MCP vs A2A
Are you exposing a tool, or coordinating work between agents?
MCP connects applications to tools and context. A2A coordinates agents and tasks. A system may use both while leaving commerce and payment semantics to other components. Use your system boundary to make the decision. A catalog lookup tool and a delegated procurement task have different lifecycle, capability and permission needs.
What this establishes
A practical way to inspect evidence and make the next merchant decision.
What it cannot establish
An unresolved dependency remains. Treat affected claims as provisional. Live merchant deployment, private account eligibility, purchase completion or guaranteed AI selection.
The overlap
MCP connects applications to tools and context. A2A coordinates agents and tasks. A system may use both while leaving commerce and payment semantics to other components.
The merchant decision
Use your system boundary to make the decision. A catalog lookup tool and a delegated procurement task have different lifecycle, capability and permission needs.
Where they overlap.
Where they complement.
Compare roles and implementation work. A shared capability does not make two systems interchangeable.
| Decision dimension | MCP | A2A |
|---|---|---|
| Layer | Transport | Agent coordination |
| Role | Provides a way for agent applications to access capabilities and context. | Defines agent capabilities, messages, tasks and cooperation. |
| Status | released | released; source scope conflict |
| Version | 2026-07-28 | 1.0.1 repository release / 1.0.0 specification banner — scope unresolved |
| Discovery | Tools and resources; not a product feed standard | Agent cards and capabilities |
| Checkout | Only when a commerce tool defines it | Application-level responsibility |
| Payment | Not a payment rail | Application-level responsibility |
| Authorization | Protocol authorization is not purchase intent | Security schemes, not blanket purchase authorization |
| Transport | MCP transports and messages | JSON-RPC, HTTP+JSON and gRPC bindings |
| Adoption | Public specification; commerce behavior depends on tools | Released spec; merchant integrations Unknown |
| What it does not solve | Tool connectivity alone does not define checkout semantics or payment authorization. | Does not itself supply a merchant catalog, checkout or payment settlement. |
| Evidence | 2 source record(s) Checked 2026-09-28 live; scope-dependent | 3 source record(s) Checked 2026-09-28 live; scope-dependent |
Unknown ≠ unsupported. Announcements and product documentation are not proof of your live integration.
Overlap and replacement risk
These entries occupy different layers. They can work together; replacing one with another may leave a commerce, communication or authorization gap. Keep your source of product truth, fulfillment responsibility and payment obligations explicit.
Go to the source.
Primary documentation records what is publicly stated. It does not independently prove outcomes or your account’s eligibility.
Claim scope: Tools, resources, prompts and transport
Claim scope: Version metadata and documented changes only; not merchant adoption.
SHA-256 of retrieved source response: 15e2f46e9f080658c5c25a4e4de6661abc9ab2d90ee56f568c9f6b9620fc0230
Claim scope: Agent coordination
Latest released version shown as 1.0.0. Agent card app version is a different field.
Claim scope: Version metadata and documented changes only; not merchant adoption.
SHA-256 of retrieved source response: 2e1ba7bba863623bca20520c60644cb11dc020783b0d0a5eb89e0cc4aea474e3
Claim scope: Version metadata and documented changes only; not merchant adoption.
SHA-256 of retrieved source response: 4805254c10d8cbde59a82f6767598c37b051d7c3cdf9d5ce636dba287cd6ab2b