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

# Connect via legacy SSE transport

> Opens a server-sent event stream using the legacy MCP SSE transport.

Deprecated — prefer the Streamable HTTP transport (`POST /mcp`).

The stream stays open until the session closes or the client disconnects.

Requires OAuth authentication.



## OpenAPI

````yaml get /mcp/sse
openapi: 3.1.0
info:
  title: HERO API
  version: current
  description: |-
    The HERO REST API.

    See https://developers.myhero.so for the rendered docs.
servers:
  - url: https://app.myhero.so
security: []
paths:
  /mcp/sse:
    get:
      tags:
        - MCP
      summary: Connect via legacy SSE transport
      description: >-
        Opens a server-sent event stream using the legacy MCP SSE transport.


        Deprecated — prefer the Streamable HTTP transport (`POST /mcp`).


        The stream stays open until the session closes or the client
        disconnects.


        Requires OAuth authentication.
      operationId: mcpSseConnect
      responses:
        '200':
          description: SSE stream — keeps open until the MCP session closes.
          content:
            text/event-stream:
              schema:
                type: string
        '401':
          description: OAuth token missing or invalid.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                    description: |-
                      Error class name (e.g.

                      ValidationError, NotFound)
                  message:
                    type: string
                    description: Human-readable error message
                  details:
                    type: array
                    items: {}
                required:
                  - error
                  - message
      security:
        - oauth2: []
components:
  securitySchemes:
    oauth2:
      type: oauth2
      flows:
        authorizationCode:
          authorizationUrl: https://app.myhero.so/oauth/authorize
          tokenUrl: https://app.myhero.so/oauth/token
          scopes: {}

````