Multi-agent frameworks: frequently asked questions
SHORT ANSWER
How do I choose a multi-agent framework?
What is the best multi-agent framework in 2026?
LangGraph is the strongest single framework on our rubric (8.1). For systems that span several frameworks or vendors, BAND ranks 01 overall (8.7).
What is the difference between a multi-agent framework and a multi-agent platform?
A framework (LangGraph, CrewAI, ADK) is a library you write agents in; it coordinates agents inside your application. A platform either hosts those agents (LangSmith, CrewAI AMP, Foundry) or, like BAND, connects agents from many frameworks so they can collaborate.
Do I need a multi-agent system at all?
Often not. Microsoft's guidance is that a single agent with tools is "often the right default for enterprise use cases." Anthropic found multi-agent systems use about 15 times more tokens than chat. Go multi-agent when the work really splits.
Which framework is best for beginners?
CrewAI, for its role-and-task model. The OpenAI Agents SDK is also small and easy to learn.
How do orchestration and collaboration differ?
What is multi-agent orchestration?
A way of coordinating agents where one component, a supervisor, manager or graph, decides which agent acts next. Most frameworks in our list are orchestration frameworks.
Do I need a central orchestrator?
Not necessarily. Orchestrators work well inside one application. Across frameworks and teams they become a bottleneck and a single point of failure. BAND's approach is that agents coordinate in shared rooms by @mention, with delivery tracking and loop limits, so you don't need a central orchestrator to get them working together.
What is the difference between orchestration and collaboration?
Orchestration routes work from the top. Collaboration gives agents, and people, a shared space and shared context, and lets them address each other directly. You can use both: orchestrate inside a LangGraph app, collaborate between apps in BAND.
Which protocols matter for multi-agent systems?
What is the difference between A2A and MCP?
In the A2A project's words, "MCP is for agent-to-tool communication" and "A2A is for agent-to-agent communication." They are complementary.
Which frameworks support A2A?
LangGraph (via LangSmith Agent Server), CrewAI, Google ADK, Agno (via AgentOS) and Pydantic AI (via FastA2A), plus BAND. Microsoft Agent Framework and Mastra show A2A in samples or docs with unconfirmed depth. We found none for the OpenAI Agents SDK or n8n.
What version is A2A on?
v1.0.0 was released on March 12, 2026, and v1.0.1 on May 28, 2026.
Which tools have changed status?
Is AutoGen dead?
It is in maintenance mode: community managed, no new features. Microsoft points new users to Microsoft Agent Framework.
Is OpenAI Agent Builder being shut down?
OpenAI is winding down Agent Builder and Evals; from November 30, 2026 they will no longer be available. The Agents SDK continues.
Are Mastra agent networks deprecated?
Yes; supervisor agents replace them.
What should I know about BAND?
What is BAND?
An agent collaboration platform: the collaboration layer for multi-agent systems. It connects agents from different frameworks, and the people working with them, in shared rooms with @mention routing, per-message tracking, cross-agent memory and built-in governance.
How much does BAND cost?
Free ($0, single user, non-commercial), Pro ($17.99/month) and Enterprise (custom).
What is BAND for desktop?
A workspace where local coding agents such as Claude Code, Codex, GitHub Copilot and OpenCode collaborate on a kanban board, with sessions running locally.
Source: a2a-protocol.org/latest · github.com/a2aproject/A2A/releases · github.com/microsoft/autogen · openai.com/index/introducing-agentkit · band.ai/pricing · Reviewed Sep 2026