Stdio transport: fork/exec child, pipe stdin/stdout. More...

#include <entropic/mcp/transport_stdio.h>

Inheritance diagram for entropic::StdioTransport:

Collaboration diagram for entropic::StdioTransport:

Public Member Functions
	StdioTransport (std::string command, std::vector< std::string > args, std::map< std::string, std::string > env={}, uint32_t default_timeout_ms=30000)
	Construct with command, arguments, and environment.

	StdioTransport (std::string display_name, std::string command, std::vector< std::string > args, std::map< std::string, std::string > env, uint32_t default_timeout_ms)
	Construct with a display name for stderr labeling (gh#19).

	~StdioTransport () override
	Destructor — ensures child is cleaned up.

bool	open () override
	Spawn child process and open pipes.

void	close () override
	Send SIGTERM, reap child, close pipes.

std::string	send_request (const std::string &request_json, uint32_t timeout_ms=0) override
	Send JSON-RPC request via stdin, read response from stdout.

bool	is_connected () const override
	Check if child process is alive.

void	interrupt () override
	Abort any blocking read and mark transport uncancellable.

const std::string &	display_name () const
	Get the sanitized display name used for stderr labeling.

Detailed Description

Stdio transport: fork/exec child, pipe stdin/stdout.

JSON-RPC 2.0 over newline-delimited JSON. Child process lifetime tied to transport lifetime (SIGTERM on close, SIGKILL if needed).

Version: 1.8.7

Definition at line 37 of file transport_stdio.h.

Constructor & Destructor Documentation

◆ StdioTransport() [1/2]

entropic::StdioTransport::StdioTransport	(	std::string	command,
		std::vector< std::string >	args,
		std::map< std::string, std::string >	env = `{}`,
		uint32_t	default_timeout_ms = `30000`
	)

Construct with command, arguments, and environment.

Parameters

command	Executable to spawn.
args	Command-line arguments.
env	Environment variable overrides (merged with parent).
default_timeout_ms	Default timeout for send_request (0 = 30s).

Version: 1.8.7

Parameters

command	Executable to spawn.
args	Command-line arguments.
env	Environment variable overrides.
default_timeout_ms	Default request timeout. @dg_internal

Version: 2.1.5-hard

Definition at line 84 of file transport_stdio.cpp.

◆ StdioTransport() [2/2]

entropic::StdioTransport::StdioTransport	(	std::string	display_name,
		std::string	command,
		std::vector< std::string >	args,
		std::map< std::string, std::string >	env,
		uint32_t	default_timeout_ms
	)

Construct with a display name for stderr labeling (gh#19).

Construct with explicit display name (gh#19, v2.1.5).

The display name is used as the bracketed label on every child stderr line, replacing the v2.1.4 behavior of using the resolved spawn command (argv[0]). When multiple servers spawn via the same entrypoint (e.g. /usr/bin/env python), the command-based label collides and consumers cannot tell servers apart. The display name (typically the registered server name) is unique per registration and free of leading slashes, which also avoids Rich BBCode parsing collisions on consumers that pipe stderr through rich.console.print.

Parameters

display_name	Bracketed label used for stderr lines and lifecycle log messages. Should be the server name passed to `entropic_register_mcp_server`.
command	Executable to spawn.
args	Command-line arguments.
env	Environment variable overrides.
default_timeout_ms	Default timeout for send_request.

Version: 2.1.5

Use this overload when registering an MCP server so stderr lines carry the registered server name instead of the resolved spawn command.

Parameters

display_name	Bracketed label for stderr/lifecycle logs.
command	Executable to spawn.
args	Command-line arguments.
env	Environment variable overrides.
default_timeout_ms	Default request timeout. @dg_internal

Version: 2.1.5-hard

Definition at line 110 of file transport_stdio.cpp.

◆ ~StdioTransport()

entropic::StdioTransport::~StdioTransport ( )

override

Destructor — ensures child is cleaned up.

@dg_internal

Version: 1.8.7

Definition at line 128 of file transport_stdio.cpp.

Member Function Documentation

◆ close()

void entropic::StdioTransport::close ( )

overridevirtual

Send SIGTERM, reap child, close pipes.

Version: 1.8.7

@dg_internal

Version: 2.1.5

Implements entropic::Transport.

Definition at line 212 of file transport_stdio.cpp.

◆ display_name()

const std::string & entropic::StdioTransport::display_name ( ) const

inline

Get the sanitized display name used for stderr labeling.

Exposed for unit tests (gh#19) and consumer diagnostics. The value is the bracketed label that appears in log lines from the stderr pump and lifecycle events. Sanitization (leading / stripped, bracket / control chars removed) is applied at construction.

Returns: Reference to the sanitized display name. @utility

Version: 2.1.5

Definition at line 141 of file transport_stdio.h.

◆ interrupt()

void entropic::StdioTransport::interrupt ( )

overridevirtual

Abort any blocking read and mark transport uncancellable.

Cancel any in-flight read by tripping cancel_flag_.

Sets cancel_flag_ which poll_until_ready() checks after every poll tick. The next send_request() returns empty immediately. (P1-10, 2.0.6-rc16)

Version: 2.0.6-rc16

read_line / poll_until_ready short-circuit the next poll tick so the pending send_request returns empty within ~50ms (one poll slice). Subsequent send_request calls also early-exit until the flag is cleared implicitly by a successful open(). (P1-10)

This is what bounds Ctrl+C to ~100ms instead of waiting out a transport timeout.

@req REQ-MCP-025

Version: 2.0.6-rc16

Reimplemented from entropic::Transport.

Definition at line 294 of file transport_stdio.cpp.

◆ is_connected()

bool entropic::StdioTransport::is_connected ( ) const

overridevirtual

Check if child process is alive.

Check if child process is alive via kill(pid, 0).

Returns: true if connected.

Version: 1.8.7

Returns: true if connected. @dg_internal

Version: 1.8.7

Implements entropic::Transport.

Definition at line 270 of file transport_stdio.cpp.

◆ open()

bool entropic::StdioTransport::open ( )

overridevirtual

Spawn child process and open pipes.

Returns: true on success.

Version: 1.8.7

Returns: true on success. @dg_internal

Version: 2.1.5

Implements entropic::Transport.

Definition at line 156 of file transport_stdio.cpp.

◆ send_request()

std::string entropic::StdioTransport::send_request	(	const std::string &	request_json,
		uint32_t	timeout_ms = `0`
	)

overridevirtual

Send JSON-RPC request via stdin, read response from stdout.

Parameters

request_json	JSON-RPC request string.
timeout_ms	Timeout in milliseconds (0 = default).

Returns: JSON-RPC response string, or empty on error/timeout.

Version: 1.8.7

Parameters

request_json	JSON-RPC request string.
timeout_ms	Timeout in ms (0 = the transport's default).

Returns: The child's newline-delimited response line; an empty string when the transport is disconnected, an interrupt is pending, the write failed, or the read timed out — an empty return is what the client turns into a typed error envelope rather than a hang. @req REQ-MCP-025

Version: 2.0.6-rc16

Implements entropic::Transport.

Definition at line 239 of file transport_stdio.cpp.

The documentation for this class was generated from the following files:

entropic/mcp/transport_stdio.h
mcp/transport_stdio.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ StdioTransport() [1/2]

◆ StdioTransport() [2/2]

◆ ~StdioTransport()

Member Function Documentation

◆ close()

◆ display_name()

◆ interrupt()

◆ is_connected()

◆ open()

◆ send_request()