open-webui/backend/open_webui/utils/context_compaction.py
Classic298 106f8ef47e fix: chat stays stuck on the context size error after a long tool run
When context compaction summarized part of a long run of tool calls, that summary was thrown away once the reply finished. The next message then sent the whole run again, every tool result included, and failed with the provider's context size error on every retry, so the chat stayed stuck. The summary is now kept with the reply, and the next message picks up from it instead of resending the whole run.

Fixes #32306
2026-10-13 14:07:48 +02:00

521 lines
20 KiB
Python

from __future__ import annotations
import logging
import re
from typing import Any
from fastapi.responses import JSONResponse
from open_webui.models.chats import Chats
from open_webui.models.config import Config
from open_webui.utils.chat_id import is_saved_chat_id
from open_webui.utils.json_codec import JSONCodec
from open_webui.utils.misc import get_content_from_message, get_last_user_message, get_message_list
from open_webui.utils.payload import apply_params_to_form_data
from open_webui.utils.task import (
prompt_template,
prompt_variables_template,
replace_messages_variable,
replace_prompt_variable,
)
log = logging.getLogger(__name__)
BASE64_DATA_URI_RE = re.compile(r'data:[\w/+.;=%-]*;base64,[A-Za-z0-9+/=]*')
DEFAULT_CONTEXT_COMPACTION_PROMPT = """### Task:
Summarize the conversation history that will be compacted out of the active chat context.
### Instructions:
- Preserve key decisions, user preferences, and constraints.
- Preserve files, artifacts, tool results, and code changes that matter going forward.
- Preserve the current task state, unresolved questions, and next steps.
- Be factual and specific. Do not invent details.
- Keep the summary concise, but complete enough for the assistant to continue without the removed messages.
### Previous Summary:
{{PREVIOUS_SUMMARY}}
### Messages Being Compacted:
{{COMPACTED_MESSAGES}}
### Recent Messages Kept In Context:
{{RECENT_MESSAGES}}"""
async def compact_messages_for_request(
request,
user,
messages: list[dict],
metadata: dict,
model_id: str,
models: dict,
system_prompt: str = '',
) -> tuple[list[dict], str | None, bool]:
config = await _load_config()
if not config['enable']:
return messages, None, False
system_messages = [messages[0]] if messages and messages[0].get('role') == 'system' else []
messages = messages[1:] if system_messages else messages
messages, previous_summary = _apply_latest_summary_checkpoint(messages)
system_prompt = system_prompt or (get_content_from_message(system_messages[0]) if system_messages else '')
token_threshold = _resolve_token_threshold(config['token_threshold'], config['token_cap'], metadata)
if not _exceeds_token_threshold(messages, system_prompt, previous_summary, token_threshold) or len(messages) <= 3:
return [*system_messages, *messages], previous_summary, False
boundary = _find_compaction_boundary(messages, config['retention_percentage'])
compacted_messages = messages[:boundary]
recent_messages = messages[boundary:]
if not compacted_messages or not recent_messages:
return [*system_messages, *messages], previous_summary, False
event_emitter = None
if metadata.get('chat_id') and metadata.get('message_id'):
from open_webui.socket.main import get_event_emitter
event_emitter = await get_event_emitter(metadata)
if event_emitter:
await event_emitter(
{
'type': 'context_compaction',
'data': {
'action': 'context_compaction',
'description': 'Compacting context',
'done': False,
},
}
)
try:
summary = await _generate_summary(
request,
user,
model_id,
models,
compacted_messages,
recent_messages,
previous_summary,
config['prompt_template'],
)
except Exception:
if event_emitter:
await event_emitter(
{
'type': 'context_compaction',
'data': {
'action': 'context_compaction',
'description': 'Context compaction failed',
'done': True,
'error': True,
},
}
)
raise
chat_id = metadata.get('chat_id')
checkpoint_message_id = (
recent_messages[0].get('id') or metadata.get('user_message_id') or metadata.get('message_id')
)
# Only whole-turn user boundaries correspond to persisted chat checkpoints.
if recent_messages[0].get('role') == 'user' and is_saved_chat_id(chat_id) and checkpoint_message_id:
await Chats.upsert_message_to_chat_by_id_and_message_id(
chat_id,
checkpoint_message_id,
{'contextSummary': summary},
touch=False,
)
log.info(
'Compacted chat context for chat=%s checkpoint=%s response=%s dropped=%d kept=%d summary_chars=%d',
chat_id,
checkpoint_message_id,
metadata.get('message_id'),
len(compacted_messages),
len(recent_messages),
len(summary),
)
if event_emitter:
await event_emitter(
{
'type': 'context_compaction',
'data': {
'action': 'context_compaction',
'description': 'Context compacted',
'done': True,
},
}
)
return [*system_messages, *recent_messages], summary, True
async def compact_chat_branch(request, user, chat: Any, model_id: str, models: dict) -> dict:
config = await _load_config()
if not config['enable']:
return {'ok': True, 'compacted': False, 'reason': 'disabled'}
chat_data = chat.chat or {}
history = chat_data.get('history') or {}
current_id = getattr(chat, 'current_message_id', None) or history.get('currentId')
if not current_id:
current_id = chat_data.get('currentId') or chat_data.get('branchPointMessageId')
if not current_id and isinstance(chat_data.get('messages'), list) and chat_data['messages']:
current_id = chat_data['messages'][-1].get('id')
if not current_id:
return {'ok': True, 'compacted': False, 'reason': 'empty'}
messages_map = await Chats.get_messages_map_by_chat_id(chat.id)
if not messages_map:
messages_map = history.get('messages') or {}
messages, previous_summary = _apply_latest_summary_checkpoint(get_message_list(messages_map, current_id))
compacted_messages = messages[:-1]
recent_messages = messages[-1:]
if not compacted_messages or not recent_messages:
return {'ok': True, 'compacted': False, 'reason': 'too_short'}
summary = await _generate_summary(
request,
user,
model_id,
models,
compacted_messages,
recent_messages,
previous_summary,
config['prompt_template'],
)
await Chats.upsert_message_to_chat_by_id_and_message_id(
chat.id, current_id, {'contextSummary': summary}, touch=False
)
return {
'ok': True,
'compacted': True,
'dropped_messages': len(compacted_messages),
'kept_messages': len(recent_messages),
'summary_chars': len(summary),
}
async def _load_config() -> dict:
values = await Config.get_many(
'chat.context_compaction.enable',
'chat.context_compaction.token_threshold',
'chat.context_compaction.token_cap',
'chat.context_compaction.retention_percentage',
'chat.context_compaction.prompt_template',
)
token_threshold = _parse_positive_int(values.get('chat.context_compaction.token_threshold')) or 80000
return {
'enable': bool(values.get('chat.context_compaction.enable', False)),
'token_threshold': token_threshold,
'token_cap': _parse_positive_int(values.get('chat.context_compaction.token_cap')) or token_threshold,
'retention_percentage': _clamp_retention_percentage(values.get('chat.context_compaction.retention_percentage')),
'prompt_template': values.get('chat.context_compaction.prompt_template', '') or '',
}
def _parse_positive_int(value: Any) -> int | None:
try:
parsed = int(value)
except (TypeError, ValueError):
return None
return parsed if parsed > 0 else None
def _clamp_retention_percentage(value: Any) -> int:
try:
parsed = int(value)
except (TypeError, ValueError):
parsed = 40
return min(50, max(10, parsed))
def _resolve_token_threshold(global_threshold: int, global_cap: int, metadata: dict) -> int:
configured_threshold = _parse_positive_int((metadata.get('params') or {}).get('compact_token_threshold'))
return min(configured_threshold or global_threshold, global_cap)
def _usage_token_count(usage: dict) -> int:
prompt_tokens = int(usage.get('prompt_tokens') or usage.get('prompt_eval_count') or 0)
if not prompt_tokens and (usage.get('prompt_n') is not None or usage.get('cache_n') is not None):
prompt_tokens = int(usage.get('prompt_n') or 0) + int(usage.get('cache_n') or 0)
if not prompt_tokens:
prompt_tokens = int(usage.get('input_tokens') or 0)
completion_tokens = int(
usage.get('completion_tokens')
or usage.get('output_tokens')
or usage.get('eval_count')
or usage.get('predicted_n')
or 0
)
return prompt_tokens + completion_tokens
async def get_chat_context_usage(chat: Any, model_id: str | None = None) -> dict | None:
chat_data = chat.chat or {}
history = chat_data.get('history') or {}
current_id = getattr(chat, 'current_message_id', None) or history.get('currentId')
if not current_id:
current_id = chat_data.get('currentId') or chat_data.get('branchPointMessageId')
if not current_id and isinstance(chat_data.get('messages'), list) and chat_data['messages']:
current_id = chat_data['messages'][-1].get('id')
if not current_id:
return None
messages_map = await Chats.get_messages_map_by_chat_id(chat.id)
messages = get_message_list(messages_map or history.get('messages') or {}, current_id)
if not messages:
return None
config = await _load_config()
if not config['enable']:
return None
params = ((chat.chat or {}).get('params') or {}).copy()
if model_id:
params['model'] = model_id
threshold = _resolve_token_threshold(config['token_threshold'], config['token_cap'], {'params': params})
messages, previous_summary = _apply_latest_summary_checkpoint(messages)
for idx in range(len(messages) - 1, -1, -1):
usage = messages[idx].get('usage') or (messages[idx].get('info') or {}).get('usage')
if isinstance(usage, dict) and (tokens := _usage_token_count(usage)):
tokens += _estimate_messages_tokens(messages[idx + 1 :])
return _build_context_usage(tokens, threshold)
tokens = _estimate_tokens(previous_summary or '') + _estimate_messages_tokens(messages)
return _build_context_usage(tokens, threshold)
def _build_context_usage(tokens: int, threshold: int) -> dict:
return {
'tokens': tokens,
'estimated_tokens': tokens,
'threshold': threshold,
'percent': round((tokens / threshold) * 100) if threshold > 0 else 0,
'source': 'estimated',
}
def _apply_latest_summary_checkpoint(messages: list[dict]) -> tuple[list[dict], str | None]:
summary = None
summary_idx = None
cut_idx = None
kept_output = None
for idx, message in enumerate(messages):
if checkpoint := _find_tool_loop_checkpoint(messages, idx):
summary, cut_idx, kept_output = checkpoint
summary_idx = cut_idx - 1
value = message.get('contextSummary') or message.get('context_summary')
if isinstance(value, str) and value.strip():
summary = value
summary_idx = idx
if summary_idx is None:
return messages, None
return [
{**message, 'output': kept_output} if idx == cut_idx else message
for idx, message in enumerate(messages)
if idx >= summary_idx
], summary
def _find_tool_loop_checkpoint(messages: list[dict], idx: int) -> tuple[str, int, list[dict]] | None:
"""Tool loop summary saved in this reply, with the reply it cut and that reply's remaining output."""
output = messages[idx].get('output') or []
marker = next((item for item in reversed(output) if item.get('type') == 'open_webui:context_compaction'), None)
if not marker:
return None
# The loop can cut into an earlier reply when this one started near the threshold.
for cut_idx in range(idx, -1, -1):
cut_output = messages[cut_idx].get('output') or []
start = next(
(
position
for position, item in enumerate(cut_output)
if item.get('type') == 'function_call' and item.get('call_id') == marker['call_id']
),
None,
)
if start is not None:
while start and cut_output[start - 1].get('type') != 'function_call_output':
start -= 1
kept_output = [item for item in cut_output[start:] if item.get('type') != 'open_webui:context_compaction']
return marker['summary'], cut_idx, kept_output
return None
def _exceeds_token_threshold(messages: list[dict], system_prompt: str, summary: str | None, threshold: int) -> bool:
if threshold <= 0:
return False
for idx in range(len(messages) - 1, -1, -1):
usage = messages[idx].get('usage') or (messages[idx].get('info') or {}).get('usage')
if isinstance(usage, dict) and (tokens := _usage_token_count(usage)):
return tokens + _estimate_messages_tokens(messages[idx + 1 :]) > threshold
estimated = _estimate_tokens(system_prompt) + _estimate_tokens(summary or '') + _estimate_messages_tokens(messages)
return estimated > threshold
def _find_compaction_boundary(messages: list[dict], retention_percentage: int = 40) -> int:
retention_percentage = _clamp_retention_percentage(retention_percentage)
keep_count = max(2, len(messages) * retention_percentage // 100)
target = max(1, len(messages) - keep_count)
if any(message.get('role') == 'tool' for message in messages):
# Keep each call/result batch and its following image messages together.
boundaries = [
idx
for idx, message in enumerate(messages)
if message.get('role') == 'assistant' and message.get('tool_calls')
][1:]
else:
boundaries = [idx for idx, message in enumerate(messages) if message.get('role') == 'user'][1:]
return next((idx for idx in reversed(boundaries) if idx <= target), 0)
async def _generate_summary(
request,
user,
model_id: str,
models: dict,
compacted_messages: list[dict],
recent_messages: list[dict],
previous_summary: str | None,
summary_prompt_template: str,
) -> str:
from open_webui.utils.chat import generate_chat_completion
if getattr(request.state, 'direct', False) and hasattr(request.state, 'model'):
models = {**dict(models.items()), request.state.model['id']: request.state.model}
task_config = await Config.get_many(
'task.model.params',
'chat.context_compaction.model',
)
context_compaction_model = task_config.get('chat.context_compaction.model')
task_model_id = context_compaction_model if context_compaction_model in models else model_id
if task_model_id not in models:
raise ValueError('No available model for context compaction')
summary_prompt_template = summary_prompt_template.strip() or DEFAULT_CONTEXT_COMPACTION_PROMPT
# The text-only prompt formatter otherwise omits tool names and arguments.
compacted_messages, recent_messages = list(compacted_messages), list(recent_messages)
for messages in (compacted_messages, recent_messages):
for idx, message in enumerate(messages):
if message.get('tool_calls'):
messages[idx] = {
**message,
'content': f'{get_content_from_message(message) or ""}\n[TOOL CALLS] {JSONCodec.dumps(message["tool_calls"])}',
}
all_messages = [*compacted_messages, *recent_messages]
prompt = replace_prompt_variable(summary_prompt_template, get_last_user_message(all_messages) or '')
prompt = replace_messages_variable(prompt, all_messages)
prompt = replace_messages_variable(prompt, compacted_messages, 'COMPACTED_MESSAGES')
prompt = replace_messages_variable(prompt, recent_messages, 'RECENT_MESSAGES')
prompt = prompt_variables_template(prompt, {'{{PREVIOUS_SUMMARY}}': previous_summary or ''})
prompt = await prompt_template(prompt, user)
task_model_params = task_config.get('task.model.params') or {}
if not isinstance(task_model_params, dict):
task_model_params = {}
task_model_params = {key: value for key, value in task_model_params.items() if value is not None and value != ''}
task_model_params = task_model_params or {
'max_tokens': models[task_model_id].get('info', {}).get('params', {}).get('max_tokens', 1000)
}
payload = {
'model': task_model_id,
'messages': [{'role': 'user', 'content': prompt}],
'stream': False,
'metadata': {
**(request.state.metadata if hasattr(request.state, 'metadata') else {}),
'task': 'context_compaction',
},
}
payload = apply_params_to_form_data(payload, models[task_model_id], task_model_params)
response = await generate_chat_completion(request, form_data=payload, user=user)
summary = _response_text(response).strip()
if summary:
return summary
parts = [previous_summary] if previous_summary else []
for message in compacted_messages:
content = get_content_from_message(message)
if content:
parts.append(f'- {message.get("role", "unknown")}: {content[:500]}')
return '\n'.join(parts)[:4000]
def _response_text(response: Any) -> str:
if isinstance(response, list) and len(response) == 1:
response = response[0]
if isinstance(response, JSONResponse):
try:
response = JSONCodec.loads(response.body.decode('utf-8', 'replace'))
except Exception:
return ''
if not isinstance(response, dict):
return ''
choices = response.get('choices') or []
if choices:
message = choices[0].get('message') or {}
return message.get('content') or message.get('reasoning_content') or ''
parts = []
for item in response.get('output') or []:
for content in item.get('content') or []:
if isinstance(content, dict):
parts.append(content.get('text') or content.get('content') or '')
return '\n'.join(part for part in parts if part)
def _estimate_messages_tokens(messages: list[dict]) -> int:
total = 0
for message in messages:
total += 4
content = message.get('content')
if isinstance(content, list):
for item in content:
if not isinstance(item, dict):
total += _estimate_tokens(item)
elif item.get('type') in {'image', 'image_url'}:
total += 1000
else:
total += _estimate_tokens(item.get('text') or item.get('content') or item)
else:
total += _estimate_tokens(content)
total += _estimate_tokens(message.get('output'))
total += _estimate_tokens(message.get('tool_calls'))
files = message.get('files')
if files:
# Inline data is not part of the file tags sent to the model.
total += _estimate_tokens(BASE64_DATA_URI_RE.sub('', JSONCodec.dumps(files, ensure_ascii=False)))
return total
def _estimate_tokens(value: Any) -> int:
if value is None:
return 0
if not isinstance(value, str):
try:
value = JSONCodec.dumps(value, ensure_ascii=False)
except Exception:
value = str(value)
if not value:
return 0
return max(1, len(value) // 4)