Workflows.That run from your agent.

Run Sim workflows with your inputs and get their result, and follow logs, tables and knowledge bases from any MCP client.

Request a key (Arabic form)Connect

Workspaces and workflows
Run a workflow with inputs
Logs, tables and knowledge bases

A read key is for viewing only; running needs a write key.

11 MCP tools
Read, write or full admin
Run logs
Import and export

Run the workflow.Get the result.

Workspaces and workflows
Run a workflow with inputs
Logs, tables and knowledge bases

A read key is for viewing only; running needs a write key.

All your workflowswithin your agent's reach.

Uses Sim's official interfaces, so every run appears in Sim's own logs.

Workflows

list_workflows and get_workflow: every workflow and its deployment status.

Run

run_workflow runs the workflow with your inputs and returns the result.

Follow-up

list_logs, list_tables, list_knowledge and sim_overview for all workspaces at once.

How it works.

Connect an MCP client
Use the service URL and your key.
Run a workflow
“Run the summarisation workflow on this text”
Get the result
The result comes back directly and appears in Sim's logs.

Connect

Transport: Streamable HTTP
URL: https://sim-mcp.marsaplatform.com/mcp
Authorization: Bearer YOUR_API_KEY

Every request needs Authorization: Bearer YOUR_API_KEY.

URLhttps://sim-mcp.marsaplatform.com/mcp

Claude Code (CLI)

Terminal

claude mcp add --transport http sim https://sim-mcp.marsaplatform.com/mcp \
  --header "Authorization: Bearer YOUR_API_KEY"

Cursor ~/.cursor/mcp.json

mcp.json

{
  "mcpServers": {
    "sim": {
      "url": "https://sim-mcp.marsaplatform.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

VS Code .vscode/mcp.json

mcp.json

{
  "servers": {
    "sim": {
      "type": "http",
      "url": "https://sim-mcp.marsaplatform.com/mcp",
      "headers": {
        "Authorization": "Bearer ${input:sim-key}"
      }
    }
  },
  "inputs": [
    {
      "type": "promptString",
      "id": "sim-key",
      "description": "Sim MCP API key",
      "password": true
    }
  ]
}

VS Code asks for the key once and stores it securely.

Claude Desktop claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "sim": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://sim-mcp.marsaplatform.com/mcp",
        "--header",
        "Authorization:${AUTH_HEADER}"
      ],
      "env": {
        "AUTH_HEADER": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Claude Desktop reaches remote servers through mcp-remote, which needs Node.js. Restart the app after editing.

Quick test with curl

Terminal

curl -s -X POST https://sim-mcp.marsaplatform.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"test","version":"1"}}}'

With a valid key you get the initialize result. Without a key you get 401.

Tools

The original page states: “11 MCP tools”. The full list is generated from tools/list once a read key is configured for this site; until then any MCP client shows it after you connect.

FAQ

What is the difference between a read and a write key?

read shows workflows and logs; write adds running.

Do I need to sign in to Sim?

No. The tool uses Sim's official keys on the server.

How do I get a key?

Request an access key from the key request page (Arabic form).

401 Unauthorized

The real response for a request without a key:

HTTP/2 401 · application/json

WWW-Authenticate: Bearer

{"error": "unauthorized"}

Send the header exactly as Authorization: Bearer YOUR_API_KEY.