A2A
AI Protocols · Free + paid
Agent-to-Agent protocol by Google for multi-agent interop
At a glance
- Korean
- UI in Korean
- Open source
- Apache-2.0
- GitHub
- 26,141 stars · Apache-2.0
What is A2A?
The Agent2Agent (A2A) protocol is an open protocol that aims to let generative AI agents, built by different companies with different frameworks and running on separate servers, communicate and collaborate effectively as agents rather than as tools. It aims to provide a common language for agents. With A2A, agents can discover each other's capabilities, negotiate how they interact (text, forms, media), and collaborate securely on long-running tasks. They operate without exposing their internal state, memory, or tools. The repository carries an Apache 2.0 license badge and a PyPI a2a-sdk package badge.
- Discover capabilities between agents
- Negotiating interaction modes (text, forms, media)
- Safe collaboration on long-running tasks
- Works without exposing internal state, memory, or tools
- Python SDK (a2a-sdk) distribution
Who uses A2A and for what
- Connecting AI agents from different frameworks, companies, and servers so they can collaborate
Pricing
Open source (free, standard/specification)
Released free as open standards/protocols, implementations distributed as open source
Estimate based on AI knowledge - please verify on the official site
AI tools similar to A2A (alternatives)
A2A vs. alternatives at a glance
| AI | Pricing | Combos on the map | Connected tools | Free | Cheapest monthly | Korean |
|---|---|---|---|---|---|---|
| A2A | Free + paid | 0 | 4 | — | — | Yes |
| ACP | Free + paid | 0 | 4 | — | — | No |
| AGENTS.md | Free | 0 | 4 | — | — | No |
| ANP | Free + paid | 0 | 4 | — | — | No |
| AP2 | Free + paid | 0 | 4 | — | — | Yes |
0 of these 5 tools have a free plan.
Combo and connection counts are based on the relationships recorded on AI Galaxy Map (2026-10-26); they are not a quality ranking.
A2A on AI Galaxy Map
- One of 9 AI tools in the AI Protocols field.
- Connected to 4 other tools — #1 in its field.
Frequently asked questions
Can I use A2A for free?
Open source (free, standard/specification). Prices can change, so check the official site before paying.
What AI can I use instead of A2A?
Tools that do the same job, such as ACP, AGENTS.md, ANP, AP2, are connected to it on the map.
Can I use A2A in Korean?
UI in Korean
Sources (official pages)
Checked on the official pages on 2026-10-14. Prices and features can change, so check the official site again before paying.