Low-level smoke mode

If you want raw MCP protocol checks without an LLM, use:

mcp-smoke-agent smoke [flags]

No API key is needed. The command initializes MCP, lists the server's capabilities, and can optionally call tools, prompts or resources directly.

Examples

mcp-smoke-agent smoke --transport=http --url http://localhost:3000/mcp
mcp-smoke-agent smoke --transport=stdio --command ./your-mcp-server -- <args>

Arguments after -- are passed to the stdio command.

What it checks

Each list step runs only if the server advertised that capability during initialize; otherwise the step is recorded as skipped, which counts as passing. Unless --no-call is set, the command then exercises one tool, one prompt and one resource:

• Tool: the one named by --tool-name, or else the first tool whose required arguments are all present in --tool-args. If --tool-name is given but required arguments are missing, the step fails. If no tool matches, the step is skipped.
• Prompt: chosen the same way from --prompt-name and --prompt-args.
• Resource: --resource-uri, or else the first listed resource.

Flags

Flag	Default	Description
--transport		stdio or http. Inferred from --url or --command when omitted.
--url		Streamable HTTP endpoint URL.
--command		Stdio command to run.
--timeout	15s	Timeout per request.
--no-call	false	Skip the tool, prompt and resource calls.
--protocol	2025-06-18	MCP protocol version the client announces.
--tool-name		Tool to call.
--tool-args	{}	JSON object passed to tools/call.
--prompt-name		Prompt to get.
--prompt-args	{}	JSON object passed to prompts/get.
--resource-uri		Resource URI to read.

The report

The command prints one JSON document to stdout:

Field	Meaning
ok	true when every step passed or was skipped.
transport, url, command, args	How the server was reached.
protocol_version	The protocol version the server returned from initialize.
capabilities	The capabilities the server advertised.
steps	One entry per step: name, ok, skipped, duration_ms, error and detail.
started_at, finished_at, duration_ms	Timing for the whole run.

Step names are initialize, tools/list, prompts/list, resources/list, tools/call, prompts/get and resources/read. If the client cannot even start, the report contains a single startup step with the error.

Exit codes

Exit code	Meaning
0	ok is true.
1	At least one step failed, or the client could not start.
2	Invalid flags.

That makes smoke mode easy to use in CI: the exit code gates the job and the JSON explains failures.