A2A ProtocolA2A Project · agent-communicationvs
AGNTCYAGNTCY · agent-communication
Two Linux-Foundation-era agent protocols. A2A standardizes task exchange and Agent Cards between agents; AGNTCY (Cisco-originated) aims at the whole 'Internet of Agents' stack — directory, SLIM messaging, identity, observability.
agentlist.io · spec diff · verified 2026-09-25 — list prices only, not benchmarks
Spec diff
Pick which
pick A2A Protocol if
You want the protocol with the widest vendor adoption signal (Google, IBM, Microsoft, Salesforce ecosystems) and a narrow, implementable scope.
pick AGNTCY if
You need the fuller stack — discovery directory and messaging fabric, not just a task-exchange schema.
watch out
The two overlap and both are young — expect convergence rather than a clean winner; avoid baking assumptions deep into application code.
Feature notes
- A2A Protocol
- 01Agent Cards for capability discovery
- 02Task lifecycle and artifacts
- 03Streaming updates
- 04Vendor-neutral governance (Linux Foundation)
- 05Composes with MCP
- AGNTCY
- 01Agent directory
- 02SLIM messaging fabric
- 03Identity and badges
- 04Observability SDKs
- 05Linux Foundation project
Frequently asked
A2A Protocol or AGNTCY — which should I pick?
Two Linux-Foundation-era agent protocols. A2A standardizes task exchange and Agent Cards between agents; AGNTCY (Cisco-originated) aims at the whole 'Internet of Agents' stack — directory, SLIM messaging, identity, observability. Pick A2A Protocol if: You want the protocol with the widest vendor adoption signal (Google, IBM, Microsoft, Salesforce ecosystems) and a narrow, implementable scope. Pick AGNTCY if: You need the fuller stack — discovery directory and messaging fabric, not just a task-exchange schema.
Is A2A Protocol or AGNTCY cheaper?
A2A Protocol: Open protocol (free). AGNTCY: Free (OSS, Apache-2.0). List prices as of 2026-09-25; usage pools and seat terms change the real cost.
Does A2A Protocol or AGNTCY run locally?
A2A Protocol hosting: local, cloud. AGNTCY hosting: local, cloud. Interfaces differ too: A2A Protocol exposes api, AGNTCY exposes api.
Are A2A Protocol and AGNTCY still maintained?
A2A Protocol: actively maintained. AGNTCY: actively maintained. Statuses are re-verified each catalog refresh (2026-09-25); see the changelog for the full history.