MemGPT/letta/schemas/memory.py
2025-01-22 19:04:40 -08:00

238 lines
10 KiB
Python

from typing import TYPE_CHECKING, List, Optional
from jinja2 import Template, TemplateSyntaxError
from pydantic import BaseModel, Field
# Forward referencing to avoid circular import with Agent -> Memory -> Agent
if TYPE_CHECKING:
pass
from openai.types.beta.function_tool import FunctionTool as OpenAITool
from letta.constants import CORE_MEMORY_BLOCK_CHAR_LIMIT
from letta.schemas.block import Block
from letta.schemas.message import Message
class ContextWindowOverview(BaseModel):
"""
Overview of the context window, including the number of messages and tokens.
"""
# top-level information
context_window_size_max: int = Field(..., description="The maximum amount of tokens the context window can hold.")
context_window_size_current: int = Field(..., description="The current number of tokens in the context window.")
# context window breakdown (in messages)
# (technically not in the context window, but useful to know)
num_messages: int = Field(..., description="The number of messages in the context window.")
num_archival_memory: int = Field(..., description="The number of messages in the archival memory.")
num_recall_memory: int = Field(..., description="The number of messages in the recall memory.")
num_tokens_external_memory_summary: int = Field(
..., description="The number of tokens in the external memory summary (archival + recall metadata)."
)
external_memory_summary: str = Field(
..., description="The metadata summary of the external memory sources (archival + recall metadata)."
)
# context window breakdown (in tokens)
# this should all add up to context_window_size_current
num_tokens_system: int = Field(..., description="The number of tokens in the system prompt.")
system_prompt: str = Field(..., description="The content of the system prompt.")
num_tokens_core_memory: int = Field(..., description="The number of tokens in the core memory.")
core_memory: str = Field(..., description="The content of the core memory.")
num_tokens_summary_memory: int = Field(..., description="The number of tokens in the summary memory.")
summary_memory: Optional[str] = Field(None, description="The content of the summary memory.")
num_tokens_functions_definitions: int = Field(..., description="The number of tokens in the functions definitions.")
functions_definitions: Optional[List[OpenAITool]] = Field(..., description="The content of the functions definitions.")
num_tokens_messages: int = Field(..., description="The number of tokens in the messages list.")
# TODO make list of messages?
# messages: List[dict] = Field(..., description="The messages in the context window.")
messages: List[Message] = Field(..., description="The messages in the context window.")
class Memory(BaseModel, validate_assignment=True):
"""
Represents the in-context memory (i.e. Core memory) of the agent. This includes both the `Block` objects (labelled by sections), as well as tools to edit the blocks.
"""
# Memory.block contains the list of memory blocks in the core memory
blocks: List[Block] = Field(..., description="Memory blocks contained in the agent's in-context memory")
# Memory.template is a Jinja2 template for compiling memory module into a prompt string.
prompt_template: str = Field(
default="{% for block in blocks %}"
'<{{ block.label }} characters="{{ block.value|length }}/{{ block.limit }}">\n'
"{{ block.value }}\n"
"</{{ block.label }}>"
"{% if not loop.last %}\n{% endif %}"
"{% endfor %}",
description="Jinja2 template for compiling memory blocks into a prompt string",
)
def get_prompt_template(self) -> str:
"""Return the current Jinja2 template string."""
return str(self.prompt_template)
def set_prompt_template(self, prompt_template: str):
"""
Set a new Jinja2 template string.
Validates the template syntax and compatibility with current memory structure.
"""
try:
# Validate Jinja2 syntax
Template(prompt_template)
# Validate compatibility with current memory structure
Template(prompt_template).render(blocks=self.blocks)
# If we get here, the template is valid and compatible
self.prompt_template = prompt_template
except TemplateSyntaxError as e:
raise ValueError(f"Invalid Jinja2 template syntax: {str(e)}")
except Exception as e:
raise ValueError(f"Prompt template is not compatible with current memory structure: {str(e)}")
def compile(self) -> str:
"""Generate a string representation of the memory in-context using the Jinja2 template"""
template = Template(self.prompt_template)
return template.render(blocks=self.blocks)
def list_block_labels(self) -> List[str]:
"""Return a list of the block names held inside the memory object"""
# return list(self.memory.keys())
return [block.label for block in self.blocks]
# TODO: these should actually be label, not name
def get_block(self, label: str) -> Block:
"""Correct way to index into the memory.memory field, returns a Block"""
keys = []
for block in self.blocks:
if block.label == label:
return block
keys.append(block.label)
raise KeyError(f"Block field {label} does not exist (available sections = {', '.join(keys)})")
def get_blocks(self) -> List[Block]:
"""Return a list of the blocks held inside the memory object"""
# return list(self.memory.values())
return self.blocks
def set_block(self, block: Block):
"""Set a block in the memory object"""
for i, b in enumerate(self.blocks):
if b.label == block.label:
self.blocks[i] = block
return
self.blocks.append(block)
def update_block_value(self, label: str, value: str):
"""Update the value of a block"""
if not isinstance(value, str):
raise ValueError(f"Provided value must be a string")
for block in self.blocks:
if block.label == label:
block.value = value
return
raise ValueError(f"Block with label {label} does not exist")
# TODO: ideally this is refactored into ChatMemory and the subclasses are given more specific names.
class BasicBlockMemory(Memory):
"""
BasicBlockMemory is a basic implemention of the Memory class, which takes in a list of blocks and links them to the memory object. These are editable by the agent via the core memory functions.
Attributes:
memory (Dict[str, Block]): Mapping from memory block section to memory block.
Methods:
core_memory_append: Append to the contents of core memory.
core_memory_replace: Replace the contents of core memory.
"""
def __init__(self, blocks: List[Block] = []):
"""
Initialize the BasicBlockMemory object with a list of pre-defined blocks.
Args:
blocks (List[Block]): List of blocks to be linked to the memory object.
"""
super().__init__(blocks=blocks)
def core_memory_append(agent_state: "AgentState", label: str, content: str) -> Optional[str]: # type: ignore
"""
Append to the contents of core memory.
Args:
label (str): Section of the memory to be edited (persona or human).
content (str): Content to write to the memory. All unicode (including emojis) are supported.
Returns:
Optional[str]: None is always returned as this function does not produce a response.
"""
current_value = str(agent_state.memory.get_block(label).value)
new_value = current_value + "\n" + str(content)
agent_state.memory.update_block_value(label=label, value=new_value)
return None
def core_memory_replace(agent_state: "AgentState", label: str, old_content: str, new_content: str) -> Optional[str]: # type: ignore
"""
Replace the contents of core memory. To delete memories, use an empty string for new_content.
Args:
label (str): Section of the memory to be edited (persona or human).
old_content (str): String to replace. Must be an exact match.
new_content (str): Content to write to the memory. All unicode (including emojis) are supported.
Returns:
Optional[str]: None is always returned as this function does not produce a response.
"""
current_value = str(agent_state.memory.get_block(label).value)
if old_content not in current_value:
raise ValueError(f"Old content '{old_content}' not found in memory block '{label}'")
new_value = current_value.replace(str(old_content), str(new_content))
agent_state.memory.update_block_value(label=label, value=new_value)
return None
class ChatMemory(BasicBlockMemory):
"""
ChatMemory initializes a BaseChatMemory with two default blocks, `human` and `persona`.
"""
def __init__(self, persona: str, human: str, limit: int = CORE_MEMORY_BLOCK_CHAR_LIMIT):
"""
Initialize the ChatMemory object with a persona and human string.
Args:
persona (str): The starter value for the persona block.
human (str): The starter value for the human block.
limit (int): The character limit for each block.
"""
# TODO: Should these be CreateBlocks?
super().__init__(blocks=[Block(value=persona, limit=limit, label="persona"), Block(value=human, limit=limit, label="human")])
class UpdateMemory(BaseModel):
"""Update the memory of the agent"""
class ArchivalMemorySummary(BaseModel):
size: int = Field(..., description="Number of rows in archival memory")
class RecallMemorySummary(BaseModel):
size: int = Field(..., description="Number of rows in recall memory")
class CreateArchivalMemory(BaseModel):
text: str = Field(..., description="Text to write to archival memory.")