Open source · IoT & Edge

MQTT Topic Contract Validator

Validate MQTT topics, QoS choices, retained messages and payload versions.

v0.1.0 · Node.js 22+ · MIT

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Offline, read-only validator of exported MQTT topic contracts and message metadata. It does not connect to a broker, subscribe, publish, retain, or parse payload bodies. Node.js 22+, zero dependencies. src/index.mjs exports validateMqttContracts(fixtures, policy, {now, deadline}) and TOOLID.

This walkthrough uses the tool's public README and checked-in example files. Run the command from a repository checkout with Node.js 22+; inspect the source before using it on your own files.

Run the checked-in example

node bin/mqtt-topic-contract-validator.mjs --root examples --policy policy.json --fixtures passing-fixtures.json
node bin/mqtt-topic-contract-validator.mjs --root examples --policy policy.json --fixtures failing-fixtures.json

Read the result

The synthetic examples exit 0 and 1. --help prints usage to stderr; normal runs print a bounded human summary to stderr. Stdout contains only the v1 JSON report.

Where this check stops

This local walkthrough does not establish the state of a live production system or replace the limits documented in the repository.

Before adapting the command to your own workflow, review the accepted inputs, exit codes and safety boundaries in the README.

Compiled with AI assistance from checked-in public documentation and example scripts. Run the example and review the repository's current documentation before relying on its result.