Initial commit: NexusOS - local AI assistant platform

This commit is contained in:
Jon Wingender
2026-07-21 22:48:38 -05:00
commit 714b9fc890
850 changed files with 28278 additions and 0 deletions
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from pathlib import Path
from typing import Any, Dict, List, Optional
from pydantic import BaseModel
from ..nexus_config import DEFAULT_MEMORY_MODEL
import sqlite3
import json
import math
import os
import time
def _cosine(a: List[float], b: List[float]) -> float:
"""Cosine similarity between two equal-length vectors. 0.0 on mismatch."""
if not a or not b or len(a) != len(b):
return 0.0
dot = sum(x * y for x, y in zip(a, b))
na = math.sqrt(sum(x * x for x in a))
nb = math.sqrt(sum(y * y for y in b))
if na == 0.0 or nb == 0.0:
return 0.0
return dot / (na * nb)
# -----------------------------
# Models
# -----------------------------
class MemoryItem(BaseModel):
id: str
section: str = "General"
text: str
tags: List[str] = []
position: int = 0
class MessageItem(BaseModel):
role: str # "user" or "assistant"
content: str
timestamp: float
model: Optional[str] = None
tokens: Optional[int] = None
class ConversationItem(BaseModel):
id: str
messages: List[MessageItem] = []
created_at: float
updated_at: float
title: Optional[str] = None
@property
def preview(self) -> str:
for msg in self.messages:
if msg.role == "user":
return msg.content[:80]
return "Empty conversation"
@property
def timestamp(self) -> float:
return self.created_at
# -----------------------------
# Persistent Store
# -----------------------------
class PersistentMemoryStore:
def __init__(self, db_path: Path):
self.db_path = db_path
os.makedirs(self.db_path.parent, exist_ok=True)
self._ensure_tables()
self._cache: Dict[str, MemoryItem] = self._load_all_memory()
# -----------------------------
# Internal helpers
# -----------------------------
def _connect(self):
conn = sqlite3.connect(self.db_path)
conn.row_factory = sqlite3.Row
conn.execute("PRAGMA journal_mode=WAL;")
return conn
def _ensure_tables(self):
conn = self._connect()
cur = conn.cursor()
cur.execute("""
CREATE TABLE IF NOT EXISTS memory (
id TEXT PRIMARY KEY,
section TEXT NOT NULL DEFAULT 'General',
text TEXT NOT NULL,
tags TEXT
)
""")
# Migrate: add section column if it doesn't exist yet
try:
cur.execute("ALTER TABLE memory ADD COLUMN section TEXT NOT NULL DEFAULT 'General'")
except Exception:
pass
# Migrate: add position column for stable ordering
try:
cur.execute("ALTER TABLE memory ADD COLUMN position INTEGER NOT NULL DEFAULT 0")
except Exception:
pass
# Backfill positions for rows added before this column existed
cur.execute("SELECT COUNT(*) FROM memory WHERE position > 0")
if cur.fetchone()[0] == 0:
cur.execute("UPDATE memory SET position = rowid")
cur.execute("""
CREATE TABLE IF NOT EXISTS conversations (
id TEXT PRIMARY KEY,
created_at REAL NOT NULL,
updated_at REAL NOT NULL,
title TEXT
)
""")
# Migrate: add title column if it doesn't exist yet
try:
cur.execute("ALTER TABLE conversations ADD COLUMN title TEXT")
except Exception:
pass
cur.execute("""
CREATE TABLE IF NOT EXISTS messages (
id INTEGER PRIMARY KEY AUTOINCREMENT,
conversation_id TEXT NOT NULL,
role TEXT NOT NULL,
content TEXT NOT NULL,
timestamp REAL NOT NULL,
model TEXT,
tokens INTEGER,
FOREIGN KEY (conversation_id) REFERENCES conversations(id)
)
""")
for col, typedef in (("model", "TEXT"), ("tokens", "INTEGER")):
try:
cur.execute(f"ALTER TABLE messages ADD COLUMN {col} {typedef}")
except Exception:
pass
cur.execute("""
CREATE INDEX IF NOT EXISTS idx_messages_conversation_id
ON messages (conversation_id)
""")
# Semantic recall: one embedding vector per message, stored as JSON.
# Backfilled lazily by semantic_search_conversations so existing history
# gets indexed on first search.
cur.execute("""
CREATE TABLE IF NOT EXISTS message_vectors (
message_id INTEGER PRIMARY KEY,
embedding TEXT NOT NULL,
FOREIGN KEY (message_id) REFERENCES messages(id)
)
""")
cur.execute("""
CREATE TABLE IF NOT EXISTS settings (
key TEXT PRIMARY KEY,
value TEXT NOT NULL
)
""")
cur.execute(
"DELETE FROM settings WHERE key IN ('anthropic_api_key', 'escalation_model')"
)
conn.commit()
conn.close()
# -----------------------------
# Loaders
# -----------------------------
def _load_all_memory(self) -> Dict[str, MemoryItem]:
conn = self._connect()
cur = conn.cursor()
cur.execute("SELECT id, section, text, tags, position FROM memory ORDER BY position ASC, rowid ASC")
rows = cur.fetchall()
conn.close()
cache = {}
for row in rows:
try:
tags = json.loads(row["tags"]) if row["tags"] else []
except Exception:
tags = []
cache[row["id"]] = MemoryItem(
id=row["id"],
section=row["section"] or "General",
text=row["text"],
tags=tags,
position=row["position"] or 0,
)
return cache
# -----------------------------
# Memory API
# -----------------------------
def add(self, item: MemoryItem):
if not item.position:
conn = self._connect()
try:
row = conn.execute(
"SELECT position FROM memory WHERE id = ?", (item.id,)
).fetchone()
if row and row["position"]:
item.position = row["position"]
else:
row = conn.execute("SELECT MAX(position) AS max_position FROM memory").fetchone()
item.position = (row["max_position"] or 0) + 1
finally:
conn.close()
self._cache[item.id] = item
conn = self._connect()
try:
cur = conn.cursor()
cur.execute(
"INSERT OR REPLACE INTO memory (id, section, text, tags, position) VALUES (?, ?, ?, ?, ?)",
(item.id, item.section or "General", item.text, json.dumps(item.tags), item.position)
)
conn.commit()
finally:
conn.close()
def update(self, item: MemoryItem):
existing = self.get(item.id)
if existing:
item.position = existing.position
self.add(item)
def delete(self, item_id: str):
self._cache.pop(item_id, None)
conn = self._connect()
try:
cur = conn.cursor()
cur.execute("DELETE FROM memory WHERE id = ?", (item_id,))
conn.commit()
finally:
conn.close()
def get(self, item_id: str) -> Optional[MemoryItem]:
conn = self._connect()
try:
row = conn.execute(
"SELECT id, section, text, tags, position FROM memory WHERE id = ?",
(item_id,),
).fetchone()
finally:
conn.close()
if not row:
self._cache.pop(item_id, None)
return None
try:
tags = json.loads(row["tags"]) if row["tags"] else []
except Exception:
tags = []
item = MemoryItem(
id=row["id"], section=row["section"] or "General", text=row["text"],
tags=tags, position=row["position"] or 0,
)
self._cache[item_id] = item
return item
def all(self) -> List[MemoryItem]:
# Always read from DB — the memory service and backend run in separate processes
# with separate caches, so the cache can be stale for facts extracted by the
# memory service after this process started.
conn = self._connect()
cur = conn.cursor()
cur.execute("SELECT id, section, text, tags, position FROM memory ORDER BY position ASC, rowid ASC")
rows = cur.fetchall()
conn.close()
items = []
for row in rows:
try:
tags = json.loads(row["tags"]) if row["tags"] else []
except Exception:
tags = []
items.append(MemoryItem(
id=row["id"],
section=row["section"] or "General",
text=row["text"],
tags=tags,
position=row["position"] or 0,
))
return items
def reorder_section(self, section: str, ordered_ids: List[str]) -> bool:
"""Rewrite the order of items in a section using its existing position pool.
ordered_ids must contain exactly the ids currently in the section."""
section_norm = section or "General"
in_section = [i for i in self.all() if (i.section or "General") == section_norm]
if len(in_section) != len(ordered_ids):
return False
by_id = {i.id: i for i in in_section}
siblings = []
for id_ in ordered_ids:
if id_ not in by_id:
return False
siblings.append(by_id[id_])
positions = sorted([i.position for i in in_section])
conn = self._connect()
try:
cur = conn.cursor()
for s, new_pos in zip(siblings, positions):
s.position = new_pos
cur.execute("UPDATE memory SET position = ? WHERE id = ?", (new_pos, s.id))
conn.commit()
finally:
conn.close()
return True
# -----------------------------
# Conversation API
# -----------------------------
def create_conversation(self, conversation_id: str) -> ConversationItem:
now = time.time()
conn = self._connect()
try:
cur = conn.cursor()
cur.execute(
"INSERT OR IGNORE INTO conversations (id, created_at, updated_at) VALUES (?, ?, ?)",
(conversation_id, now, now)
)
conn.commit()
finally:
conn.close()
return ConversationItem(id=conversation_id, created_at=now, updated_at=now)
def set_conversation_title(self, conversation_id: str, title: str):
conn = self._connect()
try:
cur = conn.cursor()
cur.execute(
"UPDATE conversations SET title = ? WHERE id = ?",
(title, conversation_id),
)
conn.commit()
finally:
conn.close()
def add_message(self, conversation_id: str, role: str, content: str, model: Optional[str] = None, tokens: Optional[int] = None):
now = time.time()
conn = self._connect()
try:
cur = conn.cursor()
cur.execute(
"INSERT INTO messages (conversation_id, role, content, timestamp, model, tokens) VALUES (?, ?, ?, ?, ?, ?)",
(conversation_id, role, content, now, model, tokens)
)
message_id = cur.lastrowid
cur.execute(
"UPDATE conversations SET updated_at = ? WHERE id = ?",
(now, conversation_id)
)
conn.commit()
return message_id
finally:
conn.close()
def get_conversation(self, conversation_id: str) -> Optional[ConversationItem]:
conn = self._connect()
cur = conn.cursor()
cur.execute("SELECT * FROM conversations WHERE id = ?", (conversation_id,))
row = cur.fetchone()
if not row:
conn.close()
return None
cur.execute(
"SELECT role, content, timestamp, model, tokens FROM messages WHERE conversation_id = ? ORDER BY timestamp ASC",
(conversation_id,)
)
msg_rows = cur.fetchall()
conn.close()
messages = [MessageItem(role=r["role"], content=r["content"], timestamp=r["timestamp"], model=r["model"], tokens=r["tokens"]) for r in msg_rows]
return ConversationItem(
id=row["id"],
messages=messages,
created_at=row["created_at"],
updated_at=row["updated_at"],
title=row["title"] if "title" in row.keys() else None,
)
def all_conversations(self) -> List[ConversationItem]:
conn = self._connect()
cur = conn.cursor()
cur.execute("""
SELECT c.id, c.created_at, c.updated_at, c.title,
m.role, m.content, m.timestamp, m.model, m.tokens
FROM conversations c
LEFT JOIN messages m ON m.conversation_id = c.id
ORDER BY c.updated_at DESC, m.timestamp ASC
""")
rows = cur.fetchall()
conn.close()
convs: Dict[str, ConversationItem] = {}
order: list[str] = []
for row in rows:
cid = row["id"]
if cid not in convs:
convs[cid] = ConversationItem(
id=cid,
created_at=row["created_at"],
updated_at=row["updated_at"],
title=row["title"],
)
order.append(cid)
if row["role"] is not None:
convs[cid].messages.append(
MessageItem(role=row["role"], content=row["content"], timestamp=row["timestamp"], model=row["model"], tokens=row["tokens"])
)
return [convs[cid] for cid in order]
def delete_conversation(self, conversation_id: str):
conn = self._connect()
try:
cur = conn.cursor()
cur.execute("DELETE FROM messages WHERE conversation_id = ?", (conversation_id,))
cur.execute("DELETE FROM conversations WHERE id = ?", (conversation_id,))
conn.commit()
finally:
conn.close()
# -----------------------------
# Search API
# -----------------------------
def search_conversations(self, query: str, limit: int = 3) -> List[dict]:
"""Return up to `limit` conversations that contain the query string,
with full user+assistant exchange pairs around each match."""
if not query or not query.strip():
return []
q = query.strip().lower()
conn = self._connect()
cur = conn.cursor()
cur.execute("""
SELECT DISTINCT c.id, c.created_at, c.updated_at
FROM conversations c
JOIN messages m ON m.conversation_id = c.id
WHERE LOWER(m.content) LIKE ?
ORDER BY c.updated_at DESC
LIMIT ?
""", (f"%{q}%", limit))
rows = cur.fetchall()
results = []
for row in rows:
# Load all messages in order so we can find complete exchange pairs
cur.execute("""
SELECT role, content FROM messages
WHERE conversation_id = ?
ORDER BY timestamp ASC
""", (row["id"],))
all_msgs = [{"role": r["role"], "content": r["content"]} for r in cur.fetchall()]
# For each matching message, collect the full user+assistant pair around it
seen_pairs: set = set()
matches = []
for i, msg in enumerate(all_msgs):
if q not in msg["content"].lower():
continue
if msg["role"] == "user":
start, end = i, i + 1 if i + 1 < len(all_msgs) else i
else:
start, end = (i - 1 if i > 0 else i), i
if (start, end) in seen_pairs:
continue
seen_pairs.add((start, end))
for m in all_msgs[start:end + 1]:
matches.append({"role": m["role"], "content": m["content"][:500]})
if len(seen_pairs) >= 2:
break
if matches:
results.append({
"id": row["id"],
"updated_at": row["updated_at"],
"matches": matches,
})
conn.close()
return results
# nomic-embed-text is an asymmetric retrieval model: queries and stored
# documents must be embedded with these task prefixes or similarity collapses
# into noise. Cached vectors are document-embeddings (search_document:).
_EMBED_QUERY_PREFIX = "search_query: "
_EMBED_DOC_PREFIX = "search_document: "
async def semantic_search_conversations(
self, query: str, embed_fn, limit: int = 3, min_score: float = 0.6
) -> List[dict]:
"""Recall past conversations relevant to `query` using hybrid retrieval.
Combines semantic similarity (embeddings — finds reworded matches with no
shared keywords) with the existing lexical substring match (catches exact
terms the embedding underweights), unioned and deduped by conversation.
`embed_fn` is an async callable returning an embedding vector for a string
(typically OllamaManager.embed). Messages without a stored vector are
embedded and cached on first use (lazy backfill). If embeddings are
unavailable (no model / Ollama down) this degrades to pure lexical match,
so recall never silently breaks.
Returns the same shape as `search_conversations`: a list of
{id, updated_at, matches:[{role, content}]} with full user+assistant
pairs around each match.
"""
if not query or not query.strip():
return []
query_vec = await embed_fn(self._EMBED_QUERY_PREFIX + query.strip())
if not query_vec:
return self.search_conversations(query, limit=limit)
conn = self._connect()
cur = conn.cursor()
# Lazy backfill: embed any messages that don't have a vector yet.
cur.execute("""
SELECT m.id, m.content
FROM messages m
LEFT JOIN message_vectors v ON v.message_id = m.id
WHERE v.message_id IS NULL AND TRIM(m.content) != ''
""")
missing = cur.fetchall()
for row in missing:
vec = await embed_fn(self._EMBED_DOC_PREFIX + row["content"][:2000])
if vec:
cur.execute(
"INSERT OR REPLACE INTO message_vectors (message_id, embedding) VALUES (?, ?)",
(row["id"], json.dumps(vec)),
)
if missing:
conn.commit()
# Score every stored message against the query vector.
cur.execute("""
SELECT v.message_id, v.embedding, m.conversation_id
FROM message_vectors v
JOIN messages m ON m.id = v.message_id
""")
scored = []
for row in cur.fetchall():
try:
vec = json.loads(row["embedding"])
except Exception:
continue
score = _cosine(query_vec, vec)
if score >= min_score:
scored.append((score, row["message_id"], row["conversation_id"]))
scored.sort(reverse=True)
results: List[dict] = []
seen_convs: set = set()
for score, message_id, conv_id in scored:
if len(results) >= limit:
break
if conv_id in seen_convs:
continue
pair = self._exchange_pair(cur, conv_id, message_id)
if pair:
seen_convs.add(conv_id)
results.append(pair)
conn.close()
# Hybrid union: fill any remaining slots with lexical matches the
# embedding missed (e.g. exact proper nouns), skipping dupes.
if len(results) < limit:
for conv in self.search_conversations(query, limit=limit):
if conv["id"] not in seen_convs:
seen_convs.add(conv["id"])
results.append(conv)
if len(results) >= limit:
break
return results
def _exchange_pair(self, cur, conv_id: str, message_id: int) -> Optional[dict]:
"""Build a {id, updated_at, matches} record with the full user+assistant
pair surrounding `message_id`, in the shape search callers expect."""
cur.execute(
"SELECT id, role, content FROM messages WHERE conversation_id = ? ORDER BY timestamp ASC",
(conv_id,),
)
all_msgs = cur.fetchall()
idx = next((i for i, m in enumerate(all_msgs) if m["id"] == message_id), None)
if idx is None:
return None
if all_msgs[idx]["role"] == "user":
start, end = idx, min(idx + 1, len(all_msgs) - 1)
else:
start, end = max(idx - 1, 0), idx
matches = [
{"role": all_msgs[i]["role"], "content": all_msgs[i]["content"][:500]}
for i in range(start, end + 1)
]
cur.execute("SELECT updated_at FROM conversations WHERE id = ?", (conv_id,))
crow = cur.fetchone()
return {
"id": conv_id,
"updated_at": crow["updated_at"] if crow else 0,
"matches": matches,
}
# -----------------------------
# Settings API
# -----------------------------
_SETTINGS_DEFAULTS: Dict[str, Any] = {
"model": "",
# Qwen3-style reasoning. Off by default: the hidden <think> block is pure
# latency for chat/memory. Turn on for hard multi-step problems.
"think": False,
"temperature": 0.7,
"system_prompt": "",
"timeout": 120,
# How long Ollama keeps the model resident in VRAM between messages.
# "30m"/"-1" (never unload)/"0" (unload now). Avoids cold-reload latency
# when you return to an idle chat. Empty → Ollama's 5-minute default.
"keep_alive": "30m",
# CPU/GPU offload: -1 = Auto (Ollama auto-fits layers to VRAM).
# 0100 = percent of model layers to force onto the GPU; the
# remainder runs on CPU. See OllamaManager.get_model_layers.
"gpu_offload": -1,
# Memory curator (the model that extracts facts after each exchange).
# Empty → same auto-selected model as chat. A dedicated model (e.g.
# "mistral:latest") gives better extraction but must share VRAM.
"memory_model": DEFAULT_MEMORY_MODEL,
# Curator CPU/GPU offload — same scale as gpu_offload above. Default 0
# (all CPU/RAM): OS-neutral and never evicts the chat model from a small
# GPU. Boxes with spare VRAM can set -1 (Auto) or a percent to use the GPU.
"memory_gpu_offload": 0,
# Similar-fact merge: when a newly extracted fact's embedding is at least
# this cosine-similar to an existing fact, UPDATE that fact in place
# instead of appending a duplicate ("edit with new info"). 0 disables
# (always append). Calibrated on nomic-embed-text: genuine updates
# (mileage/title/location changes) score 0.810.99, while distinct facts
# top out ~0.61 — so 0.80 catches updates and never merges unrelated
# facts. Lower to catch looser rephrases; raise toward 1.0 to be stricter.
"memory_merge_threshold": 0.80,
}
def get_settings(self) -> Dict[str, Any]:
conn = self._connect()
cur = conn.cursor()
cur.execute("SELECT key, value FROM settings")
rows = cur.fetchall()
conn.close()
result = dict(self._SETTINGS_DEFAULTS)
for row in rows:
try:
result[row["key"]] = json.loads(row["value"])
except Exception:
result[row["key"]] = row["value"]
return result
def update_settings(self, data: Dict[str, Any]):
conn = self._connect()
try:
cur = conn.cursor()
for key, value in data.items():
if key in self._SETTINGS_DEFAULTS:
cur.execute(
"INSERT OR REPLACE INTO settings (key, value) VALUES (?, ?)",
(key, json.dumps(value))
)
conn.commit()
finally:
conn.close()
# -----------------------------
# Store Instance
# -----------------------------
from ..nexus_config import MEMORY_DB
DB_PATH = MEMORY_DB
store = PersistentMemoryStore(DB_PATH)