Claude Desktop — Read Sensors via MCP

Configure Claude Desktop to talk to your ESP32 fleet using the jettyd MCP server. Read live sensor values and send commands in plain English.

Prerequisites You need: Claude Desktop installed, a jettyd account, and at least one device online. The MCP server handles OAuth — no API keys to manage in Claude.

What you'll build

After completing this guide, you can ask Claude things like:

"What's the soil moisture on my greenhouse sensors right now?"
"Turn on the irrigation valve in zone 2 for 60 seconds."
"Which devices have been offline in the last hour?"
"Show me temperature history for the last 24 hours."

Step 1 — Add jettyd to claude_desktop_config.json

Open your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

Add the jettyd MCP server entry:

{
  "mcpServers": {
    "jettyd": {
      "command": "npx",
      "args": ["-y", "@anthropic/mcp-client-streamable-http"],
      "env": {
        "MCP_SERVER_URL": "https://mcp.jettyd.com/mcp",
        "MCP_AUTH_URL": "https://api.jettyd.com/oauth/authorize"
      }
    }
  }
}

Note If you already have other MCP servers configured, add jettyd inside the existing mcpServers object — don't replace it.

Step 2 — Authorize Claude

Restart Claude Desktop after saving the config file.

On first use, Claude will open a browser window for OAuth authorization. Log in with Google or GitHub — the same account you used to register with jettyd.

Grant the requested scopes: devices:read, telemetry:read, commands:write.

You're connected. Claude now has access to the 9 jettyd tools.

Step 3 — Try it out

Open a new Claude conversation and try these prompts:

List your devices

What devices do I have on jettyd?

Read a sensor

Read the soil moisture from device [paste your device UUID here]

Or let Claude look it up first:

Find my greenhouse sensor and tell me the current temperature and humidity.

Send a command

Turn on the irrigation valve on my greenhouse device for 60 seconds.

Check fleet status

How many of my devices are currently online?

Available MCP Tools

Claude can use all 9 jettyd tools in conversation:

list_devices — list all devices with online/offline status
get_device — get detailed info for a specific device
describe_device — get the device's capability schema (what commands/sensors it has)
get_fleet_status — fleet overview with counts
read_sensor — latest value for a specific metric
get_history — historical telemetry (1h, 6h, 24h, 7d, 30d)
send_command — send a command to a device
configure_device — set JettyScript automation rules
list_alerts — recent alerts and rule triggers

Troubleshooting

Claude doesn't see the jettyd tools

Check that npx is available in Claude Desktop's PATH. On macOS you may need to add /usr/local/bin to the PATH in the config:

"env": {
  "PATH": "/usr/local/bin:/usr/bin:/bin",
  "MCP_SERVER_URL": "https://mcp.jettyd.com/mcp",
  "MCP_AUTH_URL": "https://api.jettyd.com/oauth/authorize"
}

Authorization failed

Make sure you're logging in with the same Google or GitHub account you used to sign up for jettyd. If you've never registered, visit jettyd.com to create an account.

Next: Cron Agent — Scheduled Commands →