mcpcall

name	mcpcall
description	Call MCP servers from shell commands through the mcpcall CLI over stdio, Streamable HTTP, or legacy SSE. Use when an agent needs to list tools, inspect schemas, read resources/prompts, diagnose endpoints, batch tool calls, or invoke tools on DCC MCP servers such as dcc-mcp-core, dcc-mcp-maya, dcc-mcp-blender, dcc-mcp-3dsmax, or any generic MCP endpoint.

mcpcall

Use mcpcall when the host can run shell commands and should interact with an MCP server without registering that server directly with the agent runtime.

Critical Rules

• Use mcpcall, not mcp; mcp commonly belongs to other MCP tooling.
• Start with mcpcall list before any mcpcall call unless the exact tool name and schema were just shown in the current conversation.
• Use mcpcall resources ... or mcpcall prompts ... when the task is about MCP context primitives instead of executable tools.
• Use mcpcall doctor before debugging flaky endpoint failures.
• Prefer --json when another script or agent step will consume the output.
• Use mcpcall batch when several tool calls should share one MCP session.
• Use mcpcall config discover when the user already has MCP servers registered in Cursor, Claude Code/Desktop, Codex, Windsurf, OpenCode, or VS Code.
• Use mcpcall auth discover for OAuth-backed HTTP servers before guessing token endpoints.
• For DCC scene-mutating tools, inspect the schema first and tell the user which endpoint and tool you are about to call.
• If a DCC host restarts, re-run mcpcall list; old tools or endpoints may be stale.

Quick Start

List tools on a Streamable HTTP MCP endpoint:

mcpcall list --url http://127.0.0.1:8765/mcp
mcpcall list --url http://127.0.0.1:8765/mcp --schema

Use a named server from a config file:

mcpcall config import --from ./mcp.json --output ./mcpcall.json
mcpcall config discover --output ./mcpcall.json --merge
mcpcall list --config ./mcpcall.json --server maya --schema

config discover scans common project and user config paths for Cursor, Claude Code/Desktop, Codex, Windsurf, OpenCode, and VS Code. Config values may use common aliases like baseUrl/serverUrl and environment placeholders such as ${MCP_TOKEN}, ${MCP_TOKEN:-fallback}, or $env:MCP_TOKEN.

Call a tool:

mcpcall call --url http://127.0.0.1:8765/mcp maya_primitives__create_sphere radius=2 name=Ball

Use JSON arguments for complex payloads:

mcpcall call --url http://127.0.0.1:8765/mcp execute_python --args '{"code":"print(\"ok\")"}'

Call several tools over one session:

mcpcall batch --url http://127.0.0.1:8765/mcp --file smoke.json --json

Diagnose endpoint capabilities:

mcpcall doctor --url http://127.0.0.1:8765/mcp --json

Read resources and prompts:

mcpcall resources --url http://127.0.0.1:8765/mcp list
mcpcall resources --url http://127.0.0.1:8765/mcp read file:///scene/status.json
mcpcall prompts --url http://127.0.0.1:8765/mcp list
mcpcall prompts --url http://127.0.0.1:8765/mcp get review_scene focus=materials

Use stdio for local MCP servers:

mcpcall list --stdio "python -m my_mcp_server"
mcpcall call --stdio "python -m my_mcp_server" my_tool key=value

Use legacy SSE when a server exposes /sse instead of Streamable HTTP:

mcpcall list --sse-url http://127.0.0.1:8765/sse

Generate helper types or shell wrappers:

mcpcall export --url http://127.0.0.1:8765/mcp types
mcpcall export --url http://127.0.0.1:8765/mcp shell --shell bash

Discover remote auth metadata:

mcpcall auth discover --url https://example.com/mcp --json

Argument Syntax

mcpcall accepts these equivalent forms:

mcpcall call --url http://127.0.0.1:8765/mcp tool_name key=value
mcpcall call --url http://127.0.0.1:8765/mcp tool_name --arg key=value
mcpcall call --url http://127.0.0.1:8765/mcp tool_name --args '{"key":"value"}'
mcpcall call --url http://127.0.0.1:8765/mcp 'tool_name(key: "value")'

Values are parsed as JSON when possible, so true, 3, 2.5, arrays, and objects become structured values. Otherwise they are strings.

Use @path to load a file as a string argument. Use @@literal to pass a value that begins with @.

Recommended DCC Workflow

1. Determine the MCP URL for the running DCC host.
2. Run mcpcall list --url <url> --brief to confirm connectivity.
3. Run mcpcall doctor --url <url> --json if connectivity or capabilities are unclear.
4. Run mcpcall list --url <url> --schema and inspect the target tool.
5. Use mcpcall resources or mcpcall prompts if the needed context is not a tool.
6. Call the tool with either KEY=VALUE pairs or --args JSON.
7. If multiple calls are part of one smoke test, put them in a JSON file and use mcpcall batch.
8. If the result has isError=true, treat the action as failed even if the CLI printed content; rerun with --json when the raw envelope is needed.