# Arista Eos Mcp

> A read-only Model Context Protocol (MCP) server for Arista EOS devices, written in Go.

- **Type:** MCP server
- **Install:** `agentstack add mcp-x86taka-arista-eos-mcp`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [x86taka](https://agentstack.voostack.com/s/x86taka)
- **Installs:** 0
- **Category:** [Integrations](https://agentstack.voostack.com/c/integrations)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [x86taka](https://github.com/x86taka)
- **Source:** https://github.com/x86taka/arista-eos-mcp

## Install

```sh
agentstack add mcp-x86taka-arista-eos-mcp
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Arista EOS MCP Server

A read-only [Model Context Protocol](https://modelcontextprotocol.io) (MCP)
server for Arista EOS devices, written in Go. It lets MCP clients such as Claude
Desktop / Claude Code query EOS switches over **eAPI** and **gNMI**.

The server is **read-only by default**: any command that would change the
configuration or device state is rejected before it reaches the device.

## Features

- eAPI tools: `run_show_command`, `get_version`, `get_interfaces`,
  `get_running_config`, `get_lldp_neighbors`, `get_bgp_summary`
- gNMI tools: `gnmi_get`, `gnmi_capabilities`
- Safety guard that rejects `configure`, `write`, `copy`, `reload`, `clear`,
  `no ...`, `bash`, and other state-changing commands in read-only mode

## Requirements

- Go 1.24+ (built with 1.26)
- An Arista EOS device with eAPI enabled (`management api http-commands`) and,
  optionally, gNMI (`management api gnmi`)

## Install

Prebuilt binaries (linux/darwin/windows, amd64/arm64) are attached to each
[GitHub Release](https://github.com/x86taka/arista-eos-mcp/releases) — download
the archive for your platform and extract the `arista-eos-mcp` binary.

Or install from source with Go:

```sh
go install github.com/x86taka/arista-eos-mcp/cmd/arista-eos-mcp@latest
```

This produces an `arista-eos-mcp` binary on your `PATH`. Pin a specific version
by replacing `@latest` with a tag, e.g. `@v0.1.0`.

## Build from source

```sh
git clone https://github.com/x86taka/arista-eos-mcp.git
cd arista-eos-mcp
go build -o arista-eos-mcp ./cmd/arista-eos-mcp
```

## Configuration

The server supports **one or more devices**. There are two ways to configure
it; `EOS_CONFIG` takes precedence when set.

### Option A: multi-device JSON inventory (recommended)

Point `EOS_CONFIG` at a JSON file describing the devices. Each tool then takes
an optional `device` argument to select the target; when only one device is
configured the argument may be omitted. Use the `list_devices` tool to see the
configured names.

```json
{
  "read_only": true,
  "timeout_seconds": 30,
  "devices": [
    {
      "name": "leaf1",
      "host": "192.0.2.10",
      "username": "admin",
      "password": "secret",
      "enable_password": "",
      "eapi_transport": "https",
      "eapi_port": 443,
      "gnmi_port": 6030,
      "gnmi_insecure": true,
      "tls_skip_verify": true
    },
    {
      "name": "spine1",
      "host": "192.0.2.20",
      "username": "readonly",
      "password": "ro-pass"
    }
  ]
}
```

See [`devices.example.json`](devices.example.json). Per-device fields default
to: `eapi_transport` = `https`, `eapi_port` = `443`, `gnmi_port` = `6030`, and
`gnmi_insecure` / `tls_skip_verify` = `true` (omit them for a lab; set to
`false` to enforce TLS).

```sh
EOS_CONFIG=/path/to/devices.json ./arista-eos-mcp
```

### Option B: single-device environment variables

When `EOS_CONFIG` is unset, the server builds a single device (named `default`,
override with `EOS_DEVICE_NAME`) from these variables.

| Variable                | Required | Default  | Description                                          |
| ----------------------- | -------- | -------- | ---------------------------------------------------- |
| `EOS_HOST`              | no*      | —        | IP/hostname of a predefined device (optional if defaults set) |
| `EOS_USERNAME`          | no*      | —        | eAPI / gNMI username (also the default credential)   |
| `EOS_PASSWORD`          | no*      | —        | password (also the default credential)               |
| `EOS_ENABLE_PASSWORD`   | no       | —        | enable (privileged exec) password, if needed         |
| `EOS_DEFAULT_USERNAME`  | no       | =`EOS_USERNAME` | shared username for ad-hoc hosts              |
| `EOS_DEFAULT_PASSWORD`  | no       | =`EOS_PASSWORD` | shared password for ad-hoc hosts              |
| `EOS_DEFAULT_ENABLE_PASSWORD` | no | =`EOS_ENABLE_PASSWORD` | shared enable password for ad-hoc hosts |
| `EOS_ALLOW_DYNAMIC_HOSTS` | no     | auto     | force-enable/disable ad-hoc hosts (auto = on if default creds set) |
| `EOS_ALLOWED_MANAGEMENT_PREFIXES` | no | —      | comma-separated CIDR allowlist for ad-hoc hosts (e.g. `192.0.2.0/24,10.10.0.0/16`) |
| `EOS_EAPI_TRANSPORT`    | no       | `https`  | `https`, `http`, `http_local`, or `socket`           |
| `EOS_EAPI_PORT`         | no       | `0`      | eAPI port (0 = transport default: https 443/http 80) |
| `EOS_GNMI_PORT`         | no       | `6030`   | gNMI gRPC port                                       |
| `EOS_GNMI_INSECURE`     | no       | `true`   | use plaintext gRPC (no TLS)                          |
| `EOS_GNMI_TLS_CA`       | no       | —        | path to a CA certificate for gNMI TLS                |
| `EOS_TLS_SKIP_VERIFY`   | no       | `true`   | skip TLS certificate verification (lab/self-signed)  |
| `EOS_DEVICE_NAME`       | no       | `default`| name reported for the single env-configured device  |
| `EOS_TIMEOUT_SECONDS`   | no       | `30`     | per-request timeout                                  |
| `EOS_READ_ONLY`         | no       | `true`   | reject write/state-changing commands                 |

\* At least one of these is required: either set `EOS_HOST` (with credentials)
for a predefined device, or provide credentials alone to run with ad-hoc hosts
only. See [Ad-hoc hosts](#ad-hoc-hosts-shared-credentials).

Transport (both config modes):

| Variable         | Default   | Description                                      |
| ---------------- | --------- | ------------------------------------------------ |
| `MCP_TRANSPORT`  | `stdio`   | `stdio` (client-spawned) or `http` (long-running) |
| `MCP_HTTP_ADDR`  | `:8080`   | listen address when `MCP_TRANSPORT=http`         |

> **Lab note:** vEOS/cEOS often use self-signed certs. Set
> `EOS_TLS_SKIP_VERIFY=true` for eAPI over HTTPS, and `EOS_GNMI_INSECURE=true`
> (or provide `EOS_GNMI_TLS_CA`) for gNMI.

## Ad-hoc hosts (shared credentials)

You don't have to predefine every device. If **shared default credentials** are
configured, any tool's `device` argument also accepts a **hostname or IP that is
not in the inventory** — the server connects to it on demand using those
credentials. Predefined devices and ad-hoc hosts can be mixed freely.

Ad-hoc access is enabled automatically when default credentials are present:

- **Env mode:** `EOS_DEFAULT_USERNAME` / `EOS_DEFAULT_PASSWORD`
  (`EOS_DEFAULT_ENABLE_PASSWORD` optional). These fall back to
  `EOS_USERNAME` / `EOS_PASSWORD`, so simply setting those — even without
  `EOS_HOST` — is enough to run with no predefined devices at all.
- **JSON mode:** a top-level `"defaults"` object:

  ```json
  {
    "defaults": {
      "username": "admin",
      "password": "secret",
      "gnmi_insecure": true,
      "tls_skip_verify": true
    },
    "devices": [ { "name": "leaf1", "host": "192.0.2.10", "username": "admin", "password": "secret" } ]
  }
  ```

The `device` value is used verbatim as the connection host. Pass a device's
**management IPv4 address** (e.g. `device: "192.0.2.50"`) — that is the intended
input, and the tool catalog instructs the model to use it. Ad-hoc hosts inherit
the default transport/port/TLS settings. Connections are cached for reuse. Set
`EOS_ALLOW_DYNAMIC_HOSTS=false` (or `"allow_dynamic_hosts": false`) to disable
the behavior even when default credentials exist.

### Restricting ad-hoc targets (management prefix allowlist)

To keep the server safe, you can restrict which addresses an ad-hoc `device`
argument may reach with an **allowlist of management prefixes**. When set, an
ad-hoc host is accepted only if it is an IP address inside one of the prefixes;
a hostname or an out-of-range IP is rejected. Predefined devices in the
inventory are always reachable and are **not** subject to the allowlist.

- **JSON mode:** a top-level `"allowed_management_prefixes"` array of CIDRs.

  ```json
  {
    "allowed_management_prefixes": ["192.0.2.0/24", "10.10.0.0/16"],
    "defaults": { "username": "admin", "password": "secret" }
  }
  ```

- **Env mode:** `EOS_ALLOWED_MANAGEMENT_PREFIXES`, a comma-separated list of
  CIDRs (e.g. `EOS_ALLOWED_MANAGEMENT_PREFIXES="192.0.2.0/24,10.10.0.0/16"`).

Leaving the allowlist empty (the default) keeps the previous behavior — any
host is accepted for ad-hoc access.

`list_devices` reports whether ad-hoc access is enabled.

## Run

```sh
EOS_HOST=192.0.2.10 EOS_USERNAME=admin EOS_PASSWORD=secret \
  EOS_TLS_SKIP_VERIFY=true ./arista-eos-mcp
```

The server speaks MCP over stdio.

## Run with Docker / Docker Compose

The server supports two MCP transports, selected with `MCP_TRANSPORT`:

- `stdio` (default) — the MCP client spawns the process and talks over
  stdin/stdout. Use `docker run -i`.
- `http` — Streamable HTTP, suitable for a long-lived service. Use
  `docker compose up`. Listens on `MCP_HTTP_ADDR` (default `:8080`).

### Docker Compose (HTTP transport, long-running service)

1. Create your inventory at `./devices.json` (copy `devices.example.json`).
2. Start it:

   ```sh
   docker compose up -d --build
   ```

   This runs the server with `MCP_TRANSPORT=http` on `http://localhost:8080`.
   Point an HTTP-capable MCP client at that URL. For Claude Code:

   ```sh
   claude mcp add --transport http arista-eos http://localhost:8080
   ```

### Docker (stdio transport, client-spawned)

Build once, then have the MCP client launch a container per session:

```sh
docker build -t arista-eos-mcp:latest .
```

```json
{
  "mcpServers": {
    "arista-eos": {
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "EOS_CONFIG=/config/devices.json",
        "-v", "/absolute/path/to/devices.json:/config/devices.json:ro",
        "arista-eos-mcp:latest"
      ]
    }
  }
}
```

> The `-i` flag is required for the stdio transport. `MCP_TRANSPORT` defaults to
> `stdio`, so no transport env var is needed for this mode.

## Register with Claude Desktop / Claude Code

Add to your MCP client config (e.g. `claude_desktop_config.json`, or via
`claude mcp add`). Use an **absolute path** for both the binary and the config
file.

Multi-device (recommended):

```json
{
  "mcpServers": {
    "arista-eos": {
      "command": "/absolute/path/to/arista-eos-mcp",
      "env": {
        "EOS_CONFIG": "/absolute/path/to/devices.json"
      }
    }
  }
}
```

Single device:

```json
{
  "mcpServers": {
    "arista-eos": {
      "command": "/absolute/path/to/arista-eos-mcp",
      "env": {
        "EOS_HOST": "192.0.2.10",
        "EOS_USERNAME": "admin",
        "EOS_PASSWORD": "secret"
      }
    }
  }
}
```

For Claude Code:

```sh
# multi-device
claude mcp add arista-eos \
  -e EOS_CONFIG=/absolute/path/to/devices.json \
  -- /absolute/path/to/arista-eos-mcp

# single device
claude mcp add arista-eos \
  -e EOS_HOST=192.0.2.10 -e EOS_USERNAME=admin -e EOS_PASSWORD=secret \
  -- /absolute/path/to/arista-eos-mcp
```

Once connected, ask Claude things like "list the devices", or "show the BGP
summary on leaf1". Every tool accepts a `device` argument; it is optional only
when a single device is configured.

## Enabling APIs on EOS

```
! eAPI
management api http-commands
   no shutdown
   protocol https

! gNMI
management api gnmi
   transport grpc default
```

## Tools

All tools except `list_devices` accept an optional `device` argument selecting
the target by name (required when more than one device is configured).

**Inventory & generic**

| Tool                | Description                                          |
| ------------------- | ---------------------------------------------------- |
| `list_devices`      | List configured device names                         |
| `run_show_command`  | Run any read-only command (`json` or `text` output)  |

**Curated read-only show tools** (eAPI)

| Tool                     | Command                          |
| ------------------------ | -------------------------------- |
| `get_version`            | `show version`                   |
| `get_running_config`     | running configuration as text    |
| `get_interfaces`         | `show interfaces` (opt. filter)  |
| `get_interfaces_status`  | `show interfaces status`         |
| `get_interface_counters` | `show interfaces counters`       |
| `get_mac_address_table`  | `show mac address-table`         |
| `get_arp_table`          | `show ip arp`                    |
| `get_ip_route`           | `show ip route` (opt. prefix/VRF)|
| `get_vlans`              | `show vlan`                      |
| `get_lldp_neighbors`     | `show lldp neighbors`            |
| `get_port_channels`      | `show port-channel summary`      |
| `get_mlag`               | `show mlag`                      |
| `get_spanning_tree`      | `show spanning-tree`             |
| `get_bgp_summary`        | `show ip bgp summary`            |
| `get_bgp_neighbors`      | `show ip bgp neighbors`          |
| `get_ospf_neighbors`     | `show ip ospf neighbor`          |
| `get_transceivers`       | `show interfaces transceiver`    |
| `get_environment`        | `show environment all`           |
| `get_ntp_status`         | `show ntp status`                |
| `get_logging`            | `show logging last 100`          |
| `get_processes`          | `show processes top once`        |

**Aggregation & diagnostics**

| Tool                | Description                                                       |
| ------------------- | ---------------------------------------------------------------- |
| `get_device_health` | Combined report: version, environment, interfaces, LAG, MLAG, BGP |
| `compare_config`    | Diff the running-config of two devices (`device_a`, `device_b`)  |
| `compare_command`   | Run one command on two devices and diff the output               |

**Active diagnostics** (read-only, still within the safety allow-list)

| Tool                        | Description                                            |
| --------------------------- | ------------------------------------------------------ |
| `ping_host`                 | Ping from a device (`destination`, opt. `count`/`vrf`/`source`) |
| `traceroute_host`           | Traceroute from a device (`destination`, opt. `vrf`)   |
| `get_bgp_advertised_routes` | Routes advertised to a `neighbor`                      |
| `get_bgp_received_routes`   | Routes received from a `neighbor`                      |

**Fleet (multi-device)**

| Tool                | Description                                                       |
| ------------------- | ---------------------------------------------------------------- |
| `fleet_run_command` | Run one command across many devices in parallel (`devices` opt.) |
| `fleet_get_version` | Collect `show version` across many devices                       |

**gNMI**

| Tool                | Description                                                       |
| ------------------- | ---------------------------------------------------------------- |
| `gnmi_get`          | Get one or more paths                                            |
| `gnmi_capabilities` | Supported models and encodings                                   |
| `gnmi_subscribe`    | Collect telemetry over a bounded window (`once`/`sample`/`on-change`) |

## Resources

Per device, the server exposes two read-only MCP resources:

- `eos:///running-config` — running configuration (text)
- `eos:///version` — `show version` output (JSON)

## Prompts

Reusable troubleshooting prompt templates:

| Prompt                  | Arguments                       | Purpose                                  |
| ----------------------- | ------------------------------- | ---------------------------------------- |
| `troubleshoot_interface`| `device`, `interface`           | Investigate a problematic interface      |
| `troubleshoot_bgp`      | `device`, `neighbor` (optional) | Investigate BGP session problems         |
| `device_health_review`  | `device`                        | Full health

…

## Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [x86taka](https://github.com/x86taka)
- **Source:** [x86taka/arista-eos-mcp](https://github.com/x86taka/arista-eos-mcp)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/mcp-x86taka-arista-eos-mcp
- Seller: https://agentstack.voostack.com/s/x86taka
- Browse the marketplace: https://agentstack.voostack.com/browse

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