Langchain memory support + ArtifactMemory

[kreneskyp]

Description

Adds general support for Langchain memory classes + adds ArtifactMemory

Memory

All Langchain memory classes that extend BaseMemory should be supported unless they have custom loading requirements. (e. g. BaseChatMemory required a backend loader for persistence storage).

Memory loader will set session_id based on session config for the memory or backend class. Memory may be scoped to chat, agent, task, or user and allows grouping within those scopes. This provides a very flexible system for shared and localized memory.

Example use cases:

• Collective memory within a chat.
• Collective memory of an agent across multiple chats.
• Subgroup of agents within a chat.
• Individual agent memory.
• "short term" task specific memory.

Artifact Memory

Artifact Memory class for loading {artifact} references into the context. The user or a bot may include a reference to a name/key and the memory class will provide it as an input for the chain & prompt template.

Demo of new ChatInput including artifact references

Changes

Chain memory

Chains now support Langchain memory

• added load_memory and load_chat_memory_backend helpers
• added get_memory_session helper for parsing session info out of runtime context
• LLMChain, LLMReply, IXSequence, MapSubchain now support memory.
• LLMChain now filters inputs keys provided by memory out of input_keys to support memory set directly on the chain when used inside a Sequence.

ArtifactMemory

• Implements ArtifactMemory
• Added ArtifactMemory to Coder v1
• Implements Artifact.data for loading artifact content (e.g. from file)
• Implements Artifact.as_memory_text() for rendering artifacts

Chat

• ChatMutation now parses {artifact} references from input into artifact_keys

Misc

• IxCallbackManager now has task_id, chat_id, agent_id, user_id properties
• fake_chat now allows task to be passed by kwarg
• mock_callback_manager now creates a chat if one does not exist

How Tested

• new unit tests covering:
  • loading tools - covers all new memory related loaders
  • ArtifactMemory - full suite
  • IXSequence - full suite
  • MapSubchain - adds coverage for memory
• manual testing with @pirate

TODOs

• test for ChatMutation changes
• need better test coverage for loading memory classes
• need to decide how to handle secrets for loading memory classes
• limit scope of artifact query
• docs