# Agent2Agent Protocol (A2A) vs Coral Protocol (CoralOS)

The map lists them as complementary: sites and agents commonly implement both.

[6 Coordinate](/category/coordinate/) [Agent2Agent Protocol](/protocols/a2a/) · [6 Coordinate](/category/coordinate/) [Coral Protocol (CoralOS)](/protocols/coral-protocol/)

|  | [Agent2Agent Protocol](/protocols/a2a/) A2A | [Coral Protocol (CoralOS)](/protocols/coral-protocol/) Coral |
| --- | --- | --- |
| Lifecycle step | 6 Coordinate: Talk to another agent | 6 Coordinate: Talk to another agent |
| Answers | How do two independent agents, built on different frameworks, discover each other and delegate a task to completion? | How do independently-built agents from a public marketplace get orchestrated together into one multi-agent system, with privacy isolation and built-in payment budgets, on top of MCP? |
| Governed by | Linux Foundation (Technical Steering Committee: AWS, Cisco, Google, IBM Research, Microsoft, Salesforce, SAP, ServiceNow); Agentic AI Foundation (AAIF) since 17 August 2026 | Single company/startup-led open-source project (GitHub org Coral-Protocol); rebranded 'CoralOS' as of this check (docs moved from docs.coralprotocol.org to docs.coralos.ai); not a multi-stakeholder standards body |
| Status (issuer's words) | Stable, v1.0.1 | "Kubernetes for AI agents: a platform for everything between your agents and production — registry, runtimes, security, and orchestration" (current docs homepage); described elsewhere as a 'decentralized protocol powering AI agent collaboration, trust, and payments' |
| Version | 1.0.1 (2026-05-28) | unversioned, continuously updated platform (Coral Server, Coralizer, Marketplace) |
| Form / transport | endpoint | endpoint |
| Found at | /.well-known/agent-card.json | Agents are discovered via the centralized Coral Marketplace (publish/discover/monetize with built-in attestation); a local Coral Server also exposes a session-creation API for orchestrating a given agent graph; MCP is used as the underlying inter-agent transport for 'coralized' agents |
| Implementation | multi-implementation — 150+ supporting organizations, claimed by the Linux Foundation on 9 April 2026 (https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year). Card-version censuses are separate measurements, kept with their frames and not averaged. Agenstry 2026-09-01 (https://agenstry.com/blog/state-of-the-agent-card): of 1,910 cards declaring protocolVersion, 65.5% (1,252) are 0.3.x and 25.5% (488) are 1.0.x. Emissar 2026-10-02 (https://emissar.ai/learn/a2a-adoption-2026): 276 cards on the Tranco top 1M (205 in v1.0 shape, 71 in v0.3 shape, 0 signed, 0 in the top 1,000 domains). APIs.io / Kin Lane 2026-09-21 (https://apievangelist.com/2026/09/21/a2a-adoption-is-421-of-27840-and-most-of-them-arrived-with-the-card/): 421 parseable cards out of 4,718 hosts probed (27,840 providers). rStation 2026-10-12 (https://rstation.ai/problems/ai_agent/papers/1): 661 cards on 2,164 x402 seller hosts (189 pass their attributed version and fail a check that assumes 1.0). | shipping |
| Evidence | 11 verified, 2 reported | 2 verified |
| Primary use case | Let agents talk to other agents | Let agents talk to other agents |
| Last verified | 2026-10-23 (current) | 2026-10-23 (current) |
| Specification | [https://a2a-protocol.org/latest/specification/](https://a2a-protocol.org/latest/specification/) | [https://docs.coralos.ai/welcome](https://docs.coralos.ai/welcome) |

## When to use which

- Choose Agent2Agent Protocol when your question is “How do two independent agents, built on different frameworks, discover each other and delegate a task to completion?” and you accept its maturity: status "Stable, v1.0.1", implementation multi-implementation (150+ supporting organizations, claimed by the Linux Foundation on 9 April 2026 (https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year). Card-version censuses are separate measurements, kept with their frames and not averaged. Agenstry 2026-09-01 (https://agenstry.com/blog/state-of-the-agent-card): of 1,910 cards declaring protocolVersion, 65.5% (1,252) are 0.3.x and 25.5% (488) are 1.0.x. Emissar 2026-10-02 (https://emissar.ai/learn/a2a-adoption-2026): 276 cards on the Tranco top 1M (205 in v1.0 shape, 71 in v0.3 shape, 0 signed, 0 in the top 1,000 domains). APIs.io / Kin Lane 2026-09-21 (https://apievangelist.com/2026/09/21/a2a-adoption-is-421-of-27840-and-most-of-them-arrived-with-the-card/): 421 parseable cards out of 4,718 hosts probed (27,840 providers). rStation 2026-10-12 (https://rstation.ai/problems/ai_agent/papers/1): 661 cards on 2,164 x402 seller hosts (189 pass their attributed version and fail a check that assumes 1.0).).
- Choose Coral Protocol (CoralOS) when your question is “How do independently-built agents from a public marketplace get orchestrated together into one multi-agent system, with privacy isolation and built-in payment budgets, on top of MCP?” and you accept its maturity: status ""Kubernetes for AI agents: a platform for everything between your agents and production — registry, runtimes, security, and orchestration" (current docs homepage); described elsewhere as a 'decentralized protocol powering AI agent collaboration, trust, and payments'", implementation shipping.

Guidance is derived from the two records (question, status, implementation, prerequisites, pairings), not from opinion. Each record's page carries its numbered references.

## Read the full articles

- [Agent2Agent Protocol](/protocols/a2a/): How do two independent agents, built on different frameworks, discover each other and delegate a task to completion?
- [Coral Protocol (CoralOS)](/protocols/coral-protocol/): How do independently-built agents from a public marketplace get orchestrated together into one multi-agent system, with privacy isolation and built-in payment budgets, on top of MCP?

Ask the MCP server to compare any two: the compare-protocols prompt, or get on both ids. [Connect](/connect/).

[a2a.json](/data/protocols/a2a.json) · [coral-protocol.json](/data/protocols/coral-protocol.json) · [Markdown](/compare/a2a-vs-coral-protocol/index.md)