Files
api/app/core/memory_middleware.py
2026-04-16 17:57:49 +02:00

597 lines
22 KiB
Python

"""Memory Middleware — enrich requests with memory context and store interactions.
Four-tier memory model (MemGPT-style):
core — persistent key/value user preferences, always injected
associative — semantic similarity search via pgvector (top-k)
episodic — recent session summaries (last N)
proactive — behavioral patterns above confidence threshold
All memory content is encrypted at rest using the per-user Fernet key
stored in User.encryption_key. Decryption happens in-memory only.
Usage:
memory = MemoryMiddleware(db_session)
context = await memory.enrich_context(user_id, message)
# ... run agent ...
await memory.store_episode(user_id, session_id, message, response)
"""
from __future__ import annotations
import asyncio
import logging
import uuid
from typing import Any
from cryptography.fernet import Fernet, InvalidToken
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from app.models import (
ExtractionQueue,
MemoryAssociative,
MemoryCore,
MemoryEpisodic,
MemoryProactive,
User,
)
logger = logging.getLogger(__name__)
# Tuning constants
_ASSOCIATIVE_TOP_K = 5
_EPISODIC_RECENT_N = 10
_PROACTIVE_CONFIDENCE_THRESHOLD = 0.6
class MemoryMiddleware:
"""Enrich orchestrator context with memory and persist interactions after."""
def __init__(self, db: AsyncSession) -> None:
self._db = db
# ── Public API ────────────────────────────────────────────────────────────
async def enrich_context(
self,
user_id: str,
message: str,
trace_id: str | None = None,
session_id: str | None = None,
) -> dict[str, Any]:
"""Build memory context dict to inject into the orchestrator before LLM call.
Returns a dict with keys:
core_memory — {key: plaintext_value, ...}
associative_memory — [plaintext_content, ...] (top-k by keyword match)
episodic_memory — [plaintext_summary, ...] (most recent N)
proactive_hints — [plaintext_pattern, ...] (above threshold)
"""
fernet = await self._get_fernet(user_id)
if fernet is None:
return {}
user_dbg = await self._get_user_debug(user_id)
user_tier: str = user_dbg.get("tier") or "free"
core = await self._load_core(user_id, fernet)
associative = await self._load_associative(user_id, message, fernet, user_tier=user_tier)
episodic = await self._load_episodic(user_id, fernet, session_id=session_id)
proactive = await self._load_proactive(user_id, fernet)
logger.info(
"memory: enrich_context trace=%s user=%s tier=%s core=%d associative=%d episodic=%d proactive=%d",
trace_id or "-",
user_id,
user_tier,
len(core),
len(associative),
len(episodic),
len(proactive),
)
return {
"core_memory": core,
"associative_memory": associative,
"episodic_memory": episodic,
"proactive_hints": proactive,
}
async def store_episode(
self,
user_id: str,
session_id: str,
message: str,
response: str,
trace_id: str | None = None,
) -> None:
"""Summarise and store a completed interaction in episodic memory.
The summary is a simple heuristic concatenation (no LLM call) to keep
latency low. After committing the episode row, dispatches the Mem0-style
extraction pipeline:
- Pro/Power/Team → asyncio.create_task (fire-and-forget, realtime).
- Free → enqueue an ExtractionQueue row for the daily cron.
"""
fernet = await self._get_fernet(user_id)
if fernet is None:
return
summary = f"User: {message[:200]}\nAssistant: {response[:200]}"
encrypted = _encrypt(fernet, summary)
episode = MemoryEpisodic(
id=str(uuid.uuid4()),
user_id=user_id,
summary_encrypted=encrypted,
session_id=session_id,
)
self._db.add(episode)
episode_id: str = episode.id
try:
await self._db.commit()
user_dbg = await self._get_user_debug(user_id)
tier = user_dbg.get("tier") or "free"
logger.info(
"memory: store_episode trace=%s user=%s tier=%s session=%s",
trace_id or "-",
user_id,
tier,
session_id,
)
except Exception as exc:
logger.error("memory: store_episode failed user=%s: %s", user_id, exc)
await self._db.rollback()
return
# ── Dispatch extraction pipeline (Phase 2) ────────────────────────────
await self._dispatch_extraction(
user_id=user_id,
episode_id=episode_id,
last_user_msg=message,
last_assistant_msg=response,
session_id=session_id,
)
async def _dispatch_extraction(
self,
user_id: str,
episode_id: str,
last_user_msg: str,
last_assistant_msg: str,
session_id: str | None,
) -> None:
"""Route extraction to realtime task or batch queue based on user tier."""
from app.billing.tier_manager import tier_manager # noqa: PLC0415
tier = await tier_manager.get_tier(user_id, self._db)
if tier_manager.check_feature(tier, "realtime_extraction"):
# Pro/Power/Team: fire-and-forget in the background.
# Must open a fresh session — request session closes after handler returns.
from app.core.memory_extraction import run_extraction # noqa: PLC0415
from app.db import async_session # noqa: PLC0415
async def _task() -> None:
try:
async with async_session() as fresh_db:
await run_extraction(
db=fresh_db,
user_id=user_id,
last_user_msg=last_user_msg,
last_assistant_msg=last_assistant_msg,
session_id=session_id,
)
except Exception as exc:
logger.warning(
"memory: extraction task failed user=%s: %s", user_id, exc
)
asyncio.create_task(_task())
logger.info("memory: realtime extraction dispatched user=%s", user_id)
else:
# Free tier: enqueue for daily batch cron.
queue_row = ExtractionQueue(
id=str(uuid.uuid4()),
user_id=user_id,
episode_id=episode_id,
)
self._db.add(queue_row)
try:
await self._db.commit()
logger.info(
"memory: extraction enqueued (batch) user=%s episode=%s",
user_id,
episode_id,
)
except Exception as exc:
logger.warning(
"memory: extraction queue insert failed user=%s: %s", user_id, exc
)
await self._db.rollback()
async def update_core(self, user_id: str, key: str, value: str, trace_id: str | None = None) -> None:
"""Upsert a core memory key/value for a user."""
fernet = await self._get_fernet(user_id)
if fernet is None:
return
encrypted = _encrypt(fernet, value)
result = await self._db.execute(
select(MemoryCore).where(
MemoryCore.user_id == user_id,
MemoryCore.key == key,
)
)
existing = result.scalar_one_or_none()
if existing is not None:
existing.value_encrypted = encrypted
else:
self._db.add(MemoryCore(
id=str(uuid.uuid4()),
user_id=user_id,
key=key,
value_encrypted=encrypted,
))
try:
await self._db.commit()
user_dbg = await self._get_user_debug(user_id)
logger.info(
"memory: update_core trace=%s user=%s tier=%s key=%s",
trace_id or "-",
user_id,
user_dbg.get("tier") or "-",
key,
)
except Exception as exc:
logger.error("memory: update_core failed user=%s key=%s: %s", user_id, key, exc)
await self._db.rollback()
async def list_core_blocks(self, user_id: str) -> list[dict[str, str]]:
"""Return core memory as editable blocks (label/value)."""
fernet = await self._get_fernet(user_id)
if fernet is None:
return []
result = await self._db.execute(
select(MemoryCore)
.where(MemoryCore.user_id == user_id)
.order_by(MemoryCore.key.asc())
)
rows = result.scalars().all()
out: list[dict[str, str]] = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.value_encrypted)
if plaintext is not None:
out.append({"label": row.key, "value": plaintext})
logger.debug("memory: list_core_blocks user=%s count=%d", user_id, len(out))
return out
async def get_core_block(self, user_id: str, label: str) -> str | None:
"""Return a single core memory block value by label."""
fernet = await self._get_fernet(user_id)
if fernet is None:
return None
result = await self._db.execute(
select(MemoryCore).where(
MemoryCore.user_id == user_id,
MemoryCore.key == label,
)
)
row = result.scalar_one_or_none()
if row is None:
logger.debug("memory: get_core_block user=%s label=%s found=0", user_id, label)
return None
value = _safe_decrypt(fernet, row.value_encrypted)
logger.debug("memory: get_core_block user=%s label=%s found=%d", user_id, label, 1 if value is not None else 0)
return value
async def delete_core(self, user_id: str, label: str) -> bool:
"""Delete a core memory block by label. Returns True if deleted."""
result = await self._db.execute(
select(MemoryCore).where(
MemoryCore.user_id == user_id,
MemoryCore.key == label,
)
)
row = result.scalar_one_or_none()
if row is None:
logger.debug("memory: delete_core user=%s label=%s found=0", user_id, label)
return False
await self._db.delete(row)
try:
await self._db.commit()
logger.info("memory: delete_core user=%s label=%s", user_id, label)
return True
except Exception as exc:
logger.error("memory: delete_core failed user=%s label=%s: %s", user_id, label, exc)
await self._db.rollback()
return False
async def append_core(self, user_id: str, label: str, content: str) -> None:
"""Append content to a core block, creating it if missing."""
current = await self.get_core_block(user_id, label)
if current is None:
await self.update_core(user_id, label, content)
logger.info("memory: append_core user=%s label=%s created=1", user_id, label)
return
await self.update_core(user_id, label, f"{current}\n{content}")
logger.info("memory: append_core user=%s label=%s created=0", user_id, label)
async def replace_core(self, user_id: str, label: str, old: str, new: str) -> bool:
"""Replace one exact string inside a core block. Returns False if not found."""
current = await self.get_core_block(user_id, label)
if current is None or old not in current:
logger.debug("memory: replace_core user=%s label=%s changed=0", user_id, label)
return False
await self.update_core(user_id, label, current.replace(old, new, 1))
logger.info("memory: replace_core user=%s label=%s changed=1", user_id, label)
return True
async def store_associative(
self,
user_id: str,
content: str,
entity_type: str | None = None,
entity_id: str | None = None,
) -> None:
"""Store associative memory; embed if user tier has real_embeddings."""
from app.billing.tier_manager import tier_manager # noqa: PLC0415
from app.core.embeddings import embed_text # noqa: PLC0415
fernet = await self._get_fernet(user_id)
if fernet is None:
return
encrypted = _encrypt(fernet, content)
user_dbg = await self._get_user_debug(user_id)
user_tier = user_dbg.get("tier") or "free"
embedding: list[float] | None = None
if tier_manager.check_feature(user_tier, "real_embeddings"):
embedding = await embed_text(content)
row = MemoryAssociative(
id=str(uuid.uuid4()),
user_id=user_id,
content_encrypted=encrypted,
embedding=embedding,
entity_type=entity_type,
entity_id=entity_id,
)
self._db.add(row)
try:
await self._db.commit()
logger.info(
"memory: store_associative user=%s embedded=%s",
user_id,
embedding is not None,
)
except Exception as exc:
logger.error("memory: store_associative failed user=%s: %s", user_id, exc)
await self._db.rollback()
async def insert_archival(self, user_id: str, content: str, source: str = "manual") -> None:
"""Insert a long-term archival memory entry."""
fernet = await self._get_fernet(user_id)
if fernet is None:
return
encrypted = _encrypt(fernet, content)
row = MemoryAssociative(
id=str(uuid.uuid4()),
user_id=user_id,
content_encrypted=encrypted,
embedding=None,
entity_type=source,
entity_id=None,
)
self._db.add(row)
try:
await self._db.commit()
logger.info("memory: insert_archival user=%s source=%s", user_id, source)
except Exception as exc:
logger.error("memory: insert_archival failed user=%s: %s", user_id, exc)
await self._db.rollback()
async def search_archival(self, user_id: str, query: str, top_k: int = 5) -> list[str]:
"""Search archival memory (keyword fallback; semantic ranking can replace this)."""
fernet = await self._get_fernet(user_id)
if fernet is None:
return []
result = await self._db.execute(
select(MemoryAssociative)
.where(MemoryAssociative.user_id == user_id)
.order_by(MemoryAssociative.updated_at.desc())
.limit(100)
)
rows = result.scalars().all()
needle = query.strip().lower()
out: list[str] = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.content_encrypted)
if plaintext is None:
continue
if not needle or needle in plaintext.lower():
out.append(plaintext)
if len(out) >= max(top_k, 1):
break
logger.info("memory: search_archival user=%s query=%s hits=%d", user_id, query[:80], len(out))
return out
async def search_recall(self, user_id: str, query: str, top_k: int = 5) -> list[str]:
"""Search recall memory (episodic summaries) by keyword."""
fernet = await self._get_fernet(user_id)
if fernet is None:
return []
result = await self._db.execute(
select(MemoryEpisodic)
.where(MemoryEpisodic.user_id == user_id)
.order_by(MemoryEpisodic.created_at.desc())
.limit(100)
)
rows = result.scalars().all()
needle = query.strip().lower()
out: list[str] = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.summary_encrypted)
if plaintext is None:
continue
if not needle or needle in plaintext.lower():
out.append(plaintext)
if len(out) >= max(top_k, 1):
break
logger.info("memory: search_recall user=%s query=%s hits=%d", user_id, query[:80], len(out))
return out
# ── Private helpers ───────────────────────────────────────────────────────
async def _get_fernet(self, user_id: str) -> Fernet | None:
"""Load the user's Fernet key from DB. Returns None if missing."""
result = await self._db.execute(select(User).where(User.id == user_id))
user = result.scalar_one_or_none()
if user is None or not user.encryption_key:
logger.warning("memory: no encryption_key for user=%s", user_id)
return None
return Fernet(user.encryption_key.encode())
async def _get_user_debug(self, user_id: str) -> dict[str, str | None]:
"""Load lightweight user debug fields for trace logs."""
result = await self._db.execute(select(User).where(User.id == user_id))
user = result.scalar_one_or_none()
if user is None:
return {"tier": None}
return {
"tier": user.tier,
}
async def _load_core(self, user_id: str, fernet: Fernet) -> dict[str, str]:
result = await self._db.execute(
select(MemoryCore).where(MemoryCore.user_id == user_id)
)
rows = result.scalars().all()
out: dict[str, str] = {}
for row in rows:
plaintext = _safe_decrypt(fernet, row.value_encrypted)
if plaintext is not None:
out[row.key] = plaintext
return out
async def _load_associative(
self, user_id: str, message: str, fernet: Fernet, *, user_tier: str = "free"
) -> list[str]:
"""Load top-k associative memories.
Pro+: pgvector cosine similarity on the message embedding (real_embeddings feature).
Free / embedding failure: keyword-ordered fallback (most recent rows).
"""
from app.billing.tier_manager import tier_manager # noqa: PLC0415
from app.core.embeddings import embed_text # noqa: PLC0415
if tier_manager.check_feature(user_tier, "real_embeddings"):
vec = await embed_text(message)
if vec is not None:
try:
result = await self._db.execute(
select(MemoryAssociative)
.where(
MemoryAssociative.user_id == user_id,
MemoryAssociative.embedding.isnot(None),
)
.order_by(MemoryAssociative.embedding.cosine_distance(vec))
.limit(_ASSOCIATIVE_TOP_K)
)
rows = result.scalars().all()
out: list[str] = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.content_encrypted)
if plaintext is not None:
out.append(plaintext)
logger.info(
"memory: _load_associative user=%s mode=vector hits=%d",
user_id,
len(out),
)
return out
except Exception as exc:
logger.warning(
"memory: vector search failed user=%s, falling back to keyword: %s",
user_id,
exc,
)
# Keyword fallback: most recent rows
result = await self._db.execute(
select(MemoryAssociative)
.where(MemoryAssociative.user_id == user_id)
.order_by(MemoryAssociative.updated_at.desc())
.limit(_ASSOCIATIVE_TOP_K)
)
rows = result.scalars().all()
out = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.content_encrypted)
if plaintext is not None:
out.append(plaintext)
return out
async def _load_episodic(
self,
user_id: str,
fernet: Fernet,
session_id: str | None = None,
) -> list[str]:
query = select(MemoryEpisodic).where(MemoryEpisodic.user_id == user_id)
if session_id:
query = query.where(MemoryEpisodic.session_id == session_id)
result = await self._db.execute(
query
.order_by(MemoryEpisodic.created_at.desc())
.limit(_EPISODIC_RECENT_N)
)
rows = result.scalars().all()
out: list[str] = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.summary_encrypted)
if plaintext is not None:
out.append(plaintext)
return out
async def _load_proactive(self, user_id: str, fernet: Fernet) -> list[str]:
result = await self._db.execute(
select(MemoryProactive)
.where(
MemoryProactive.user_id == user_id,
MemoryProactive.confidence >= _PROACTIVE_CONFIDENCE_THRESHOLD,
)
.order_by(MemoryProactive.confidence.desc())
)
rows = result.scalars().all()
out: list[str] = []
for row in rows:
plaintext = _safe_decrypt(fernet, row.pattern_encrypted)
if plaintext is not None:
out.append(plaintext)
return out
# ── Encryption helpers ────────────────────────────────────────────────────────
def _encrypt(fernet: Fernet, plaintext: str) -> str:
return fernet.encrypt(plaintext.encode()).decode()
def _safe_decrypt(fernet: Fernet, ciphertext: str) -> str | None:
"""Decrypt and return plaintext, or None on error (corrupted/wrong key)."""
try:
return fernet.decrypt(ciphertext.encode()).decode()
except (InvalidToken, Exception) as exc:
logger.warning("memory: decrypt failed: %s", exc)
return None