How do I install MCP Simulate?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does MCP Simulate need an API key?

The publisher lists these environment variables: CRYPTOAPIS_API_KEY.

What transport does MCP Simulate use?

MCP Simulate runs locally over stdio.

When was MCP Simulate last checked?

Last checked 2026-11-09. MCP server for dry-run Ethereum transaction simulation via Crypto APIs

MCP Simulate MCP server

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y @cryptoapis-io/[email protected]

Credentials from the publisher

CRYPTOAPIS_API_KEY — Crypto APIs API key

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1CRYPTOAPIS_API_KEY=<secret> claude mcp add io.github.cryptoapis-io-mcp-simulate -- npx -y @cryptoapis-io/mcp-simulate@0.4.0

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.cryptoapis-io-mcp-simulate": {4      "command": "npx",5      "args": [6        "-y",7        "@cryptoapis-io/[email protected]"8      ],9      "env": {10        "CRYPTOAPIS_API_KEY": "<secret>"11      }12    }13  }14}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 0.4.0
API key

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

@cryptoapis-io/mcp-simulate

MCP server for Crypto APIs Simulate product. Dry-run Ethereum transactions to preview results without broadcasting.

API Version: Compatible with Crypto APIs version 2024-12-12

Features

Simulate Ethereum transactions before broadcasting
Preview transaction results, gas usage, and state changes
Ethereum only (mainnet, sepolia) — the underlying API endpoint has no blockchain parameter

Prerequisites

Node.js 18+
Crypto APIs account and API key (sign up | get API key)

Installation

npm install @cryptoapis-io/mcp-simulate

Or install all Crypto APIs MCP servers: npm install @cryptoapis-io/mcp

Usage

# Run with API key
npx @cryptoapis-io/mcp-simulate --api-key YOUR_API_KEY

# Or use environment variable
export CRYPTOAPIS_API_KEY=YOUR_API_KEY
npx @cryptoapis-io/mcp-simulate

# HTTP transport (listens on 127.0.0.1; see "Exposing the server beyond localhost")
npx @cryptoapis-io/mcp-simulate --transport http --port 3000 --api-key YOUR_API_KEY

Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS, %APPDATA%\Claude\claude_desktop_config.json on Windows):

{
  "mcpServers": {
    "cryptoapis-simulate": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-simulate"],
      "env": {
        "CRYPTOAPIS_API_KEY": "your_api_key_here"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "cryptoapis-simulate": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-simulate"],
      "env": {
        "CRYPTOAPIS_API_KEY": "your_api_key_here"
      }
    }
  }
}

MCP Inspector

npx @modelcontextprotocol/inspector npx @cryptoapis-io/mcp-simulate --api-key YOUR_API_KEY

n8n

Start the server in HTTP mode:

npx @cryptoapis-io/mcp-simulate --transport http --port 3000 --api-key YOUR_API_KEY

In your n8n workflow, add an AI Agent node
Under Tools, add an MCP Client Tool and set the URL to http://localhost:3000/mcp

n8n in Docker: localhost inside the container is not your machine. Start the server with --host 0.0.0.0 and MCP_AUTH_TOKEN set (see Exposing the server beyond localhost), use http://host.docker.internal:3000/mcp as the URL, and add an Authorization: Bearer <token> header to the MCP Client Tool credential.

All servers default to port 3000. Use --port to assign different ports when running multiple servers.

Available Tools

`simulate_evm`

Simulate an Ethereum transaction (dry run). Ethereum only — the underlying endpoint has no blockchain parameter.

Parameter	Description
`network`	Network: `mainnet` or `sepolia`
`fromAddress`	Sender address
`toAddress`	Recipient address
`value`	Amount to send (in native coin)
`data`	Contract call data (hex)
`gasLimit`	Gas limit
`gasPrice`	Gas price

CLI Arguments

Argument	Description	Default
`--api-key`	Crypto APIs API key	`CRYPTOAPIS_API_KEY` env var
`--transport`	Transport type: `stdio` or `http`	`stdio`
`--host`	HTTP host (use `0.0.0.0` to accept remote connections — requires an auth token with `--api-key`)	`127.0.0.1`
`--auth-token`	Bearer token callers must send (`Authorization: Bearer <token>`); prefer the `MCP_AUTH_TOKEN` env var	`MCP_AUTH_TOKEN` env var
`--allowed-hosts`	Comma-separated `Host` header allowlist for non-loopback binds	—
`--port`	HTTP port	`3000`
`--path`	HTTP path	`/mcp`
`--stateless`	Enable stateless HTTP mode	`false`

HTTP API Key Modes

When using HTTP transport, the server supports two API key modes:

With --api-key: The key is used for all requests. x-api-key request headers are ignored.
Without --api-key: Each request must include an x-api-key header with a valid Crypto APIs key. This enables hosting a public server where each user provides their own key.

# Per-request key mode (multi-tenant)
npx @cryptoapis-io/mcp-simulate --transport http --port 3000
# Clients send x-api-key header with each request

Exposing the server beyond localhost

HTTP mode listens on 127.0.0.1 by default, so only processes on the same machine can reach it. To accept connections from other machines or containers, bind explicitly and protect the port:

# Startup-key mode: callers must present the token (the server refuses to start without one)
export MCP_AUTH_TOKEN=$(openssl rand -hex 32)
npx @cryptoapis-io/mcp-simulate --transport http --host 0.0.0.0 --port 3000 --api-key YOUR_API_KEY \
  --allowed-hosts mcp.internal.example
# Clients send: Authorization: Bearer $MCP_AUTH_TOKEN

# Per-request key mode: no startup key, every request must carry the caller's own x-api-key
npx @cryptoapis-io/mcp-simulate --transport http --host 0.0.0.0 --port 3000

--allowed-hosts restricts the Host header (DNS rebinding protection) when not bound to loopback. Prefer MCP_AUTH_TOKEN over --auth-token: command-line arguments are visible in the process list.

Stdio transport always requires an API key at startup.

Important: API Key Required

Warning: Making requests without a valid API key — or with an incorrect one — may result in your IP being banned from the Crypto APIs ecosystem. Always ensure a valid API key is configured before starting any server.

Remote MCP Server

Crypto APIs provides an official remote MCP server with all tools available via HTTP Streamable transport at https://ai.cryptoapis.io/mcp. Pass your API key via the x-api-key header — no installation required.

License

MIT

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install MCP Simulate?

Does MCP Simulate need an API key?

What transport does MCP Simulate use?

When was MCP Simulate last checked?

Documentation

@cryptoapis-io/mcp-simulate

Features

Prerequisites

Installation

Usage

Claude Desktop

Cursor

MCP Inspector

n8n

Available Tools

simulate_evm

CLI Arguments

HTTP API Key Modes

Exposing the server beyond localhost

Important: API Key Required

Remote MCP Server

License

`simulate_evm`