CLI tool for exploring MCP servers
Install this tool using pip:
pip install mcp-explorerList the tools exposed by a streamable HTTP MCP server:
mcp-explorer list https://agentic-mermaid.dev/mcpThe default output is deliberately compact: each tool is shown as a signature and a one-line description. Use -N or --no-truncate for full descriptions and detailed parameter metadata:
mcp-explorer list -N https://agentic-mermaid.dev/mcpThis forces the current MCP 2 stateless protocol by default. Use --legacy to force the older initialize-handshake protocol instead:
mcp-explorer list https://agentic-mermaid.dev/mcp --legacyUse --json to output the complete tool definitions, including their input schemas:
mcp-explorer list https://agentic-mermaid.dev/mcp --jsonInspect a single tool in detail:
mcp-explorer inspect https://agentic-mermaid.dev/mcp render_svgThis displays the tool's complete description, nested input and output schemas, annotations, execution metadata, icons, and _meta. Use --json for the complete tool definition as a single JSON object:
mcp-explorer inspect https://agentic-mermaid.dev/mcp render_svg --jsonCall a tool by passing its arguments as a JSON object:
mcp-explorer call \
https://agentic-mermaid.dev/mcp \
verify \
'{"source":"graph TD; A-->B"}'Alternatively, use repeatable -a/--argument NAME VALUE options:
mcp-explorer call \
https://agentic-mermaid.dev/mcp \
render_svg \
-a source 'graph TD; A-->B' \
-a options '{"padding":24}'Use - to read the raw JSON object from standard input:
mcp-explorer call URL TOOL - < arguments.jsonWhen raw JSON and -a are combined, individual arguments override matching top-level keys in the JSON object and later -a values win. Values are interpreted using the tool's input schema: strings remain literal, while numbers, booleans, arrays, objects, and null are parsed as JSON. The assembled arguments are validated against the input schema before the tool is called.
Use --json to print the tool's structuredContent as JSON. If the result has no structured content, this falls back to printing the first text content block:
mcp-explorer call \
https://datasette.simonwillison.net/-/mcp \
execute_sql \
-a database simonwillisonblog \
-a sql 'select count(*) from blog_entry' \
--jsonUse --raw for the complete MCP CallToolResult as JSON:
mcp-explorer call URL TOOL -a name value --rawList every prompt exposed by a server:
mcp-explorer prompts URL
mcp-explorer prompts URL --json
mcp-explorer prompts URL --legacyThe human-readable output includes prompt arguments and whether each is required. JSON output contains the complete prompt definitions.
List every directly-addressable resource exposed by a server:
mcp-explorer resources URL
mcp-explorer resources URL --json
mcp-explorer resources URL --legacyThe human-readable output includes each resource URI, MIME type, size, and description when available. Both commands follow pagination until all results have been collected.
Use info to show the selected protocol, negotiation mechanism, supported versions, server identity, capabilities, and instructions:
mcp-explorer info https://agentic-mermaid.dev/mcp
mcp-explorer info https://agentic-mermaid.dev/mcp --jsonUse doctor to check both stateless and legacy compatibility. The selected mode is checked first and determines the exit status:
mcp-explorer doctor https://agentic-mermaid.dev/mcp
mcp-explorer doctor https://agentic-mermaid.dev/mcp --legacyEvery command accepts --json and --stateless/--legacy. These options can appear anywhere after the command name. The call command also accepts --raw.
For help, run:
mcp-explorer --helpYou can also use:
python -m mcp_explorer --helpTo contribute to this tool, first checkout the code. Run the tests like this:
cd mcp-explorer
uv run pytestAnd the development version of the tool like this:
uv run mcp-explorer --helpTo update the --help reference in the README:
uv run cog -r README.mdUsage: mcp-explorer list [OPTIONS] URL
List the tools exposed by an MCP server at URL.
Options:
-N, --no-truncate Show full descriptions and detailed parameters.
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
Usage: mcp-explorer prompts [OPTIONS] URL
List the prompts exposed by an MCP server at URL.
Options:
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
Usage: mcp-explorer resources [OPTIONS] URL
List the resources exposed by an MCP server at URL.
Options:
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
Usage: mcp-explorer inspect [OPTIONS] URL TOOL_NAME
Inspect one tool exposed by an MCP server at URL.
Options:
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
Usage: mcp-explorer call [OPTIONS] URL TOOL_NAME [ARGUMENTS_JSON]
Call a tool with optional JSON and individual arguments.
Options:
-a, --argument NAME VALUE Set one tool argument; repeat for multiple
arguments.
--raw Output the complete MCP CallToolResult as JSON.
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
Usage: mcp-explorer info [OPTIONS] URL
Show protocol and metadata for an MCP server at URL.
Options:
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
Usage: mcp-explorer doctor [OPTIONS] URL
Check stateless and legacy compatibility for an MCP server at URL.
Options:
--json Output JSON.
--stateless / --legacy Force stateless MCP 2 (default) or the legacy
initialize handshake.
--help Show this message and exit.
