI_IMAGEN_ASPECT_RATIOS:
parameters["aspectRatio"] = aspect_ratio
body: dict[str, Any] = {
"instances": [{"prompt": prompt}],
"parameters": parameters,
}
body.update(self.extra_body)
url = f"{self.api_base}/models/{model}:predict"
headers = {
"x-goog-api-key": self.api_key or "",
"Content-Type": "application/json",
**self.extra_headers,
}
response = await self._http_post(url, headers=headers, body=body)
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = _http_error_detail(response)
logger.error("Gemini Imagen generation failed (HTTP {}): {}", response.status_code, detail)
raise ImageGenerationError(
f"Gemini Imagen generation failed (HTTP {response.status_code}): {detail}"
) from exc
data = response.json()
images: list[str] = []
for prediction in data.get("predictions") or []:
if not isinstance(prediction, dict):
continue
b64 = prediction.get("bytesBase64Encoded")
mime = prediction.get("mimeType", "image/png")
if isinstance(b64, str) and b64:
images.append(f"data:{mime};base64,{b64}")
self._require_images(images, data)
return GeneratedImageResponse(images=images, content="", raw=data)
async def _generate_gemini_flash(
self,
*,
prompt: str,
model: str,
reference_images: list[str],
) -> GeneratedImageResponse:
parts: list[dict[str, Any]] = [
{"inlineData": image_path_to_inline_data(path)} for path in reference_images
]
parts.append({"text": prompt})
body: dict[str, Any] = {
"contents": [{"role": "user", "parts": parts}],
"generationConfig": {"responseModalities": ["TEXT", "IMAGE"]},
}
body.update(self.extra_body)
url = f"{self.api_base}/models/{model}:generateContent"
headers = {
"x-goog-api-key": self.api_key or "",
"Content-Type": "application/json",
**self.extra_headers,
}
response = await self._http_post(url, headers=headers, body=body)
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = _http_error_detail(response)
logger.error("Gemini image generation failed (HTTP {}): {}", response.status_code, detail)
raise ImageGenerationError(
f"Gemini image generation failed (HTTP {response.status_code}): {detail}"
) from exc
data = response.json()
images: list[str] = []
text_parts: list[str] = []
for candidate in data.get("candidates") or []:
if not isinstance(candidate, dict):
continue
content = candidate.get("content") or {}
for part in content.get("parts") or []:
if not isinstance(part, dict):
continue
if "text" in part:
text_parts.append(part["text"])
inline = part.get("inlineData")
if isinstance(inline, dict):
mime = inline.get("mimeType", "image/png")
b64 = inline.get("data", "")
if b64:
images.append(f"data:{mime};base64,{b64}")
self._require_images(images, data)
return GeneratedImageResponse(
images=images,
content="\n".join(t for t in text_parts if t).strip(),
raw=data,
)
async def _aihubmix_images_from_payload(
client: httpx.AsyncClient,
payload: dict[str, Any],
) -> list[str]:
images: list[str] = []
candidates: list[Any] = []
if "data" in payload:
candidates.append(payload["data"])
if "output" in payload:
candidates.append(payload["output"])
async def collect(value: Any) -> None:
if isinstance(value, list):
for item in value:
await collect(item)
return
if isinstance(value, str):
if value.startswith("data:image/"):
images.append(value)
elif value.startswith(("http://", "https://")):
images.append(await _download_image_data_url(client, value))
return
if not isinstance(value, dict):
return
b64_json = value.get("b64_json")
if isinstance(b64_json, str) and b64_json:
images.append(_b64_image_data_url(b64_json))
elif b64_json is not None:
await collect(b64_json)
bytes_base64 = value.get("bytesBase64") or value.get("bytes_base64") or value.get("base64")
if isinstance(bytes_base64, str) and bytes_base64:
images.append(_b64_image_data_url(bytes_base64))
image_url = value.get("image_url") or value.get("imageUrl")
if isinstance(image_url, dict):
await collect(image_url.get("url"))
elif image_url is not None:
await collect(image_url)
url_value = value.get("url")
if url_value is not None:
await collect(url_value)
for key in ("images", "image", "output"):
if key in value:
await collect(value[key])
for candidate in candidates:
await collect(candidate)
return images
_MINIMAX_TIMEOUT_S = 300.0
_MINIMAX_ASPECT_RATIO_SIZES = {
"1:1": "1:1",
"16:9": "16:9",
"4:3": "4:3",
"3:2": "3:2",
"2:3": "2:3",
"3:4": "3:4",
"9:16": "9:16",
"21:9": "21:9",
}
class MiniMaxImageGenerationClient(ImageGenerationProvider):
"""Async client for MiniMax image generation API."""
provider_name = "minimax"
missing_key_message = (
"MiniMax API key is not configured. Set providers.minimax.apiKey."
)
default_timeout = _MINIMAX_TIMEOUT_S
def _default_base_url(self) -> str:
return "https://api.minimaxi.com/v1"
def _resolve_aspect_ratio(self, aspect_ratio: str | None) -> str:
if aspect_ratio and aspect_ratio in _MINIMAX_ASPECT_RATIO_SIZES:
return _MINIMAX_ASPECT_RATIO_SIZES[aspect_ratio]
return "1:1"
async def generate(
self,
*,
prompt: str,
model: str,
reference_images: list[str] | None = None,
aspect_ratio: str | None = None,
image_size: str | None = None,
) -> GeneratedImageResponse:
if not self.api_key:
raise ImageGenerationError(self.missing_key_message)
headers = {
"Authorization": f"Bearer {self.api_key}",
"Content-Type": "application/json",
**self.extra_headers,
}
body: dict[str, Any] = {
"model": model,
"prompt": prompt,
"response_format": "base64",
}
resolved_ratio = self._resolve_aspect_ratio(aspect_ratio)
body["aspect_ratio"] = resolved_ratio
refs = list(reference_images or [])
if refs:
image_refs = [image_path_to_data_url(path) for path in refs]
body["subject_reference"] = [
{"type": "character", "image_file": ref} for ref in image_refs
]
body.update(self.extra_body)
client = self._client or httpx.AsyncClient(timeout=self.timeout)
try:
return await self._generate_with_client(client, body, headers)
finally:
if self._client is None:
await client.aclose()
async def _generate_with_client(
self,
client: httpx.AsyncClient,
body: dict[str, Any],
headers: dict[str, str],
) -> GeneratedImageResponse:
url = f"{self.api_base}/image_generation"
try:
response = await client.post(url, headers=headers, json=body)
except httpx.TimeoutException as exc:
raise ImageGenerationError("MiniMax image generation timed out") from exc
except httpx.RequestError as exc:
raise ImageGenerationError(f"MiniMax image generation request failed: {exc}") from exc
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = response.text[:500]
raise ImageGenerationError(f"MiniMax image generation failed: {detail}") from exc
payload = response.json()
images = _minimax_images_from_payload(payload)
self._require_images(images, payload)
return GeneratedImageResponse(images=images, content="", raw=payload)
def _minimax_images_from_payload(payload: dict[str, Any]) -> list[str]:
"""Extract base64 images from MiniMax API response.
MiniMax returns images in ``data.image_base64`` (list of base64 strings).
"""
images: list[str] = []
data = payload.get("data")
if not isinstance(data, dict):
return images
for b64 in data.get("image_base64") or []:
if isinstance(b64, str) and b64:
images.append(_b64_image_data_url(b64))
return images
# ---------------------------------------------------------------------------
# StepFun (阶跃星辰) image generation
# ---------------------------------------------------------------------------
_STEPFUN_ASPECT_RATIO_SIZES = {
"1:1": "1024x1024",
"16:9": "1280x800",
"9:16": "800x1280",
"3:4": "768x1360",
"4:3": "1360x768",
}
class StepFunImageGenerationClient(ImageGenerationProvider):
"""Async client for StepFun (阶跃星辰) image generation.
Supports:
- Text-to-image via step-image-edit-2 (default model)
- Reference-image-guided generation via style_reference (step-1x-medium)
"""
provider_name = "stepfun"
missing_key_message = (
"StepFun API key is not configured. Set providers.stepfun.apiKey."
)
default_timeout = 120.0
def _default_base_url(self) -> str:
return "https://api.stepfun.com/v1"
async def generate(
self,
*,
prompt: str,
model: str,
reference_images: list[str] | None = None,
aspect_ratio: str | None = None,
image_size: str | None = None,
) -> GeneratedImageResponse:
if not self.api_key:
raise ImageGenerationError(self.missing_key_message)
headers = {
"Authorization": f"Bearer {self.api_key}",
"Content-Type": "application/json",
**self.extra_headers,
}
body: dict[str, Any] = {
"model": model,
"prompt": prompt,
"response_format": "b64_json",
"n": 1,
}
# Map aspect ratio / image_size to StepFun size string
size = _stepfun_size(aspect_ratio, image_size)
if size:
body["size"] = size
# step-1x-medium supports style_reference for reference-image-guided generation
refs = list(reference_images or [])
if refs and "1x" in model:
body["style_reference"] = {
"source_url": image_path_to_data_url(refs[0]),
}
body.update(self.extra_body)
response = await self._http_post(
f"{self.api_base}/images/generations",
headers=headers,
body=body,
)
try:
response.raise_for_status()
except httpx.HTTPStatusError as exc:
detail = response.text[:500]
raise ImageGenerationError(
f"StepFun image generation failed: {detail}"
) from exc
payload = response.json()
images = _stepfun_images_from_payload(payload)
self._require_images(images, payload)
return GeneratedImageResponse(images=images, content="", raw=payload)
def _stepfun_size(
aspect_ratio: str | None,
image_size: str | None,
) -> str:
"""Resolve aspect ratio / image_size to StepFun size string.
StepFun expects ``WIDTHxHEIGHT`` (note: width x height, not the more
common ``HxW`` order used by other providers). The accepted sizes are
``1024x1024``, ``768x1360``, ``896x1184``, ``1360x768``, ``1184x896``.
"""
if image_size and "x" in image_size.lower():
return image_size
if aspect_ratio and aspect_ratio in _STEPFUN_ASPECT_RATIO_SIZES:
return _STEPFUN_ASPECT_RATIO_SIZES[aspect_ratio]
return "1024x1024"
def _stepfun_images_from_payload(payload: dict[str, Any]) -> list[str]:
"""Extract base64 images from StepFun API response.
StepFun returns images in ``data[].b64_json`` (base64 strings).
"""
images: list[str] = []
for item in payload.get("data") or []:
if not isinstance(item, dict):
continue
b64 = item.get("b64_json")
if isinstance(b64, str) and b64:
images.append(_b64_image_data_url(b64))
return images
# ---------------------------------------------------------------------------
# Provider registration
# ---------------------------------------------------------------------------
register_image_gen_provider(OpenRouterImageGenerationClient)
register_image_gen_provider(AIHubMixImageGenerationClient)
register_image_gen_provider(GeminiImageGenerationClient)
register_image_gen_provider(MiniMaxImageGenerationClient)
register_image_gen_provider(StepFunImageGenerationClient)