A2A Protocol alternatives
6 agents tools in the same lane as A2A Protocol, ranked by editorial score.
MC
Model Context Protocol
Agents · Model-agnostic
7.4
Open standard that lets AI apps plug into data sources, tools, and workflows like USB-C for LLMs.
Free· Free and open source (MIT)agent-toolingide-integrations
OA
OpenAI Agents SDK (Python)
Agents · GPT-4o / GPT-4.1 / gpt-realtime (provider-pluggable via LiteLLM)
A lightweight Python framework for building multi-agent LLM applications with handoffs, guardrails, and built-in tracing.
Free· SDK is free and open source (MIT-licensed). Cost is pass-through to whichever model provider you point it at — OpenAI API pricing applies when using GPT models; third-party providers billed separately.Multi-agent customer support with specialist handoffsVoice agents using gpt-realtime for phone or in-app calls
EL
ElizaOS
Agents · Multi-model (BYO via plugins)
7.1
Open-source agentic OS for building and orchestrating multi-agent swarms across Discord, Telegram, X, and onchain.
Free· Free, open-source (self-hosted); bring your own model API keysmulti-agent-swarmssocial-bots
GA
Guild AI
Agents · Multi-model (bring your own)
6.9
Control plane for deploying, governing, and auditing AI agents in production.
Freemium· Free: $0 · Individual: $20 · Team: $200 · Enterprise: Contact usagent deploymentagent governance
AU
AutoGPT
Agents · BYO (Claude / GPT / open)
7.5
Open-source platform for building autonomous AI agents.
Free· Free / open-source; hosted platform paidautonomous agentstask automation
PL
Plano
Agents · Multi-model
7.2
Envoy-based data plane for AI agents that handles routing, guardrails, and observability outside your app code.
Free· Open source; commercial pricing not disclosedagent-orchestrationllm-routing