from __future__ import annotations import json import os import re import time from collections.abc import Iterator from pathlib import Path from typing import Any import httpx import uvicorn from fastapi import FastAPI, Request from fastapi.responses import HTMLResponse, StreamingResponse from fastapi.staticfiles import StaticFiles from open_cortex.runtime.client import stream_chat_events from open_cortex.runtime.events import RuntimeEvent from open_cortex.runtime.messages import ChatMessage from open_cortex.runtime.metrics import RuntimeSnapshot ASSET_DIR = Path(__file__).with_name("assets") CSS_FILE = ASSET_DIR / "open_cortex.css" JS_FILE = ASSET_DIR / "open_cortex.js" MAX_COLLAPSE_RETAINED_CHARS = 3000 COLLAPSED_MESSAGE_CHARS = 1200 DEFAULT_CONTEXT_SIZE = 2048 def _backend_mode() -> str: explicit = os.getenv("OPEN_CORTEX_BACKEND") if explicit: return explicit if os.getenv("SPACE_ID"): return "simulated" return "llama_cpp" def _simulator_delay_seconds() -> float: return float(os.getenv("OPEN_CORTEX_SIMULATOR_DELAY_SECONDS", "0.025")) def _asset_version() -> int: return int(max(CSS_FILE.stat().st_mtime, JS_FILE.stat().st_mtime)) def _memory_blocks() -> str: return "\n".join( '' if index < 1 else "" for index in range(12) ) def _token_particles() -> str: return "\n".join('' for _ in range(9)) def _latency_trace() -> str: return "\n".join("" for _ in range(8)) def render_index() -> str: asset_version = _asset_version() return f""" OpenCortex Runtime Observatory
OpenCortex
llama.cpp · local
Conversation
Live local chat
↵ SEND · SHIFT + ↵ NEW LINE
Runtime Observatory
Qwen2.5 1.5B · Q4_K_M
IDLE
READY
Working Memory
Memory quiet
%
{_memory_blocks()}
Context Window
Context resting
0/ —
Token Stream
Stream dormant
0.0tok/s
{_token_particles()}
Engine State
Engine healthy
ms
{_latency_trace()}
Cortex Core
Ready for input
ENGINE IDLE · SLOT AVAILABLE
Measured live by llama.cpp
Prompt eval
measuring
KV evidence
unavailable
""" def _snapshot_to_payload(snapshot: RuntimeSnapshot | None) -> dict[str, Any] | None: if snapshot is None: return None return { "prompt_tps": snapshot.prompt_tps, "decode_tps": snapshot.decode_tps, "requests_processing": snapshot.requests_processing, "requests_deferred": snapshot.requests_deferred, "active_slots": snapshot.active_slots, "slot_context_tokens": list(snapshot.slot_context_tokens), "slot_context_size": snapshot.slot_context_size, } def event_to_payload(event: RuntimeEvent) -> dict[str, Any]: return { "kind": event.kind, "text_delta": event.text_delta, "ttft_ms": event.ttft_ms, "snapshot": _snapshot_to_payload(event.snapshot), "generated_tokens": event.generated_tokens, "elapsed_ms": event.elapsed_ms, "live_tps": event.live_tps, "repetition_detected": event.repetition_detected, "context_tokens": event.context_tokens, "context_size": event.context_size, "working_memory_percent": event.working_memory_percent, "prompt_tokens": event.prompt_tokens, "completion_tokens": event.completion_tokens, "prompt_tps": event.prompt_tps, "decode_tps": event.decode_tps, } def _http_error_text(exc: httpx.HTTPStatusError) -> str: try: return exc.response.text except httpx.ResponseNotRead: try: exc.response.read() except (httpx.HTTPError, httpx.StreamError): return "" return exc.response.text def _is_context_overflow(exc: httpx.HTTPStatusError) -> bool: return ( exc.response.status_code == 400 and "exceeds the available context size" in _http_error_text(exc) ) def _context_size_from_error(exc: httpx.HTTPStatusError) -> int | None: match = re.search(r"context size \((\d+) tokens\)", _http_error_text(exc)) if match is None: return None return int(match.group(1)) def _trim_for_context_collapse( messages: list[ChatMessage], ) -> tuple[list[ChatMessage], int]: system_messages = [message for message in messages if message.role == "system"] conversation = [message for message in messages if message.role != "system"] if not conversation: return messages, 0 latest_user_index = next( ( index for index in range(len(conversation) - 1, -1, -1) if conversation[index].role == "user" ), len(conversation) - 1, ) latest_user = conversation[latest_user_index] recent_start = max(1, len(conversation) - 3) recent = conversation[recent_start:] retained: list[ChatMessage] = [] for message in recent: if message is latest_user: retained.append(message) continue if len(message.content) > MAX_COLLAPSE_RETAINED_CHARS: retained.append( ChatMessage( role=message.role, content=( "[Earlier content collapsed; recent tail retained.]\n" + message.content[-COLLAPSED_MESSAGE_CHARS:] ), ) ) else: retained.append(message) if latest_user not in retained: retained.append(latest_user) retained = list(dict.fromkeys(retained)) dropped = len(conversation) - len(retained) return [*system_messages, *retained], max(0, dropped) def _parse_messages(raw_messages: Any) -> list[ChatMessage]: if not isinstance(raw_messages, list): return [] messages: list[ChatMessage] = [] for raw_message in raw_messages: if not isinstance(raw_message, dict): continue role = raw_message.get("role") content = raw_message.get("content") if role not in {"system", "user", "assistant"}: continue if not isinstance(content, str) or not content.strip(): continue messages.append(ChatMessage(role=role, content=content.strip())) return messages def _latest_user_text(messages: list[ChatMessage]) -> str: for message in reversed(messages): if message.role == "user": return message.content return "" def _simulated_answer(messages: list[ChatMessage]) -> str: latest = _latest_user_text(messages).lower() if any(marker in latest for marker in ("story", "故事", "repeat", "loop")): phrase = ( "A tiny local model begins exploring a hidden runtime chamber. " "It finds the same sentence again, and the same sentence again. " ) return ( "I can feel the decode rhythm becoming unstable.\n\n" + phrase * 8 + "\n\nOpenCortex marks this as a thought loop because recent generated " "text is repeating instead of moving forward." ) if any(marker in latest for marker in ("context", "window", "memory", "上下文", "记忆")): return ( "OpenCortex treats the context window as the model's active workspace. " "As the conversation grows, more tokens must be prefetched before decode " "can begin. When the active window fills, older turns are still visible in " "the chat log, but they fall outside what the model can reliably use." ) return ( "OpenCortex is running in Space demo mode. It simulates the same runtime " "event stream used by the local llama.cpp integration: prefill, first token, " "decode throughput, context pressure, and completion. Run it locally with " "llama.cpp to replace this simulated stream with live engine evidence." ) def _token_chunks(text: str) -> list[str]: chunks = re.findall(r"\S+\s*", text) return chunks or [text] def _stream_simulated_events(messages: list[ChatMessage]) -> Iterator[RuntimeEvent]: answer = _simulated_answer(messages) chunks = _token_chunks(answer) context_size = DEFAULT_CONTEXT_SIZE prompt_tokens = max(24, sum(len(message.content) for message in messages) // 3) base_context_tokens = min(context_size, prompt_tokens + 96) delay_seconds = _simulator_delay_seconds() yield RuntimeEvent(kind="request_started", text_delta="", ttft_ms=None, snapshot=None) snapshot = RuntimeSnapshot( prompt_tps=72.4, decode_tps=24.6, requests_processing=1, requests_deferred=0, active_slots=1, slot_context_tokens=(base_context_tokens,), slot_context_size=context_size, ) generated_text = "" started_at = time.perf_counter() for index, chunk in enumerate(chunks, start=1): if delay_seconds: time.sleep(delay_seconds) generated_text += chunk context_tokens = min(context_size, base_context_tokens + index) event_kind = "first_token" if index == 1 else "token" elapsed_ms = max(0.0, (time.perf_counter() - started_at) * 1000) live_tps = None if index == 1 or elapsed_ms == 0 else index / (elapsed_ms / 1000) repetition_detected = "same sentence again" in generated_text and index > 18 yield RuntimeEvent( kind=event_kind, text_delta=chunk, ttft_ms=420.0 if index == 1 else None, snapshot=snapshot if index == 1 else None, generated_tokens=index, elapsed_ms=0.0 if index == 1 else elapsed_ms, live_tps=live_tps, repetition_detected=repetition_detected, context_tokens=context_tokens, context_size=context_size, working_memory_percent=round(min(100.0, context_tokens / context_size * 100), 1), ) final_context_tokens = min(context_size, base_context_tokens + len(chunks)) yield RuntimeEvent( kind="request_completed", text_delta="", ttft_ms=None, snapshot=None, generated_tokens=len(chunks), repetition_detected="same sentence again" in generated_text, context_tokens=final_context_tokens, context_size=context_size, working_memory_percent=round(min(100.0, final_context_tokens / context_size * 100), 1), prompt_tokens=prompt_tokens, completion_tokens=len(chunks), prompt_tps=72.4, decode_tps=24.6, ) def _stream_events(messages: list[ChatMessage]) -> Iterator[str]: if _backend_mode() == "simulated": for event in _stream_simulated_events(messages): yield json.dumps(event_to_payload(event), ensure_ascii=False) + "\n" return try: for event in stream_chat_events(messages): yield json.dumps(event_to_payload(event), ensure_ascii=False) + "\n" except httpx.HTTPStatusError as exc: if _is_context_overflow(exc): trimmed_messages, dropped_messages = _trim_for_context_collapse(messages) yield json.dumps( { "kind": "context_collapse", "message": ( "The earliest turns fell outside the active context. " "OpenCortex trimmed old history and retried with recent memory." ), "dropped_messages": dropped_messages, "retained_messages": len(trimmed_messages), "context_size": _context_size_from_error(exc), }, ensure_ascii=False, ) + "\n" try: for event in stream_chat_events(trimmed_messages): yield json.dumps(event_to_payload(event), ensure_ascii=False) + "\n" return except httpx.HTTPStatusError as retry_exc: if _is_context_overflow(retry_exc): payload = { "kind": "error", "code": "context_overflow", "message": ( "The conversation still exceeds llama.cpp's context window " "after collapse. Start a new run or restart llama-server with " "a larger -c value." ), } else: payload = { "kind": "error", "code": "backend_http_error", "message": f"{type(retry_exc).__name__}: {retry_exc}", } else: payload = { "kind": "error", "code": "backend_http_error", "message": f"{type(exc).__name__}: {exc}", } yield json.dumps(payload, ensure_ascii=False) + "\n" except Exception as exc: yield json.dumps( { "kind": "error", "code": "backend_error", "message": f"{type(exc).__name__}: {exc}", }, ensure_ascii=False, ) + "\n" def create_app() -> FastAPI: app = FastAPI(title="OpenCortex") app.mount("/assets", StaticFiles(directory=ASSET_DIR), name="assets") @app.get("/", response_class=HTMLResponse) def index() -> str: return render_index() @app.post("/api/chat") async def chat(request: Request) -> StreamingResponse: payload = await request.json() messages = _parse_messages(payload.get("messages")) return StreamingResponse( _stream_events(messages), media_type="application/x-ndjson", ) return app app = create_app() def main() -> None: host = os.getenv("OPEN_CORTEX_HOST", "0.0.0.0" if os.getenv("SPACE_ID") else "127.0.0.1") uvicorn.run( "open_cortex.ui.app:app", host=host, port=7860, reload=False, ) if __name__ == "__main__": main()