hermes-agent/tools/image_generation_tool.py
Teknium c02192ff6a
feat(image-gen): add image-to-image / editing to image_generate (#48705)
* feat(image-gen): add image-to-image / editing to image_generate

Brings image generation to parity with video generation: the unified
image_generate tool now edits/transforms a source image (image-to-image)
when given image_url / reference_image_urls, routing to each backend's
edit endpoint, exactly as video_generate routes to image-to-video.

- ImageGenProvider ABC: generate() gains keyword-only image_url +
  reference_image_urls; new capabilities() declares modalities +
  max_reference_images (defaults to text-only, backward compatible).
  success_response gains a modality field; adds normalize_reference_images.
- image_generate tool: schema exposes image_url + reference_image_urls;
  dynamic schema reflects the active model's actual edit capability so the
  agent knows when image_url is honored. Handler + plugin dispatch forward
  the new inputs; legacy/text-only providers get a clear modality_unsupported
  error instead of silently dropping the source image.
- In-tree FAL: 7 models gain edit endpoints (flux-2-klein, flux-2-pro,
  nano-banana-pro, gpt-image-1.5, gpt-image-2, ideogram/v3, qwen-image)
  with per-model edit_supports whitelists + reference caps; routes to the
  /edit endpoint and skips the upscaler for edits.
- Plugins: openai (images.edit, 16 refs), xai (/v1/images/edits via
  grok-imagine-image-quality, JSON body per xAI docs), krea
  (image_style_references, 10 refs). openai-codex stays text-only and
  rejects edits with an actionable error.
- Tests: 15 new (payload, routing, dispatch forwarding, dynamic schema,
  capabilities); updated 2 change-detector/lambda tests for the new schema.
- Docs: image-generation feature page, image-gen provider plugin guide,
  tools reference.

* fix(image-gen): preserve legacy passthrough in fal/krea plugin tests

Two existing plugin tests asserted pre-image-to-image behavior:
- fal: forward image_url/reference_image_urls only when supplied, so a
  text-to-image delegation stays byte-identical (no None kwargs).
- krea: keep dict-shaped image_style_references refs verbatim (the unified
  string refs go through normalize_reference_images; legacy non-string ref
  objects pass through unchanged) — fixes KeyError when callers pass the
  richer Krea ref-object shape.

* fix(image-gen): clearer not-capable message for text-to-image-only models

When a text-to-image-only model (incl. gpt-image-2 on the Codex OAuth path,
which can't do editing through the Responses image_generation tool) gets a
source image, say 'this model is not capable of image-to-image / editing —
provide a text-only prompt' rather than sending the user shopping for other
backends. Applies to the openai-codex guard, the in-tree FAL no-edit-endpoint
error, and the dynamic tool-schema text-only line.
2026-06-18 22:13:07 -07:00

1546 lines
59 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#!/usr/bin/env python3
"""
Image Generation Tools Module
Provides image generation via FAL.ai. Multiple FAL models are supported and
selectable via ``hermes tools`` → Image Generation; the active model is
persisted to ``image_gen.model`` in ``config.yaml``.
Architecture:
- ``FAL_MODELS`` is a catalog of supported models with per-model metadata
(size-style family, defaults, ``supports`` whitelist, upscaler flag).
- ``_build_fal_payload()`` translates the agent's unified inputs (prompt +
aspect_ratio) into the model-specific payload and filters to the
``supports`` whitelist so models never receive rejected keys.
- Upscaling via FAL's Clarity Upscaler is gated per-model via the ``upscale``
flag — on for FLUX 2 Pro (backward-compat), off for all faster/newer models
where upscaling would either hurt latency or add marginal quality.
Pricing shown in UI strings is as-of the initial commit; we accept drift and
update when it's noticed.
"""
import json
import logging
import os
import datetime
import threading
import uuid
from typing import Any, Dict, Optional
# fal_client is imported lazily — see _load_fal_client(). Pulling it
# eagerly added ~64 ms to every CLI cold start because
# discover_builtin_tools() imports this module unconditionally during
# the registry walk, even when image generation is never used.
#
# Tests that monkeypatch this attribute (e.g.
# ``monkeypatch.setattr(image_tool, "fal_client", fake_fal_client)``)
# still work: _load_fal_client() short-circuits when the attribute is
# anything truthy, so a test-installed mock is not overwritten by a
# subsequent real import.
fal_client: Any = None
def _load_fal_client() -> Any:
"""Lazily import fal_client and rebind the module global on first use.
Idempotent. Returns the (now-loaded) ``fal_client`` module reference.
Skips the import if the global is already truthy — this preserves the
test pattern of monkeypatching the module global to install a mock.
"""
global fal_client
if fal_client is not None:
return fal_client
from tools.fal_common import import_fal_client
fal_client = import_fal_client()
return fal_client
from tools.debug_helpers import DebugSession
from tools.fal_common import (
_ManagedFalSyncClient,
_extract_http_status,
_normalize_fal_queue_url_format, # noqa: F401 — re-exported for tests
)
from tools.managed_tool_gateway import resolve_managed_tool_gateway
from tools.tool_backend_helpers import (
fal_key_is_configured,
managed_nous_tools_enabled,
nous_tool_gateway_unavailable_message,
prefers_gateway,
)
logger = logging.getLogger(__name__)
# ---------------------------------------------------------------------------
# FAL model catalog
# ---------------------------------------------------------------------------
#
# Each entry declares how to translate our unified inputs into the model's
# native payload shape. Size specification falls into three families:
#
# "image_size_preset" — preset enum ("square_hd", "landscape_16_9", ...)
# used by the flux family, z-image, qwen, recraft,
# ideogram.
# "aspect_ratio" — aspect ratio enum ("16:9", "1:1", ...) used by
# nano-banana (Gemini).
# "gpt_literal" — literal dimension strings ("1024x1024", etc.)
# used by gpt-image-1.5.
#
# ``supports`` is a whitelist of keys allowed in the outgoing payload — any
# key outside this set is stripped before submission so models never receive
# rejected parameters (each FAL model rejects unknown keys differently).
#
# ``upscale`` controls whether to chain Clarity Upscaler after generation.
FAL_MODELS: Dict[str, Dict[str, Any]] = {
"fal-ai/flux-2/klein/9b": {
"display": "FLUX 2 Klein 9B",
"speed": "<1s",
"strengths": "Fast, crisp text",
"price": "$0.006/MP",
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_16_9",
"square": "square_hd",
"portrait": "portrait_16_9",
},
"defaults": {
"num_inference_steps": 4,
"output_format": "png",
"enable_safety_checker": False,
},
"supports": {
"prompt", "image_size", "num_inference_steps", "seed",
"output_format", "enable_safety_checker",
},
"upscale": False,
# Image-to-image / editing: FLUX.2 [klein] 9B edit endpoint takes
# `image_urls` (list). Natural-language edits, multi-ref.
"edit_endpoint": "fal-ai/flux-2/klein/9b/edit",
"edit_supports": {
"prompt", "image_urls", "num_inference_steps", "seed",
"output_format", "enable_safety_checker",
},
"max_reference_images": 9,
},
"fal-ai/flux-2-pro": {
"display": "FLUX 2 Pro",
"speed": "~6s",
"strengths": "Studio photorealism",
"price": "$0.03/MP",
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_16_9",
"square": "square_hd",
"portrait": "portrait_16_9",
},
"defaults": {
"num_inference_steps": 50,
"guidance_scale": 4.5,
"num_images": 1,
"output_format": "png",
"enable_safety_checker": False,
"safety_tolerance": "5",
"sync_mode": True,
},
"supports": {
"prompt", "image_size", "num_inference_steps", "guidance_scale",
"num_images", "output_format", "enable_safety_checker",
"safety_tolerance", "sync_mode", "seed",
},
"upscale": True, # Backward-compat: current default behavior.
# Edit endpoint accepts up to 9 reference images.
"edit_endpoint": "fal-ai/flux-2-pro/edit",
"edit_supports": {
"prompt", "image_urls", "num_inference_steps", "guidance_scale",
"num_images", "output_format", "enable_safety_checker",
"safety_tolerance", "sync_mode", "seed",
},
"max_reference_images": 9,
},
"fal-ai/z-image/turbo": {
"display": "Z-Image Turbo",
"speed": "~2s",
"strengths": "Bilingual EN/CN, 6B",
"price": "$0.005/MP",
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_16_9",
"square": "square_hd",
"portrait": "portrait_16_9",
},
"defaults": {
"num_inference_steps": 8,
"num_images": 1,
"output_format": "png",
"enable_safety_checker": False,
"enable_prompt_expansion": False, # avoid the extra per-request charge
},
"supports": {
"prompt", "image_size", "num_inference_steps", "num_images",
"seed", "output_format", "enable_safety_checker",
"enable_prompt_expansion",
},
"upscale": False,
},
"fal-ai/nano-banana-pro": {
"display": "Nano Banana Pro (Gemini 3 Pro Image)",
"speed": "~8s",
"strengths": "Gemini 3 Pro, reasoning depth, text rendering",
"price": "$0.15/image (1K)",
"size_style": "aspect_ratio",
"sizes": {
"landscape": "16:9",
"square": "1:1",
"portrait": "9:16",
},
"defaults": {
"num_images": 1,
"output_format": "png",
"safety_tolerance": "5",
# "1K" is the cheapest tier; 4K doubles the per-image cost.
# Users on Nous Subscription should stay at 1K for predictable billing.
"resolution": "1K",
},
"supports": {
"prompt", "aspect_ratio", "num_images", "output_format",
"safety_tolerance", "seed", "sync_mode", "resolution",
"enable_web_search", "limit_generations",
},
"upscale": False,
# Nano Banana Pro edit (Gemini 3 Pro Image): natural-language edits
# with up to 2 reference images via `image_urls`.
"edit_endpoint": "fal-ai/nano-banana-pro/edit",
"edit_supports": {
"prompt", "image_urls", "aspect_ratio", "num_images",
"output_format", "safety_tolerance", "seed", "sync_mode",
"resolution", "enable_web_search", "limit_generations",
},
"max_reference_images": 2,
},
"fal-ai/gpt-image-1.5": {
"display": "GPT Image 1.5",
"speed": "~15s",
"strengths": "Prompt adherence",
"price": "$0.034/image",
"size_style": "gpt_literal",
"sizes": {
"landscape": "1536x1024",
"square": "1024x1024",
"portrait": "1024x1536",
},
"defaults": {
# Quality is pinned to medium to keep portal billing predictable
# across all users (low is too rough, high is 4-6x more expensive).
"quality": "medium",
"num_images": 1,
"output_format": "png",
},
"supports": {
"prompt", "image_size", "quality", "num_images", "output_format",
"background", "sync_mode",
},
"upscale": False,
# Edit endpoint: high-fidelity edits preserving composition/lighting.
"edit_endpoint": "fal-ai/gpt-image-1.5/edit",
"edit_supports": {
"prompt", "image_urls", "image_size", "quality", "num_images",
"output_format", "sync_mode",
},
"max_reference_images": 16,
},
"fal-ai/gpt-image-2": {
"display": "GPT Image 2",
"speed": "~20s",
"strengths": "SOTA text rendering + CJK, world-aware photorealism",
"price": "$0.040.06/image",
# GPT Image 2 uses FAL's standard preset enum (unlike 1.5's literal
# dimensions). We map to the 4:3 variants — the 16:9 presets
# (1024x576) fall below GPT-Image-2's 655,360 min-pixel requirement
# and would be rejected. 4:3 keeps us above the minimum on all
# three aspect ratios.
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_4_3", # 1024x768
"square": "square_hd", # 1024x1024
"portrait": "portrait_4_3", # 768x1024
},
"defaults": {
# Same quality pinning as gpt-image-1.5: medium keeps Nous
# Portal billing predictable. "high" is 3-4x the per-image
# cost at the same size; "low" is too rough for production use.
"quality": "medium",
"num_images": 1,
"output_format": "png",
},
"supports": {
"prompt", "image_size", "quality", "num_images", "output_format",
"sync_mode",
# openai_api_key (BYOK) intentionally omitted — all users go
# through the shared FAL billing path.
},
"upscale": False,
# GPT Image 2 edit endpoint lives under the OpenAI namespace on FAL
# (NOT fal-ai/). Takes `image_urls` (list) + optional mask. We don't
# send `image_size` on edit so the model auto-infers from input.
"edit_endpoint": "openai/gpt-image-2/edit",
"edit_supports": {
"prompt", "image_urls", "quality", "num_images", "output_format",
"sync_mode", "mask_image_url",
},
"max_reference_images": 16,
},
"fal-ai/ideogram/v3": {
"display": "Ideogram V3",
"speed": "~5s",
"strengths": "Best typography",
"price": "$0.03-0.09/image",
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_16_9",
"square": "square_hd",
"portrait": "portrait_16_9",
},
"defaults": {
"rendering_speed": "BALANCED",
"expand_prompt": True,
"style": "AUTO",
},
"supports": {
"prompt", "image_size", "rendering_speed", "expand_prompt",
"style", "seed",
},
"upscale": False,
# Ideogram V3 edit endpoint takes `image_urls` (list).
"edit_endpoint": "fal-ai/ideogram/v3/edit",
"edit_supports": {
"prompt", "image_urls", "rendering_speed", "expand_prompt",
"style", "seed",
},
"max_reference_images": 1,
},
"fal-ai/recraft/v4/pro/text-to-image": {
"display": "Recraft V4 Pro",
"speed": "~8s",
"strengths": "Design, brand systems, production-ready",
"price": "$0.25/image",
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_16_9",
"square": "square_hd",
"portrait": "portrait_16_9",
},
"defaults": {
# V4 Pro dropped V3's required `style` enum — defaults handle taste now.
"enable_safety_checker": False,
},
"supports": {
"prompt", "image_size", "enable_safety_checker",
"colors", "background_color",
},
"upscale": False,
},
"fal-ai/qwen-image": {
"display": "Qwen Image",
"speed": "~12s",
"strengths": "LLM-based, complex text",
"price": "$0.02/MP",
"size_style": "image_size_preset",
"sizes": {
"landscape": "landscape_16_9",
"square": "square_hd",
"portrait": "portrait_16_9",
},
"defaults": {
"num_inference_steps": 30,
"guidance_scale": 2.5,
"num_images": 1,
"output_format": "png",
"acceleration": "regular",
},
"supports": {
"prompt", "image_size", "num_inference_steps", "guidance_scale",
"num_images", "output_format", "acceleration", "seed", "sync_mode",
},
"upscale": False,
# Qwen edit uses the Qwen Image 2.0 Pro editing endpoint, which takes
# `image_urls` (list) + natural-language edit instructions.
"edit_endpoint": "fal-ai/qwen-image-2/pro/edit",
"edit_supports": {
"prompt", "image_urls", "num_inference_steps", "guidance_scale",
"num_images", "output_format", "acceleration", "seed", "sync_mode",
},
"max_reference_images": 3,
},
# Krea 2 — Krea's first foundation image model, day-0 partner launch on
# fal (2026-05-27). Same model family as our direct ``plugins/image_gen/krea``
# backend, exposed here for users who prefer to bill through their
# existing FAL key / Nous Portal subscription rather than register
# directly with Krea. Both variants share the same parameter schema —
# only model id, price, and recommended use case differ.
"fal-ai/krea/v2/medium/text-to-image": {
"display": "Krea 2 Medium",
"speed": "~15-25s",
"strengths": "Illustration, anime, painting, expressive/artistic styles",
"price": "$0.030 (text) / $0.035 (style refs)",
"size_style": "aspect_ratio",
# Krea natively accepts 1:1, 4:3, 3:2, 16:9, 2.35:1, 4:5, 2:3, 9:16 —
# we map our 3 abstract ratios to the closest match.
"sizes": {
"landscape": "16:9",
"square": "1:1",
"portrait": "9:16",
},
"defaults": {
"creativity": "medium",
},
"supports": {
"prompt", "aspect_ratio", "creativity", "seed",
"image_style_references",
},
"upscale": False,
},
"fal-ai/krea/v2/large/text-to-image": {
"display": "Krea 2 Large",
"speed": "~25-60s",
"strengths": "Photorealism, raw textured looks (motion blur, grain, film)",
"price": "$0.060 (text) / $0.065 (style refs)",
"size_style": "aspect_ratio",
"sizes": {
"landscape": "16:9",
"square": "1:1",
"portrait": "9:16",
},
"defaults": {
"creativity": "medium",
},
"supports": {
"prompt", "aspect_ratio", "creativity", "seed",
"image_style_references",
},
"upscale": False,
},
}
# Default model is the fastest reasonable option. Kept cheap and sub-1s.
DEFAULT_MODEL = "fal-ai/flux-2/klein/9b"
DEFAULT_ASPECT_RATIO = "landscape"
VALID_ASPECT_RATIOS = ("landscape", "square", "portrait")
# ---------------------------------------------------------------------------
# Upscaler (Clarity Upscaler — unchanged from previous implementation)
# ---------------------------------------------------------------------------
UPSCALER_MODEL = "fal-ai/clarity-upscaler"
UPSCALER_FACTOR = 2
UPSCALER_SAFETY_CHECKER = False
UPSCALER_DEFAULT_PROMPT = "masterpiece, best quality, highres"
UPSCALER_NEGATIVE_PROMPT = "(worst quality, low quality, normal quality:2)"
UPSCALER_CREATIVITY = 0.35
UPSCALER_RESEMBLANCE = 0.6
UPSCALER_GUIDANCE_SCALE = 4
UPSCALER_NUM_INFERENCE_STEPS = 18
_debug = DebugSession("image_tools", env_var="IMAGE_TOOLS_DEBUG")
_managed_fal_client = None
_managed_fal_client_config = None
_managed_fal_client_lock = threading.Lock()
# ---------------------------------------------------------------------------
# Managed FAL gateway (Nous Subscription)
# ---------------------------------------------------------------------------
def _resolve_managed_fal_gateway():
"""Return managed fal-queue gateway config when the user prefers the gateway
or direct FAL credentials are absent."""
if fal_key_is_configured() and not prefers_gateway("image_gen"):
return None
return resolve_managed_tool_gateway("fal-queue")
def _get_managed_fal_client(managed_gateway):
"""Reuse the managed FAL client so its internal httpx.Client is not leaked per call."""
global _managed_fal_client, _managed_fal_client_config
client_config = (
managed_gateway.gateway_origin.rstrip("/"),
managed_gateway.nous_user_token,
)
with _managed_fal_client_lock:
if _managed_fal_client is not None and _managed_fal_client_config == client_config:
return _managed_fal_client
# Resolve fal_client on the legacy module — preserves the test
# pattern of monkey-patching ``image_generation_tool.fal_client``.
_load_fal_client()
_managed_fal_client = _ManagedFalSyncClient(
fal_client,
key=managed_gateway.nous_user_token,
queue_run_origin=managed_gateway.gateway_origin,
)
_managed_fal_client_config = client_config
return _managed_fal_client
def _submit_fal_request(model: str, arguments: Dict[str, Any]):
"""Submit a FAL request using direct credentials or the managed queue gateway."""
# Trigger the lazy import on first call. Idempotent.
_load_fal_client()
request_headers = {"x-idempotency-key": str(uuid.uuid4())}
managed_gateway = _resolve_managed_fal_gateway()
if managed_gateway is None:
return fal_client.submit(model, arguments=arguments, headers=request_headers)
managed_client = _get_managed_fal_client(managed_gateway)
try:
return managed_client.submit(
model,
arguments=arguments,
headers=request_headers,
)
except Exception as exc:
# 4xx from the managed gateway typically means the portal doesn't
# currently proxy this model (allowlist miss, billing gate, etc.)
# — surface a clearer message with actionable remediation instead
# of a raw HTTP error from httpx.
status = _extract_http_status(exc)
if status is not None and 400 <= status < 500:
gateway_message = ""
if status in {401, 402, 403}:
gateway_message = (
"\n\n"
+ nous_tool_gateway_unavailable_message(
"managed FAL image generation",
force_fresh=True,
)
)
raise ValueError(
f"Nous Subscription gateway rejected model '{model}' "
f"(HTTP {status}). This model may not yet be enabled on "
f"the Nous Portal's FAL proxy. Either:\n"
f" • Set FAL_KEY in your environment to use FAL.ai directly, or\n"
f" • Pick a different model via `hermes tools` → Image Generation."
f"{gateway_message}"
) from exc
raise
# ---------------------------------------------------------------------------
# Model resolution + payload construction
# ---------------------------------------------------------------------------
def _resolve_fal_model() -> tuple:
"""Resolve the active FAL model from config.yaml (primary) or default.
Returns (model_id, metadata_dict). Falls back to DEFAULT_MODEL if the
configured model is unknown (logged as a warning).
"""
model_id = ""
try:
from hermes_cli.config import load_config
cfg = load_config()
img_cfg = cfg.get("image_gen") if isinstance(cfg, dict) else None
if isinstance(img_cfg, dict):
raw = img_cfg.get("model")
if isinstance(raw, str):
model_id = raw.strip()
except Exception as exc:
logger.debug("Could not load image_gen.model from config: %s", exc)
# Env var escape hatch (undocumented; backward-compat for tests/scripts).
if not model_id:
model_id = os.getenv("FAL_IMAGE_MODEL", "").strip()
if not model_id:
return DEFAULT_MODEL, FAL_MODELS[DEFAULT_MODEL]
if model_id not in FAL_MODELS:
logger.warning(
"Unknown FAL model '%s' in config; falling back to %s",
model_id, DEFAULT_MODEL,
)
return DEFAULT_MODEL, FAL_MODELS[DEFAULT_MODEL]
return model_id, FAL_MODELS[model_id]
def _build_fal_payload(
model_id: str,
prompt: str,
aspect_ratio: str = DEFAULT_ASPECT_RATIO,
seed: Optional[int] = None,
overrides: Optional[Dict[str, Any]] = None,
) -> Dict[str, Any]:
"""Build a FAL request payload for `model_id` from unified inputs.
Translates aspect_ratio into the model's native size spec (preset enum,
aspect-ratio enum, or GPT literal string), merges model defaults, applies
caller overrides, then filters to the model's ``supports`` whitelist.
"""
meta = FAL_MODELS[model_id]
size_style = meta["size_style"]
sizes = meta["sizes"]
aspect = (aspect_ratio or DEFAULT_ASPECT_RATIO).lower().strip()
if aspect not in sizes:
aspect = DEFAULT_ASPECT_RATIO
payload: Dict[str, Any] = dict(meta.get("defaults", {}))
payload["prompt"] = (prompt or "").strip()
if size_style in {"image_size_preset", "gpt_literal"}:
payload["image_size"] = sizes[aspect]
elif size_style == "aspect_ratio":
payload["aspect_ratio"] = sizes[aspect]
else:
raise ValueError(f"Unknown size_style: {size_style!r}")
if seed is not None and isinstance(seed, int):
payload["seed"] = seed
if overrides:
for k, v in overrides.items():
if v is not None:
payload[k] = v
supports = meta["supports"]
return {k: v for k, v in payload.items() if k in supports}
def _build_fal_edit_payload(
model_id: str,
prompt: str,
image_urls: list,
aspect_ratio: str = DEFAULT_ASPECT_RATIO,
seed: Optional[int] = None,
overrides: Optional[Dict[str, Any]] = None,
) -> Dict[str, Any]:
"""Build a FAL *edit* request payload (image-to-image) from unified inputs.
Every FAL edit endpoint takes ``image_urls`` (a list of source/reference
image URLs) plus the prompt. Size handling differs from text-to-image:
most edit endpoints auto-infer output dimensions from the input image, so
we only send ``image_size`` / ``aspect_ratio`` when the edit endpoint's
``edit_supports`` whitelist accepts it. Keys outside ``edit_supports`` are
stripped before submission.
"""
meta = FAL_MODELS[model_id]
edit_supports = meta.get("edit_supports") or set()
size_style = meta["size_style"]
sizes = meta["sizes"]
aspect = (aspect_ratio or DEFAULT_ASPECT_RATIO).lower().strip()
if aspect not in sizes:
aspect = DEFAULT_ASPECT_RATIO
payload: Dict[str, Any] = dict(meta.get("defaults", {}))
payload["prompt"] = (prompt or "").strip()
payload["image_urls"] = list(image_urls)
# Only express output size when the edit endpoint advertises the key.
# gpt-image-2 edit auto-infers size from the input, so `image_size` is
# intentionally absent from its edit_supports whitelist.
if size_style in {"image_size_preset", "gpt_literal"} and "image_size" in edit_supports:
payload["image_size"] = sizes[aspect]
elif size_style == "aspect_ratio" and "aspect_ratio" in edit_supports:
payload["aspect_ratio"] = sizes[aspect]
if seed is not None and isinstance(seed, int):
payload["seed"] = seed
if overrides:
for k, v in overrides.items():
if v is not None:
payload[k] = v
return {k: v for k, v in payload.items() if k in edit_supports}
# ---------------------------------------------------------------------------
# Upscaler
# ---------------------------------------------------------------------------
def _upscale_image(image_url: str, original_prompt: str) -> Optional[Dict[str, Any]]:
"""Upscale an image using FAL.ai's Clarity Upscaler.
Returns upscaled image dict, or None on failure (caller falls back to
the original image).
"""
try:
logger.info("Upscaling image with Clarity Upscaler...")
upscaler_arguments = {
"image_url": image_url,
"prompt": f"{UPSCALER_DEFAULT_PROMPT}, {original_prompt}",
"upscale_factor": UPSCALER_FACTOR,
"negative_prompt": UPSCALER_NEGATIVE_PROMPT,
"creativity": UPSCALER_CREATIVITY,
"resemblance": UPSCALER_RESEMBLANCE,
"guidance_scale": UPSCALER_GUIDANCE_SCALE,
"num_inference_steps": UPSCALER_NUM_INFERENCE_STEPS,
"enable_safety_checker": UPSCALER_SAFETY_CHECKER,
}
handler = _submit_fal_request(UPSCALER_MODEL, arguments=upscaler_arguments)
result = handler.get()
if result and "image" in result:
upscaled_image = result["image"]
logger.info(
"Image upscaled successfully to %sx%s",
upscaled_image.get("width", "unknown"),
upscaled_image.get("height", "unknown"),
)
return {
"url": upscaled_image["url"],
"width": upscaled_image.get("width", 0),
"height": upscaled_image.get("height", 0),
"upscaled": True,
"upscale_factor": UPSCALER_FACTOR,
}
logger.error("Upscaler returned invalid response")
return None
except Exception as e:
logger.error("Error upscaling image: %s", e, exc_info=True)
return None
# ---------------------------------------------------------------------------
# Tool entry point
# ---------------------------------------------------------------------------
def _looks_like_absolute_file_path(value: str) -> bool:
if not value or not isinstance(value, str):
return False
lower = value.lower()
if lower.startswith(("http://", "https://", "data:")):
return False
if os.path.isabs(value):
return True
return len(value) >= 3 and value[1] == ":" and value[2] in {"/", "\\"}
def _active_terminal_env(task_id: str | None):
try:
from tools.terminal_tool import get_active_env
return get_active_env(task_id or "default")
except Exception as exc: # noqa: BLE001 - artifact hinting must not break generation
logger.debug("Could not inspect active terminal environment: %s", exc)
return None
def _agent_cache_base_for_env(env: Any) -> str | None:
if env is not None:
# Forward-looking optional override: an environment may expose its own
# agent-visible cache root via this callable. No backend defines it yet
# — it's an extension hook, not a typo. The getattr/callable guards make
# it a safe no-op until a producer exists.
explicit = getattr(env, "agent_visible_cache_base", None)
if callable(explicit):
try:
value = explicit()
if value:
return str(value).rstrip("/")
except Exception as exc: # noqa: BLE001
logger.debug("active env agent_visible_cache_base failed: %s", exc)
remote_home = getattr(env, "_remote_home", None)
if remote_home:
return f"{str(remote_home).rstrip('/')}/.hermes"
env_name = env.__class__.__name__
if env_name in {"DockerEnvironment", "SingularityEnvironment", "ModalEnvironment"}:
return "/root/.hermes"
# If no environment has been created yet, only backends with deterministic
# Hermes cache roots can be translated without side effects. SSH can still
# use a shell-visible tilde path; its first environment sync will upload
# the cache file before the first command runs.
backend = (os.getenv("TERMINAL_ENV") or "local").strip().lower()
if backend in {"docker", "singularity", "modal"}:
return "/root/.hermes"
if backend == "ssh":
return "~/.hermes"
return None
def _agent_visible_cache_path(host_path: str, env: Any) -> str | None:
if not _looks_like_absolute_file_path(host_path):
return None
cache_base = _agent_cache_base_for_env(env)
if not cache_base:
return None
try:
from tools.credential_files import map_cache_path_to_container
return map_cache_path_to_container(host_path, container_base=cache_base)
except Exception as exc: # noqa: BLE001
logger.debug("Could not translate image cache path for backend: %s", exc)
return None
def _force_artifact_sync(env: Any) -> None:
sync_manager = getattr(env, "_sync_manager", None)
if sync_manager is None:
return
try:
sync_manager.sync(force=True)
except Exception as exc: # noqa: BLE001 - keep generation success; log for operators
logger.warning("Could not force-sync generated image artifact: %s", exc)
def _postprocess_image_generate_result(raw: str, task_id: str | None = None) -> str:
"""Annotate successful local image results with backend-visible paths.
``image`` remains the host/gateway-deliverable path. When the active
terminal backend has a different filesystem, ``agent_visible_image`` gives
the path the agent can use with terminal/file tools.
"""
try:
payload = json.loads(raw) if isinstance(raw, str) else raw
except Exception:
return raw
if not isinstance(payload, dict) or not payload.get("success"):
return raw
image = payload.get("image")
if not isinstance(image, str) or not _looks_like_absolute_file_path(image):
return raw
env = _active_terminal_env(task_id)
agent_path = _agent_visible_cache_path(image, env)
if not agent_path or agent_path == image:
return raw
if env is not None:
_force_artifact_sync(env)
payload.setdefault("host_image", image)
payload.setdefault("agent_visible_image", agent_path)
return json.dumps(payload, ensure_ascii=False)
def image_generate_tool(
prompt: str,
aspect_ratio: str = DEFAULT_ASPECT_RATIO,
num_inference_steps: Optional[int] = None,
guidance_scale: Optional[float] = None,
num_images: Optional[int] = None,
output_format: Optional[str] = None,
seed: Optional[int] = None,
image_url: Optional[str] = None,
reference_image_urls: Optional[list] = None,
) -> str:
"""Generate an image from a text prompt, or edit a source image, via FAL.
Routing: when ``image_url`` (or ``reference_image_urls``) is provided AND
the configured model declares an ``edit_endpoint``, the call routes to that
image-to-image / edit endpoint; otherwise it's plain text-to-image.
The agent-facing schema exposes ``prompt``, ``aspect_ratio``, ``image_url``
and ``reference_image_urls``; the remaining kwargs are overrides for direct
Python callers and are filtered per-model via the ``supports`` /
``edit_supports`` whitelist (unsupported overrides are silently dropped so
legacy callers don't break when switching models).
Returns a JSON string with ``{"success": bool, "image": url | None,
"modality": "text" | "image", "error": str, "error_type": str}``.
"""
model_id, meta = _resolve_fal_model()
# Collect any source images (primary + references) into one ordered list.
source_images: list = []
if isinstance(image_url, str) and image_url.strip():
source_images.append(image_url.strip())
if isinstance(reference_image_urls, (list, tuple)):
for ref in reference_image_urls:
if isinstance(ref, str) and ref.strip():
source_images.append(ref.strip())
edit_endpoint = meta.get("edit_endpoint")
use_edit = bool(source_images) and bool(edit_endpoint)
modality = "image" if use_edit else "text"
debug_call_data = {
"model": model_id,
"parameters": {
"prompt": prompt,
"aspect_ratio": aspect_ratio,
"num_inference_steps": num_inference_steps,
"guidance_scale": guidance_scale,
"num_images": num_images,
"output_format": output_format,
"seed": seed,
"modality": modality,
"source_images": len(source_images),
},
"error": None,
"success": False,
"images_generated": 0,
"generation_time": 0,
}
start_time = datetime.datetime.now()
try:
if not prompt or not isinstance(prompt, str) or len(prompt.strip()) == 0:
raise ValueError("Prompt is required and must be a non-empty string")
if not (fal_key_is_configured() or _resolve_managed_fal_gateway()):
raise ValueError(_build_no_backend_setup_message())
# If the caller supplied source images but the active model has no
# edit endpoint, fail with a clear, actionable message instead of
# silently dropping the images and producing an unrelated picture.
if source_images and not edit_endpoint:
raise ValueError(
f"Model '{meta.get('display', model_id)}' ({model_id}) is not "
f"capable of image-to-image / editing. Provide a text-only "
f"prompt (omit image_url), or switch to an edit-capable model "
f"via `hermes tools` → Image Generation."
)
aspect_lc = (aspect_ratio or DEFAULT_ASPECT_RATIO).lower().strip()
if aspect_lc not in VALID_ASPECT_RATIOS:
logger.warning(
"Invalid aspect_ratio '%s', defaulting to '%s'",
aspect_ratio, DEFAULT_ASPECT_RATIO,
)
aspect_lc = DEFAULT_ASPECT_RATIO
overrides: Dict[str, Any] = {}
if num_inference_steps is not None:
overrides["num_inference_steps"] = num_inference_steps
if guidance_scale is not None:
overrides["guidance_scale"] = guidance_scale
if num_images is not None:
overrides["num_images"] = num_images
if output_format is not None:
overrides["output_format"] = output_format
if use_edit:
# Clamp reference count to the model's declared cap.
max_refs = int(meta.get("max_reference_images") or 1)
clamped_sources = source_images[:max_refs] if max_refs > 0 else source_images
arguments = _build_fal_edit_payload(
model_id, prompt, clamped_sources, aspect_lc,
seed=seed, overrides=overrides,
)
endpoint = edit_endpoint
logger.info(
"Editing image with %s (%s) — %d source image(s), prompt: %s",
meta.get("display", model_id), endpoint, len(clamped_sources),
prompt[:80],
)
else:
arguments = _build_fal_payload(
model_id, prompt, aspect_lc, seed=seed, overrides=overrides,
)
endpoint = model_id
logger.info(
"Generating image with %s (%s) — prompt: %s",
meta.get("display", model_id), model_id, prompt[:80],
)
handler = _submit_fal_request(endpoint, arguments=arguments)
result = handler.get()
generation_time = (datetime.datetime.now() - start_time).total_seconds()
if not result or "images" not in result:
raise ValueError("Invalid response from FAL.ai API — no images returned")
images = result.get("images", [])
if not images:
raise ValueError("No images were generated")
# Edit endpoints already return the final composition; the Clarity
# upscaler is a text-to-image quality pass, so skip it for edits.
should_upscale = bool(meta.get("upscale", False)) and not use_edit
formatted_images = []
for img in images:
if not (isinstance(img, dict) and "url" in img):
continue
original_image = {
"url": img["url"],
"width": img.get("width", 0),
"height": img.get("height", 0),
}
if should_upscale:
upscaled_image = _upscale_image(img["url"], prompt.strip())
if upscaled_image:
formatted_images.append(upscaled_image)
continue
logger.warning("Using original image as fallback (upscale failed)")
original_image["upscaled"] = False
formatted_images.append(original_image)
if not formatted_images:
raise ValueError("No valid image URLs returned from API")
upscaled_count = sum(1 for img in formatted_images if img.get("upscaled"))
logger.info(
"Generated %s image(s) in %.1fs (%s upscaled) via %s [%s]",
len(formatted_images), generation_time, upscaled_count, endpoint,
modality,
)
response_data = {
"success": True,
"image": formatted_images[0]["url"] if formatted_images else None,
"modality": modality,
}
debug_call_data["success"] = True
debug_call_data["images_generated"] = len(formatted_images)
debug_call_data["generation_time"] = generation_time
_debug.log_call("image_generate_tool", debug_call_data)
_debug.save()
return json.dumps(response_data, indent=2, ensure_ascii=False)
except Exception as e:
generation_time = (datetime.datetime.now() - start_time).total_seconds()
error_msg = f"Error generating image: {str(e)}"
logger.error("%s", error_msg, exc_info=True)
response_data = {
"success": False,
"image": None,
"error": str(e),
"error_type": type(e).__name__,
}
debug_call_data["error"] = error_msg
debug_call_data["generation_time"] = generation_time
_debug.log_call("image_generate_tool", debug_call_data)
_debug.save()
return json.dumps(response_data, indent=2, ensure_ascii=False)
def check_fal_api_key() -> bool:
"""True if the FAL.ai API key (direct or managed gateway) is available."""
return bool(fal_key_is_configured() or _resolve_managed_fal_gateway())
def _build_no_backend_setup_message() -> str:
"""Build an actionable error string when no FAL backend is reachable.
Used by the in-tree FAL path. Mentions:
- FAL_KEY signup link
- managed-gateway status (if Nous tools are enabled)
- plugin alternative pointer (so users on a stale ``image_gen.provider``
know the registry exists and how to inspect it)
"""
lines = ["Image generation is unavailable in this environment.", ""]
lines.append("Missing requirements:")
if managed_nous_tools_enabled():
lines.append(
" - FAL_KEY is not set and the managed FAL gateway is unreachable"
)
else:
lines.append(" - FAL_KEY environment variable is not set")
gateway_message = nous_tool_gateway_unavailable_message(
"managed FAL image generation",
)
if gateway_message:
lines.append(f" - {gateway_message}")
lines.append("")
lines.append("To enable image generation, do one of:")
lines.append(
" 1. Get a free API key at https://fal.ai and set "
"FAL_KEY=<your-key> (then restart the session)"
)
if managed_nous_tools_enabled():
lines.append(
" 2. Sign in to a Nous account that has the managed FAL "
"gateway enabled (`hermes setup`)"
)
lines.append(
" 3. Configure a different image_gen provider via `hermes tools` "
"→ Image Generation (run `hermes plugins list` to see installed "
"backends)"
)
return "\n".join(lines)
def check_image_generation_requirements() -> bool:
"""True if any image gen backend is available.
Providers are considered in this order:
1. The in-tree FAL backend (FAL_KEY or managed gateway).
2. Any plugin-registered provider whose ``is_available()`` returns True.
Plugins win only when the in-tree FAL path is NOT ready, which matches
the historical behavior: shipping hermes with a FAL key configured
should still expose the tool. The active selection among ready
providers is resolved per-call by ``image_gen.provider``.
"""
try:
if check_fal_api_key():
# Trigger the lazy fal_client import here as the SDK presence
# check. Raises ImportError if the optional ``fal-client``
# package isn't installed; the caller's except ImportError
# below catches that and continues to plugin probing.
_load_fal_client()
return True
except ImportError:
pass
# Probe plugin providers. Discovery is idempotent and cheap.
try:
from agent.image_gen_registry import list_providers
from hermes_cli.plugins import _ensure_plugins_discovered
_ensure_plugins_discovered()
for provider in list_providers():
try:
if provider.is_available():
return True
except Exception:
continue
except Exception:
pass
return False
# ---------------------------------------------------------------------------
# Demo / CLI entry point
# ---------------------------------------------------------------------------
if __name__ == "__main__":
print("🎨 Image Generation Tools — FAL.ai multi-model support")
print("=" * 60)
if not check_fal_api_key():
print("❌ FAL_KEY environment variable not set")
print(" Set it via: export FAL_KEY='your-key-here'")
print(" Get a key: https://fal.ai/")
raise SystemExit(1)
print("✅ FAL.ai API key found")
try:
import fal_client # noqa: F401
print("✅ fal_client library available")
except ImportError:
print("❌ fal_client library not found — pip install fal-client")
raise SystemExit(1)
model_id, meta = _resolve_fal_model()
print(f"🤖 Active model: {meta.get('display', model_id)} ({model_id})")
print(f" Speed: {meta.get('speed', '?')} · Price: {meta.get('price', '?')}")
print(f" Upscaler: {'on' if meta.get('upscale') else 'off'}")
print("\nAvailable models:")
for mid, m in FAL_MODELS.items():
marker = " ← active" if mid == model_id else ""
print(f" {mid:<32} {m.get('speed', '?'):<6} {m.get('price', '?')}{marker}")
if _debug.active:
print(f"\n🐛 Debug mode enabled — session {_debug.session_id}")
# ---------------------------------------------------------------------------
# Registry
# ---------------------------------------------------------------------------
from tools.registry import registry, tool_error
IMAGE_GENERATE_SCHEMA = {
"name": "image_generate",
# Placeholder — the real description is rebuilt dynamically at
# get_tool_definitions() time so it reflects the active backend's actual
# capabilities (whether the selected model supports image-to-image /
# editing). See _build_dynamic_image_schema() below and the
# dynamic-tool-schemas skill.
"description": (
"Generate high-quality images from text prompts (text-to-image), or "
"edit / transform an existing image (image-to-image) when the active "
"model supports it. Pass `image_url` to edit that image; add "
"`reference_image_urls` for style/composition references; omit both "
"for text-to-image. The underlying backend (FAL, OpenAI, xAI, etc.) "
"and model are user-configured and not selectable by the agent. "
"Returns either a URL or an absolute file path in the `image` field; "
"display it with markdown ![description](url-or-path) and the gateway "
"will deliver it. When the active terminal backend has a different "
"filesystem, successful local-file results may also include "
"`agent_visible_image` for follow-up terminal/file operations."
),
"parameters": {
"type": "object",
"properties": {
"prompt": {
"type": "string",
"description": (
"The text prompt describing the desired image (text-to-"
"image) or the edit to apply (image-to-image). Be detailed "
"and descriptive."
),
},
"aspect_ratio": {
"type": "string",
"enum": list(VALID_ASPECT_RATIOS),
"description": "The aspect ratio of the generated image. 'landscape' is 16:9 wide, 'portrait' is 16:9 tall, 'square' is 1:1.",
"default": DEFAULT_ASPECT_RATIO,
},
"image_url": {
"type": "string",
"description": (
"Optional source image to edit/transform (image-to-image). "
"When provided, the active backend routes to its image "
"editing endpoint; when omitted, it generates from text "
"alone. Pass a public URL or an absolute local file path "
"from the conversation. Only honored by models that "
"support editing — the description above indicates whether "
"the active model does."
),
},
"reference_image_urls": {
"type": "array",
"items": {"type": "string"},
"description": (
"Optional list of additional reference image URLs / paths "
"(style, character, or composition references) to guide an "
"image-to-image edit. Supported only by some models and "
"capped per-model; the description above indicates the max."
),
},
},
"required": ["prompt"],
},
}
def _read_configured_image_model():
"""Return the value of ``image_gen.model`` from config.yaml, or None."""
try:
from hermes_cli.config import load_config
cfg = load_config()
section = cfg.get("image_gen") if isinstance(cfg, dict) else None
if isinstance(section, dict):
value = section.get("model")
if isinstance(value, str) and value.strip():
return value.strip()
except Exception as exc:
logger.debug("Could not read image_gen.model: %s", exc)
return None
def _read_configured_image_provider():
"""Return the value of ``image_gen.provider`` from config.yaml, or None.
We only consult the plugin registry when this is explicitly set — an
unset value keeps users on the in-tree FAL fallback even when other
providers happen to be registered (e.g. a user has OPENAI_API_KEY set
for other features but never asked for OpenAI image gen). ``"fal"``
explicitly routes through ``plugins/image_gen/fal/`` (which delegates
back into this module's pipeline via call-time indirection — see
issue #26241).
"""
try:
from hermes_cli.config import load_config
cfg = load_config()
section = cfg.get("image_gen") if isinstance(cfg, dict) else None
if isinstance(section, dict):
value = section.get("provider")
if isinstance(value, str) and value.strip():
return value.strip()
except Exception as exc:
logger.debug("Could not read image_gen.provider: %s", exc)
return None
def _dispatch_to_plugin_provider(
prompt: str,
aspect_ratio: str,
image_url: Optional[str] = None,
reference_image_urls: Optional[list] = None,
):
"""Route the call to a plugin-registered provider when one is selected.
Returns a JSON string on dispatch, or ``None`` to fall through to the
in-tree FAL fallback in ``image_generate_tool``.
Dispatch fires when ``image_gen.provider`` is explicitly set — including
``"fal"`` itself, which now resolves to the
``plugins/image_gen/fal/`` plugin (the plugin re-enters this module's
pipeline via ``_it`` indirection so behavior is identical to the
direct call, just routed through the registry).
``image_url`` / ``reference_image_urls`` enable image-to-image / editing:
they are forwarded to the provider's ``generate()`` so the backend can
route to its edit endpoint.
"""
configured = _read_configured_image_provider()
if not configured:
return None
# Also read configured model so we can pass it to the plugin
configured_model = _read_configured_image_model()
try:
# Import locally so plugin discovery isn't triggered just by
# importing this module (tests rely on that).
from agent.image_gen_registry import get_provider
from hermes_cli.plugins import _ensure_plugins_discovered
_ensure_plugins_discovered()
provider = get_provider(configured)
except Exception as exc:
logger.debug("image_gen plugin dispatch skipped: %s", exc)
return None
if provider is None:
try:
# Long-lived sessions may have discovered plugins before a bundled
# backend was patched in or before config changed. Retry once with
# a forced refresh before surfacing a missing-provider error.
_ensure_plugins_discovered(force=True)
provider = get_provider(configured)
except Exception as exc:
logger.debug("image_gen plugin force-refresh skipped: %s", exc)
if provider is None:
return json.dumps({
"success": False,
"image": None,
"error": (
f"image_gen.provider='{configured}' is set but no plugin "
f"registered that name. Run `hermes plugins list` to see "
f"available image gen backends."
),
"error_type": "provider_not_registered",
})
kwargs: Dict[str, Any] = {"prompt": prompt, "aspect_ratio": aspect_ratio}
try:
if configured_model:
kwargs["model"] = configured_model
if isinstance(image_url, str) and image_url.strip():
kwargs["image_url"] = image_url.strip()
norm_refs = None
if reference_image_urls is not None:
from agent.image_gen_provider import normalize_reference_images
norm_refs = normalize_reference_images(reference_image_urls)
if norm_refs:
kwargs["reference_image_urls"] = norm_refs
result = provider.generate(**kwargs)
except TypeError as exc:
# A provider whose generate() signature predates image_url support
# (third-party plugin not yet updated) — retry without the new kwargs
# so text-to-image keeps working, but surface a clear note when the
# user actually asked for an edit.
if "image_url" in kwargs or "reference_image_urls" in kwargs:
logger.warning(
"image_gen provider '%s' rejected image-to-image kwargs "
"(signature too narrow): %s",
getattr(provider, "name", "?"), exc,
)
return json.dumps({
"success": False,
"image": None,
"error": (
f"Provider '{getattr(provider, 'name', '?')}' does not "
f"support image-to-image / editing (its generate() "
f"signature is out of date with the image_generate schema). "
f"Omit image_url for text-to-image, or pick a backend that "
f"supports editing via `hermes tools` → Image Generation."
),
"error_type": "modality_unsupported",
})
logger.warning(
"Image gen provider '%s' raised TypeError: %s",
getattr(provider, "name", "?"), exc,
)
return json.dumps({
"success": False,
"image": None,
"error": f"Provider '{getattr(provider, 'name', '?')}' error: {exc}",
"error_type": "provider_exception",
})
except Exception as exc:
logger.warning(
"Image gen provider '%s' raised: %s",
getattr(provider, "name", "?"), exc,
)
return json.dumps({
"success": False,
"image": None,
"error": f"Provider '{getattr(provider, 'name', '?')}' error: {exc}",
"error_type": "provider_exception",
})
if not isinstance(result, dict):
return json.dumps({
"success": False,
"image": None,
"error": "Provider returned a non-dict result",
"error_type": "provider_contract",
})
return json.dumps(result)
def _handle_image_generate(args, **kw):
prompt = args.get("prompt", "")
if not prompt:
return tool_error("prompt is required for image generation")
aspect_ratio = args.get("aspect_ratio", DEFAULT_ASPECT_RATIO)
image_url = args.get("image_url")
reference_image_urls = args.get("reference_image_urls")
task_id = kw.get("task_id")
# Route to a plugin-registered provider if one is active (and it's
# not the in-tree FAL path).
dispatched = _dispatch_to_plugin_provider(
prompt, aspect_ratio,
image_url=image_url,
reference_image_urls=reference_image_urls,
)
if dispatched is not None:
return _postprocess_image_generate_result(dispatched, task_id=task_id)
raw = image_generate_tool(
prompt=prompt,
aspect_ratio=aspect_ratio,
image_url=image_url,
reference_image_urls=reference_image_urls,
)
return _postprocess_image_generate_result(raw, task_id=task_id)
# ---------------------------------------------------------------------------
# Dynamic schema — reflect the active backend's image-to-image capability
# ---------------------------------------------------------------------------
#
# Why dynamic: whether the active model supports image-to-image / editing
# depends entirely on the user's configured backend + model. Telling the
# model up front ("the active model is text-to-image only — image_url will be
# rejected") saves a wasted turn. Memoized by config.yaml mtime in
# model_tools.get_tool_definitions(), so it rebuilds when the user switches
# model/provider via `hermes tools` or `/skills`.
_GENERIC_IMAGE_DESCRIPTION = IMAGE_GENERATE_SCHEMA["description"]
def _active_image_capabilities() -> Dict[str, Any]:
"""Best-effort: return the active backend/model's image capabilities.
Resolution order mirrors the runtime dispatch:
1. If ``image_gen.provider`` is set, ask that plugin provider.
2. Otherwise inspect the in-tree FAL model catalog for the active model.
Returns a dict like ``{"modalities": [...], "max_reference_images": N,
"model": "...", "provider": "..."}``. Never raises.
"""
info: Dict[str, Any] = {"modalities": ["text"], "max_reference_images": 0}
configured_provider = _read_configured_image_provider()
if configured_provider and configured_provider != "fal":
try:
from agent.image_gen_registry import get_provider
from hermes_cli.plugins import _ensure_plugins_discovered
_ensure_plugins_discovered()
provider = get_provider(configured_provider)
if provider is not None:
caps = {}
try:
caps = provider.capabilities() or {}
except Exception: # noqa: BLE001
caps = {}
info["provider"] = provider.display_name
info["model"] = _read_configured_image_model() or (provider.default_model() or "")
if caps.get("modalities"):
info["modalities"] = list(caps["modalities"])
if caps.get("max_reference_images"):
info["max_reference_images"] = int(caps["max_reference_images"])
return info
except Exception: # noqa: BLE001
pass
# In-tree FAL path (provider unset or == "fal").
try:
model_id, meta = _resolve_fal_model()
info["provider"] = "FAL.ai"
info["model"] = meta.get("display", model_id)
if meta.get("edit_endpoint"):
info["modalities"] = ["text", "image"]
info["max_reference_images"] = int(meta.get("max_reference_images") or 1)
else:
info["modalities"] = ["text"]
info["max_reference_images"] = 0
except Exception: # noqa: BLE001
pass
return info
def _build_dynamic_image_schema() -> Dict[str, Any]:
"""Build a description reflecting whether the active model supports editing."""
parts = [_GENERIC_IMAGE_DESCRIPTION]
try:
info = _active_image_capabilities()
except Exception: # noqa: BLE001
return {"description": _GENERIC_IMAGE_DESCRIPTION}
provider = info.get("provider")
model = info.get("model")
modalities = set(info.get("modalities") or ["text"])
line = "\nActive backend"
if provider:
line += f": {provider}"
if model:
line += f" · model: {model}"
parts.append(line)
if "image" in modalities and "text" in modalities:
max_refs = info.get("max_reference_images") or 0
ref_note = (
f"; up to {max_refs} reference image(s) via reference_image_urls"
if max_refs and max_refs > 1
else ""
)
parts.append(
"- supports both text-to-image (omit image_url) and "
f"image-to-image / editing (pass image_url){ref_note}"
"routes automatically"
)
elif "image" in modalities and "text" not in modalities:
parts.append(
"- this model is image-to-image / edit only — image_url is REQUIRED"
)
else:
parts.append(
"- this model is text-to-image only — it is NOT capable of "
"image-to-image / editing; do not pass image_url or "
"reference_image_urls (they will be rejected). Provide a "
"text-only prompt."
)
return {"description": "\n".join(parts)}
registry.register(
name="image_generate",
toolset="image_gen",
schema=IMAGE_GENERATE_SCHEMA,
handler=_handle_image_generate,
check_fn=check_image_generation_requirements,
requires_env=[],
is_async=False, # sync fal_client API to avoid "Event loop is closed" in gateway
emoji="🎨",
dynamic_schema_overrides=_build_dynamic_image_schema,
)