Files
hermes-agent/agent/context_compressor.py
Teknium 1bb8ed4495 chore: lower default compression threshold from 85% to 50% (#1096)
* fix: ClawHub skill install — use /download ZIP endpoint

The ClawHub API v1 version endpoint only returns file metadata
(path, size, sha256, contentType) without inline content or download
URLs. Our code was looking for inline content in the metadata, which
never existed, causing all ClawHub installs to fail with:
'no inline/raw file content was available'

Fix: Use the /api/v1/download endpoint (same as the official clawhub
CLI) to download skills as ZIP bundles and extract files in-memory.

Changes:
- Add _download_zip() method that downloads and extracts ZIP bundles
- Retry on 429 rate limiting with Retry-After header support
- Path sanitization and binary file filtering for security
- Keep _extract_files() as a fallback for inline/raw content
- Also fix nested file lookup (version_data.version.files)

* chore: lower default compression threshold from 85% to 50%

Triggers context compression earlier — at 50% of the model's context
window instead of 85%. Updated in all four places where the default
is defined: context_compressor.py, cli.py, run_agent.py, config.py,
and gateway/run.py.
2026-03-12 15:51:50 -07:00

311 lines
13 KiB
Python

"""Automatic context window compression for long conversations.
Self-contained class with its own OpenAI client for summarization.
Uses Gemini Flash (cheap/fast) to summarize middle turns while
protecting head and tail context.
"""
import logging
import os
from typing import Any, Dict, List, Optional
from agent.auxiliary_client import call_llm
from agent.model_metadata import (
get_model_context_length,
estimate_messages_tokens_rough,
)
logger = logging.getLogger(__name__)
class ContextCompressor:
"""Compresses conversation context when approaching the model's context limit.
Algorithm: protect first N + last N turns, summarize everything in between.
Token tracking uses actual counts from API responses for accuracy.
"""
def __init__(
self,
model: str,
threshold_percent: float = 0.50,
protect_first_n: int = 3,
protect_last_n: int = 4,
summary_target_tokens: int = 2500,
quiet_mode: bool = False,
summary_model_override: str = None,
base_url: str = "",
):
self.model = model
self.base_url = base_url
self.threshold_percent = threshold_percent
self.protect_first_n = protect_first_n
self.protect_last_n = protect_last_n
self.summary_target_tokens = summary_target_tokens
self.quiet_mode = quiet_mode
self.context_length = get_model_context_length(model, base_url=base_url)
self.threshold_tokens = int(self.context_length * threshold_percent)
self.compression_count = 0
self._context_probed = False # True after a step-down from context error
self.last_prompt_tokens = 0
self.last_completion_tokens = 0
self.last_total_tokens = 0
self.summary_model = summary_model_override or ""
def update_from_response(self, usage: Dict[str, Any]):
"""Update tracked token usage from API response."""
self.last_prompt_tokens = usage.get("prompt_tokens", 0)
self.last_completion_tokens = usage.get("completion_tokens", 0)
self.last_total_tokens = usage.get("total_tokens", 0)
def should_compress(self, prompt_tokens: int = None) -> bool:
"""Check if context exceeds the compression threshold."""
tokens = prompt_tokens if prompt_tokens is not None else self.last_prompt_tokens
return tokens >= self.threshold_tokens
def should_compress_preflight(self, messages: List[Dict[str, Any]]) -> bool:
"""Quick pre-flight check using rough estimate (before API call)."""
rough_estimate = estimate_messages_tokens_rough(messages)
return rough_estimate >= self.threshold_tokens
def get_status(self) -> Dict[str, Any]:
"""Get current compression status for display/logging."""
return {
"last_prompt_tokens": self.last_prompt_tokens,
"threshold_tokens": self.threshold_tokens,
"context_length": self.context_length,
"usage_percent": (self.last_prompt_tokens / self.context_length * 100) if self.context_length else 0,
"compression_count": self.compression_count,
}
def _generate_summary(self, turns_to_summarize: List[Dict[str, Any]]) -> Optional[str]:
"""Generate a concise summary of conversation turns.
Tries the auxiliary model first, then falls back to the user's main
model. Returns None if all attempts fail — the caller should drop
the middle turns without a summary rather than inject a useless
placeholder.
"""
parts = []
for msg in turns_to_summarize:
role = msg.get("role", "unknown")
content = msg.get("content") or ""
if len(content) > 2000:
content = content[:1000] + "\n...[truncated]...\n" + content[-500:]
tool_calls = msg.get("tool_calls", [])
if tool_calls:
tool_names = [tc.get("function", {}).get("name", "?") for tc in tool_calls if isinstance(tc, dict)]
content += f"\n[Tool calls: {', '.join(tool_names)}]"
parts.append(f"[{role.upper()}]: {content}")
content_to_summarize = "\n\n".join(parts)
prompt = f"""Summarize these conversation turns concisely. This summary will replace these turns in the conversation history.
Write from a neutral perspective describing:
1. What actions were taken (tool calls, searches, file operations)
2. Key information or results obtained
3. Important decisions or findings
4. Relevant data, file names, or outputs
Keep factual and informative. Target ~{self.summary_target_tokens} tokens.
---
TURNS TO SUMMARIZE:
{content_to_summarize}
---
Write only the summary, starting with "[CONTEXT SUMMARY]:" prefix."""
# Use the centralized LLM router — handles provider resolution,
# auth, and fallback internally.
try:
call_kwargs = {
"task": "compression",
"messages": [{"role": "user", "content": prompt}],
"temperature": 0.3,
"max_tokens": self.summary_target_tokens * 2,
"timeout": 30.0,
}
if self.summary_model:
call_kwargs["model"] = self.summary_model
response = call_llm(**call_kwargs)
summary = response.choices[0].message.content.strip()
if not summary.startswith("[CONTEXT SUMMARY]:"):
summary = "[CONTEXT SUMMARY]: " + summary
return summary
except RuntimeError:
logging.warning("Context compression: no provider available for "
"summary. Middle turns will be dropped without summary.")
return None
except Exception as e:
logging.warning("Failed to generate context summary: %s", e)
return None
# ------------------------------------------------------------------
# Tool-call / tool-result pair integrity helpers
# ------------------------------------------------------------------
@staticmethod
def _get_tool_call_id(tc) -> str:
"""Extract the call ID from a tool_call entry (dict or SimpleNamespace)."""
if isinstance(tc, dict):
return tc.get("id", "")
return getattr(tc, "id", "") or ""
def _sanitize_tool_pairs(self, messages: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
"""Fix orphaned tool_call / tool_result pairs after compression.
Two failure modes:
1. A tool *result* references a call_id whose assistant tool_call was
removed (summarized/truncated). The API rejects this with
"No tool call found for function call output with call_id ...".
2. An assistant message has tool_calls whose results were dropped.
The API rejects this because every tool_call must be followed by
a tool result with the matching call_id.
This method removes orphaned results and inserts stub results for
orphaned calls so the message list is always well-formed.
"""
surviving_call_ids: set = set()
for msg in messages:
if msg.get("role") == "assistant":
for tc in msg.get("tool_calls") or []:
cid = self._get_tool_call_id(tc)
if cid:
surviving_call_ids.add(cid)
result_call_ids: set = set()
for msg in messages:
if msg.get("role") == "tool":
cid = msg.get("tool_call_id")
if cid:
result_call_ids.add(cid)
# 1. Remove tool results whose call_id has no matching assistant tool_call
orphaned_results = result_call_ids - surviving_call_ids
if orphaned_results:
messages = [
m for m in messages
if not (m.get("role") == "tool" and m.get("tool_call_id") in orphaned_results)
]
if not self.quiet_mode:
logger.info("Compression sanitizer: removed %d orphaned tool result(s)", len(orphaned_results))
# 2. Add stub results for assistant tool_calls whose results were dropped
missing_results = surviving_call_ids - result_call_ids
if missing_results:
patched: List[Dict[str, Any]] = []
for msg in messages:
patched.append(msg)
if msg.get("role") == "assistant":
for tc in msg.get("tool_calls") or []:
cid = self._get_tool_call_id(tc)
if cid in missing_results:
patched.append({
"role": "tool",
"content": "[Result from earlier conversation — see context summary above]",
"tool_call_id": cid,
})
messages = patched
if not self.quiet_mode:
logger.info("Compression sanitizer: added %d stub tool result(s)", len(missing_results))
return messages
def _align_boundary_forward(self, messages: List[Dict[str, Any]], idx: int) -> int:
"""Push a compress-start boundary forward past any orphan tool results.
If ``messages[idx]`` is a tool result, slide forward until we hit a
non-tool message so we don't start the summarised region mid-group.
"""
while idx < len(messages) and messages[idx].get("role") == "tool":
idx += 1
return idx
def _align_boundary_backward(self, messages: List[Dict[str, Any]], idx: int) -> int:
"""Pull a compress-end boundary backward to avoid splitting a
tool_call / result group.
If the message just before ``idx`` is an assistant message with
tool_calls, those tool results will start at ``idx`` and would be
separated from their parent. Move backwards to include the whole
group in the summarised region.
"""
if idx <= 0 or idx >= len(messages):
return idx
prev = messages[idx - 1]
if prev.get("role") == "assistant" and prev.get("tool_calls"):
# The results for this assistant turn sit at idx..idx+k.
# Include the assistant message in the summarised region too.
idx -= 1
return idx
def compress(self, messages: List[Dict[str, Any]], current_tokens: int = None) -> List[Dict[str, Any]]:
"""Compress conversation messages by summarizing middle turns.
Keeps first N + last N turns, summarizes everything in between.
After compression, orphaned tool_call / tool_result pairs are cleaned
up so the API never receives mismatched IDs.
"""
n_messages = len(messages)
if n_messages <= self.protect_first_n + self.protect_last_n + 1:
if not self.quiet_mode:
print(f"⚠️ Cannot compress: only {n_messages} messages (need > {self.protect_first_n + self.protect_last_n + 1})")
return messages
compress_start = self.protect_first_n
compress_end = n_messages - self.protect_last_n
if compress_start >= compress_end:
return messages
# Adjust boundaries to avoid splitting tool_call/result groups.
compress_start = self._align_boundary_forward(messages, compress_start)
compress_end = self._align_boundary_backward(messages, compress_end)
if compress_start >= compress_end:
return messages
turns_to_summarize = messages[compress_start:compress_end]
display_tokens = current_tokens if current_tokens else self.last_prompt_tokens or estimate_messages_tokens_rough(messages)
if not self.quiet_mode:
print(f"\n📦 Context compression triggered ({display_tokens:,} tokens ≥ {self.threshold_tokens:,} threshold)")
print(f" 📊 Model context limit: {self.context_length:,} tokens ({self.threshold_percent*100:.0f}% = {self.threshold_tokens:,})")
if not self.quiet_mode:
print(f" 🗜️ Summarizing turns {compress_start+1}-{compress_end} ({len(turns_to_summarize)} turns)")
summary = self._generate_summary(turns_to_summarize)
compressed = []
for i in range(compress_start):
msg = messages[i].copy()
if i == 0 and msg.get("role") == "system" and self.compression_count == 0:
msg["content"] = (msg.get("content") or "") + "\n\n[Note: Some earlier conversation turns may be summarized to preserve context space.]"
compressed.append(msg)
if summary:
last_head_role = messages[compress_start - 1].get("role", "user") if compress_start > 0 else "user"
summary_role = "user" if last_head_role in ("assistant", "tool") else "assistant"
compressed.append({"role": summary_role, "content": summary})
else:
if not self.quiet_mode:
print(" ⚠️ No summary model available — middle turns dropped without summary")
for i in range(compress_end, n_messages):
compressed.append(messages[i].copy())
self.compression_count += 1
compressed = self._sanitize_tool_pairs(compressed)
if not self.quiet_mode:
new_estimate = estimate_messages_tokens_rough(compressed)
saved_estimate = display_tokens - new_estimate
print(f" ✅ Compressed: {n_messages}{len(compressed)} messages (~{saved_estimate:,} tokens saved)")
print(f" 💡 Compression #{self.compression_count} complete")
return compressed