---
title: "Open an MCP server-to-client event stream"
method: GET
path: "/mcp"
tags: ["mcp"]
---

# Open an MCP server-to-client event stream

`GET /mcp`

Opens the optional Streamable HTTP GET channel for server-initiated MCP messages on an existing session.

## Headers

- `Mcp-Session-Id` string

## Response `200`

Server-sent event stream.

## Other responses

- `401` — Missing, expired, or revoked credential. The WWW-Authenticate header points at the RFC 9728 protected resource metadata to bootstrap OAuth discovery.

---

[API](https://skmtc.dev/superset/apis/superset-api.md) · [All operations](https://skmtc.dev/superset/apis/superset-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/superset/superset-api/revisions/dee6e20fae0d/schema)