analysis_claude_code/agents/s06_context_compact.py
CrazyBoyM c6a27ef1d7 feat: build an AI agent from 0 to 1 -- 11 progressive sessions
- 11 sessions from basic agent loop to autonomous teams
- Python MVP implementations for each session
- Mental-model-first docs in en/zh/ja
- Interactive web platform with step-through visualizations
- Incremental architecture: each session adds one mechanism
2026-02-21 17:02:43 +08:00

243 lines
9.3 KiB
Python

#!/usr/bin/env python3
"""
s06_context_compact.py - Compact
Three-layer compression pipeline so the agent can work forever:
Every turn:
+------------------+
| Tool call result |
+------------------+
|
v
[Layer 1: micro_compact] (silent, every turn)
Replace tool_result content older than last 3
with "[Previous: used {tool_name}]"
|
v
[Check: tokens > 50000?]
| |
no yes
| |
v v
continue [Layer 2: auto_compact]
Save full transcript to .transcripts/
Ask LLM to summarize conversation.
Replace all messages with [summary].
|
v
[Layer 3: compact tool]
Model calls compact -> immediate summarization.
Same as auto, triggered manually.
Key insight: "The agent can forget strategically and keep working forever."
"""
import json
import os
import subprocess
import time
from pathlib import Path
from anthropic import Anthropic
from dotenv import load_dotenv
load_dotenv(override=True)
if os.getenv("ANTHROPIC_BASE_URL"):
os.environ.pop("ANTHROPIC_AUTH_TOKEN", None)
WORKDIR = Path.cwd()
client = Anthropic(base_url=os.getenv("ANTHROPIC_BASE_URL"))
MODEL = os.environ["MODEL_ID"]
SYSTEM = f"You are a coding agent at {WORKDIR}. Use tools to solve tasks."
THRESHOLD = 50000
TRANSCRIPT_DIR = WORKDIR / ".transcripts"
KEEP_RECENT = 3
def estimate_tokens(messages: list) -> int:
"""Rough token count: ~4 chars per token."""
return len(str(messages)) // 4
# -- Layer 1: micro_compact - replace old tool results with placeholders --
def micro_compact(messages: list) -> list:
# Collect (msg_index, part_index, tool_result_dict) for all tool_result entries
tool_results = []
for msg_idx, msg in enumerate(messages):
if msg["role"] == "user" and isinstance(msg.get("content"), list):
for part_idx, part in enumerate(msg["content"]):
if isinstance(part, dict) and part.get("type") == "tool_result":
tool_results.append((msg_idx, part_idx, part))
if len(tool_results) <= KEEP_RECENT:
return messages
# Find tool_name for each result by matching tool_use_id in prior assistant messages
tool_name_map = {}
for msg in messages:
if msg["role"] == "assistant":
content = msg.get("content", [])
if isinstance(content, list):
for block in content:
if hasattr(block, "type") and block.type == "tool_use":
tool_name_map[block.id] = block.name
# Clear old results (keep last KEEP_RECENT)
to_clear = tool_results[:-KEEP_RECENT]
for _, _, result in to_clear:
if isinstance(result.get("content"), str) and len(result["content"]) > 100:
tool_id = result.get("tool_use_id", "")
tool_name = tool_name_map.get(tool_id, "unknown")
result["content"] = f"[Previous: used {tool_name}]"
return messages
# -- Layer 2: auto_compact - save transcript, summarize, replace messages --
def auto_compact(messages: list) -> list:
# Save full transcript to disk
TRANSCRIPT_DIR.mkdir(exist_ok=True)
transcript_path = TRANSCRIPT_DIR / f"transcript_{int(time.time())}.jsonl"
with open(transcript_path, "w") as f:
for msg in messages:
f.write(json.dumps(msg, default=str) + "\n")
print(f"[transcript saved: {transcript_path}]")
# Ask LLM to summarize
conversation_text = json.dumps(messages, default=str)[:80000]
response = client.messages.create(
model=MODEL,
messages=[{"role": "user", "content":
"Summarize this conversation for continuity. Include: "
"1) What was accomplished, 2) Current state, 3) Key decisions made. "
"Be concise but preserve critical details.\n\n" + conversation_text}],
max_tokens=2000,
)
summary = response.content[0].text
# Replace all messages with compressed summary
return [
{"role": "user", "content": f"[Conversation compressed. Transcript: {transcript_path}]\n\n{summary}"},
{"role": "assistant", "content": "Understood. I have the context from the summary. Continuing."},
]
# -- Tool implementations --
def safe_path(p: str) -> Path:
path = (WORKDIR / p).resolve()
if not path.is_relative_to(WORKDIR):
raise ValueError(f"Path escapes workspace: {p}")
return path
def run_bash(command: str) -> str:
dangerous = ["rm -rf /", "sudo", "shutdown", "reboot", "> /dev/"]
if any(d in command for d in dangerous):
return "Error: Dangerous command blocked"
try:
r = subprocess.run(command, shell=True, cwd=WORKDIR,
capture_output=True, text=True, timeout=120)
out = (r.stdout + r.stderr).strip()
return out[:50000] if out else "(no output)"
except subprocess.TimeoutExpired:
return "Error: Timeout (120s)"
def run_read(path: str, limit: int = None) -> str:
try:
lines = safe_path(path).read_text().splitlines()
if limit and limit < len(lines):
lines = lines[:limit] + [f"... ({len(lines) - limit} more)"]
return "\n".join(lines)[:50000]
except Exception as e:
return f"Error: {e}"
def run_write(path: str, content: str) -> str:
try:
fp = safe_path(path)
fp.parent.mkdir(parents=True, exist_ok=True)
fp.write_text(content)
return f"Wrote {len(content)} bytes"
except Exception as e:
return f"Error: {e}"
def run_edit(path: str, old_text: str, new_text: str) -> str:
try:
fp = safe_path(path)
content = fp.read_text()
if old_text not in content:
return f"Error: Text not found in {path}"
fp.write_text(content.replace(old_text, new_text, 1))
return f"Edited {path}"
except Exception as e:
return f"Error: {e}"
TOOL_HANDLERS = {
"bash": lambda **kw: run_bash(kw["command"]),
"read_file": lambda **kw: run_read(kw["path"], kw.get("limit")),
"write_file": lambda **kw: run_write(kw["path"], kw["content"]),
"edit_file": lambda **kw: run_edit(kw["path"], kw["old_text"], kw["new_text"]),
"compact": lambda **kw: "Manual compression requested.",
}
TOOLS = [
{"name": "bash", "description": "Run a shell command.",
"input_schema": {"type": "object", "properties": {"command": {"type": "string"}}, "required": ["command"]}},
{"name": "read_file", "description": "Read file contents.",
"input_schema": {"type": "object", "properties": {"path": {"type": "string"}, "limit": {"type": "integer"}}, "required": ["path"]}},
{"name": "write_file", "description": "Write content to file.",
"input_schema": {"type": "object", "properties": {"path": {"type": "string"}, "content": {"type": "string"}}, "required": ["path", "content"]}},
{"name": "edit_file", "description": "Replace exact text in file.",
"input_schema": {"type": "object", "properties": {"path": {"type": "string"}, "old_text": {"type": "string"}, "new_text": {"type": "string"}}, "required": ["path", "old_text", "new_text"]}},
{"name": "compact", "description": "Trigger manual conversation compression.",
"input_schema": {"type": "object", "properties": {"focus": {"type": "string", "description": "What to preserve in the summary"}}}},
]
def agent_loop(messages: list):
while True:
# Layer 1: micro_compact before each LLM call
micro_compact(messages)
# Layer 2: auto_compact if token estimate exceeds threshold
if estimate_tokens(messages) > THRESHOLD:
print("[auto_compact triggered]")
messages[:] = auto_compact(messages)
response = client.messages.create(
model=MODEL, system=SYSTEM, messages=messages,
tools=TOOLS, max_tokens=8000,
)
messages.append({"role": "assistant", "content": response.content})
if response.stop_reason != "tool_use":
return
results = []
manual_compact = False
for block in response.content:
if block.type == "tool_use":
if block.name == "compact":
manual_compact = True
output = "Compressing..."
else:
handler = TOOL_HANDLERS.get(block.name)
try:
output = handler(**block.input) if handler else f"Unknown tool: {block.name}"
except Exception as e:
output = f"Error: {e}"
print(f"> {block.name}: {str(output)[:200]}")
results.append({"type": "tool_result", "tool_use_id": block.id, "content": str(output)})
messages.append({"role": "user", "content": results})
# Layer 3: manual compact triggered by the compact tool
if manual_compact:
print("[manual compact]")
messages[:] = auto_compact(messages)
if __name__ == "__main__":
history = []
while True:
try:
query = input("\033[36ms06 >> \033[0m")
except (EOFError, KeyboardInterrupt):
break
if query.strip().lower() in ("q", "exit", ""):
break
history.append({"role": "user", "content": query})
agent_loop(history)
print()