Files
hermes-agent/tools/budget_config.py
teknium1 3f59b5c594 refactor(agent): /context breakdown and native-compaction retention use the canonical token estimator
context_breakdown._chars_to_tokens and native_compaction._approx_tokens did raw
chars//4, under-counting CJK/Cyrillic by 2-4x next to the conversation slice
that already used estimate_tokens_rough — the /context pie chart mixed two
estimators. Both now call the canonical. The four private `= 4` ratio
constants import one CHARS_PER_TOKEN from agent/model_metadata.py. Estimates
only feed UI and budgets; no prompt or message bytes change.
2026-09-13 05:09:43 -07:00

115 lines
5.5 KiB
Python

"""Configurable budget constants for tool result persistence.
Per-tool resolution: pinned > config overrides > registry > default."""
from dataclasses import dataclass, field
from typing import Dict
from agent.model_metadata import CHARS_PER_TOKEN
# Never overridden; read_file=inf prevents infinite persist->read->persist loops.
PINNED_THRESHOLDS: Dict[str, float] = {"read_file": float("inf")}
# Single source of truth for the defaults; tool_result_storage.py imports these.
DEFAULT_RESULT_SIZE_CHARS: int = 100_000
DEFAULT_TURN_BUDGET_CHARS: int = 200_000
DEFAULT_PREVIEW_SIZE_CHARS: int = 1_500
# Tighter per-result default for ``mcp_`` tools: MCP servers routinely return
# un-paginated 20-50K payloads that sail under the generic 100K threshold; spillover
# keeps the full payload on disk. Config: ``tool_budget.mcp_result_size_chars``.
DEFAULT_MCP_RESULT_SIZE_CHARS: int = 50_000
# Same prefix the untrusted-content wrapper keys on (agent/tool_dispatch_helpers.py).
MCP_TOOL_PREFIX: str = "mcp_"
def _configured_mcp_result_size() -> int:
"""Read ``tool_budget.mcp_result_size_chars`` via ``load_config_readonly`` (the
sanctioned path; raw config.yaml parsing outside owner modules is test-guarded).
Any error, missing key or non-positive value returns the built-in default.
The ``tool_budget:`` block name is shared with the wider configurable-caps proposal (#80508) so the two
can merge without a key rename.
"""
try:
from hermes_cli.config import load_config_readonly
data = load_config_readonly()
block = data.get("tool_budget") if isinstance(data, dict) else None
raw = block.get("mcp_result_size_chars") if isinstance(block, dict) else None
if raw is not None and int(raw) > 0:
return int(raw)
except Exception:
pass
return DEFAULT_MCP_RESULT_SIZE_CHARS
@dataclass(frozen=True)
class BudgetConfig:
"""Immutable budget constants: per-result threshold (``resolve_threshold``),
per-turn aggregate (``turn_budget``) and inline snippet size (``preview_size``)."""
default_result_size: int = DEFAULT_RESULT_SIZE_CHARS
turn_budget: int = DEFAULT_TURN_BUDGET_CHARS
preview_size: int = DEFAULT_PREVIEW_SIZE_CHARS
mcp_result_size: int = DEFAULT_MCP_RESULT_SIZE_CHARS
tool_overrides: Dict[str, int] = field(default_factory=dict)
def resolve_threshold(self, tool_name: str) -> int | float:
"""Priority: pinned -> tool_overrides -> mcp_ prefix -> registry per-tool -> default.
MCP tools get ``mcp_result_size`` (no registry entry). MCP and registry values
are capped at ``default_result_size`` so a context-scaled budget for a small
model still constrains tools registering a fixed 100K ``max_result_size_chars``.
For the default budget this is a no-op because both equal 100K; for a scaled-down budget it prevents
a per-tool registry value from re-inflating the cap past the model's window (#23767).
"""
if tool_name in PINNED_THRESHOLDS:
return PINNED_THRESHOLDS[tool_name]
if tool_name in self.tool_overrides:
return self.tool_overrides[tool_name]
if tool_name.startswith(MCP_TOOL_PREFIX):
return min(self.mcp_result_size, self.default_result_size)
from tools.registry import registry
registry_value = registry.get_max_result_size(tool_name, default=self.default_result_size)
if registry_value == float("inf"):
return registry_value
return min(registry_value, self.default_result_size)
# Default config -- matches the historical hardcoded behavior exactly.
DEFAULT_BUDGET = BudgetConfig()
# Same rough chars-per-token the estimator uses; a smaller divisor would UNDER-protect small models.
_CHARS_PER_TOKEN: int = CHARS_PER_TOKEN
# Window fraction ONE result / the WHOLE turn's tool output may occupy — well
# under 1.0 since system prompt, schemas, history and the reply all compete.
_PER_RESULT_WINDOW_FRACTION: float = 0.15
_PER_TURN_WINDOW_FRACTION: float = 0.30
# Floors so a tiny model still gets a usable result, never a 0-char budget.
_MIN_RESULT_SIZE_CHARS: int = 8_000
_MIN_TURN_BUDGET_CHARS: int = 16_000
def budget_for_context_window(context_length: int | None) -> BudgetConfig:
"""Return a BudgetConfig scaled to the model's context window: the fixed
defaults suit 200K+ models but on 65K one result/turn can fill the window.
The proportional value is clamped to the defaults as a CAP (large models
stay byte-identical) and floored so a usable preview always survives.
The fixed defaults (100K result / 200K turn chars) are correct for large (200K+ token) models but blind
to small ones: on a 65K-token model a single tool result persisted at the 100K-char threshold, or a
200K-char turn budget (~50K tokens), can by itself approach or exceed the whole window and force an
oversized request (#23767).
"""
mcp_result_size = _configured_mcp_result_size()
if not context_length or context_length <= 0:
if mcp_result_size == DEFAULT_MCP_RESULT_SIZE_CHARS:
return DEFAULT_BUDGET
return BudgetConfig(mcp_result_size=mcp_result_size)
window_chars = context_length * _CHARS_PER_TOKEN
return BudgetConfig(
default_result_size=max(_MIN_RESULT_SIZE_CHARS, min(int(window_chars * _PER_RESULT_WINDOW_FRACTION), DEFAULT_RESULT_SIZE_CHARS)),
turn_budget=max(_MIN_TURN_BUDGET_CHARS, min(int(window_chars * _PER_TURN_WINDOW_FRACTION), DEFAULT_TURN_BUDGET_CHARS)),
preview_size=DEFAULT_PREVIEW_SIZE_CHARS,
mcp_result_size=mcp_result_size,
)