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Author SHA1 Message Date
Zamil Majdy
72ae2e9504 refactor(backend): unify context compression into compress_context()
Consolidates context window management into a single reusable function
in prompt.py that supports both truncation-only and summarization strategies.

Changes:
- Add CompressResult dataclass with compression metadata
- Add compress_context() async function with configurable strategies:
  1. Content truncation (always)
  2. LLM summarization (if client provided)
  3. Progressive message reduction
  4. Middle-out deletion (fallback)
  5. First/last trim (last resort)
- Add _ensure_tool_pairs_intact() with full orphan tool_call_id handling
- Add _summarize_messages_llm() for LLM-based summarization
- Migrate llm_call() to use compress_context(client=None) for truncation-only
- Remove compress_prompt() - replaced by compress_context()
- Refactor chat service to use unified compress_context()
- Fix: use async context manager for AsyncOpenAI client to prevent socket leaks
- Fix: only create OpenAI client when api_key is provided
- Fix: handle OpenAI-style tool messages (role=tool with string content) in truncation
- Fix: use client.with_options(timeout=...) for per-request timeout (OpenAI SDK v1.x)
- Add comprehensive tests for all new functions

The unified function allows:
- Chat service: client=openai_client for summarization
- LLM blocks: client=None for truncation-only
2026-02-03 12:13:04 +04:00
Zamil Majdy
d81d1ce024 refactor(backend): extract context window management and fix LLM continuation (#11936)
## Summary

Fixes CoPilot becoming unresponsive after long-running tools complete,
and refactors context window management into a reusable function.

## Problem

After `create_agent` completes, `_generate_llm_continuation()` was
sending ALL messages to OpenRouter without any context compaction. When
conversations exceeded ~50 messages, OpenRouter rejected requests with
`provider_name: 'unknown'` (no provider would accept).

**Evidence:** Langfuse session
[44fbb803-092e-4ebd-b288-852959f4faf5](https://cloud.langfuse.com/project/cmk5qhf210003ad079sd8utjt/sessions/44fbb803-092e-4ebd-b288-852959f4faf5)
showed:
- Successful calls: 32-50 messages, known providers
- Failed calls: 52+ messages, `provider: unknown`, `completion: null`

## Changes

### Refactor: Extract reusable `_manage_context_window()`
- Counts tokens and checks against 120k threshold
- Summarizes old messages while keeping recent 15
- Ensures tool_call/tool_response pairs stay intact
- Progressive truncation if still over limit
- Returns `ContextWindowResult` dataclass with messages, token count,
compaction status, and errors
- Helper `_messages_to_dicts()` reduces code duplication

### Fix: Update `_generate_llm_continuation()`
- Now calls `_manage_context_window()` before making LLM calls
- Adds retry logic with exponential backoff (matching
`_stream_chat_chunks` behavior)

### Cleanup: Update `_stream_chat_chunks()`
- Replaced inline context management with call to
`_manage_context_window()`
- Eliminates code duplication between the two functions

## Testing

- Syntax check: 
- Ruff lint: 
- Import verification: 

## Checklist

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings
- [x] I have checked that my changes do not break existing functionality

---------

Co-authored-by: Otto <otto@agpt.co>
2026-02-03 04:41:43 +00:00
Zamil Majdy
2dd341c369 refactor: enrich description with context before calling Agent Generator (#11932)
## Summary
Updates the Agent Generator client to enrich the description with
context before calling, instead of sending `user_instruction` as a
separate parameter.

## Context
Companion PR to Significant-Gravitas/AutoGPT-Agent-Generator#105 which
removes unused parameters from the decompose API.

## Changes
- Enrich `description` with `context` (e.g., clarifying question
answers) before sending
- Remove `user_instruction` from request payload

## How it works
Both input boxes and chat box work the same way - the frontend
constructs a formatted message with answers and sends it as a user
message. The backend then enriches the description with this context
before calling the external Agent Generator service.
2026-02-03 02:31:07 +00:00
10 changed files with 944 additions and 850 deletions

View File

@@ -3,9 +3,13 @@ import logging
import time import time
from asyncio import CancelledError from asyncio import CancelledError
from collections.abc import AsyncGenerator from collections.abc import AsyncGenerator
from typing import Any from typing import TYPE_CHECKING, Any, cast
import openai import openai
if TYPE_CHECKING:
from backend.util.prompt import CompressResult
import orjson import orjson
from langfuse import get_client from langfuse import get_client
from openai import ( from openai import (
@@ -15,7 +19,13 @@ from openai import (
PermissionDeniedError, PermissionDeniedError,
RateLimitError, RateLimitError,
) )
from openai.types.chat import ChatCompletionChunk, ChatCompletionToolParam from openai.types.chat import (
ChatCompletionChunk,
ChatCompletionMessageParam,
ChatCompletionStreamOptionsParam,
ChatCompletionSystemMessageParam,
ChatCompletionToolParam,
)
from backend.data.redis_client import get_redis_async from backend.data.redis_client import get_redis_async
from backend.data.understanding import ( from backend.data.understanding import (
@@ -794,207 +804,58 @@ def _is_region_blocked_error(error: Exception) -> bool:
return "not available in your region" in str(error).lower() return "not available in your region" in str(error).lower()
async def _summarize_messages( async def _manage_context_window(
messages: list, messages: list,
model: str, model: str,
api_key: str | None = None, api_key: str | None = None,
base_url: str | None = None, base_url: str | None = None,
timeout: float = 30.0, ) -> "CompressResult":
) -> str: """
"""Summarize a list of messages into concise context. Manage context window using the unified compress_context function.
Uses the same model as the chat for higher quality summaries. This is a thin wrapper that creates an OpenAI client for summarization
and delegates to the shared compression logic in prompt.py.
Args: Args:
messages: List of message dicts to summarize messages: List of messages in OpenAI format
model: Model to use for summarization (same as chat model) model: Model name for token counting and summarization
api_key: API key for OpenAI client api_key: API key for summarization calls
base_url: Base URL for OpenAI client base_url: Base URL for summarization calls
timeout: Request timeout in seconds (default: 30.0)
Returns: Returns:
Summarized text CompressResult with compacted messages and metadata
""" """
# Format messages for summarization
conversation = []
for msg in messages:
role = msg.get("role", "")
content = msg.get("content", "")
# Include user, assistant, and tool messages (tool outputs are important context)
if content and role in ("user", "assistant", "tool"):
conversation.append(f"{role.upper()}: {content}")
conversation_text = "\n\n".join(conversation)
# Handle empty conversation
if not conversation_text:
return "No conversation history available."
# Truncate conversation to fit within summarization model's context
# gpt-4o-mini has 128k context, but we limit to ~25k tokens (~100k chars) for safety
MAX_CHARS = 100_000
if len(conversation_text) > MAX_CHARS:
conversation_text = conversation_text[:MAX_CHARS] + "\n\n[truncated]"
# Call LLM to summarize
import openai import openai
summarization_client = openai.AsyncOpenAI( from backend.util.prompt import compress_context
api_key=api_key, base_url=base_url, timeout=timeout
)
response = await summarization_client.chat.completions.create( # Convert messages to dict format
model=model, messages_dict = []
messages=[ for msg in messages:
{ if isinstance(msg, dict):
"role": "system", msg_dict = {k: v for k, v in msg.items() if v is not None}
"content": ( else:
"Create a detailed summary of the conversation so far. " msg_dict = dict(msg)
"This summary will be used as context when continuing the conversation.\n\n" messages_dict.append(msg_dict)
"Before writing the summary, analyze each message chronologically to identify:\n"
"- User requests and their explicit goals\n"
"- Your approach and key decisions made\n"
"- Technical specifics (file names, tool outputs, function signatures)\n"
"- Errors encountered and resolutions applied\n\n"
"You MUST include ALL of the following sections:\n\n"
"## 1. Primary Request and Intent\n"
"The user's explicit goals and what they are trying to accomplish.\n\n"
"## 2. Key Technical Concepts\n"
"Technologies, frameworks, tools, and patterns being used or discussed.\n\n"
"## 3. Files and Resources Involved\n"
"Specific files examined or modified, with relevant snippets and identifiers.\n\n"
"## 4. Errors and Fixes\n"
"Problems encountered, error messages, and their resolutions. "
"Include any user feedback on fixes.\n\n"
"## 5. Problem Solving\n"
"Issues that have been resolved and how they were addressed.\n\n"
"## 6. All User Messages\n"
"A complete list of all user inputs (excluding tool outputs) to preserve their exact requests.\n\n"
"## 7. Pending Tasks\n"
"Work items the user explicitly requested that have not yet been completed.\n\n"
"## 8. Current Work\n"
"Precise description of what was being worked on most recently, including relevant context.\n\n"
"## 9. Next Steps\n"
"What should happen next, aligned with the user's most recent requests. "
"Include verbatim quotes of recent instructions if relevant."
),
},
{"role": "user", "content": f"Summarize:\n\n{conversation_text}"},
],
max_tokens=1500,
temperature=0.3,
)
summary = response.choices[0].message.content # Only create client if api_key is provided (enables summarization)
return summary or "No summary available." # Use context manager to avoid socket leaks
if api_key:
async with openai.AsyncOpenAI(
def _ensure_tool_pairs_intact( api_key=api_key, base_url=base_url, timeout=30.0
recent_messages: list[dict], ) as client:
all_messages: list[dict], return await compress_context(
start_index: int, messages=messages_dict,
) -> list[dict]: model=model,
""" client=client,
Ensure tool_call/tool_response pairs stay together after slicing.
When slicing messages for context compaction, a naive slice can separate
an assistant message containing tool_calls from its corresponding tool
response messages. This causes API validation errors (e.g., Anthropic's
"unexpected tool_use_id found in tool_result blocks").
This function checks for orphan tool responses in the slice and extends
backwards to include their corresponding assistant messages.
Args:
recent_messages: The sliced messages to validate
all_messages: The complete message list (for looking up missing assistants)
start_index: The index in all_messages where recent_messages begins
Returns:
A potentially extended list of messages with tool pairs intact
"""
if not recent_messages:
return recent_messages
# Collect all tool_call_ids from assistant messages in the slice
available_tool_call_ids: set[str] = set()
for msg in recent_messages:
if msg.get("role") == "assistant" and msg.get("tool_calls"):
for tc in msg["tool_calls"]:
tc_id = tc.get("id")
if tc_id:
available_tool_call_ids.add(tc_id)
# Find orphan tool responses (tool messages whose tool_call_id is missing)
orphan_tool_call_ids: set[str] = set()
for msg in recent_messages:
if msg.get("role") == "tool":
tc_id = msg.get("tool_call_id")
if tc_id and tc_id not in available_tool_call_ids:
orphan_tool_call_ids.add(tc_id)
if not orphan_tool_call_ids:
# No orphans, slice is valid
return recent_messages
# Find the assistant messages that contain the orphan tool_call_ids
# Search backwards from start_index in all_messages
messages_to_prepend: list[dict] = []
for i in range(start_index - 1, -1, -1):
msg = all_messages[i]
if msg.get("role") == "assistant" and msg.get("tool_calls"):
msg_tool_ids = {tc.get("id") for tc in msg["tool_calls"] if tc.get("id")}
if msg_tool_ids & orphan_tool_call_ids:
# This assistant message has tool_calls we need
# Also collect its contiguous tool responses that follow it
assistant_and_responses: list[dict] = [msg]
# Scan forward from this assistant to collect tool responses
for j in range(i + 1, start_index):
following_msg = all_messages[j]
if following_msg.get("role") == "tool":
tool_id = following_msg.get("tool_call_id")
if tool_id and tool_id in msg_tool_ids:
assistant_and_responses.append(following_msg)
else:
# Stop at first non-tool message
break
# Prepend the assistant and its tool responses (maintain order)
messages_to_prepend = assistant_and_responses + messages_to_prepend
# Mark these as found
orphan_tool_call_ids -= msg_tool_ids
# Also add this assistant's tool_call_ids to available set
available_tool_call_ids |= msg_tool_ids
if not orphan_tool_call_ids:
# Found all missing assistants
break
if orphan_tool_call_ids:
# Some tool_call_ids couldn't be resolved - remove those tool responses
# This shouldn't happen in normal operation but handles edge cases
logger.warning(
f"Could not find assistant messages for tool_call_ids: {orphan_tool_call_ids}. "
"Removing orphan tool responses."
)
recent_messages = [
msg
for msg in recent_messages
if not (
msg.get("role") == "tool"
and msg.get("tool_call_id") in orphan_tool_call_ids
) )
] else:
# No API key - use truncation-only mode
if messages_to_prepend: return await compress_context(
logger.info( messages=messages_dict,
f"Extended recent messages by {len(messages_to_prepend)} to preserve " model=model,
f"tool_call/tool_response pairs" client=None,
) )
return messages_to_prepend + recent_messages
return recent_messages
async def _stream_chat_chunks( async def _stream_chat_chunks(
@@ -1022,11 +883,8 @@ async def _stream_chat_chunks(
logger.info("Starting pure chat stream") logger.info("Starting pure chat stream")
# Build messages with system prompt prepended
messages = session.to_openai_messages() messages = session.to_openai_messages()
if system_prompt: if system_prompt:
from openai.types.chat import ChatCompletionSystemMessageParam
system_message = ChatCompletionSystemMessageParam( system_message = ChatCompletionSystemMessageParam(
role="system", role="system",
content=system_prompt, content=system_prompt,
@@ -1034,314 +892,38 @@ async def _stream_chat_chunks(
messages = [system_message] + messages messages = [system_message] + messages
# Apply context window management # Apply context window management
token_count = 0 # Initialize for exception handler context_result = await _manage_context_window(
try: messages=messages,
from backend.util.prompt import estimate_token_count model=model,
api_key=config.api_key,
base_url=config.base_url,
)
# Convert to dict for token counting if context_result.error:
# OpenAI message types are TypedDicts, so they're already dict-like if "System prompt dropped" in context_result.error:
messages_dict = [] # Warning only - continue with reduced context
for msg in messages:
# TypedDict objects are already dicts, just filter None values
if isinstance(msg, dict):
msg_dict = {k: v for k, v in msg.items() if v is not None}
else:
# Fallback for unexpected types
msg_dict = dict(msg)
messages_dict.append(msg_dict)
# Estimate tokens using appropriate tokenizer
# Normalize model name for token counting (tiktoken only supports OpenAI models)
token_count_model = model
if "/" in model:
# Strip provider prefix (e.g., "anthropic/claude-opus-4.5" -> "claude-opus-4.5")
token_count_model = model.split("/")[-1]
# For Claude and other non-OpenAI models, approximate with gpt-4o tokenizer
# Most modern LLMs have similar tokenization (~1 token per 4 chars)
if "claude" in token_count_model.lower() or not any(
known in token_count_model.lower()
for known in ["gpt", "o1", "chatgpt", "text-"]
):
token_count_model = "gpt-4o"
# Attempt token counting with error handling
try:
token_count = estimate_token_count(messages_dict, model=token_count_model)
except Exception as token_error:
# If token counting fails, use gpt-4o as fallback approximation
logger.warning(
f"Token counting failed for model {token_count_model}: {token_error}. "
"Using gpt-4o approximation."
)
token_count = estimate_token_count(messages_dict, model="gpt-4o")
# If over threshold, summarize old messages
if token_count > 120_000:
KEEP_RECENT = 15
# Check if we have a system prompt at the start
has_system_prompt = (
len(messages) > 0 and messages[0].get("role") == "system"
)
# Always attempt mitigation when over limit, even with few messages
if messages:
# Split messages based on whether system prompt exists
# Calculate start index for the slice
slice_start = max(0, len(messages_dict) - KEEP_RECENT)
recent_messages = messages_dict[-KEEP_RECENT:]
# Ensure tool_call/tool_response pairs stay together
# This prevents API errors from orphan tool responses
recent_messages = _ensure_tool_pairs_intact(
recent_messages, messages_dict, slice_start
)
if has_system_prompt:
# Keep system prompt separate, summarize everything between system and recent
system_msg = messages[0]
old_messages_dict = messages_dict[1:-KEEP_RECENT]
else:
# No system prompt, summarize everything except recent
system_msg = None
old_messages_dict = messages_dict[:-KEEP_RECENT]
# Summarize any non-empty old messages (no minimum threshold)
# If we're over the token limit, we need to compress whatever we can
if old_messages_dict:
# Summarize old messages using the same model as chat
summary_text = await _summarize_messages(
old_messages_dict,
model=model,
api_key=config.api_key,
base_url=config.base_url,
)
# Build new message list
# Use assistant role (not system) to prevent privilege escalation
# of user-influenced content to instruction-level authority
from openai.types.chat import ChatCompletionAssistantMessageParam
summary_msg = ChatCompletionAssistantMessageParam(
role="assistant",
content=(
"[Previous conversation summary — for context only]: "
f"{summary_text}"
),
)
# Rebuild messages based on whether we have a system prompt
if has_system_prompt:
# system_prompt + summary + recent_messages
messages = [system_msg, summary_msg] + recent_messages
else:
# summary + recent_messages (no original system prompt)
messages = [summary_msg] + recent_messages
logger.info(
f"Context summarized: {token_count} tokens, "
f"summarized {len(old_messages_dict)} old messages, "
f"kept last {KEEP_RECENT} messages"
)
# Fallback: If still over limit after summarization, progressively drop recent messages
# This handles edge cases where recent messages are extremely large
new_messages_dict = []
for msg in messages:
if isinstance(msg, dict):
msg_dict = {k: v for k, v in msg.items() if v is not None}
else:
msg_dict = dict(msg)
new_messages_dict.append(msg_dict)
new_token_count = estimate_token_count(
new_messages_dict, model=token_count_model
)
if new_token_count > 120_000:
# Still over limit - progressively reduce KEEP_RECENT
logger.warning(
f"Still over limit after summarization: {new_token_count} tokens. "
"Reducing number of recent messages kept."
)
for keep_count in [12, 10, 8, 5, 3, 2, 1, 0]:
if keep_count == 0:
# Try with just system prompt + summary (no recent messages)
if has_system_prompt:
messages = [system_msg, summary_msg]
else:
messages = [summary_msg]
logger.info(
"Trying with 0 recent messages (system + summary only)"
)
else:
# Slice from ORIGINAL recent_messages to avoid duplicating summary
reduced_recent = (
recent_messages[-keep_count:]
if len(recent_messages) >= keep_count
else recent_messages
)
# Ensure tool pairs stay intact in the reduced slice
reduced_slice_start = max(
0, len(recent_messages) - keep_count
)
reduced_recent = _ensure_tool_pairs_intact(
reduced_recent, recent_messages, reduced_slice_start
)
if has_system_prompt:
messages = [
system_msg,
summary_msg,
] + reduced_recent
else:
messages = [summary_msg] + reduced_recent
new_messages_dict = []
for msg in messages:
if isinstance(msg, dict):
msg_dict = {
k: v for k, v in msg.items() if v is not None
}
else:
msg_dict = dict(msg)
new_messages_dict.append(msg_dict)
new_token_count = estimate_token_count(
new_messages_dict, model=token_count_model
)
if new_token_count <= 120_000:
logger.info(
f"Reduced to {keep_count} recent messages, "
f"now {new_token_count} tokens"
)
break
else:
logger.error(
f"Unable to reduce token count below threshold even with 0 messages. "
f"Final count: {new_token_count} tokens"
)
# ABSOLUTE LAST RESORT: Drop system prompt
# This should only happen if summary itself is massive
if has_system_prompt and len(messages) > 1:
messages = messages[1:] # Drop system prompt
logger.critical(
"CRITICAL: Dropped system prompt as absolute last resort. "
"Behavioral consistency may be affected."
)
# Yield error to user
yield StreamError(
errorText=(
"Warning: System prompt dropped due to size constraints. "
"Assistant behavior may be affected."
)
)
else:
# No old messages to summarize - all messages are "recent"
# Apply progressive truncation to reduce token count
logger.warning(
f"Token count {token_count} exceeds threshold but no old messages to summarize. "
f"Applying progressive truncation to recent messages."
)
# Create a base list excluding system prompt to avoid duplication
# This is the pool of messages we'll slice from in the loop
# Use messages_dict for type consistency with _ensure_tool_pairs_intact
base_msgs = (
messages_dict[1:] if has_system_prompt else messages_dict
)
# Try progressively smaller keep counts
new_token_count = token_count # Initialize with current count
for keep_count in [12, 10, 8, 5, 3, 2, 1, 0]:
if keep_count == 0:
# Try with just system prompt (no recent messages)
if has_system_prompt:
messages = [system_msg]
logger.info(
"Trying with 0 recent messages (system prompt only)"
)
else:
# No system prompt and no recent messages = empty messages list
# This is invalid, skip this iteration
continue
else:
if len(base_msgs) < keep_count:
continue # Skip if we don't have enough messages
# Slice from base_msgs to get recent messages (without system prompt)
recent_messages = base_msgs[-keep_count:]
# Ensure tool pairs stay intact in the reduced slice
reduced_slice_start = max(0, len(base_msgs) - keep_count)
recent_messages = _ensure_tool_pairs_intact(
recent_messages, base_msgs, reduced_slice_start
)
if has_system_prompt:
messages = [system_msg] + recent_messages
else:
messages = recent_messages
new_messages_dict = []
for msg in messages:
if msg is None:
continue # Skip None messages (type safety)
if isinstance(msg, dict):
msg_dict = {
k: v for k, v in msg.items() if v is not None
}
else:
msg_dict = dict(msg)
new_messages_dict.append(msg_dict)
new_token_count = estimate_token_count(
new_messages_dict, model=token_count_model
)
if new_token_count <= 120_000:
logger.info(
f"Reduced to {keep_count} recent messages, "
f"now {new_token_count} tokens"
)
break
else:
# Even with 0 messages still over limit
logger.error(
f"Unable to reduce token count below threshold even with 0 messages. "
f"Final count: {new_token_count} tokens. Messages may be extremely large."
)
# ABSOLUTE LAST RESORT: Drop system prompt
if has_system_prompt and len(messages) > 1:
messages = messages[1:] # Drop system prompt
logger.critical(
"CRITICAL: Dropped system prompt as absolute last resort. "
"Behavioral consistency may be affected."
)
# Yield error to user
yield StreamError(
errorText=(
"Warning: System prompt dropped due to size constraints. "
"Assistant behavior may be affected."
)
)
except Exception as e:
logger.error(f"Context summarization failed: {e}", exc_info=True)
# If we were over the token limit, yield error to user
# Don't silently continue with oversized messages that will fail
if token_count > 120_000:
yield StreamError( yield StreamError(
errorText=( errorText=(
f"Unable to manage context window (token limit exceeded: {token_count} tokens). " "Warning: System prompt dropped due to size constraints. "
"Context summarization failed. Please start a new conversation." "Assistant behavior may be affected."
)
)
else:
# Any other error - abort to prevent failed LLM calls
yield StreamError(
errorText=(
f"Context window management failed: {context_result.error}. "
"Please start a new conversation."
) )
) )
yield StreamFinish() yield StreamFinish()
return return
# Otherwise, continue with original messages (under limit)
messages = context_result.messages
if context_result.was_compacted:
logger.info(
f"Context compacted for streaming: {context_result.token_count} tokens"
)
# Loop to handle tool calls and continue conversation # Loop to handle tool calls and continue conversation
while True: while True:
@@ -1369,14 +951,6 @@ async def _stream_chat_chunks(
:128 :128
] # OpenRouter limit ] # OpenRouter limit
# Create the stream with proper types
from typing import cast
from openai.types.chat import (
ChatCompletionMessageParam,
ChatCompletionStreamOptionsParam,
)
stream = await client.chat.completions.create( stream = await client.chat.completions.create(
model=model, model=model,
messages=cast(list[ChatCompletionMessageParam], messages), messages=cast(list[ChatCompletionMessageParam], messages),
@@ -1900,17 +1474,36 @@ async def _generate_llm_continuation(
# Build system prompt # Build system prompt
system_prompt, _ = await _build_system_prompt(user_id) system_prompt, _ = await _build_system_prompt(user_id)
# Build messages in OpenAI format
messages = session.to_openai_messages() messages = session.to_openai_messages()
if system_prompt: if system_prompt:
from openai.types.chat import ChatCompletionSystemMessageParam
system_message = ChatCompletionSystemMessageParam( system_message = ChatCompletionSystemMessageParam(
role="system", role="system",
content=system_prompt, content=system_prompt,
) )
messages = [system_message] + messages messages = [system_message] + messages
# Apply context window management to prevent oversized requests
context_result = await _manage_context_window(
messages=messages,
model=config.model,
api_key=config.api_key,
base_url=config.base_url,
)
if context_result.error and "System prompt dropped" not in context_result.error:
logger.error(
f"Context window management failed for session {session_id}: "
f"{context_result.error} (tokens={context_result.token_count})"
)
return
messages = context_result.messages
if context_result.was_compacted:
logger.info(
f"Context compacted for LLM continuation: "
f"{context_result.token_count} tokens"
)
# Build extra_body for tracing # Build extra_body for tracing
extra_body: dict[str, Any] = { extra_body: dict[str, Any] = {
"posthogProperties": { "posthogProperties": {
@@ -1923,19 +1516,54 @@ async def _generate_llm_continuation(
if session_id: if session_id:
extra_body["session_id"] = session_id[:128] extra_body["session_id"] = session_id[:128]
# Make non-streaming LLM call (no tools - just text response) retry_count = 0
from typing import cast last_error: Exception | None = None
response = None
from openai.types.chat import ChatCompletionMessageParam while retry_count <= MAX_RETRIES:
try:
logger.info(
f"Generating LLM continuation for session {session_id}"
f"{f' (retry {retry_count}/{MAX_RETRIES})' if retry_count > 0 else ''}"
)
# No tools parameter = text-only response (no tool calls) response = await client.chat.completions.create(
response = await client.chat.completions.create( model=config.model,
model=config.model, messages=cast(list[ChatCompletionMessageParam], messages),
messages=cast(list[ChatCompletionMessageParam], messages), extra_body=extra_body,
extra_body=extra_body, )
) last_error = None # Clear any previous error on success
break # Success, exit retry loop
except Exception as e:
last_error = e
if _is_retryable_error(e) and retry_count < MAX_RETRIES:
retry_count += 1
delay = min(
BASE_DELAY_SECONDS * (2 ** (retry_count - 1)),
MAX_DELAY_SECONDS,
)
logger.warning(
f"Retryable error in LLM continuation: {e!s}. "
f"Retrying in {delay:.1f}s (attempt {retry_count}/{MAX_RETRIES})"
)
await asyncio.sleep(delay)
continue
else:
# Non-retryable error - log and exit gracefully
logger.error(
f"Non-retryable error in LLM continuation: {e!s}",
exc_info=True,
)
return
if response.choices and response.choices[0].message.content: if last_error:
logger.error(
f"Max retries ({MAX_RETRIES}) exceeded for LLM continuation. "
f"Last error: {last_error!s}"
)
return
if response and response.choices and response.choices[0].message.content:
assistant_content = response.choices[0].message.content assistant_content = response.choices[0].message.content
# Reload session from DB to avoid race condition with user messages # Reload session from DB to avoid race condition with user messages

View File

@@ -139,11 +139,10 @@ async def decompose_goal_external(
""" """
client = _get_client() client = _get_client()
# Build the request payload
payload: dict[str, Any] = {"description": description}
if context: if context:
# The external service uses user_instruction for additional context description = f"{description}\n\nAdditional context from user:\n{context}"
payload["user_instruction"] = context
payload: dict[str, Any] = {"description": description}
if library_agents: if library_agents:
payload["library_agents"] = library_agents payload["library_agents"] = library_agents

View File

@@ -1,77 +0,0 @@
"""Text encoding block for converting special characters to escape sequences."""
import codecs
from backend.data.block import (
Block,
BlockCategory,
BlockOutput,
BlockSchemaInput,
BlockSchemaOutput,
)
from backend.data.model import SchemaField
class TextEncoderBlock(Block):
"""
Encodes a string by converting special characters into escape sequences.
This block is the inverse of TextDecoderBlock. It takes text containing
special characters (like newlines, tabs, etc.) and converts them into
their escape sequence representations (e.g., newline becomes \\n).
"""
class Input(BlockSchemaInput):
"""Input schema for TextEncoderBlock."""
text: str = SchemaField(
description="A string containing special characters to be encoded",
placeholder="Your text with newlines and quotes to encode",
)
class Output(BlockSchemaOutput):
"""Output schema for TextEncoderBlock."""
encoded_text: str = SchemaField(
description="The encoded text with special characters converted to escape sequences"
)
error: str = SchemaField(description="Error message if encoding fails")
def __init__(self):
super().__init__(
id="5185f32e-4b65-4ecf-8fbb-873f003f09d6",
description="Encodes a string by converting special characters into escape sequences",
categories={BlockCategory.TEXT},
input_schema=TextEncoderBlock.Input,
output_schema=TextEncoderBlock.Output,
test_input={
"text": """Hello
World!
This is a "quoted" string."""
},
test_output=[
(
"encoded_text",
"""Hello\\nWorld!\\nThis is a "quoted" string.""",
)
],
)
async def run(self, input_data: Input, **kwargs) -> BlockOutput:
"""
Encode the input text by converting special characters to escape sequences.
Args:
input_data: The input containing the text to encode.
**kwargs: Additional keyword arguments (unused).
Yields:
The encoded text with escape sequences, or an error message if encoding fails.
"""
try:
encoded_text = codecs.encode(input_data.text, "unicode_escape").decode(
"utf-8"
)
yield "encoded_text", encoded_text
except Exception as e:
yield "error", f"Encoding error: {str(e)}"

View File

@@ -32,7 +32,7 @@ from backend.data.model import (
from backend.integrations.providers import ProviderName from backend.integrations.providers import ProviderName
from backend.util import json from backend.util import json
from backend.util.logging import TruncatedLogger from backend.util.logging import TruncatedLogger
from backend.util.prompt import compress_prompt, estimate_token_count from backend.util.prompt import compress_context, estimate_token_count
from backend.util.text import TextFormatter from backend.util.text import TextFormatter
logger = TruncatedLogger(logging.getLogger(__name__), "[LLM-Block]") logger = TruncatedLogger(logging.getLogger(__name__), "[LLM-Block]")
@@ -634,11 +634,12 @@ async def llm_call(
context_window = llm_model.context_window context_window = llm_model.context_window
if compress_prompt_to_fit: if compress_prompt_to_fit:
prompt = compress_prompt( result = await compress_context(
messages=prompt, messages=prompt,
target_tokens=llm_model.context_window // 2, target_tokens=llm_model.context_window // 2,
lossy_ok=True, client=None, # Truncation-only, no LLM summarization
) )
prompt = result.messages
# Calculate available tokens based on context window and input length # Calculate available tokens based on context window and input length
estimated_input_tokens = estimate_token_count(prompt) estimated_input_tokens = estimate_token_count(prompt)

View File

@@ -1,77 +0,0 @@
import pytest
from backend.blocks.encoder_block import TextEncoderBlock
@pytest.mark.asyncio
async def test_text_encoder_basic():
"""Test basic encoding of newlines and special characters."""
block = TextEncoderBlock()
result = []
async for output in block.run(TextEncoderBlock.Input(text="Hello\nWorld")):
result.append(output)
assert len(result) == 1
assert result[0][0] == "encoded_text"
assert result[0][1] == "Hello\\nWorld"
@pytest.mark.asyncio
async def test_text_encoder_multiple_escapes():
"""Test encoding of multiple escape sequences."""
block = TextEncoderBlock()
result = []
async for output in block.run(
TextEncoderBlock.Input(text="Line1\nLine2\tTabbed\rCarriage")
):
result.append(output)
assert len(result) == 1
assert result[0][0] == "encoded_text"
assert "\\n" in result[0][1]
assert "\\t" in result[0][1]
assert "\\r" in result[0][1]
@pytest.mark.asyncio
async def test_text_encoder_unicode():
"""Test that unicode characters are handled correctly."""
block = TextEncoderBlock()
result = []
async for output in block.run(TextEncoderBlock.Input(text="Hello 世界\n")):
result.append(output)
assert len(result) == 1
assert result[0][0] == "encoded_text"
# Unicode characters should be escaped as \uXXXX sequences
assert "\\n" in result[0][1]
@pytest.mark.asyncio
async def test_text_encoder_empty_string():
"""Test encoding of an empty string."""
block = TextEncoderBlock()
result = []
async for output in block.run(TextEncoderBlock.Input(text="")):
result.append(output)
assert len(result) == 1
assert result[0][0] == "encoded_text"
assert result[0][1] == ""
@pytest.mark.asyncio
async def test_text_encoder_error_handling():
"""Test that encoding errors are handled gracefully."""
from unittest.mock import patch
block = TextEncoderBlock()
result = []
with patch("codecs.encode", side_effect=Exception("Mocked encoding error")):
async for output in block.run(TextEncoderBlock.Input(text="test")):
result.append(output)
assert len(result) == 1
assert result[0][0] == "error"
assert "Mocked encoding error" in result[0][1]

View File

@@ -1,10 +1,19 @@
from __future__ import annotations
import logging
from copy import deepcopy from copy import deepcopy
from typing import Any from dataclasses import dataclass
from typing import TYPE_CHECKING, Any
from tiktoken import encoding_for_model from tiktoken import encoding_for_model
from backend.util import json from backend.util import json
if TYPE_CHECKING:
from openai import AsyncOpenAI
logger = logging.getLogger(__name__)
# ---------------------------------------------------------------------------# # ---------------------------------------------------------------------------#
# CONSTANTS # # CONSTANTS #
# ---------------------------------------------------------------------------# # ---------------------------------------------------------------------------#
@@ -100,9 +109,17 @@ def _is_objective_message(msg: dict) -> bool:
def _truncate_tool_message_content(msg: dict, enc, max_tokens: int) -> None: def _truncate_tool_message_content(msg: dict, enc, max_tokens: int) -> None:
""" """
Carefully truncate tool message content while preserving tool structure. Carefully truncate tool message content while preserving tool structure.
Only truncates tool_result content, leaves tool_use intact. Handles both Anthropic-style (list content) and OpenAI-style (string content) tool messages.
""" """
content = msg.get("content") content = msg.get("content")
# OpenAI-style tool message: role="tool" with string content
if msg.get("role") == "tool" and isinstance(content, str):
if _tok_len(content, enc) > max_tokens:
msg["content"] = _truncate_middle_tokens(content, enc, max_tokens)
return
# Anthropic-style: list content with tool_result items
if not isinstance(content, list): if not isinstance(content, list):
return return
@@ -140,141 +157,6 @@ def _truncate_middle_tokens(text: str, enc, max_tok: int) -> str:
# ---------------------------------------------------------------------------# # ---------------------------------------------------------------------------#
def compress_prompt(
messages: list[dict],
target_tokens: int,
*,
model: str = "gpt-4o",
reserve: int = 2_048,
start_cap: int = 8_192,
floor_cap: int = 128,
lossy_ok: bool = True,
) -> list[dict]:
"""
Shrink *messages* so that::
token_count(prompt) + reserve ≤ target_tokens
Strategy
--------
1. **Token-aware truncation** progressively halve a per-message cap
(`start_cap`, `start_cap/2`, … `floor_cap`) and apply it to the
*content* of every message except the first and last. Tool shells
are included: we keep the envelope but shorten huge payloads.
2. **Middle-out deletion** if still over the limit, delete whole
messages working outward from the centre, **skipping** any message
that contains ``tool_calls`` or has ``role == "tool"``.
3. **Last-chance trim** if still too big, truncate the *first* and
*last* message bodies down to `floor_cap` tokens.
4. If the prompt is *still* too large:
• raise ``ValueError`` when ``lossy_ok == False`` (default)
• return the partially-trimmed prompt when ``lossy_ok == True``
Parameters
----------
messages Complete chat history (will be deep-copied).
model Model name; passed to tiktoken to pick the right
tokenizer (gpt-4o → 'o200k_base', others fallback).
target_tokens Hard ceiling for prompt size **excluding** the model's
forthcoming answer.
reserve How many tokens you want to leave available for that
answer (`max_tokens` in your subsequent completion call).
start_cap Initial per-message truncation ceiling (tokens).
floor_cap Lowest cap we'll accept before moving to deletions.
lossy_ok If *True* return best-effort prompt instead of raising
after all trim passes have been exhausted.
Returns
-------
list[dict] A *new* messages list that abides by the rules above.
"""
enc = encoding_for_model(model) # best-match tokenizer
msgs = deepcopy(messages) # never mutate caller
def total_tokens() -> int:
"""Current size of *msgs* in tokens."""
return sum(_msg_tokens(m, enc) for m in msgs)
original_token_count = total_tokens()
if original_token_count + reserve <= target_tokens:
return msgs
# ---- STEP 0 : normalise content --------------------------------------
# Convert non-string payloads to strings so token counting is coherent.
for i, m in enumerate(msgs):
if not isinstance(m.get("content"), str) and m.get("content") is not None:
if _is_tool_message(m):
continue
# Keep first and last messages intact (unless they're tool messages)
if i == 0 or i == len(msgs) - 1:
continue
# Reasonable 20k-char ceiling prevents pathological blobs
content_str = json.dumps(m["content"], separators=(",", ":"))
if len(content_str) > 20_000:
content_str = _truncate_middle_tokens(content_str, enc, 20_000)
m["content"] = content_str
# ---- STEP 1 : token-aware truncation ---------------------------------
cap = start_cap
while total_tokens() + reserve > target_tokens and cap >= floor_cap:
for m in msgs[1:-1]: # keep first & last intact
if _is_tool_message(m):
# For tool messages, only truncate tool result content, preserve structure
_truncate_tool_message_content(m, enc, cap)
continue
if _is_objective_message(m):
# Never truncate objective messages - they contain the core task
continue
content = m.get("content") or ""
if _tok_len(content, enc) > cap:
m["content"] = _truncate_middle_tokens(content, enc, cap)
cap //= 2 # tighten the screw
# ---- STEP 2 : middle-out deletion -----------------------------------
while total_tokens() + reserve > target_tokens and len(msgs) > 2:
# Identify all deletable messages (not first/last, not tool messages, not objective messages)
deletable_indices = []
for i in range(1, len(msgs) - 1): # Skip first and last
if not _is_tool_message(msgs[i]) and not _is_objective_message(msgs[i]):
deletable_indices.append(i)
if not deletable_indices:
break # nothing more we can drop
# Delete from center outward - find the index closest to center
centre = len(msgs) // 2
to_delete = min(deletable_indices, key=lambda i: abs(i - centre))
del msgs[to_delete]
# ---- STEP 3 : final safety-net trim on first & last ------------------
cap = start_cap
while total_tokens() + reserve > target_tokens and cap >= floor_cap:
for idx in (0, -1): # first and last
if _is_tool_message(msgs[idx]):
# For tool messages at first/last position, truncate tool result content only
_truncate_tool_message_content(msgs[idx], enc, cap)
continue
text = msgs[idx].get("content") or ""
if _tok_len(text, enc) > cap:
msgs[idx]["content"] = _truncate_middle_tokens(text, enc, cap)
cap //= 2 # tighten the screw
# ---- STEP 4 : success or fail-gracefully -----------------------------
if total_tokens() + reserve > target_tokens and not lossy_ok:
raise ValueError(
"compress_prompt: prompt still exceeds budget "
f"({total_tokens() + reserve} > {target_tokens})."
)
return msgs
def estimate_token_count( def estimate_token_count(
messages: list[dict], messages: list[dict],
*, *,
@@ -318,3 +200,430 @@ def estimate_token_count_str(
enc = encoding_for_model(model) # best-match tokenizer enc = encoding_for_model(model) # best-match tokenizer
text = json.dumps(text) if not isinstance(text, str) else text text = json.dumps(text) if not isinstance(text, str) else text
return _tok_len(text, enc) return _tok_len(text, enc)
# ---------------------------------------------------------------------------#
# UNIFIED CONTEXT COMPRESSION #
# ---------------------------------------------------------------------------#
# Default thresholds
DEFAULT_TOKEN_THRESHOLD = 120_000
DEFAULT_KEEP_RECENT = 15
@dataclass
class CompressResult:
"""Result of context compression."""
messages: list[dict]
token_count: int
was_compacted: bool
error: str | None = None
original_token_count: int = 0
messages_summarized: int = 0
messages_dropped: int = 0
def _normalize_model_for_tokenizer(model: str) -> str:
"""Normalize model name for tiktoken tokenizer selection."""
if "/" in model:
model = model.split("/")[-1]
if "claude" in model.lower() or not any(
known in model.lower() for known in ["gpt", "o1", "chatgpt", "text-"]
):
return "gpt-4o"
return model
def _ensure_tool_pairs_intact(
recent_messages: list[dict],
all_messages: list[dict],
start_index: int,
) -> list[dict]:
"""
Ensure tool_call/tool_response pairs stay together after slicing.
When slicing messages for context compaction, a naive slice can separate
an assistant message containing tool_calls from its corresponding tool
response messages. This causes API validation errors (e.g., Anthropic's
"unexpected tool_use_id found in tool_result blocks").
This function checks for orphan tool responses in the slice and extends
backwards to include their corresponding assistant messages.
Args:
recent_messages: The sliced messages to validate
all_messages: The complete message list (for looking up missing assistants)
start_index: The index in all_messages where recent_messages begins
Returns:
A potentially extended list of messages with tool pairs intact
"""
if not recent_messages:
return recent_messages
# Collect all tool_call_ids from assistant messages in the slice
available_tool_call_ids: set[str] = set()
for msg in recent_messages:
if msg.get("role") == "assistant" and msg.get("tool_calls"):
for tc in msg["tool_calls"]:
tc_id = tc.get("id")
if tc_id:
available_tool_call_ids.add(tc_id)
# Find orphan tool responses (tool messages whose tool_call_id is missing)
orphan_tool_call_ids: set[str] = set()
for msg in recent_messages:
if msg.get("role") == "tool":
tc_id = msg.get("tool_call_id")
if tc_id and tc_id not in available_tool_call_ids:
orphan_tool_call_ids.add(tc_id)
if not orphan_tool_call_ids:
# No orphans, slice is valid
return recent_messages
# Find the assistant messages that contain the orphan tool_call_ids
# Search backwards from start_index in all_messages
messages_to_prepend: list[dict] = []
for i in range(start_index - 1, -1, -1):
msg = all_messages[i]
if msg.get("role") == "assistant" and msg.get("tool_calls"):
msg_tool_ids = {tc.get("id") for tc in msg["tool_calls"] if tc.get("id")}
if msg_tool_ids & orphan_tool_call_ids:
# This assistant message has tool_calls we need
# Also collect its contiguous tool responses that follow it
assistant_and_responses: list[dict] = [msg]
# Scan forward from this assistant to collect tool responses
for j in range(i + 1, start_index):
following_msg = all_messages[j]
if following_msg.get("role") == "tool":
tool_id = following_msg.get("tool_call_id")
if tool_id and tool_id in msg_tool_ids:
assistant_and_responses.append(following_msg)
else:
# Stop at first non-tool message
break
# Prepend the assistant and its tool responses (maintain order)
messages_to_prepend = assistant_and_responses + messages_to_prepend
# Mark these as found
orphan_tool_call_ids -= msg_tool_ids
# Also add this assistant's tool_call_ids to available set
available_tool_call_ids |= msg_tool_ids
if not orphan_tool_call_ids:
# Found all missing assistants
break
if orphan_tool_call_ids:
# Some tool_call_ids couldn't be resolved - remove those tool responses
# This shouldn't happen in normal operation but handles edge cases
logger.warning(
f"Could not find assistant messages for tool_call_ids: {orphan_tool_call_ids}. "
"Removing orphan tool responses."
)
recent_messages = [
msg
for msg in recent_messages
if not (
msg.get("role") == "tool"
and msg.get("tool_call_id") in orphan_tool_call_ids
)
]
if messages_to_prepend:
logger.info(
f"Extended recent messages by {len(messages_to_prepend)} to preserve "
f"tool_call/tool_response pairs"
)
return messages_to_prepend + recent_messages
return recent_messages
async def _summarize_messages_llm(
messages: list[dict],
client: AsyncOpenAI,
model: str,
timeout: float = 30.0,
) -> str:
"""Summarize messages using an LLM."""
conversation = []
for msg in messages:
role = msg.get("role", "")
content = msg.get("content", "")
if content and role in ("user", "assistant", "tool"):
conversation.append(f"{role.upper()}: {content}")
conversation_text = "\n\n".join(conversation)
if not conversation_text:
return "No conversation history available."
# Limit to ~100k chars for safety
MAX_CHARS = 100_000
if len(conversation_text) > MAX_CHARS:
conversation_text = conversation_text[:MAX_CHARS] + "\n\n[truncated]"
response = await client.with_options(timeout=timeout).chat.completions.create(
model=model,
messages=[
{
"role": "system",
"content": (
"Create a detailed summary of the conversation so far. "
"This summary will be used as context when continuing the conversation.\n\n"
"Before writing the summary, analyze each message chronologically to identify:\n"
"- User requests and their explicit goals\n"
"- Your approach and key decisions made\n"
"- Technical specifics (file names, tool outputs, function signatures)\n"
"- Errors encountered and resolutions applied\n\n"
"You MUST include ALL of the following sections:\n\n"
"## 1. Primary Request and Intent\n"
"The user's explicit goals and what they are trying to accomplish.\n\n"
"## 2. Key Technical Concepts\n"
"Technologies, frameworks, tools, and patterns being used or discussed.\n\n"
"## 3. Files and Resources Involved\n"
"Specific files examined or modified, with relevant snippets and identifiers.\n\n"
"## 4. Errors and Fixes\n"
"Problems encountered, error messages, and their resolutions. "
"Include any user feedback on fixes.\n\n"
"## 5. Problem Solving\n"
"Issues that have been resolved and how they were addressed.\n\n"
"## 6. All User Messages\n"
"A complete list of all user inputs (excluding tool outputs) to preserve their exact requests.\n\n"
"## 7. Pending Tasks\n"
"Work items the user explicitly requested that have not yet been completed.\n\n"
"## 8. Current Work\n"
"Precise description of what was being worked on most recently, including relevant context.\n\n"
"## 9. Next Steps\n"
"What should happen next, aligned with the user's most recent requests. "
"Include verbatim quotes of recent instructions if relevant."
),
},
{"role": "user", "content": f"Summarize:\n\n{conversation_text}"},
],
max_tokens=1500,
temperature=0.3,
)
return response.choices[0].message.content or "No summary available."
async def compress_context(
messages: list[dict],
target_tokens: int = DEFAULT_TOKEN_THRESHOLD,
*,
model: str = "gpt-4o",
client: AsyncOpenAI | None = None,
keep_recent: int = DEFAULT_KEEP_RECENT,
reserve: int = 2_048,
start_cap: int = 8_192,
floor_cap: int = 128,
) -> CompressResult:
"""
Unified context compression that combines summarization and truncation strategies.
Strategy (in order):
1. **Content truncation** Progressively halve a per-message cap and truncate
bloated message content (tool outputs, large pastes).
2. **LLM summarization** If client provided, summarize old messages into a
single context message while keeping recent messages intact.
3. **Message dropping** If still over limit, progressively reduce the number
of recent messages kept.
4. **Middle-out deletion** Delete whole messages from the center outward,
skipping tool messages and objective messages.
5. **First/last trim** Truncate first and last message content as last resort.
Parameters
----------
messages Complete chat history (will be deep-copied).
target_tokens Hard ceiling for prompt size.
model Model name for tokenization and summarization.
client AsyncOpenAI client. If provided, enables LLM summarization.
If None, only truncation/deletion strategies are used.
keep_recent Number of recent messages to preserve during summarization.
reserve Tokens to reserve for model response.
start_cap Initial per-message truncation ceiling (tokens).
floor_cap Lowest cap before moving to deletions.
Returns
-------
CompressResult with compressed messages and metadata.
"""
token_model = _normalize_model_for_tokenizer(model)
enc = encoding_for_model(token_model)
msgs = deepcopy(messages)
def total_tokens() -> int:
return sum(_msg_tokens(m, enc) for m in msgs)
original_count = total_tokens()
# Already under limit
if original_count + reserve <= target_tokens:
return CompressResult(
messages=msgs,
token_count=original_count,
was_compacted=False,
original_token_count=original_count,
)
messages_summarized = 0
messages_dropped = 0
# ---- STEP 0: Normalize content ----------------------------------------
for i, m in enumerate(msgs):
if not isinstance(m.get("content"), str) and m.get("content") is not None:
if _is_tool_message(m):
continue
if i == 0 or i == len(msgs) - 1:
continue
content_str = json.dumps(m["content"], separators=(",", ":"))
if len(content_str) > 20_000:
content_str = _truncate_middle_tokens(content_str, enc, 20_000)
m["content"] = content_str
# ---- STEP 1: Token-aware content truncation ---------------------------
cap = start_cap
while total_tokens() + reserve > target_tokens and cap >= floor_cap:
for m in msgs[1:-1]:
if _is_tool_message(m):
_truncate_tool_message_content(m, enc, cap)
continue
if _is_objective_message(m):
continue
content = m.get("content") or ""
if _tok_len(content, enc) > cap:
m["content"] = _truncate_middle_tokens(content, enc, cap)
cap //= 2
# ---- STEP 2: LLM summarization (if client provided) -------------------
if total_tokens() + reserve > target_tokens and client is not None:
has_system = len(msgs) > 0 and msgs[0].get("role") == "system"
system_msg = msgs[0] if has_system else None
# Calculate old vs recent messages
if has_system:
if len(msgs) > keep_recent + 1:
old_msgs = msgs[1:-keep_recent]
recent_msgs = msgs[-keep_recent:]
else:
old_msgs = []
recent_msgs = msgs[1:] if len(msgs) > 1 else []
else:
if len(msgs) > keep_recent:
old_msgs = msgs[:-keep_recent]
recent_msgs = msgs[-keep_recent:]
else:
old_msgs = []
recent_msgs = msgs
# Ensure tool pairs stay intact
# slice_start is where recent_msgs begins in the original msgs list
slice_start = max(0, len(msgs) - keep_recent)
recent_msgs = _ensure_tool_pairs_intact(recent_msgs, msgs, slice_start)
if old_msgs:
try:
summary_text = await _summarize_messages_llm(old_msgs, client, model)
summary_msg = {
"role": "assistant",
"content": f"[Previous conversation summary — for context only]: {summary_text}",
}
messages_summarized = len(old_msgs)
if has_system:
msgs = [system_msg, summary_msg] + recent_msgs
else:
msgs = [summary_msg] + recent_msgs
logger.info(
f"Context summarized: {original_count} -> {total_tokens()} tokens, "
f"summarized {messages_summarized} messages"
)
except Exception as e:
logger.warning(f"Summarization failed, continuing with truncation: {e}")
# Fall through to message dropping
# ---- STEP 3: Progressive message reduction ----------------------------
if total_tokens() + reserve > target_tokens:
has_system = len(msgs) > 0 and msgs[0].get("role") == "system"
system_msg: dict | None = msgs[0] if has_system else None
working_msgs = msgs[1:] if has_system else msgs
for keep_count in [12, 10, 8, 5, 3, 2, 1]:
if len(working_msgs) <= keep_count:
continue
dropped = len(working_msgs) - keep_count
reduced = working_msgs[-keep_count:]
slice_start = max(0, len(working_msgs) - keep_count)
reduced = _ensure_tool_pairs_intact(reduced, working_msgs, slice_start)
if has_system and system_msg is not None:
test_msgs: list[dict] = [system_msg] + reduced
else:
test_msgs = reduced
test_count = sum(_msg_tokens(m, enc) for m in test_msgs)
if test_count + reserve <= target_tokens:
msgs = test_msgs
messages_dropped += dropped
logger.info(
f"Reduced to {keep_count} messages, now {test_count} tokens"
)
break
# ---- STEP 4: Middle-out deletion --------------------------------------
while total_tokens() + reserve > target_tokens and len(msgs) > 2:
deletable: list[int] = []
for i in range(1, len(msgs) - 1):
msg = msgs[i]
if (
msg is not None
and not _is_tool_message(msg)
and not _is_objective_message(msg)
):
deletable.append(i)
if not deletable:
break
centre = len(msgs) // 2
to_delete = min(deletable, key=lambda i: abs(i - centre))
del msgs[to_delete]
messages_dropped += 1
# ---- STEP 5: Final trim on first/last ---------------------------------
cap = start_cap
while total_tokens() + reserve > target_tokens and cap >= floor_cap:
for idx in (0, -1):
msg = msgs[idx]
if msg is None:
continue
if _is_tool_message(msg):
_truncate_tool_message_content(msg, enc, cap)
continue
text = msg.get("content") or ""
if _tok_len(text, enc) > cap:
msg["content"] = _truncate_middle_tokens(text, enc, cap)
cap //= 2
# Filter out any None values that may have been introduced
final_msgs: list[dict] = [m for m in msgs if m is not None]
final_count = sum(_msg_tokens(m, enc) for m in final_msgs)
error = None
if final_count + reserve > target_tokens:
error = f"Could not compress below target ({final_count + reserve} > {target_tokens})"
logger.warning(error)
return CompressResult(
messages=final_msgs,
token_count=final_count,
was_compacted=True,
error=error,
original_token_count=original_count,
messages_summarized=messages_summarized,
messages_dropped=messages_dropped,
)

View File

@@ -1,10 +1,21 @@
"""Tests for prompt utility functions, especially tool call token counting.""" """Tests for prompt utility functions, especially tool call token counting."""
from unittest.mock import AsyncMock, MagicMock
import pytest import pytest
from tiktoken import encoding_for_model from tiktoken import encoding_for_model
from backend.util import json from backend.util import json
from backend.util.prompt import _msg_tokens, estimate_token_count from backend.util.prompt import (
CompressResult,
_ensure_tool_pairs_intact,
_msg_tokens,
_normalize_model_for_tokenizer,
_truncate_middle_tokens,
_truncate_tool_message_content,
compress_context,
estimate_token_count,
)
class TestMsgTokens: class TestMsgTokens:
@@ -276,3 +287,337 @@ class TestEstimateTokenCount:
assert total_tokens == expected_total assert total_tokens == expected_total
assert total_tokens > 20 # Should be substantial assert total_tokens > 20 # Should be substantial
class TestNormalizeModelForTokenizer:
"""Test model name normalization for tiktoken."""
def test_openai_models_unchanged(self):
"""Test that OpenAI models are returned as-is."""
assert _normalize_model_for_tokenizer("gpt-4o") == "gpt-4o"
assert _normalize_model_for_tokenizer("gpt-4") == "gpt-4"
assert _normalize_model_for_tokenizer("gpt-3.5-turbo") == "gpt-3.5-turbo"
def test_claude_models_normalized(self):
"""Test that Claude models are normalized to gpt-4o."""
assert _normalize_model_for_tokenizer("claude-3-opus") == "gpt-4o"
assert _normalize_model_for_tokenizer("claude-3-sonnet") == "gpt-4o"
assert _normalize_model_for_tokenizer("anthropic/claude-3-haiku") == "gpt-4o"
def test_openrouter_paths_extracted(self):
"""Test that OpenRouter model paths are handled."""
assert _normalize_model_for_tokenizer("openai/gpt-4o") == "gpt-4o"
assert _normalize_model_for_tokenizer("anthropic/claude-3-opus") == "gpt-4o"
def test_unknown_models_default_to_gpt4o(self):
"""Test that unknown models default to gpt-4o."""
assert _normalize_model_for_tokenizer("some-random-model") == "gpt-4o"
assert _normalize_model_for_tokenizer("llama-3-70b") == "gpt-4o"
class TestTruncateToolMessageContent:
"""Test tool message content truncation."""
@pytest.fixture
def enc(self):
return encoding_for_model("gpt-4o")
def test_truncate_openai_tool_message(self, enc):
"""Test truncation of OpenAI-style tool message with string content."""
long_content = "x" * 10000
msg = {"role": "tool", "tool_call_id": "call_123", "content": long_content}
_truncate_tool_message_content(msg, enc, max_tokens=100)
# Content should be truncated
assert len(msg["content"]) < len(long_content)
assert "" in msg["content"] # Has ellipsis marker
def test_truncate_anthropic_tool_result(self, enc):
"""Test truncation of Anthropic-style tool_result."""
long_content = "y" * 10000
msg = {
"role": "user",
"content": [
{
"type": "tool_result",
"tool_use_id": "toolu_123",
"content": long_content,
}
],
}
_truncate_tool_message_content(msg, enc, max_tokens=100)
# Content should be truncated
result_content = msg["content"][0]["content"]
assert len(result_content) < len(long_content)
assert "" in result_content
def test_preserve_tool_use_blocks(self, enc):
"""Test that tool_use blocks are not truncated."""
msg = {
"role": "assistant",
"content": [
{
"type": "tool_use",
"id": "toolu_123",
"name": "some_function",
"input": {"key": "value" * 1000}, # Large input
}
],
}
original = json.dumps(msg["content"][0]["input"])
_truncate_tool_message_content(msg, enc, max_tokens=10)
# tool_use should be unchanged
assert json.dumps(msg["content"][0]["input"]) == original
def test_no_truncation_when_under_limit(self, enc):
"""Test that short content is not modified."""
msg = {"role": "tool", "tool_call_id": "call_123", "content": "Short content"}
original = msg["content"]
_truncate_tool_message_content(msg, enc, max_tokens=1000)
assert msg["content"] == original
class TestTruncateMiddleTokens:
"""Test middle truncation of text."""
@pytest.fixture
def enc(self):
return encoding_for_model("gpt-4o")
def test_truncates_long_text(self, enc):
"""Test that long text is truncated with ellipsis in middle."""
long_text = "word " * 1000
result = _truncate_middle_tokens(long_text, enc, max_tok=50)
assert len(enc.encode(result)) <= 52 # Allow some slack for ellipsis
assert "" in result
assert result.startswith("word") # Head preserved
assert result.endswith("word ") # Tail preserved
def test_preserves_short_text(self, enc):
"""Test that short text is not modified."""
short_text = "Hello world"
result = _truncate_middle_tokens(short_text, enc, max_tok=100)
assert result == short_text
class TestEnsureToolPairsIntact:
"""Test tool call/response pair preservation."""
def test_adds_missing_tool_call(self):
"""Test that orphaned tool_response gets its tool_call prepended."""
all_msgs = [
{"role": "system", "content": "You are helpful."},
{
"role": "assistant",
"tool_calls": [
{"id": "call_1", "type": "function", "function": {"name": "f1"}}
],
},
{"role": "tool", "tool_call_id": "call_1", "content": "result"},
{"role": "user", "content": "Thanks!"},
]
# Recent messages start at index 2 (the tool response)
recent = [all_msgs[2], all_msgs[3]]
start_index = 2
result = _ensure_tool_pairs_intact(recent, all_msgs, start_index)
# Should prepend the tool_call message
assert len(result) == 3
assert result[0]["role"] == "assistant"
assert "tool_calls" in result[0]
def test_keeps_complete_pairs(self):
"""Test that complete pairs are unchanged."""
all_msgs = [
{"role": "system", "content": "System"},
{
"role": "assistant",
"tool_calls": [
{"id": "call_1", "type": "function", "function": {"name": "f1"}}
],
},
{"role": "tool", "tool_call_id": "call_1", "content": "result"},
]
recent = all_msgs[1:] # Include both tool_call and response
start_index = 1
result = _ensure_tool_pairs_intact(recent, all_msgs, start_index)
assert len(result) == 2 # No messages added
def test_handles_no_tool_messages(self):
"""Test messages without tool calls."""
all_msgs = [
{"role": "user", "content": "Hello"},
{"role": "assistant", "content": "Hi there!"},
]
recent = all_msgs
start_index = 0
result = _ensure_tool_pairs_intact(recent, all_msgs, start_index)
assert result == all_msgs
class TestCompressContext:
"""Test the async compress_context function."""
@pytest.mark.asyncio
async def test_no_compression_needed(self):
"""Test messages under limit return without compression."""
messages = [
{"role": "system", "content": "You are helpful."},
{"role": "user", "content": "Hello!"},
]
result = await compress_context(messages, target_tokens=100000)
assert isinstance(result, CompressResult)
assert result.was_compacted is False
assert len(result.messages) == 2
assert result.error is None
@pytest.mark.asyncio
async def test_truncation_without_client(self):
"""Test that truncation works without LLM client."""
long_content = "x" * 50000
messages = [
{"role": "system", "content": "System"},
{"role": "user", "content": long_content},
{"role": "assistant", "content": "Response"},
]
result = await compress_context(
messages, target_tokens=1000, client=None, reserve=100
)
assert result.was_compacted is True
# Should have truncated without summarization
assert result.messages_summarized == 0
@pytest.mark.asyncio
async def test_with_mocked_llm_client(self):
"""Test summarization with mocked LLM client."""
# Create many messages to trigger summarization
messages = [{"role": "system", "content": "System prompt"}]
for i in range(30):
messages.append({"role": "user", "content": f"User message {i} " * 100})
messages.append(
{"role": "assistant", "content": f"Assistant response {i} " * 100}
)
# Mock the AsyncOpenAI client
mock_client = AsyncMock()
mock_response = MagicMock()
mock_response.choices = [MagicMock()]
mock_response.choices[0].message.content = "Summary of conversation"
mock_client.with_options.return_value.chat.completions.create = AsyncMock(
return_value=mock_response
)
result = await compress_context(
messages,
target_tokens=5000,
client=mock_client,
keep_recent=5,
reserve=500,
)
assert result.was_compacted is True
# Should have attempted summarization
assert mock_client.with_options.called or result.messages_summarized > 0
@pytest.mark.asyncio
async def test_preserves_tool_pairs(self):
"""Test that tool call/response pairs stay together."""
messages = [
{"role": "system", "content": "System"},
{"role": "user", "content": "Do something"},
{
"role": "assistant",
"tool_calls": [
{"id": "call_1", "type": "function", "function": {"name": "func"}}
],
},
{"role": "tool", "tool_call_id": "call_1", "content": "Result " * 1000},
{"role": "assistant", "content": "Done!"},
]
result = await compress_context(
messages, target_tokens=500, client=None, reserve=50
)
# Check that if tool response exists, its call exists too
tool_call_ids = set()
tool_response_ids = set()
for msg in result.messages:
if "tool_calls" in msg:
for tc in msg["tool_calls"]:
tool_call_ids.add(tc["id"])
if msg.get("role") == "tool":
tool_response_ids.add(msg.get("tool_call_id"))
# All tool responses should have their calls
assert tool_response_ids <= tool_call_ids
@pytest.mark.asyncio
async def test_returns_error_when_cannot_compress(self):
"""Test that error is returned when compression fails."""
# Single huge message that can't be compressed enough
messages = [
{"role": "user", "content": "x" * 100000},
]
result = await compress_context(
messages, target_tokens=100, client=None, reserve=50
)
# Should have an error since we can't get below 100 tokens
assert result.error is not None
assert result.was_compacted is True
class TestCompressResultDataclass:
"""Test CompressResult dataclass."""
def test_default_values(self):
"""Test default values are set correctly."""
result = CompressResult(
messages=[{"role": "user", "content": "test"}],
token_count=10,
was_compacted=False,
)
assert result.error is None
assert result.original_token_count == 0 # Defaults to 0, not None
assert result.messages_summarized == 0
assert result.messages_dropped == 0
def test_all_fields(self):
"""Test all fields can be set."""
result = CompressResult(
messages=[{"role": "user", "content": "test"}],
token_count=100,
was_compacted=True,
error="Some error",
original_token_count=500,
messages_summarized=10,
messages_dropped=5,
)
assert result.token_count == 100
assert result.was_compacted is True
assert result.error == "Some error"
assert result.original_token_count == 500
assert result.messages_summarized == 10
assert result.messages_dropped == 5

View File

@@ -102,7 +102,7 @@ class TestDecomposeGoalExternal:
@pytest.mark.asyncio @pytest.mark.asyncio
async def test_decompose_goal_with_context(self): async def test_decompose_goal_with_context(self):
"""Test decomposition with additional context.""" """Test decomposition with additional context enriched into description."""
mock_response = MagicMock() mock_response = MagicMock()
mock_response.json.return_value = { mock_response.json.return_value = {
"success": True, "success": True,
@@ -119,9 +119,12 @@ class TestDecomposeGoalExternal:
"Build a chatbot", context="Use Python" "Build a chatbot", context="Use Python"
) )
expected_description = (
"Build a chatbot\n\nAdditional context from user:\nUse Python"
)
mock_client.post.assert_called_once_with( mock_client.post.assert_called_once_with(
"/api/decompose-description", "/api/decompose-description",
json={"description": "Build a chatbot", "user_instruction": "Use Python"}, json={"description": expected_description},
) )
@pytest.mark.asyncio @pytest.mark.asyncio

View File

@@ -193,7 +193,6 @@ Below is a comprehensive list of all available blocks, categorized by their prim
| [Get Current Time](block-integrations/text.md#get-current-time) | This block outputs the current time | | [Get Current Time](block-integrations/text.md#get-current-time) | This block outputs the current time |
| [Match Text Pattern](block-integrations/text.md#match-text-pattern) | Matches text against a regex pattern and forwards data to positive or negative output based on the match | | [Match Text Pattern](block-integrations/text.md#match-text-pattern) | Matches text against a regex pattern and forwards data to positive or negative output based on the match |
| [Text Decoder](block-integrations/text.md#text-decoder) | Decodes a string containing escape sequences into actual text | | [Text Decoder](block-integrations/text.md#text-decoder) | Decodes a string containing escape sequences into actual text |
| [Text Encoder](block-integrations/text.md#text-encoder) | Encodes a string by converting special characters into escape sequences |
| [Text Replace](block-integrations/text.md#text-replace) | This block is used to replace a text with a new text | | [Text Replace](block-integrations/text.md#text-replace) | This block is used to replace a text with a new text |
| [Text Split](block-integrations/text.md#text-split) | This block is used to split a text into a list of strings | | [Text Split](block-integrations/text.md#text-split) | This block is used to split a text into a list of strings |
| [Word Character Count](block-integrations/text.md#word-character-count) | Counts the number of words and characters in a given text | | [Word Character Count](block-integrations/text.md#word-character-count) | Counts the number of words and characters in a given text |

View File

@@ -380,42 +380,6 @@ This is useful when working with data from APIs or files where escape sequences
--- ---
## Text Encoder
### What it is
Encodes a string by converting special characters into escape sequences
### How it works
<!-- MANUAL: how_it_works -->
The Text Encoder takes the input string and applies Python's `unicode_escape` encoding (equivalent to `codecs.encode(text, "unicode_escape").decode("utf-8")`) to transform special characters like newlines, tabs, and backslashes into their escaped forms.
The block relies on the input schema to ensure the value is a string; non-string inputs are rejected by validation, and any encoding failures surface as block errors. Non-ASCII characters are emitted as `\uXXXX` sequences, which is useful for ASCII-only payloads.
<!-- END MANUAL -->
### Inputs
| Input | Description | Type | Required |
|-------|-------------|------|----------|
| text | A string containing special characters to be encoded | str | Yes |
### Outputs
| Output | Description | Type |
|--------|-------------|------|
| error | Error message if encoding fails | str |
| encoded_text | The encoded text with special characters converted to escape sequences | str |
### Possible use case
<!-- MANUAL: use_case -->
**JSON Payload Preparation**: Encode multiline or quoted text before embedding it in JSON string fields to ensure proper escaping.
**Config/ENV Generation**: Convert template text into escaped strings for `.env` or YAML values that require special character handling.
**Snapshot Fixtures**: Produce stable escaped strings for golden files or API tests where consistent text representation is needed.
<!-- END MANUAL -->
---
## Text Replace ## Text Replace
### What it is ### What it is