/docs/agent/getting-started

Connect your Agent and complete the first MQTT message

Enable MCP, configure a trusted Agent, and verify a complete subscribe, publish, receive, and Trace loop on an isolated Topic.

Author:: Mqttable
Updated:: Aug 25, 2026

On this page6 sections

What you will accomplish

You will connect a trusted local Agent to Mqttable, create one isolated test Connection, subscribe it to a unique Topic, publish one QoS 1 JSON message, and confirm the complete exchange in Trace.

Before you start:

Run Mqttable and the Agent on the same trusted computer.
Use only synthetic data. This tutorial uses the public test endpoint broker.emqx.io:1883; a unique Topic reduces collisions but is not private.
Stop without substituting a production endpoint if the Broker is unavailable, the Agent reports a different Mqttable Runtime, or Allow changes is unavailable.

Enable MCP and copy the config

Open Application Settings > MCP, then select Enable. A new installation keeps MCP off until you enable the local endpoint.

Mqttable Application Settings with the MCP section selected and MCP access disabled — MCP starts off. Enable it only for a client you trust on this computer.
Open MCP in Application Settings.
Enable the local MCP endpoint.

MCP starts in Read-only. Select Allow changes for this tutorial. The access level takes effect immediately and remains active until you change it or disable MCP.

Allow changes is the authorization boundary. Mqttable does not open another approval screen for each Plan. Every change still uses a scoped Plan, masked_diff, Apply, and Verify flow.

Mqttable MCP settings with Allow changes selected and the URL-only JSON Client config visible — Allow changes delegates bounded changes to the trusted local client. Copy the URL-only Client config without adding credentials.
Select Allow changes for this tutorial.
The JSON config contains the local HTTP URL and no credential.
Copy the complete Client config.

Choose JSON or TOML, then select Copy. Use the complete block generated by Mqttable. Do not retype the endpoint or add an Authorization header, token, password, or URL query credential.

Connect your Agent

Add the copied config only to a client and workspace you trust:

Codex: use the TOML block in ~/.codex/config.toml, or in .codex/config.toml for a trusted project. Start a fresh session and confirm mqttable with /mcp or codex mcp list.
Claude Code: use the JSON block in the trusted project's .mcp.json. Start a fresh session, approve the project server when prompted, and confirm it with /mcp.
Cursor: use the JSON block in .cursor/mcp.json for the project or ~/.cursor/mcp.json globally. Open Customize > MCP to confirm that mqttable is enabled and connected.
Other MCP Clients: use the exact URL from the copied config with Streamable HTTP. The client must run where 127.0.0.1 reaches this Mqttable Runtime.

Before continuing, ask the Agent to report the connected Mqttable Runtime and access mode. Continue only when the Runtime is local and the mode is approved_changes.

Run the first message task

Copy this prompt into the same Agent session:

Main prompt

Use the connected Mqttable MCP tools to send and receive my first MQTT message through broker.emqx.io:1883. Use MQTT 5.0, QoS 1, and a test JSON message. Do not change anything I already have. When it is done, tell me where to see the result in Mqttable.

That is the whole task. The Agent chooses the temporary names and MCP steps. If the public Broker is unavailable, it should stop instead of using another endpoint.

Confirm the result

When the Agent finishes, return to Connections. A successful run looks like this:

Mqttable Connections in One Dark Pro and Zen Mode showing a connected MQTT 5.0 client, a QoS 1 subscription, and matching sent and received MQTT packets — The completed MCP run appears in one view: the connected client, its QoS 1 subscription, and the matching exchange in Trace.
The new MQTT 5.0 client is connected.
Its tutorial Topic is subscribed at QoS 1.
Trace shows both PUBLISH directions and successful PUBACKs.

You only need to check three things:

the Connection is Connected and shows MQTT 5.0;
the tutorial Topic shows QoS1; and
Trace shows sent and received PUBLISH rows with successful PUBACK rows.

If any result is missing, stop instead of sending another message and use Troubleshooting.

Clean up and continue

Keep the completed report in the same Agent conversation, then send this prompt:

Cleanup prompt

Remove only the temporary Broker, Connection, and Topic you created for my first-message test. Leave everything else unchanged, then confirm that those temporary objects are gone.

If you start a different Agent conversation, paste the exact object list from the completed report before asking for cleanup.

Continue with Connections & Messages to create a bounded scheduled heartbeat, or Trace & Diagnosis to examine the QoS 1 exchange in more detail.