Anubis.Transport behaviour
(anubis_mcp v1.0.0)
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Functional behaviour for MCP transport implementations.
Unlike Anubis.Transport.Behaviour (which defines a GenServer-oriented transport
interface), this behaviour defines a functional transport interface for
parsing, encoding, sending messages, and extracting metadata.
Transport modules implementing this behaviour provide pure functions for message framing — the actual I/O process (Port, Plug conn, SSE handler) already exists and calls these functions internally.
Adapters
Anubis.Transport.STDIO— newline-delimited JSON over stdin/stdout (client)Anubis.Transport.StreamableHTTP— JSON over HTTP request/response bodies (client)Anubis.Transport.SSE— JSON wrapped in SSE event format (client)
Example
{:ok, state} = MyTransport.transport_init(opts)
{:ok, message, state} = MyTransport.parse(raw_data, state)
{:ok, encoded, state} = MyTransport.encode(response, state)Summary
Callbacks
Encode an MCP message map for this transport's wire format.
Extract transport-specific metadata from raw input.
Parse raw input into decoded MCP message(s).
Initialize transport-specific state (parse options, configure connection).
Types
Callbacks
@callback encode(message :: map(), transport_state()) :: {:ok, raw_message(), transport_state()} | {:error, term()}
Encode an MCP message map for this transport's wire format.
Returns the encoded binary ready to be sent.
@callback extract_metadata(raw_input :: term(), transport_state()) :: map()
Extract transport-specific metadata from raw input.
For HTTP, this extracts session_id from headers, request context, etc. For STDIO, this returns basic process metadata.
@callback parse(raw_message() | map(), transport_state()) :: {:ok, [map()], transport_state()} | {:error, term()}
Parse raw input into decoded MCP message(s).
For STDIO, raw input is newline-delimited JSON. For HTTP, raw input is a JSON body string or already-parsed map. For SSE, raw input is SSE event data.
@callback transport_init(keyword()) :: {:ok, transport_state()} | {:error, term()}
Initialize transport-specific state (parse options, configure connection).