---
title: "A2A Jsonrpc"
method: POST
path: "/api/v1/a2a/{flow_id}/jsonrpc"
tags: ["a2a"]
---

# A2A Jsonrpc

`POST /api/v1/a2a/{flow_id}/jsonrpc`

Serve the A2A JSON-RPC surface (message/send, message/stream, tasks/get, tasks/resubscribe) for an agent flow.

Gated like the card route; apikey-folder flows additionally require a valid owner
key (401). The flow runs as its owner. Returns the SDK's JSON-RPC response (HTTP 200
even for JSON-RPC-level errors). No ``DbSession`` dependency here: holding a session
open across the run would fight the v2 surface's lock-avoidance design, and the
gate/run resolve from flow_id via short self-managed sessions.

## Path parameters

- `flow_id` string, uuid, required

## Response `200`

Successful Response

- unknown

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.net/langflow-ai/apis/langflow.md) · [All operations](https://skmtc.net/langflow-ai/apis/langflow/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/langflow-ai/langflow/revisions/22962dc5e81b/schema)