Best Anthropic Agent SDK Alternatives

Composio connects AI agents to 1,000+ app toolkits with managed auth, delegated user connections, sessions, tool search, MCP gateway support, CLI workflows, and sandboxed workbench execution. It targets developers building Claude, Codex, Cursor, LangChain, CrewAI, OpenAI Agents SDK, and custom agent workflows that need authenticated business actions without hand-rolling every API integration.

Registry and management platform for Model Context Protocol (MCP) servers that helps teams securely discover, install, deploy, and connect MCP servers for AI assistants. Smithery combines a searchable catalog, CLI setup, hosted deployments, namespaces, connection APIs, and scoped service-token flows for clients such as Claude, Cursor, Windsurf, and Codex.

Model Context Protocol (MCP) is Anthropic's open standard that defines how AI models communicate with external tools, resources, and data sources. Provides a universal client-server architecture for connecting LLMs to any API or service through standardized tool definitions, resource access, and prompt templates. Rapidly adopted across the AI industry as the interoperability standard for AI tool integration.