MQTT

Overview#

The MQTT connector proxies MQTT 3.1.1 / 5.0 publish and subscribe operations. Broker credentials are sealed in QuantaVault. Supports TLS brokers (mqtts://) and plain MQTT over TCP.

Prerequisites#

• 1An MQTT broker (Mosquitto, HiveMQ, AWS IoT Core, etc.)
• 2Broker hostname, port, username, and password (or client certificate)
• 3A QuantaSeal API key

Configuration#

Follow these steps to connect MQTT to QuantaSeal. You can configure integrations via the Admin Console or directly via the API.

1. 1

   Obtain broker hostname, port, username, and password.

2. 2

   Seal: POST /api/v2/vault/seal with credential_type: custom_kv and values: {hostname, port, username, password}.

3. 3

   Create integration with system_type: mqtt, config: {topic, qos: 1}.

Authentication Types#

Seal hostname, port, username, and password as custom_kv. For certificate-based auth, also include client_cert and client_key.

All credential types are sealed in QuantaVault with ML-KEM-768 + AES-256-GCM and wrapped by your tenant AWS KMS CMK before storage. See the Vault API reference for the full list of credential types and seal/unseal endpoints.

Available Operations#

QuantaSeal enforces a default-deny operation policy. Only operations listed in your integration's allowed_operations array will be permitted. Add operations when creating or updating the integration.

Code Example#

Every proxy call returns a HybridCryptoEnvelope - the response is ML-KEM-768 key-encapsulated, AES-256-GCM encrypted, and signed with ML-DSA-65 + HMAC-SHA-512. Verify both signatures before trusting the decrypted payload.

curl -X POST https://api.quantaseal.io/api/v2/proxy/outbound \
  -H "X-API-Key: qs_live_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"integration_id":"int_MQTT001","operation":"publish","payload":{"topic":"sensors/temperature","message":"22.5","qos":1}}'

Troubleshooting#