pyATS MCP Server

MCP server that wraps Cisco pyATS and Genie, letting AI agents (Claude, LangGraph, etc.) run show commands, apply configuration, and query network state over STDIO using JSON-RPC 2.0.

All communication is via STDIN/STDOUT — no HTTP ports, no REST endpoints.

Quick Start

# 1. Clone and install
git clone https://github.com/automateyournetwork/pyATS_MCP
cd pyATS_MCP
pip install -r requirements.txt

# 2. Configure your environment
cp .env.example .env
# Edit .env — see Configuration below

# 3. Run
python3 pyats_mcp_server.py

Configuration

All device details and credentials live in a .env file — nothing is hard-coded in the repo.

1. Copy the template

cp .env.example .env

2. Set the server variables

PYATS_TESTBED_PATH=/absolute/path/to/your/testbed.yaml
PYATS_MCP_ARTIFACTS_DIR=          # default: ~/.pyats-mcp/artifacts
PYATS_MCP_KEEP_ARTIFACTS=1        # 1 = keep, 0 = delete after each run
PYATS_MCP_TESTBED_CACHE_TTL=30    # seconds before testbed reloads from disk
PYATS_MCP_CONN_CACHE_TTL=0        # seconds to keep connections alive (0 = off)
PYATS_MCP_OP_LOG_MAX=500          # max entries in the in-memory operation log

3. Add a block for each device

Every device in your testbed.yaml uses %ENV{VAR} substitution, so credentials and connection details are read from .env at runtime.

Use the {DEVICENAME}_{FIELD} naming convention:

# Supported os values: iosxe | iosxr | nxos | ios | eos | junos | panos | linux | windows
# Set os=generic and platform="" to let Unicon autodetect on first connect.

CORE1_IP=10.1.1.1
CORE1_PORT=22
CORE1_OS=iosxe
CORE1_PLATFORM=cat9k
CORE1_USERNAME=admin
CORE1_PASSWORD=s3cr3t
CORE1_ENABLE_PASSWORD=s3cr3t

FW1_IP=10.1.1.2
FW1_PORT=22
FW1_OS=panos
FW1_PLATFORM=
FW1_USERNAME=admin
FW1_PASSWORD=s3cr3t
# (no enable password for Palo Alto)

LINUX1_IP=10.1.1.3
LINUX1_PORT=22
LINUX1_OS=linux
LINUX1_PLATFORM=ubuntu
LINUX1_USERNAME=admin
LINUX1_PASSWORD=s3cr3t
# (no enable password for Linux)

If a group of devices shares credentials you can define group-level vars and reference them across devices:

SITE_A_USERNAME=netops
SITE_A_PASSWORD=s3cr3t
SITE_A_ENABLE_PASSWORD=s3cr3t

4. Reference the variables in testbed.yaml

devices:
  CORE1:
    alias: "Core Switch 1"
    type: "switch"
    os: "%ENV{CORE1_OS}"
    platform: "%ENV{CORE1_PLATFORM}"
    credentials:
      default:
        username: "%ENV{CORE1_USERNAME}"
        password: "%ENV{CORE1_PASSWORD}"
      enable:
        password: "%ENV{CORE1_ENABLE_PASSWORD}"
    connections:
      cli:
        protocol: ssh
        ip: "%ENV{CORE1_IP}"
        port: "%ENV{CORE1_PORT}"
        arguments:
          connection_timeout: 360

For devices with unknown OS, set os: "%ENV{DEVICE_OS}" with DEVICE_OS=generic in .env and optionally add learn_os: true under arguments: — Unicon will detect and cache the OS after the first connection.

Docker

Build

docker build -t pyats-mcp-server .

Run (pass .env directly)

docker run -i --rm \
  --env-file /absolute/path/to/.env \
  -v /absolute/path/to/testbed.yaml:/app/testbed.yaml \
  pyats-mcp-server

MCP client config (Docker)

{
  "mcpServers": {
    "pyats": {
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "--env-file", "/absolute/path/to/.env",
        "-v", "/absolute/path/to/testbed.yaml:/app/testbed.yaml",
        "pyats-mcp-server"
      ]
    }
  }
}

MCP client config (local Python)

{
  "mcpServers": {
    "pyats": {
      "command": "python3",
      "args": ["-u", "/path/to/pyats_mcp_server.py"],
      "env": {
        "PYATS_TESTBED_PATH": "/absolute/path/to/testbed.yaml"
      }
    }
  }
}


... [View full README on GitHub](https://github.com/automateyournetwork/pyATS_MCP#readme)