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Move From Solver Plugins to Agent Engines

Alpha channel only

The prerelease channel carries this content. A stable or testing install does not have it, and a plain pip install does not get it: the install needs --pre. Read Release Channels before you mix channels.

This page ports a solver plugin to the agent engine classes, and updates a persona file that lists solver plugins. You maintain a solver plugin, or a persona file that names solver plugins. Solver plugins still load and answer, and each solver class logs a deprecation warning. A ChatEngine gets the full message list and the session id, so it can use the persona memory. A QuestionSolver gets only the last question.

Class mapping

Solver base class Agent base class Method to implement
QuestionSolver ChatEngine continue_chat(messages, session_id, lang, units, tools)
ChatMessageSolver ChatEngine continue_chat(messages, session_id, lang, units, tools)
CorpusSolver, QACorpusSolver RetrievalEngine query(query, lang, k)

The solver classes are in ovos_plugin_manager.templates.solvers. The agent classes are in ovos_plugin_manager.templates.agents.

Port a solver

  1. Install the packages:

    pip install --pre ovos-persona ovos-openai-plugin

  2. Run this script. It runs a solver and its port side by side:

    from typing import List, Optional

from ovos_plugin_manager.templates.agents import AgentMessage, ChatEngine, MessageRole
from ovos_plugin_manager.templates.solvers import QuestionSolver


class EchoSolver(QuestionSolver):
    def get_spoken_answer(self, query, lang=None, units=None):
        return f"you said {query}"


class EchoEngine(ChatEngine):
    def continue_chat(self, messages: List[AgentMessage], session_id: str = "default",
                      lang: Optional[str] = None, units: Optional[str] = None,
                      tools=None) -> AgentMessage:
        return AgentMessage(MessageRole.ASSISTANT, f"you said {messages[-1].content}")


print("solver:", EchoSolver().spoken_answer("hello", lang="en-US"))
reply = EchoEngine().continue_chat([AgentMessage(MessageRole.USER, "hello")], session_id="kitchen")
print("engine:", reply.content)

Output of a run, with the log lines shortened:

WARNING - Deprecation version=3.0.0. ... ovos_plugin_manager.templates.solvers has been deprecated and will be removed in the next major release.
WARNING - Deprecation version=3.0.0. ... QuestionSolver has been deprecated and will be removed in the next major release. Please migrate your code to use ChatEngine / RetrievalEngine
solver: you said hello
engine: you said hello

The version in the warning is the next major version of the installed ovos-plugin-manager. It does not state when the class goes away.

Register the engine class under an agent entry point group in pyproject.toml. A chat engine uses opm.agents.chat. A retrieval engine uses opm.agents.retrieval.

Update a persona file

A persona file names plugins by their entry point names. These names belong to no package:

Name that does not load Entry point name
ovos-solver-openai-plugin ovos-chat-openai-plugin
ovos-solver-wikipedia-plugin ovos-wikipedia-plugin
ovos-solver-ddg-plugin ovos-ddg-plugin
ovos-solver-plugin-wolfram-alpha ovos-wolfram-alpha-plugin
ovos-solver-wordnet-plugin ovos-wordnet-plugin

A persona with one unknown or uninstalled name does not load. The log says:

Failed to load '<persona>': '<name>' not installed