> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hyperterse.com/llms.txt
> Use this file to discover all available pages before exploring further.

# A2A transport

> Per-agent A2A HTTP surface in Hyperterse—JSON-RPC, agent card, tasks, and streaming—separate from MCP.

Every agent you define is served at its own route prefix. Clients use JSON-RPC over `POST`, in the A2A (Agent2Agent) style: agent card, messages, tasks, and optional streaming. That is separate from MCP—there are no MCP tool-list or prompt endpoints on these routes. For tools, prompts, and resources, use [MCP transport](/runtime/mcp-transport) at `/mcp`.

<Tip>
  Configuration and permissions live in the agent guides. Start with [Agents
  overview](/agents/overview); for every method and curl example, see [Runtime
  API](/agents/runtime-api).
</Tip>

## How it fits next to MCP

| Surface | Path                 | Role                                                                      |
| ------- | -------------------- | ------------------------------------------------------------------------- |
| MCP     | `/mcp`               | Tools (`search` / `execute`), prompts, resources, completion, MCP session |
| A2A     | `/agent/{agentName}` | Agent card, messaging, tasks, streaming, push config                      |

MCP and A2A share one Hyperterse server and the same tool-access rules for agents, but the protocols and client contracts differ.

## Endpoints

| Endpoint                                         | Method(s) | Purpose                                                |
| ------------------------------------------------ | --------- | ------------------------------------------------------ |
| `/agent/{agentName}/.well-known/agent-card.json` | `GET`     | Public agent card for discovery                        |
| `/agent/{agentName}`                             | `POST`    | A2A JSON-RPC (messages, tasks, streaming, push config) |

Replace `{agentName}` with your agent’s name (see [Agents overview](/agents/overview)).

## What the transport covers

* Discovery — clients fetch the agent card before calling the JSON-RPC endpoint.
* Messaging — `SendMessage` and `SendStreamingMessage` (SSE when using streaming).
* Tasks — create, poll, list, cancel, and subscribe to task updates when responses include trackable work.
* Push — list, create, or delete task push notification configuration when you use those flows.

Method names and payloads match the A2A-style contract in [Runtime API](/agents/runtime-api).

## Protocol

Requests use JSON-RPC 2.0 over HTTP `POST` on `/agent/{agentName}`. The surface is A2A-compatible so standard agent clients can integrate without a custom protocol. For the exact methods Hyperterse exposes, see [Runtime API](/agents/runtime-api).

## Session and reload

* Task state is how you continue work across turns (not a legacy session-only API).
* After a model reload, agent routes match your latest config; see [Runtime API](/agents/runtime-api) for behavior notes.

## CORS

Hyperterse applies CORS on agent routes so browser and cross-origin clients can call them in development. Tighten rules in production like any HTTP API (see [Production hardening](/security/production-hardening)).

## Related docs

* [MCP transport](/runtime/mcp-transport) — Streamable HTTP MCP on `/mcp`
* [Runtime API](/agents/runtime-api) — Full A2A method list and examples
* [Agents overview](/agents/overview) — Declarative agents and routing
* [Tool access](/agents/tool-access) — Which tools an agent may call