hermes / environments /tool_context.py
lenson78's picture
initial upload: v2026.3.23 with HF Spaces deployment
9aa5185 verified
"""
ToolContext -- Unrestricted Tool Access for Reward Functions
A per-rollout handle that gives reward/verification functions direct access to
ALL hermes-agent tools, scoped to the rollout's task_id. The same task_id means
the terminal/browser session is the SAME one the model used during its rollout --
all state (files, processes, browser tabs) is preserved.
The verifier author decides which tools to use. Nothing is hardcoded or gated.
Example usage in a compute_reward():
async def compute_reward(self, item, result, ctx):
# Run tests in the model's terminal sandbox
test = ctx.terminal("pytest -v")
if test["exit_code"] == 0:
return 1.0
# Check if a file was created
content = ctx.read_file("/workspace/solution.py")
if content.get("content"):
return 0.5
return 0.0
"""
import json
import logging
import os
from typing import Any, Dict, List, Optional
import asyncio
import concurrent.futures
from model_tools import handle_function_call
from tools.terminal_tool import cleanup_vm
from tools.browser_tool import cleanup_browser
logger = logging.getLogger(__name__)
# Thread pool for running sync tool calls that internally use asyncio.run()
_tool_executor = concurrent.futures.ThreadPoolExecutor(max_workers=4)
def _run_tool_in_thread(tool_name: str, arguments: Dict[str, Any], task_id: str) -> str:
"""
Run a tool call in a thread pool executor so backends that use asyncio.run()
internally (modal, docker, daytona) get a clean event loop.
If we're already in an async context, executes handle_function_call() in a
disposable worker thread and blocks for the result.
If not (e.g., called from sync code), runs directly.
"""
try:
loop = asyncio.get_running_loop()
# We're in an async context -- need to run in thread
import concurrent.futures
with concurrent.futures.ThreadPoolExecutor(max_workers=1) as pool:
future = pool.submit(
handle_function_call, tool_name, arguments, task_id
)
return future.result(timeout=300)
except RuntimeError:
# No running event loop -- safe to call directly
return handle_function_call(tool_name, arguments, task_id)
class ToolContext:
"""
Open-ended access to all hermes-agent tools for a specific rollout.
Passed to compute_reward() so verifiers can use any tool they need:
terminal commands, file reads/writes, web searches, browser automation, etc.
All calls share the rollout's task_id for session isolation.
"""
def __init__(self, task_id: str):
self.task_id = task_id
# -------------------------------------------------------------------------
# Terminal tools
# -------------------------------------------------------------------------
def terminal(self, command: str, timeout: int = 180) -> Dict[str, Any]:
"""
Run a command in the rollout's terminal session.
Args:
command: Shell command to execute
timeout: Command timeout in seconds
Returns:
Dict with 'exit_code' (int) and 'output' (str)
"""
import os
backend = os.getenv("TERMINAL_ENV", "local")
logger.debug("ToolContext.terminal [%s backend] task=%s: %s", backend, self.task_id[:8], command[:100])
# Run via thread helper so modal/docker/daytona backends' asyncio.run() doesn't deadlock
result = _run_tool_in_thread(
"terminal",
{"command": command, "timeout": timeout},
self.task_id,
)
try:
return json.loads(result)
except json.JSONDecodeError:
return {"exit_code": -1, "output": result}
# -------------------------------------------------------------------------
# File tools
# -------------------------------------------------------------------------
def read_file(self, path: str) -> Dict[str, Any]:
"""
Read a file from the rollout's filesystem.
Args:
path: File path to read
Returns:
Dict with file content or error
"""
result = handle_function_call(
"read_file", {"path": path}, task_id=self.task_id
)
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
def write_file(self, path: str, content: str) -> Dict[str, Any]:
"""
Write a TEXT file in the rollout's filesystem.
Uses a shell heredoc under the hood, so this is only safe for text content.
For binary files (images, compiled artifacts, etc.), use upload_file() instead.
Args:
path: File path to write
content: Text content to write
Returns:
Dict with success status or error
"""
result = handle_function_call(
"write_file", {"path": path, "content": content}, task_id=self.task_id
)
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
def upload_file(self, local_path: str, remote_path: str) -> Dict[str, Any]:
"""
Upload a local file to the rollout's sandbox (binary-safe).
Unlike write_file() which passes content through a shell heredoc (text-only),
this method base64-encodes the file and decodes it inside the sandbox.
Safe for any file type: binaries, images, archives, etc.
For large files (>1MB), the content is split into chunks to avoid
hitting shell command-length limits.
Args:
local_path: Path to a local file on the host
remote_path: Destination path inside the sandbox
Returns:
Dict with 'exit_code' and 'output'
"""
import base64
from pathlib import Path as _Path
local = _Path(local_path)
if not local.exists():
return {"exit_code": -1, "output": f"Local file not found: {local_path}"}
raw = local.read_bytes()
b64 = base64.b64encode(raw).decode("ascii")
# Ensure parent directory exists in the sandbox
parent = str(_Path(remote_path).parent)
if parent not in (".", "/"):
self.terminal(f"mkdir -p {parent}", timeout=10)
# For small files, single command is fine
chunk_size = 60_000 # ~60KB per chunk (well within shell limits)
if len(b64) <= chunk_size:
result = self.terminal(
f"printf '%s' '{b64}' | base64 -d > {remote_path}",
timeout=30,
)
else:
# For larger files, write base64 in chunks then decode
tmp_b64 = "/tmp/_hermes_upload.b64"
self.terminal(f": > {tmp_b64}", timeout=5) # truncate
for i in range(0, len(b64), chunk_size):
chunk = b64[i : i + chunk_size]
self.terminal(f"printf '%s' '{chunk}' >> {tmp_b64}", timeout=15)
result = self.terminal(
f"base64 -d {tmp_b64} > {remote_path} && rm -f {tmp_b64}",
timeout=30,
)
return result
def upload_dir(self, local_dir: str, remote_dir: str) -> List[Dict[str, Any]]:
"""
Upload an entire local directory to the rollout's sandbox (binary-safe).
Recursively uploads all files, preserving directory structure.
Args:
local_dir: Path to a local directory on the host
remote_dir: Destination directory inside the sandbox
Returns:
List of results, one per file uploaded
"""
from pathlib import Path as _Path
local = _Path(local_dir)
if not local.exists() or not local.is_dir():
return [{"exit_code": -1, "output": f"Local directory not found: {local_dir}"}]
results = []
for file_path in sorted(local.rglob("*")):
if file_path.is_file():
relative = file_path.relative_to(local)
target = f"{remote_dir}/{relative}"
results.append(self.upload_file(str(file_path), target))
return results
def download_file(self, remote_path: str, local_path: str) -> Dict[str, Any]:
"""
Download a file from the rollout's sandbox to the host (binary-safe).
The inverse of upload_file(). Base64-encodes the file inside the sandbox,
reads the encoded data through the terminal, and decodes it locally.
Safe for any file type.
Args:
remote_path: Path to the file inside the sandbox
local_path: Destination path on the host
Returns:
Dict with 'success' (bool) and 'bytes' (int) or 'error' (str)
"""
import base64
from pathlib import Path as _Path
# Base64-encode the file inside the sandbox and capture output
result = self.terminal(
f"base64 {remote_path} 2>/dev/null",
timeout=30,
)
if result.get("exit_code", -1) != 0:
return {
"success": False,
"error": f"Failed to read remote file: {result.get('output', '')}",
}
b64_data = result.get("output", "").strip()
if not b64_data:
return {"success": False, "error": f"Remote file is empty or missing: {remote_path}"}
try:
raw = base64.b64decode(b64_data)
except Exception as e:
return {"success": False, "error": f"Base64 decode failed: {e}"}
# Write to local host filesystem
local = _Path(local_path)
local.parent.mkdir(parents=True, exist_ok=True)
local.write_bytes(raw)
return {"success": True, "bytes": len(raw)}
def download_dir(self, remote_dir: str, local_dir: str) -> List[Dict[str, Any]]:
"""
Download a directory from the rollout's sandbox to the host (binary-safe).
Lists all files in the remote directory, then downloads each one.
Preserves directory structure.
Args:
remote_dir: Path to the directory inside the sandbox
local_dir: Destination directory on the host
Returns:
List of results, one per file downloaded
"""
from pathlib import Path as _Path
# List files in the remote directory
ls_result = self.terminal(
f"find {remote_dir} -type f 2>/dev/null",
timeout=15,
)
if ls_result.get("exit_code", -1) != 0:
return [{"success": False, "error": f"Failed to list remote dir: {remote_dir}"}]
file_list = ls_result.get("output", "").strip()
if not file_list:
return [{"success": False, "error": f"Remote directory is empty or missing: {remote_dir}"}]
results = []
for remote_file in file_list.splitlines():
remote_file = remote_file.strip()
if not remote_file:
continue
# Compute the relative path to preserve directory structure
if remote_file.startswith(remote_dir):
relative = remote_file[len(remote_dir):].lstrip("/")
else:
relative = _Path(remote_file).name
local_file = str(_Path(local_dir) / relative)
results.append(self.download_file(remote_file, local_file))
return results
def search(self, query: str, path: str = ".") -> Dict[str, Any]:
"""
Search for text in the rollout's filesystem.
Args:
query: Search query
path: Directory to search in
Returns:
Dict with search results
"""
result = handle_function_call(
"search_files", {"pattern": query, "path": path}, task_id=self.task_id
)
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
# -------------------------------------------------------------------------
# Web tools
# -------------------------------------------------------------------------
def web_search(self, query: str) -> Dict[str, Any]:
"""
Search the web.
Args:
query: Search query
Returns:
Dict with search results
"""
result = handle_function_call("web_search", {"query": query})
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
def web_extract(self, urls: List[str]) -> Dict[str, Any]:
"""
Extract content from URLs.
Args:
urls: List of URLs to extract content from
Returns:
Dict with extracted content
"""
result = handle_function_call("web_extract", {"urls": urls})
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
# -------------------------------------------------------------------------
# Browser tools
# -------------------------------------------------------------------------
def browser_navigate(self, url: str) -> Dict[str, Any]:
"""
Navigate the rollout's browser session to a URL.
Args:
url: URL to navigate to
Returns:
Dict with page snapshot or error
"""
result = handle_function_call(
"browser_navigate", {"url": url}, task_id=self.task_id
)
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
def browser_snapshot(self) -> Dict[str, Any]:
"""
Take a snapshot of the current browser page.
Returns:
Dict with page content/accessibility snapshot
"""
result = handle_function_call(
"browser_snapshot", {}, task_id=self.task_id
)
try:
return json.loads(result)
except json.JSONDecodeError:
return {"error": result}
# -------------------------------------------------------------------------
# Generic tool access
# -------------------------------------------------------------------------
def call_tool(self, tool_name: str, arguments: Dict[str, Any]) -> str:
"""
Call any hermes-agent tool by name.
This is the generic escape hatch -- if a tool doesn't have a convenience
wrapper above, you can call it directly here.
Args:
tool_name: Name of the tool (e.g., "vision_analyze", "skills_list")
arguments: Dict of arguments for the tool
Returns:
Raw JSON string result from the tool
"""
return _run_tool_in_thread(tool_name, arguments, self.task_id)
# -------------------------------------------------------------------------
# Cleanup
# -------------------------------------------------------------------------
def cleanup(self):
"""
Release all resources (terminal VMs, browser sessions, background processes)
for this rollout.
Called automatically by the base environment via try/finally after
compute_reward() completes. You generally don't need to call this yourself.
"""
# Kill any background processes from this rollout (safety net)
try:
from tools.process_registry import process_registry
killed = process_registry.kill_all(task_id=self.task_id)
if killed:
logger.debug("Process cleanup for task %s: killed %d process(es)", self.task_id, killed)
except Exception as e:
logger.debug("Process cleanup for task %s: %s", self.task_id, e)
try:
cleanup_vm(self.task_id)
except Exception as e:
logger.debug("VM cleanup for task %s: %s", self.task_id, e)
# Suppress browser_tool's noisy debug prints during cleanup.
# The cleanup still runs (safe), it just doesn't spam the console.
_prev_quiet = os.environ.get("HERMES_QUIET")
os.environ["HERMES_QUIET"] = "1"
try:
cleanup_browser(self.task_id)
except Exception as e:
logger.debug("Browser cleanup for task %s: %s", self.task_id, e)
finally:
if _prev_quiet is None:
os.environ.pop("HERMES_QUIET", None)
else:
os.environ["HERMES_QUIET"] = _prev_quiet