Files
hermes-agent/tools/browser_tool_vision.py
Mohamad Kanso f37336522b feat(vision): vision.embed_target_bytes replaces the hardcoded 256 KB native embed budget
The native vision_analyze fast path (and the browser screenshot twins) downscaled every
embed to a fixed _EMBED_TARGET_BYTES = 256 KB. That is fine for photos but turns a
1080x2340 phone screenshot of a table into 540x1170, which the model then reads as
"unreadable" and re-requests (#112095).

The budget is now `vision.embed_target_bytes` in config.yaml (default unchanged: 256 KB,
clamped to 64 KiB..4 MiB so one setting cannot make every later request a multi-megabyte
resend), resolved in the new topical sibling tools/vision_tools_history_budget.py and read
by vision_analyze, browser_vision and browser_exec screenshots alike.

Ported from #112947 by @MohamadKanso (resolver + clamp), relocated out of the facade.
2026-09-17 09:02:55 -07:00

145 lines
7.1 KiB
Python

"""browser_vision helpers: Lightpanda pre-route, native provider vision, auxiliary-LLM screenshot analysis.
Split out of ``tools/browser_tool.py``. Facade-owned state is read through ``_bt`` (``tools.browser_tool``, resolved per call) — no import cycle.
"""
import os
import shutil
from pathlib import Path
from typing import Any, Dict, Optional, Tuple
from hermes_cli.config import cfg_get
from tools.browser_tool_origin import origin as _bt
from tools import browser_tool_cloud as _cloud
from tools import browser_tool_lightpanda_fallback as _lp
def _vision_mode_label() -> str:
_cp = _cloud._get_cloud_provider()
return "local" if _cp is None else f"cloud ({_cp.display_name})"
def _lightpanda_vision_preroute(
effective_task_id: str, annotate: bool, screenshot_path: Path,
) -> Tuple[bool, Optional[str], Path]:
"""Capture the vision screenshot via the Chrome fallback when Lightpanda is the engine
(it has no graphical renderer). Returns ``(prerouted, fallback_warning, path)``;
on fallback failure ``prerouted`` is False and the caller takes the normal
screenshot path (forcing Chrome) so the standard fallback metadata still applies."""
engine = _cloud._get_browser_engine()
if engine != "lightpanda" or not _cloud._should_inject_engine(engine):
return False, None, screenshot_path
_bt.logger.debug("browser_vision: pre-routing screenshot to Chrome (engine=lightpanda)")
screenshot_args = ["--annotate"] if annotate else []
fb_result = _lp._chrome_fallback_screenshot(effective_task_id, screenshot_args, _bt._get_command_timeout())
fb_result = _lp._annotate_lightpanda_fallback(fb_result, _bt._LP_VISION_FALLBACK_REASON)
if not fb_result.get("success"):
_bt.logger.warning("Lightpanda Chrome fallback vision screenshot failed: %s", fb_result.get("error"))
return False, None, screenshot_path
fb_path = fb_result.get("data", {}).get("path", "")
if fb_path and os.path.exists(fb_path):
import uuid as uuid_mod
from hermes_constants import get_hermes_dir
screenshots_dir = get_hermes_dir("cache/screenshots", "browser_screenshots")
screenshots_dir.mkdir(parents=True, exist_ok=True)
persistent_path = screenshots_dir / f"browser_screenshot_{uuid_mod.uuid4().hex}.png"
shutil.copy2(fb_path, persistent_path)
screenshot_path = persistent_path
return True, fb_result.get("fallback_warning"), screenshot_path
def _native_vision_result(
screenshot_path: Path, question: str, annotate: bool,
result: Dict[str, Any], lp_fallback_warning: Optional[str],
) -> Dict[str, Any]:
"""Multimodal tool-result envelope: the main model inspects the pixels itself.
The embed is baked into history and re-sent every later turn, so apply the same
proactive resize as vision_analyze's native path (skipped when already under
both caps; without Pillow it fails open to the raw bytes).
"""
from tools.vision_tools import (
_EMBED_MAX_DIMENSION,
_build_native_vision_tool_result,
_resize_image_for_vision,
)
from tools.vision_tools_history_budget import resolve_embed_target_bytes
data_url = _resize_image_for_vision(screenshot_path, mime_type="image/png",
max_base64_bytes=resolve_embed_target_bytes(),
max_dimension=_EMBED_MAX_DIMENSION, force_jpeg=True)
native_result = _build_native_vision_tool_result(image_url=str(screenshot_path), question=question,
image_data_url=data_url,
image_size_bytes=screenshot_path.stat().st_size)
meta = native_result.setdefault("meta", {})
meta["screenshot_path"] = str(screenshot_path)
if lp_fallback_warning:
meta["fallback_warning"] = lp_fallback_warning
if annotate and result.get("data", {}).get("annotations"):
meta["annotations"] = result["data"]["annotations"]
native_result["text_summary"] = f"{native_result.get('text_summary', '')} Screenshot path: {screenshot_path}".strip()
return native_result
def _analyze_screenshot_with_aux_llm(screenshot_path: Path, question: str) -> str:
"""One-shot aux vision-LLM analysis (not baked into history), secret-redacted.
Full resolution first; on a size-related provider rejection the image is
downscaled once and retried. ``auxiliary.vision.timeout/temperature`` — local
vision models can take well over 30s, so the default timeout is generous.
"""
import base64
vision_prompt = (
f"You are analyzing a screenshot of a web browser.\n\n"
f"User's question: {question}\n\n"
f"Provide a detailed and helpful answer based on what you see in the screenshot. "
f"If there are interactive elements, describe them. If there are verification challenges "
f"or CAPTCHAs, describe what type they are and what action might be needed. "
f"Focus on answering the user's specific question."
)
_screenshot_bytes = screenshot_path.read_bytes()
_screenshot_b64 = base64.b64encode(_screenshot_bytes).decode("ascii")
data_url = f"data:image/png;base64,{_screenshot_b64}"
vision_model = _bt._get_vision_model()
_bt.logger.debug("browser_vision: analysing screenshot (%d bytes)", len(_screenshot_bytes))
vision_timeout = 120.0
vision_temperature = 0.1
try:
from hermes_cli.config import load_config
_vision_cfg = cfg_get(load_config(), "auxiliary", "vision", default={})
if _vision_cfg.get("timeout") is not None:
vision_timeout = float(_vision_cfg["timeout"])
if _vision_cfg.get("temperature") is not None:
vision_temperature = float(_vision_cfg["temperature"])
except Exception:
pass
from agent.auxiliary_client import call_llm # lazy: heavy client, only needed on the vision path
call_kwargs = {
"task": "vision", "temperature": vision_temperature, "timeout": vision_timeout,
"messages": [{"role": "user", "content": [
{"type": "text", "text": vision_prompt},
{"type": "image_url", "image_url": {"url": data_url}},
]}],
}
if vision_model:
call_kwargs["model"] = vision_model
try:
response = call_llm(**call_kwargs)
except Exception as _api_err:
from tools.vision_tools import _is_image_size_error, _resize_image_for_vision, _RESIZE_TARGET_BYTES
if not (_is_image_size_error(_api_err) and len(data_url) > _RESIZE_TARGET_BYTES):
raise
_bt.logger.info("Vision API rejected screenshot (%.1f MB); auto-resizing to ~%.0f MB and retrying...",
len(data_url) / (1024 * 1024), _RESIZE_TARGET_BYTES / (1024 * 1024))
data_url = _resize_image_for_vision(screenshot_path, mime_type="image/png")
call_kwargs["messages"][0]["content"][1]["image_url"]["url"] = data_url
response = call_llm(**call_kwargs)
from agent.redact import redact_sensitive_text # the LLM may have read secrets off the screenshot
return redact_sensitive_text((response.choices[0].message.content or "").strip())