ats-mcp

An MCP server that lets an LLM drive ActionTestScript test sessions — web, mobile, desktop, and API — through ats-core's built-in REPL.

Use it with Claude Code, Claude Desktop, Cursor, or any MCP-capable client to have the assistant actually interact with a system under test: launch channels, click elements, capture screenshots, inspect the DOM or the mobile view hierarchy, and run ATS scripts — all as tool calls.

How it works

MCP client (Claude Code / Desktop / …)
         │
         ▼
    ats-mcp (Node.js)           ← this package
         │
   spawns / HTTP
         │
         ▼
  AtsReplServer (ats-core)      ← Java, resolved via Maven
         │
  ┌──────┼──────┬───────┐
  ▼      ▼      ▼       ▼
 web   mobile  desktop api

On first invocation, ats-mcp uses Maven to resolve ats-core + its transitive dependencies into your local ~/.m2 cache, then launches com.ats.tools.AtsReplServer on an ephemeral port and keeps it alive for the session.

Prerequisites

• Node.js 18+
• Java 17+ (for ats-core)
• Maven 3.8+ on PATH (or set MVN_BIN)

Install

npm install -g ats-mcp

Or use via npx in your MCP client config (recommended — always pulls the latest version).

Configure your MCP client

Claude Code

Add to .claude/settings.json in the project, or globally:

{
  "mcpServers": {
    "ats": {
      "command": "npx",
      "args": ["-y", "ats-mcp@latest"]
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "ats": {
      "command": "npx",
      "args": ["-y", "ats-mcp@latest"]
    }
  }
}

Environment variables

| Name | Purpose | Default | |-------------------------|------------------------------------------------------------------|----------------| | ATS_VERSION | Version of com.actiontestscript:ats-automated-testing to use. | 3.6.6 | | JAVA_BIN | Path to the java executable. | java on PATH | | MVN_BIN | Path to the mvn executable. | mvn on PATH | | ATS_READY_TIMEOUT_MS | How long to wait for AtsReplServer to start up. | 30000 |

Tools exposed

| Tool | What it does | |-------------------|-----------------------------------------------------------| | start_channel | Open a web / mobile / desktop / api channel | | stop_channel | Close a channel | | switch_channel | Make a channel active | | goto_url | Navigate to a URL (web) | | click | Mouse-click on an element | | send_keys | Type text into an element | | scroll | Scroll the active channel | | screenshot | Capture a PNG of the current state | | capture_tree | Dump the DOM / view hierarchy | | list_elements | Enumerate interactable elements | | run_ats_block | Execute a sequence of raw ATS action lines |

More tools (assertions, gestures, mobile-specific flows) will land in upcoming releases. For anything not yet covered, run_ats_block accepts arbitrary ATS lines.

Example session (from an LLM perspective)

start_channel(name="site", type="web", target="https://example.com")
screenshot()                     # → /tmp/ats-img-001.png
click(element="A [@href='/about']")
capture_tree()                   # → full DOM dump
send_keys(element="INPUT [@name='q']", text="hello")
stop_channel(name="site")

License

Apache-2.0 — same as ats-core.