Files
hermes-agent/environments/agent_loop.py
teknium 07b615e96e Add support for Atropos Agentic RL environments (requires branch tool_call_support in Atropos atm)
- Added new environments for reinforcement learning, including `HermesSweEnv` for software engineering tasks and `TerminalTestEnv` for inline testing.
- Introduced `ToolContext` for unrestricted access to tools during reward computation.
- Updated `.gitignore` to exclude `wandb/` directory.
- Enhanced `README.md` with detailed architecture and usage instructions for Atropos environments.
- Added configuration files for SWE and terminal test environments to streamline setup.
- Removed unnecessary compiled Python files from `__pycache__`.
2026-02-07 09:17:16 +00:00

307 lines
12 KiB
Python

"""
HermesAgentLoop -- Reusable Multi-Turn Agent Engine
Runs the hermes-agent tool-calling loop using standard OpenAI-spec tool calling.
Works with any server that returns ChatCompletion objects with tool_calls:
- Phase 1: OpenAI server type (VLLM, SGLang, OpenRouter, OpenAI API)
- Phase 2: ManagedServer with client-side tool call parser
The loop passes tools= and checks response.choices[0].message.tool_calls,
identical to hermes-agent's run_agent.py. Tool execution is dispatched via
handle_function_call() from model_tools.py.
"""
import json
import logging
import uuid
from dataclasses import dataclass, field
from typing import Any, Dict, List, Optional, Set
from model_tools import handle_function_call
logger = logging.getLogger(__name__)
@dataclass
class AgentResult:
"""Result of running the agent loop."""
# Full conversation history in OpenAI message format
messages: List[Dict[str, Any]]
# ManagedServer.get_state() if available (Phase 2), None otherwise
managed_state: Optional[Dict[str, Any]] = None
# How many LLM calls were made
turns_used: int = 0
# True if model stopped calling tools naturally (vs hitting max_turns)
finished_naturally: bool = False
# Extracted reasoning content per turn (from PR #297 helpers)
reasoning_per_turn: List[Optional[str]] = field(default_factory=list)
def _extract_reasoning_from_message(message) -> Optional[str]:
"""
Extract reasoning content from a ChatCompletion message.
Handles multiple provider formats:
1. message.reasoning_content field (some providers)
2. message.reasoning field (some providers)
3. message.reasoning_details[].text (OpenRouter style)
Note: <think> block extraction from content is NOT done here -- that's
handled by the response already in Phase 1 (server does it) or by
ManagedServer's patch in Phase 2.
Args:
message: The assistant message from ChatCompletion response
Returns:
Extracted reasoning text, or None if not found
"""
# Check reasoning_content field (common across providers)
if hasattr(message, "reasoning_content") and message.reasoning_content:
return message.reasoning_content
# Check reasoning field
if hasattr(message, "reasoning") and message.reasoning:
return message.reasoning
# Check reasoning_details (OpenRouter style)
if hasattr(message, "reasoning_details") and message.reasoning_details:
for detail in message.reasoning_details:
if hasattr(detail, "text") and detail.text:
return detail.text
if isinstance(detail, dict) and detail.get("text"):
return detail["text"]
return None
class HermesAgentLoop:
"""
Runs hermes-agent's tool-calling loop using standard OpenAI-spec tool calling.
Same pattern as run_agent.py:
- Pass tools= to the API
- Check response.choices[0].message.tool_calls
- Dispatch via handle_function_call()
Works identically with any server type -- OpenAI, VLLM, SGLang, OpenRouter,
or ManagedServer with a parser. The server determines how tool_calls get
populated on the response.
"""
def __init__(
self,
server,
tool_schemas: List[Dict[str, Any]],
valid_tool_names: Set[str],
max_turns: int = 30,
task_id: Optional[str] = None,
temperature: float = 1.0,
max_tokens: Optional[int] = None,
):
"""
Initialize the agent loop.
Args:
server: Server object with chat_completion() method (OpenAIServer,
ManagedServer, ServerManager, etc.)
tool_schemas: OpenAI-format tool definitions from get_tool_definitions()
valid_tool_names: Set of tool names the model is allowed to call
max_turns: Maximum number of LLM calls before stopping
task_id: Unique ID for terminal/browser session isolation
temperature: Sampling temperature for generation
max_tokens: Max tokens per generation (None for server default)
"""
self.server = server
self.tool_schemas = tool_schemas
self.valid_tool_names = valid_tool_names
self.max_turns = max_turns
self.task_id = task_id or str(uuid.uuid4())
self.temperature = temperature
self.max_tokens = max_tokens
async def run(self, messages: List[Dict[str, Any]]) -> AgentResult:
"""
Execute the full agent loop using standard OpenAI tool calling.
Args:
messages: Initial conversation messages (system + user).
Modified in-place as the conversation progresses.
Returns:
AgentResult with full conversation history, managed state, and metadata
"""
reasoning_per_turn = []
for turn in range(self.max_turns):
# Build the chat_completion kwargs
chat_kwargs = {
"messages": messages,
"n": 1,
"temperature": self.temperature,
}
# Only pass tools if we have them
if self.tool_schemas:
chat_kwargs["tools"] = self.tool_schemas
# Only pass max_tokens if explicitly set
if self.max_tokens is not None:
chat_kwargs["max_tokens"] = self.max_tokens
# Make the API call -- standard OpenAI spec
try:
response = await self.server.chat_completion(**chat_kwargs)
except Exception as e:
logger.error("API call failed on turn %d: %s", turn + 1, e)
return AgentResult(
messages=messages,
managed_state=self._get_managed_state(),
turns_used=turn + 1,
finished_naturally=False,
reasoning_per_turn=reasoning_per_turn,
)
if not response or not response.choices:
logger.warning("Empty response on turn %d", turn + 1)
return AgentResult(
messages=messages,
managed_state=self._get_managed_state(),
turns_used=turn + 1,
finished_naturally=False,
reasoning_per_turn=reasoning_per_turn,
)
assistant_msg = response.choices[0].message
# Extract reasoning content from the response (all provider formats)
reasoning = _extract_reasoning_from_message(assistant_msg)
reasoning_per_turn.append(reasoning)
# Check for tool calls -- standard OpenAI spec
if assistant_msg.tool_calls:
# Build the assistant message dict for conversation history
msg_dict: Dict[str, Any] = {
"role": "assistant",
"content": assistant_msg.content or "",
"tool_calls": [
{
"id": tc.id,
"type": "function",
"function": {
"name": tc.function.name,
"arguments": tc.function.arguments,
},
}
for tc in assistant_msg.tool_calls
],
}
# Preserve reasoning_content for multi-turn chat template handling
# (e.g., Kimi-K2's template renders <think> blocks differently
# for history vs. the latest turn based on this field)
if reasoning:
msg_dict["reasoning_content"] = reasoning
messages.append(msg_dict)
# Execute each tool call via hermes-agent's dispatch
for tc in assistant_msg.tool_calls:
tool_name = tc.function.name
# Validate tool name
if tool_name not in self.valid_tool_names:
tool_result = json.dumps(
{
"error": f"Unknown tool '{tool_name}'. "
f"Available tools: {sorted(self.valid_tool_names)}"
}
)
logger.warning(
"Model called unknown tool '%s' on turn %d",
tool_name,
turn + 1,
)
else:
# Parse arguments and dispatch
try:
args = json.loads(tc.function.arguments)
except json.JSONDecodeError:
args = {}
logger.warning(
"Invalid JSON in tool call arguments for '%s': %s",
tool_name,
tc.function.arguments[:200],
)
try:
tool_result = handle_function_call(
tool_name, args, task_id=self.task_id
)
except Exception as e:
tool_result = json.dumps(
{"error": f"Tool execution failed: {str(e)}"}
)
logger.error(
"Tool '%s' execution failed: %s", tool_name, e
)
# Add tool response to conversation
messages.append(
{
"role": "tool",
"tool_call_id": tc.id,
"content": tool_result,
}
)
logger.debug(
"Turn %d: %d tool calls executed",
turn + 1,
len(assistant_msg.tool_calls),
)
else:
# No tool calls -- model is done
msg_dict = {
"role": "assistant",
"content": assistant_msg.content or "",
}
if reasoning:
msg_dict["reasoning_content"] = reasoning
messages.append(msg_dict)
logger.debug(
"Turn %d: model finished naturally (no tool calls)", turn + 1
)
return AgentResult(
messages=messages,
managed_state=self._get_managed_state(),
turns_used=turn + 1,
finished_naturally=True,
reasoning_per_turn=reasoning_per_turn,
)
# Hit max turns without the model stopping
logger.info("Agent hit max_turns (%d) without finishing", self.max_turns)
return AgentResult(
messages=messages,
managed_state=self._get_managed_state(),
turns_used=self.max_turns,
finished_naturally=False,
reasoning_per_turn=reasoning_per_turn,
)
def _get_managed_state(self) -> Optional[Dict[str, Any]]:
"""
Get ManagedServer state if the server supports it.
Returns state dict with SequenceNodes containing tokens/logprobs/masks,
or None if the server doesn't support get_state() (e.g., regular OpenAI server).
"""
if hasattr(self.server, "get_state"):
return self.server.get_state()
return None