harness-sdk

Composio creates a separate session for each user and gives an agent runtime access to app authentication, tool discovery, and execution without loading hundreds of definitions into context. It offers TypeScript and Python SDKs, a CLI, framework adapters, and hosted MCP endpoints for more than 1,000 app toolkits. Setup requires a Composio API key and the relevant connected user accounts.

Semantic Kernel is a model-agnostic SDK for building, orchestrating, and deploying AI agents and multi-agent systems across Python, .NET, and Java. It supports multiple model providers, plugins, structured workflows, and vector-database integrations. The project now identifies Microsoft Agent Framework as its successor and provides a migration guide, which is relevant when maintaining or starting an application.

OpenAI Agents SDK lets Python developers define agents with instructions, tools, guardrails, and delegation between specialized workers. It includes session history, human approval points, tracing, sandboxed long-running agents, and realtime voice support. The framework can use OpenAI APIs or other supported model providers and requires Python 3.10 or newer.

Claude Agent SDK for Python exposes an async query function and ClaudeSDKClient for bidirectional, interactive conversations with Claude Code. Custom tools and hooks can run as in-process MCP servers, while external MCP servers can be used alongside them. The package bundles the Claude Code CLI by default, requires Python 3.10 or newer, and allows a custom CLI path.