"""Shared execution loop for tool-using agents.""" from __future__ import annotations import asyncio import inspect import os from contextlib import suppress from copy import deepcopy from dataclasses import dataclass, field from pathlib import Path from typing import Any, Callable from loguru import logger from nanobot.agent.context_governance import ( ContextGovernanceConfig, ContextGovernor, ) from nanobot.agent.hook import AgentHook, AgentHookContext, AgentRunHookContext from nanobot.agent.tools.registry import ToolRegistry, is_tool_error_result from nanobot.providers.base import LLMProvider, LLMResponse, ToolCallRequest from nanobot.utils.file_edit_events import ( StreamingFileEditTracker, build_file_edit_end_event, build_file_edit_error_event, build_file_edit_start_event, prepare_file_edit_trackers, ) from nanobot.utils.file_edit_events import ( prepare_file_edit_tracker as _prepare_file_edit_tracker, ) from nanobot.utils.helpers import ( IncrementalThinkExtractor, build_assistant_message, estimate_message_tokens, estimate_prompt_tokens_chain, extract_reasoning, strip_reasoning_tags, strip_think, ) from nanobot.utils.progress_events import ( invoke_file_edit_progress, on_progress_accepts_file_edit_events, ) from nanobot.utils.prompt_templates import render_template from nanobot.utils.runtime import ( EMPTY_FINAL_RESPONSE_MESSAGE, build_budget_exhausted_finalization_message, build_finalization_retry_message, build_goal_continue_message, build_length_recovery_message, is_blank_text, repeated_external_lookup_error, repeated_workspace_violation_error, ) GoalContinueMessage = str | Callable[[], str | None] _DEFAULT_ERROR_MESSAGE = "Sorry, I encountered an error calling the AI model." _ARREARAGE_ERROR_MESSAGE = ( "The AI provider rejected the request because the API key is out of quota or the " "account is in arrears. Please top up / check the billing status of your API key and try again." ) _PERSISTED_MODEL_ERROR_PLACEHOLDER = "[Assistant reply unavailable due to model error.]" _MAX_EMPTY_RETRIES = 2 _MAX_LENGTH_RECOVERIES = 3 _MAX_INJECTIONS_PER_TURN = 3 _MAX_INJECTION_CYCLES = 5 # Backward-compatible module attribute for tests/extensions that monkeypatch # the former single-file tracker hook. Runtime uses prepare_file_edit_trackers. prepare_file_edit_tracker = _prepare_file_edit_tracker @dataclass(slots=True) class AgentRunSpec: """Configuration for a single agent execution.""" initial_messages: list[dict[str, Any]] tools: ToolRegistry model: str max_iterations: int max_tool_result_chars: int temperature: float | None = None max_tokens: int | None = None reasoning_effort: str | None = None hook: AgentHook | None = None error_message: str | None = _DEFAULT_ERROR_MESSAGE max_iterations_message: str | None = None concurrent_tools: bool = False fail_on_tool_error: bool = False workspace: Path | None = None session_key: str | None = None context_window_tokens: int | None = None context_block_limit: int | None = None provider_retry_mode: str = "standard" progress_callback: Any | None = None stream_progress_deltas: bool = True retry_wait_callback: Any | None = None checkpoint_callback: Any | None = None injection_callback: Any | None = None llm_timeout_s: float | None = None goal_active_predicate: Callable[[], bool] | None = None goal_continue_message: GoalContinueMessage | None = None finalize_on_max_iterations: bool = True @dataclass(slots=True) class AgentRunResult: """Outcome of a shared agent execution.""" final_content: str | None messages: list[dict[str, Any]] tools_used: list[str] = field(default_factory=list) usage: dict[str, int] = field(default_factory=dict) stop_reason: str = "completed" error: str | None = None tool_events: list[dict[str, str]] = field(default_factory=list) had_injections: bool = False class AgentRunner: """Run a tool-capable LLM loop without product-layer concerns.""" def __init__(self, provider: LLMProvider): self.provider = provider self.context_governor = ContextGovernor() @staticmethod def _merge_message_content(left: Any, right: Any) -> str | list[dict[str, Any]]: if isinstance(left, str) and isinstance(right, str): return f"{left}\n\n{right}" if left else right def _to_blocks(value: Any) -> list[dict[str, Any]]: if isinstance(value, list): return [ item if isinstance(item, dict) else {"type": "text", "text": str(item)} for item in value ] if value is None: return [] return [{"type": "text", "text": str(value)}] return _to_blocks(left) + _to_blocks(right) @classmethod def _append_injected_messages( cls, messages: list[dict[str, Any]], injections: list[dict[str, Any]], ) -> None: """Append injected user messages while preserving role alternation.""" for injection in injections: if ( messages and injection.get("role") == "user" and messages[-1].get("role") == "user" ): merged = dict(messages[-1]) merged["content"] = cls._merge_message_content( merged.get("content"), injection.get("content"), ) messages[-1] = merged continue messages.append(injection) async def _try_drain_injections( self, spec: AgentRunSpec, messages: list[dict[str, Any]], assistant_message: dict[str, Any] | None, injection_cycles: int, *, phase: str = "after error", iteration: int | None = None, allow_goal_continue: bool = False, ) -> tuple[bool, int]: """Drain pending injections. Returns (should_continue, updated_cycles). If injections are found and we haven't exceeded _MAX_INJECTION_CYCLES, append them to *messages* (and emit a checkpoint if *assistant_message* and *iteration* are both provided) and return (True, cycles+1) so the caller continues the iteration loop. Otherwise return (False, cycles). """ injections: list[dict[str, Any]] = [] real_injection = False if injection_cycles < _MAX_INJECTION_CYCLES: injections = await self._drain_injections(spec) real_injection = bool(injections) if not injections and allow_goal_continue and assistant_message is not None: predicate = spec.goal_active_predicate if predicate is not None and predicate(): injections = [self._build_goal_continue_message(spec)] if not injections: return False, injection_cycles if real_injection: injection_cycles += 1 if assistant_message is not None: messages.append(assistant_message) if iteration is not None: await self._emit_checkpoint( spec, { "phase": "final_response", "iteration": iteration, "model": spec.model, "assistant_message": assistant_message, "completed_tool_results": [], "pending_tool_calls": [], }, ) self._append_injected_messages(messages, injections) if real_injection: logger.info( "Injected {} follow-up message(s) {} ({}/{})", len(injections), phase, injection_cycles, _MAX_INJECTION_CYCLES, ) else: logger.info("Injected sustained-goal continuation {}", phase) return True, injection_cycles def _build_goal_continue_message(self, spec: AgentRunSpec) -> dict[str, str]: custom = spec.goal_continue_message if callable(custom): try: custom = custom() except Exception: logger.exception("goal_continue_message callback failed") custom = None return build_goal_continue_message(custom) async def _drain_injections(self, spec: AgentRunSpec) -> list[dict[str, Any]]: """Drain pending user messages via the injection callback. Returns normalized user messages (capped by ``_MAX_INJECTIONS_PER_TURN``), or an empty list when there is nothing to inject. Messages beyond the cap are logged so they are not silently lost. """ if spec.injection_callback is None: return [] try: signature = inspect.signature(spec.injection_callback) accepts_limit = ( "limit" in signature.parameters or any( parameter.kind is inspect.Parameter.VAR_KEYWORD for parameter in signature.parameters.values() ) ) if accepts_limit: items = await spec.injection_callback(limit=_MAX_INJECTIONS_PER_TURN) else: items = await spec.injection_callback() except Exception: logger.exception("injection_callback failed") return [] if not items: return [] injected_messages: list[dict[str, Any]] = [] for item in items: if item is None: continue if isinstance(item, dict) and item.get("role") == "user" and "content" in item: if self._has_injection_content(item.get("content")): injected_messages.append(item) continue if isinstance(item, dict): continue content = getattr(item, "content") if hasattr(item, "content") else str(item) if self._has_injection_content(content): injected_messages.append({"role": "user", "content": content}) if len(injected_messages) > _MAX_INJECTIONS_PER_TURN: dropped = len(injected_messages) - _MAX_INJECTIONS_PER_TURN logger.warning( "Injection callback returned {} messages, capping to {} ({} dropped)", len(injected_messages), _MAX_INJECTIONS_PER_TURN, dropped, ) injected_messages = injected_messages[:_MAX_INJECTIONS_PER_TURN] return injected_messages @staticmethod def _has_injection_content(content: Any) -> bool: if content is None: return False if isinstance(content, str): return bool(content.strip()) if isinstance(content, list): return bool(content) return True async def run(self, spec: AgentRunSpec) -> AgentRunResult: hook = spec.hook or AgentHook() messages = list(spec.initial_messages) context = AgentRunHookContext(messages=deepcopy(messages)) try: await hook.before_run(context) result = await self._run_core(spec, hook, messages) except asyncio.CancelledError as exc: context.messages = deepcopy(messages) context.stop_reason = "cancelled" context.error = None context.exception = exc raise except Exception as exc: context.messages = deepcopy(messages) context.stop_reason = "error" context.error = f"Error: {type(exc).__name__}: {exc}" context.exception = exc await hook.on_error(context) raise else: context.messages = deepcopy(result.messages) context.final_content = result.final_content context.tools_used = list(result.tools_used) context.usage = dict(result.usage) context.stop_reason = result.stop_reason context.error = result.error context.tool_events = deepcopy(result.tool_events) context.had_injections = result.had_injections context.exception = None if context.error is not None: await hook.on_error(context) await hook.after_run(context) return result finally: context.messages = deepcopy(messages) if context.exception is None: await hook.on_finally(context) else: try: await hook.on_finally(context) except Exception: logger.exception( "AgentHook.on_finally error after {}", context.stop_reason or "run exception", ) async def _run_core( self, spec: AgentRunSpec, hook: AgentHook, messages: list[dict[str, Any]], ) -> AgentRunResult: final_content: str | None = None tools_used: list[str] = [] usage: dict[str, int] = {"prompt_tokens": 0, "completion_tokens": 0} error: str | None = None stop_reason = "completed" tool_events: list[dict[str, str]] = [] external_lookup_counts: dict[str, int] = {} # Per-turn throttle for repeated attempts against the same outside target. workspace_violation_counts: dict[str, int] = {} empty_content_retries = 0 length_recovery_count = 0 had_injections = False injection_cycles = 0 compacted_tool_call_ids: set[str] = set() governance_config = ContextGovernanceConfig( provider=self.provider, model=spec.model, tools=spec.tools, workspace=spec.workspace, session_key=spec.session_key, max_tool_result_chars=spec.max_tool_result_chars, context_window_tokens=spec.context_window_tokens, context_block_limit=spec.context_block_limit, max_tokens=spec.max_tokens, inflight_start_index=len(spec.initial_messages), ) for iteration in range(spec.max_iterations): try: # Keep the persisted conversation untouched. Context governance # may repair or compact historical messages for the model, but # those synthetic edits must not shift the append boundary used # later when the caller saves only the new turn. messages_for_model = self.context_governor.prepare_for_model( governance_config, messages, compacted_tool_call_ids, ) except Exception: logger.exception( "Context governance failed on turn {} for {}; applying minimal repair", iteration, spec.session_key or "default", ) try: messages_for_model = ContextGovernor.strip_placeholder_assistant_messages( messages ) messages_for_model = ContextGovernor.strip_malformed_tool_calls( messages_for_model ) messages_for_model = ContextGovernor.drop_orphan_tool_results( messages_for_model ) messages_for_model = ContextGovernor.backfill_missing_tool_results( messages_for_model ) except Exception: messages_for_model = messages context = AgentHookContext( iteration=iteration, messages=messages, session_key=spec.session_key, ) await hook.before_iteration(context) response = await self._request_model(spec, messages_for_model, hook, context) context.response = response context.tool_calls = list(response.tool_calls) reasoning_text, cleaned_content = extract_reasoning( response.reasoning_content, response.thinking_blocks, response.content, ) response.content = cleaned_content raw_usage = self._usage_or_estimate(spec, messages_for_model, response) context.usage = dict(raw_usage) self._accumulate_usage(usage, raw_usage) if reasoning_text and not context.streamed_reasoning: await hook.emit_reasoning(reasoning_text) await hook.emit_reasoning_end() context.streamed_reasoning = True if response.should_execute_tools: context.tool_calls = list(response.tool_calls) if hook.wants_streaming(): await hook.on_stream_end(context, resuming=True) assistant_message = build_assistant_message( response.content or "", tool_calls=[tc.to_openai_tool_call() for tc in response.tool_calls], reasoning_content=response.reasoning_content, thinking_blocks=response.thinking_blocks, ) messages.append(assistant_message) await self._emit_checkpoint( spec, { "phase": "awaiting_tools", "iteration": iteration, "model": spec.model, "assistant_message": assistant_message, "completed_tool_results": [], "pending_tool_calls": [tc.to_openai_tool_call() for tc in response.tool_calls], }, ) await hook.before_execute_tools(context) results, new_events, fatal_error = await self._execute_tools( spec, response.tool_calls, external_lookup_counts, workspace_violation_counts, ) tool_events.extend(new_events) tools_used.extend( tool_call.name for tool_call, event in zip(response.tool_calls, new_events) if event.get("status") == "ok" ) context.tool_results = list(results) context.tool_events = list(new_events) completed_tool_results: list[dict[str, Any]] = [] for tool_call, result in zip(response.tool_calls, results): tool_message = { "role": "tool", "tool_call_id": tool_call.id, "name": tool_call.name, "content": self.context_governor.normalize_tool_result( governance_config, tool_call.id, tool_call.name, result, ), } messages.append(tool_message) completed_tool_results.append(tool_message) if fatal_error is not None: error = f"Error: {type(fatal_error).__name__}: {fatal_error}" final_content = error stop_reason = "tool_error" self._append_final_message(messages, final_content) context.final_content = final_content context.error = error context.stop_reason = stop_reason await hook.after_iteration(context) should_continue, injection_cycles = await self._try_drain_injections( spec, messages, None, injection_cycles, phase="after tool error", ) if should_continue: had_injections = True continue break await self._emit_checkpoint( spec, { "phase": "tools_completed", "iteration": iteration, "model": spec.model, "assistant_message": assistant_message, "completed_tool_results": completed_tool_results, "pending_tool_calls": [], }, ) empty_content_retries = 0 length_recovery_count = 0 # Checkpoint 1: drain injections after tools, before next LLM call _drained, injection_cycles = await self._try_drain_injections( spec, messages, None, injection_cycles, phase="after tool execution", ) if _drained: had_injections = True await hook.after_iteration(context) continue if response.has_tool_calls: logger.warning( "Ignoring tool calls under finish_reason='{}' for {}", response.finish_reason, spec.session_key or "default", ) clean = hook.finalize_content(context, response.content) if response.finish_reason != "error" and is_blank_text(clean): empty_content_retries += 1 if empty_content_retries < _MAX_EMPTY_RETRIES: logger.warning( "Empty response on turn {} for {} ({}/{}); retrying", iteration, spec.session_key or "default", empty_content_retries, _MAX_EMPTY_RETRIES, ) if hook.wants_streaming(): await hook.on_stream_end(context, resuming=False) await hook.after_iteration(context) continue logger.warning( "Empty response on turn {} for {} after {} retries; attempting finalization", iteration, spec.session_key or "default", empty_content_retries, ) if hook.wants_streaming(): await hook.on_stream_end(context, resuming=False) retry_messages = self._finalization_retry_messages(messages_for_model) response = await self._request_finalization_retry(spec, messages_for_model) retry_usage = self._usage_or_estimate(spec, retry_messages, response) self._accumulate_usage(usage, retry_usage) raw_usage = self._merge_usage(raw_usage, retry_usage) context.response = response context.usage = dict(raw_usage) context.tool_calls = list(response.tool_calls) clean = hook.finalize_content(context, response.content) if response.finish_reason == "length" and not is_blank_text(clean): length_recovery_count += 1 if length_recovery_count <= _MAX_LENGTH_RECOVERIES: logger.info( "Output truncated on turn {} for {} ({}/{}); continuing", iteration, spec.session_key or "default", length_recovery_count, _MAX_LENGTH_RECOVERIES, ) if hook.wants_streaming(): await hook.on_stream_end(context, resuming=True) messages.append(build_assistant_message( clean, reasoning_content=response.reasoning_content, thinking_blocks=response.thinking_blocks, )) messages.append(build_length_recovery_message()) await hook.after_iteration(context) continue assistant_message: dict[str, Any] | None = None if response.finish_reason != "error" and not is_blank_text(clean): assistant_message = build_assistant_message( clean, reasoning_content=response.reasoning_content, thinking_blocks=response.thinking_blocks, ) # Check for mid-turn injections BEFORE signaling stream end. # If injections are found we keep the stream alive (resuming=True) # so streaming channels don't prematurely finalize the card. should_continue, injection_cycles = await self._try_drain_injections( spec, messages, assistant_message, injection_cycles, phase="after final response", iteration=iteration, allow_goal_continue=True, ) if should_continue: had_injections = True if hook.wants_streaming(): await hook.on_stream_end(context, resuming=should_continue) if should_continue: await hook.after_iteration(context) continue if response.finish_reason == "error": if LLMProvider.is_arrearage_response(response): final_content = _ARREARAGE_ERROR_MESSAGE else: final_content = clean or spec.error_message or _DEFAULT_ERROR_MESSAGE stop_reason = "error" error = final_content self._append_model_error_placeholder(messages) context.final_content = final_content context.error = error context.stop_reason = stop_reason await hook.after_iteration(context) should_continue, injection_cycles = await self._try_drain_injections( spec, messages, None, injection_cycles, phase="after LLM error", ) if should_continue: had_injections = True continue break if is_blank_text(clean): final_content = EMPTY_FINAL_RESPONSE_MESSAGE stop_reason = "empty_final_response" error = final_content self._append_final_message(messages, final_content) context.final_content = final_content context.error = error context.stop_reason = stop_reason await hook.after_iteration(context) should_continue, injection_cycles = await self._try_drain_injections( spec, messages, None, injection_cycles, phase="after empty response", ) if should_continue: had_injections = True continue break messages.append(assistant_message or build_assistant_message( clean, reasoning_content=response.reasoning_content, thinking_blocks=response.thinking_blocks, )) await self._emit_checkpoint( spec, { "phase": "final_response", "iteration": iteration, "model": spec.model, "assistant_message": messages[-1], "completed_tool_results": [], "pending_tool_calls": [], }, ) final_content = clean context.final_content = final_content context.stop_reason = stop_reason await hook.after_iteration(context) break else: stop_reason = "max_iterations" # Drain any remaining injections so they are appended to the # conversation history instead of being re-published as # independent inbound messages by _dispatch's finally block. # We include them before the no-tools finalization pass so the # final response can account for every known follow-up. drained_after_max_iterations, injection_cycles = await self._try_drain_injections( spec, messages, None, injection_cycles, phase="after max_iterations", ) if drained_after_max_iterations: had_injections = True final_content = None if spec.finalize_on_max_iterations: final_content = await self._try_finalize_after_max_iterations( spec, hook, messages, usage, ) if final_content is None: final_content = self._max_iterations_fallback(spec) self._append_final_message(messages, final_content) return AgentRunResult( final_content=final_content, messages=messages, tools_used=tools_used, usage=usage, stop_reason=stop_reason, error=error, tool_events=tool_events, had_injections=had_injections, ) def _build_request_kwargs( self, spec: AgentRunSpec, messages: list[dict[str, Any]], *, tools: list[dict[str, Any]] | None, ) -> dict[str, Any]: kwargs: dict[str, Any] = { "messages": messages, "tools": tools, "model": spec.model, "retry_mode": spec.provider_retry_mode, "on_retry_wait": spec.retry_wait_callback, } if spec.temperature is not None: kwargs["temperature"] = spec.temperature if spec.max_tokens is not None: kwargs["max_tokens"] = spec.max_tokens if spec.reasoning_effort is not None: kwargs["reasoning_effort"] = spec.reasoning_effort return kwargs async def _request_model( self, spec: AgentRunSpec, messages: list[dict[str, Any]], hook: AgentHook, context: AgentHookContext, *, malformed_retry: bool = False, ): timeout_s: float | None = spec.llm_timeout_s if timeout_s is None: # Default to a finite timeout to avoid per-session lock starvation when an LLM # request hangs indefinitely (e.g. gateway/network stall). # Set NANOBOT_LLM_TIMEOUT_S=0 to disable. raw = os.environ.get("NANOBOT_LLM_TIMEOUT_S", "300").strip() try: timeout_s = float(raw) except (TypeError, ValueError): timeout_s = 300.0 if timeout_s is not None and timeout_s <= 0: timeout_s = None kwargs = self._build_request_kwargs( spec, messages, tools=spec.tools.get_definitions(), ) wants_streaming = hook.wants_streaming() wants_progress_streaming = ( not wants_streaming and spec.stream_progress_deltas and spec.progress_callback is not None and getattr(self.provider, "supports_progress_deltas", False) is True ) progress_state: dict[str, bool] | None = None live_file_edits: StreamingFileEditTracker | None = None if ( spec.progress_callback is not None and on_progress_accepts_file_edit_events(spec.progress_callback) ): async def _emit_live_file_edits(events: list[dict[str, Any]]) -> None: await invoke_file_edit_progress(spec.progress_callback, events) live_file_edits = StreamingFileEditTracker( workspace=spec.workspace, tools=spec.tools, emit=_emit_live_file_edits, ) async def _tool_call_delta(delta: dict[str, Any]) -> None: if live_file_edits is not None: await live_file_edits.update(delta) if wants_streaming: thinking_buf = "" async def _stream(delta: str) -> None: if delta: context.streamed_content = True await hook.on_stream(context, delta) async def _thinking(delta: str) -> None: nonlocal thinking_buf if not delta: return prev_clean = strip_reasoning_tags(thinking_buf) thinking_buf += delta new_clean = strip_reasoning_tags(thinking_buf) incremental = new_clean[len(prev_clean):] if incremental: context.streamed_reasoning = True await hook.emit_reasoning(incremental) async def _stream_recover() -> None: await hook.on_stream_end(context, resuming=True) coro = self.provider.chat_stream_with_retry( **kwargs, on_content_delta=_stream, on_thinking_delta=_thinking, on_tool_call_delta=_tool_call_delta if live_file_edits is not None else None, on_stream_recover=_stream_recover, ) elif wants_progress_streaming: stream_buf = "" think_extractor = IncrementalThinkExtractor() progress_state = {"reasoning_open": False} async def _stream_progress(delta: str) -> None: nonlocal stream_buf if not delta: return prev_clean = strip_think(stream_buf) stream_buf += delta new_clean = strip_think(stream_buf) incremental = new_clean[len(prev_clean):] if await think_extractor.feed(stream_buf, hook.emit_reasoning): context.streamed_reasoning = True progress_state["reasoning_open"] = True if incremental: if progress_state["reasoning_open"]: await hook.emit_reasoning_end() progress_state["reasoning_open"] = False context.streamed_content = True await spec.progress_callback(incremental) coro = self.provider.chat_stream_with_retry( **kwargs, on_content_delta=_stream_progress, on_tool_call_delta=_tool_call_delta if live_file_edits is not None else None, ) else: coro = self.provider.chat_with_retry(**kwargs) # Streaming requests already have provider-level idle timeouts # (NANOBOT_STREAM_IDLE_TIMEOUT_S). Do not also apply the outer wall-clock # LLM timeout here, or healthy long reasoning streams can be killed just # because total elapsed time exceeded NANOBOT_LLM_TIMEOUT_S. outer_timeout_s = None if (wants_streaming or wants_progress_streaming) else timeout_s try: response = ( await coro if outer_timeout_s is None else await asyncio.wait_for(coro, timeout=outer_timeout_s) ) if live_file_edits is not None: await live_file_edits.flush() if response.should_execute_tools: live_file_edits.apply_final_call_ids(response.tool_calls) await live_file_edits.error_unmatched( response.tool_calls if response.should_execute_tools else [], "Tool call did not complete.", ) except asyncio.TimeoutError: if outer_timeout_s is None: return LLMResponse( content="Error calling LLM: stream stalled", finish_reason="error", error_kind="timeout", ) return LLMResponse( content=f"Error calling LLM: timed out after {outer_timeout_s:g}s", finish_reason="error", error_kind="timeout", ) if progress_state and progress_state.get("reasoning_open"): await hook.emit_reasoning_end() dropped, all_dropped, original_finish_reason = ( self._drop_malformed_tool_calls(response) ) if ( all_dropped and original_finish_reason in ("tool_calls", "function_call") and not malformed_retry ): logger.warning( "Retrying LLM request after all {} malformed tool call(s) were dropped", dropped, ) retry_messages = self._malformed_tool_call_retry_messages( messages, response.content, ) return await self._request_model( spec, retry_messages, hook, context, malformed_retry=True, ) if ( all_dropped and original_finish_reason in ("tool_calls", "function_call") and malformed_retry ): logger.warning( "Malformed tool calls persisted after retry; falling back to no-tools request", ) fallback_messages = self._malformed_tool_call_retry_messages( messages, response.content, ) return await self._request_no_tools(spec, fallback_messages) return response @staticmethod def _drop_malformed_tool_calls( response: LLMResponse, ) -> tuple[int, bool, str | None]: """Strip tool calls whose name is missing/non-string from the response. Returns (dropped_count, all_dropped, original_finish_reason). A degenerate call (name=None or "") cannot be executed, and if it were persisted into the assistant message it would be replayed on every subsequent turn, causing upstream validation errors (``tool_use.name: Input should be a valid string``) that permanently wedge the session. Dropping it here keeps it out of execution, the assistant message, and the saved history in one place. """ calls = getattr(response, "tool_calls", None) if not calls: return (0, False, getattr(response, "finish_reason", None)) valid = [tc for tc in calls if tc.has_valid_name()] if len(valid) == len(calls): return (0, False, getattr(response, "finish_reason", None)) dropped = len(calls) - len(valid) original_finish_reason = getattr(response, "finish_reason", None) logger.warning( "Dropped {} malformed tool call(s) with missing/non-string name " "from LLM response (finish_reason={!r})", dropped, original_finish_reason, ) response.tool_calls = valid if not valid: response.finish_reason = "stop" return (dropped, not valid, original_finish_reason) @staticmethod def _malformed_tool_call_retry_messages( messages: list[dict[str, Any]], assistant_text: str | None, ) -> list[dict[str, Any]]: retry_messages = list(messages) note = ( "The previous model response attempted to call tools, but every tool call " "was malformed: the tool_use blocks had missing or non-string tool names. " "Do not answer with a promise to use tools. Either call the required tools again " "using valid tool names from the provided tool list and JSON object inputs, or give " "a final answer only if no tool is required." ) if assistant_text: note += ( f"\n\nPrevious assistant text before the malformed calls:\n" f"{assistant_text}" ) retry_messages.append({"role": "user", "content": note}) return retry_messages async def _request_finalization_retry( self, spec: AgentRunSpec, messages: list[dict[str, Any]], ): retry_messages = self._finalization_retry_messages(messages) return await self._request_no_tools(spec, retry_messages) @staticmethod def _finalization_retry_messages(messages: list[dict[str, Any]]) -> list[dict[str, Any]]: retry_messages = list(messages) retry_messages.append(build_finalization_retry_message()) return retry_messages async def _try_finalize_after_max_iterations( self, spec: AgentRunSpec, hook: AgentHook, messages: list[dict[str, Any]], usage: dict[str, int], ) -> str | None: retry_messages = self._budget_exhausted_finalization_messages(messages) try: response = await self._request_no_tools(spec, retry_messages) except Exception: logger.exception( "Budget-exhausted finalization failed for {}; using fallback", spec.session_key or "default", ) return None raw_usage = self._usage_or_estimate(spec, retry_messages, response) self._accumulate_usage(usage, raw_usage) if response.finish_reason == "error" or response.has_tool_calls: logger.warning( "Budget-exhausted finalization returned finish_reason='{}' " "with {} tool call(s) for {}; using fallback", response.finish_reason, len(response.tool_calls), spec.session_key or "default", ) return None context = AgentHookContext( iteration=spec.max_iterations, messages=messages, response=response, usage=dict(raw_usage), session_key=spec.session_key, ) clean = hook.finalize_content(context, response.content) if is_blank_text(clean): return None return clean async def _request_no_tools( self, spec: AgentRunSpec, messages: list[dict[str, Any]], ) -> LLMResponse: kwargs = self._build_request_kwargs(spec, messages, tools=None) return await self.provider.chat_with_retry(**kwargs) @staticmethod def _budget_exhausted_finalization_messages( messages: list[dict[str, Any]], ) -> list[dict[str, Any]]: retry_messages = list(messages) retry_messages.append(build_budget_exhausted_finalization_message()) return retry_messages @staticmethod def _max_iterations_fallback(spec: AgentRunSpec) -> str: if spec.max_iterations_message: return spec.max_iterations_message.format( max_iterations=spec.max_iterations, ) return render_template( "agent/max_iterations_message.md", strip=True, max_iterations=spec.max_iterations, ) def _usage_or_estimate( self, spec: AgentRunSpec, messages: list[dict[str, Any]], response: LLMResponse, ) -> dict[str, int]: usage = self._usage_dict(response.usage) total = self._usage_total(usage) if total > 0: usage["total_tokens"] = total usage.setdefault("provider_tokens", total) return usage if response.finish_reason == "error": return {} return self._estimate_response_usage(spec, messages, response) def _estimate_response_usage( self, spec: AgentRunSpec, messages: list[dict[str, Any]], response: LLMResponse, ) -> dict[str, int]: try: tools = spec.tools.get_definitions() except Exception: tools = None prompt_tokens, _ = estimate_prompt_tokens_chain(self.provider, spec.model, messages, tools) assistant_message = build_assistant_message( response.content or "", tool_calls=[tc.to_openai_tool_call() for tc in response.tool_calls], reasoning_content=response.reasoning_content, thinking_blocks=response.thinking_blocks, ) completion_tokens = estimate_message_tokens(assistant_message) total_tokens = max(0, prompt_tokens) + max(0, completion_tokens) if total_tokens <= 0: return {} return { "prompt_tokens": max(0, prompt_tokens), "completion_tokens": max(0, completion_tokens), "total_tokens": total_tokens, "estimated_tokens": total_tokens, } @staticmethod def _usage_dict(usage: dict[str, Any] | None) -> dict[str, int]: if not usage: return {} result: dict[str, int] = {} for key, value in usage.items(): try: result[key] = int(value or 0) except (TypeError, ValueError): continue return result @staticmethod def _usage_total(usage: dict[str, int]) -> int: return max(0, usage.get("total_tokens", 0) or ( usage.get("prompt_tokens", 0) + usage.get("completion_tokens", 0) )) @staticmethod def _accumulate_usage(target: dict[str, int], addition: dict[str, int]) -> None: for key, value in addition.items(): target[key] = target.get(key, 0) + value @staticmethod def _merge_usage(left: dict[str, int], right: dict[str, int]) -> dict[str, int]: merged = dict(left) for key, value in right.items(): merged[key] = merged.get(key, 0) + value return merged async def _execute_tools( self, spec: AgentRunSpec, tool_calls: list[ToolCallRequest], external_lookup_counts: dict[str, int], workspace_violation_counts: dict[str, int], ) -> tuple[list[Any], list[dict[str, str]], BaseException | None]: batches = self._partition_tool_batches(spec, tool_calls) tool_results: list[tuple[Any, dict[str, str], BaseException | None]] = [] for batch in batches: if spec.concurrent_tools and len(batch) > 1: batch_results = await asyncio.gather(*( self._run_tool( spec, tool_call, external_lookup_counts, workspace_violation_counts, ) for tool_call in batch )) tool_results.extend(batch_results) else: batch_results = [] for tool_call in batch: result = await self._run_tool( spec, tool_call, external_lookup_counts, workspace_violation_counts, ) tool_results.append(result) batch_results.append(result) results: list[Any] = [] events: list[dict[str, str]] = [] fatal_error: BaseException | None = None for result, event, error in tool_results: results.append(result) events.append(event) if error is not None and fatal_error is None: fatal_error = error return results, events, fatal_error async def _run_tool( self, spec: AgentRunSpec, tool_call: ToolCallRequest, external_lookup_counts: dict[str, int], workspace_violation_counts: dict[str, int], ) -> tuple[Any, dict[str, str], BaseException | None]: hint = "\n\n[Analyze the error above and try a different approach.]" lookup_error = repeated_external_lookup_error( tool_call.name, tool_call.arguments, external_lookup_counts, ) if lookup_error: event = { "name": tool_call.name, "status": "error", "detail": "repeated external lookup blocked", } if spec.fail_on_tool_error: return lookup_error + hint, event, RuntimeError(lookup_error) return lookup_error + hint, event, None prepare_call = getattr(spec.tools, "prepare_call", None) tool, params, prep_error = None, tool_call.arguments, None if callable(prepare_call): with suppress(Exception): prepared = prepare_call(tool_call.name, tool_call.arguments) if isinstance(prepared, tuple) and len(prepared) == 3: tool, params, prep_error = prepared if prep_error: event = { "name": tool_call.name, "status": "error", "detail": prep_error.split(": ", 1)[-1][:120], } handled = self._classify_violation( raw_text=prep_error, soft_payload=prep_error + hint, event=event, tool_call=tool_call, workspace_violation_counts=workspace_violation_counts, ) if handled is not None: return handled return prep_error + hint, event, ( RuntimeError(prep_error) if spec.fail_on_tool_error else None ) emit_file_edit_events = ( spec.progress_callback is not None and on_progress_accepts_file_edit_events(spec.progress_callback) ) progress_callback = spec.progress_callback if emit_file_edit_events else None file_edit_trackers = ( prepare_file_edit_trackers( call_id=tool_call.id, tool_name=tool_call.name, tool=tool, workspace=spec.workspace, params=params if isinstance(params, dict) else None, ) if progress_callback is not None else None ) if file_edit_trackers and progress_callback is not None: await invoke_file_edit_progress( progress_callback, [build_file_edit_start_event( file_edit_tracker, params if isinstance(params, dict) else None, ) for file_edit_tracker in file_edit_trackers], ) try: if tool is not None: result = await tool.execute(**params) else: result = await spec.tools.execute(tool_call.name, params) except asyncio.CancelledError: raise except BaseException as exc: if file_edit_trackers and progress_callback is not None: await invoke_file_edit_progress( progress_callback, [ build_file_edit_error_event(file_edit_tracker, str(exc)) for file_edit_tracker in file_edit_trackers ], ) event = { "name": tool_call.name, "status": "error", "detail": str(exc), } payload = f"Error: {type(exc).__name__}: {exc}" handled = self._classify_violation( raw_text=str(exc), # Preserve legacy exception payloads without the retry hint. soft_payload=payload, event=event, tool_call=tool_call, workspace_violation_counts=workspace_violation_counts, ) if handled is not None: return handled if spec.fail_on_tool_error: return payload, event, exc return payload, event, None if is_tool_error_result(tool_call.name, result): if file_edit_trackers and progress_callback is not None: await invoke_file_edit_progress( progress_callback, [ build_file_edit_error_event(file_edit_tracker, result) for file_edit_tracker in file_edit_trackers ], ) event = { "name": tool_call.name, "status": "error", "detail": result.replace("\n", " ").strip()[:120], } handled = self._classify_violation( raw_text=result, soft_payload=result + hint, event=event, tool_call=tool_call, workspace_violation_counts=workspace_violation_counts, ) if handled is not None: return handled if spec.fail_on_tool_error: return result + hint, event, RuntimeError(result) return result + hint, event, None if file_edit_trackers and progress_callback is not None: await invoke_file_edit_progress( progress_callback, [build_file_edit_end_event( file_edit_tracker, params if isinstance(params, dict) else None, ) for file_edit_tracker in file_edit_trackers], ) detail = "" if result is None else str(result) detail = detail.replace("\n", " ").strip() if not detail: detail = "(empty)" elif len(detail) > 120: detail = detail[:120] + "..." return result, {"name": tool_call.name, "status": "ok", "detail": detail}, None # SSRF is a hard security block at the tool boundary, but the agent turn # should recover conversationally instead of aborting the runtime. _SSRF_MARKERS: tuple[str, ...] = ( "internal/private url detected", "private/internal address", "private address", ) _SSRF_BOUNDARY_NOTE: str = ( "This is a non-bypassable security boundary. Stop trying to access " "private/internal URLs. Do not retry with curl, wget, encoded IPs, " "alternate DNS, redirects, proxies, or another tool. Ask the user for " "local files, logs, screenshots, or an explicit safe public URL instead. " "If the user explicitly trusts this private URL, ask them to whitelist " "the exact IP/CIDR via tools.ssrfWhitelist." ) # Non-SSRF boundary markers returned to the LLM as recoverable tool errors. _WORKSPACE_VIOLATION_MARKERS: tuple[str, ...] = ( "outside the configured workspace", "outside allowed directory", "working_dir is outside", "working_dir could not be resolved", "path outside working dir", "path traversal detected", ) @classmethod def _is_ssrf_violation(cls, text: str) -> bool: if not text: return False lowered = text.lower() return any(marker in lowered for marker in cls._SSRF_MARKERS) @classmethod def _is_workspace_violation(cls, text: str) -> bool: """True when *text* looks like any policy boundary rejection.""" if not text: return False lowered = text.lower() if cls._is_ssrf_violation(lowered): return True return any(marker in lowered for marker in cls._WORKSPACE_VIOLATION_MARKERS) def _classify_violation( self, *, raw_text: str, soft_payload: str, event: dict[str, str], tool_call: ToolCallRequest, workspace_violation_counts: dict[str, int], ) -> tuple[Any, dict[str, str], BaseException | None] | None: """Classify safety-boundary failures, or return ``None`` to pass through.""" if self._is_ssrf_violation(raw_text): logger.warning( "Tool {} blocked by SSRF guard; returning non-retryable tool error: {}", tool_call.name, raw_text.replace("\n", " ").strip()[:200], ) event["detail"] = self._event_detail("ssrf_violation: ", raw_text) return self._ssrf_soft_payload(raw_text), event, None if self._is_workspace_violation(raw_text): escalation = repeated_workspace_violation_error( tool_call.name, tool_call.arguments, workspace_violation_counts, ) event["detail"] = self._event_detail("workspace_violation: ", raw_text) if escalation is not None: logger.warning( "Tool {} hit workspace boundary repeatedly; escalating hint", tool_call.name, ) event["detail"] = self._event_detail( "workspace_violation_escalated: ", raw_text, ) return escalation, event, None return soft_payload, event, None return None @classmethod def _ssrf_soft_payload(cls, raw_text: str) -> str: text = raw_text.strip() or "Error: request blocked by SSRF guard" return f"{text}\n\n{cls._SSRF_BOUNDARY_NOTE}" @staticmethod def _event_detail(prefix: str, text: str, limit: int = 160) -> str: return (prefix + text.replace("\n", " ").strip())[:limit] async def _emit_checkpoint( self, spec: AgentRunSpec, payload: dict[str, Any], ) -> None: callback = spec.checkpoint_callback if callback is not None: await callback(payload) @staticmethod def _append_final_message(messages: list[dict[str, Any]], content: str | None) -> None: if not content: return if ( messages and messages[-1].get("role") == "assistant" and not messages[-1].get("tool_calls") ): if messages[-1].get("content") == content: return messages[-1] = build_assistant_message(content) return messages.append(build_assistant_message(content)) @staticmethod def _append_model_error_placeholder(messages: list[dict[str, Any]]) -> None: if messages and messages[-1].get("role") == "assistant" and not messages[-1].get("tool_calls"): return messages.append(build_assistant_message(_PERSISTED_MODEL_ERROR_PLACEHOLDER)) def _partition_tool_batches( self, spec: AgentRunSpec, tool_calls: list[ToolCallRequest], ) -> list[list[ToolCallRequest]]: if not spec.concurrent_tools: return [[tool_call] for tool_call in tool_calls] batches: list[list[ToolCallRequest]] = [] current: list[ToolCallRequest] = [] for tool_call in tool_calls: get_tool = getattr(spec.tools, "get", None) tool = get_tool(tool_call.name) if callable(get_tool) else None can_batch = bool(tool and tool.concurrency_safe) if can_batch: current.append(tool_call) continue if current: batches.append(current) current = [] batches.append([tool_call]) if current: batches.append(current) return batches