// Query and invoke tools on MCP servers using fastmcp list and fastmcp call. Use when you need to discover what tools a server offers, call tools, or integrate MCP servers into workflows.
Review an incoming external issue (and any gated-closed PR behind it) and decide whether to assign the contributor or decline. Use when the maintainer says "look at this issue", "review issue
Monitor and respond to automated PR reviews (Codex bot). Use when pushing a PR, checking review status, or responding to bot feedback. Handles the full cycle of push -> wait for review -> evaluate comments -> fix -> re-push.
Review code for quality, maintainability, and correctness. Use when reviewing pull requests, evaluating code changes, or providing feedback on implementations. Focuses on API design, patterns, and actionable feedback.
Write and evaluate effective Python tests using pytest. Use when writing tests, reviewing test code, debugging test failures, or improving test coverage. Covers test design, fixtures, parameterization, mocking, and async testing.
| name | fastmcp-client-cli |
| description | Query and invoke tools on MCP servers using fastmcp list and fastmcp call. Use when you need to discover what tools a server offers, call tools, or integrate MCP servers into workflows. |
Use fastmcp list and fastmcp call to interact with any MCP server from the command line.
# Remote server
fastmcp list http://localhost:8000/mcp
# Local Python file (runs via fastmcp run automatically)
fastmcp list server.py
# MCPConfig with multiple servers
fastmcp list mcp.json
# Stdio command (npx, uvx, etc.)
fastmcp list --command 'npx -y @modelcontextprotocol/server-github'
# Include full input/output schemas
fastmcp list server.py --input-schema --output-schema
# Machine-readable JSON
fastmcp list server.py --json
# Include resources and prompts
fastmcp list server.py --resources --prompts
Default output shows tool signatures and descriptions. Use --input-schema or --output-schema to include full JSON schemas, --json for structured output.
# Key=value arguments (auto-coerced to correct types)
fastmcp call server.py greet name=World
fastmcp call server.py add a=3 b=4
# Single JSON object for complex/nested args
fastmcp call server.py create_item '{"name": "Widget", "tags": ["a", "b"]}'
# --input-json with key=value overrides
fastmcp call server.py search --input-json '{"query": "hello", "limit": 5}' limit=10
# JSON output for scripting
fastmcp call server.py add a=3 b=4 --json
Type coercion is automatic: limit=5 becomes an integer, verbose=true becomes a boolean, based on the tool's input schema.
All commands accept the same server targets:
| Target | Example |
|---|---|
| HTTP/HTTPS URL | http://localhost:8000/mcp |
| Python file | server.py |
| MCPConfig JSON | mcp.json (must have mcpServers key) |
| Stdio command | --command 'npx -y @mcp/server' |
| Discovered name | weather or source:name |
Servers configured in editor configs (Claude Desktop, Claude Code, Cursor, Gemini CLI, Goose) or project-level mcp.json can be referenced by name. Use source:name (e.g. claude-code:my-server, cursor:weather) to target a specific source. Run fastmcp discover to see available names.
For SSE servers, pass --transport sse:
fastmcp list http://localhost:8000/mcp --transport sse
HTTP targets automatically use OAuth (no-ops if the server doesn't require auth). Disable with --auth none:
fastmcp call http://server/mcp tool --auth none
# See all MCP servers in editor/project configs
fastmcp discover
# Filter by source
fastmcp discover --source claude-code
# JSON output
fastmcp discover --json
Scans Claude Desktop, Claude Code, Cursor, Gemini CLI, Goose, and ./mcp.json. Sources: claude-desktop, claude-code, cursor, gemini, goose, project.
Discover tools first, then call them:
# 1. See what servers are configured
fastmcp discover
# 2. See what tools a server has
fastmcp list weather
# 3. Call a tool
fastmcp call weather get_forecast city=London
If you call a nonexistent tool, FastMCP suggests close matches.