# `ConduitMcp.Transport.SSE`
[🔗](https://github.com/nyo16/conduit_mcp/blob/v0.10.1/lib/conduit_mcp/transport/sse.ex#L1)

Server-Sent Events (SSE) transport layer for MCP.

Provides two endpoints:
- GET /sse - Server-Sent Events stream for server-to-client messages
- POST /message - HTTP endpoint for client-to-server messages

## Options

- `:server_module` (required) - The MCP server module to route requests to
- `:cors_origin` - CORS allow-origin header (default: "*")
- `:cors_methods` - CORS allow-methods header (default: "GET, POST, OPTIONS")
- `:cors_headers` - CORS allow-headers header (default: "content-type, authorization")
- `:auth` - Authentication plug configuration (optional)
- `:base_url` - Public base URL advertised in the SSE `endpoint` event
  (e.g. `"https://mcp.example.com"`). Defaults to deriving it from the
  request's `Host` header (sanitized). Set this when running behind a proxy.
- `:allowed_origins` - list of allowed `Origin` header values. Unset means
  no Origin validation (a startup warning is logged) — see
  `ConduitMcp.Plugs.OriginValidation`.

## Example

    {Bandit,
     plug: {ConduitMcp.Transport.SSE,
            server_module: MyApp.MCPServer,
            cors_origin: "https://myapp.com"},
     port: 4001}

## With Authentication

    {Bandit,
     plug: {ConduitMcp.Transport.SSE,
            server_module: MyApp.MCPServer,
            auth: [
              strategy: :bearer_token,
              token: "my-secret-token"
            ]},
     port: 4001}

# `call`

# `init`

---

*Consult [api-reference.md](api-reference.md) for complete listing*