Fetch Device Credentials

Use this node to fetch the originator device’s credentials and add them to the message — for example, retrieving the access token or MQTT client ID before forwarding a provisioning payload to an external system that needs to know how the device authenticates. The originator must be a DEVICE; any other entity type results in Failure.

• Fetch credentials to — required. Where to place the fetched credentials:
  • Message — adds to message data payload. The data must be a JSON object. Complex credentials (MQTT Basic) are added as a JSON object; simple credentials (Access Token, X.509) as strings.
  • Metadata — adds to message metadata. All credentials are serialized as strings; complex credentials are stringified JSON.

Two fields are always added:

1. Verify that the message originator is a DEVICE. If not, route via Failure.
2. Asynchronously fetch credentials for the originator device. If not found, route via Failure.
3. Prepare credentialsType and credentials fields based on destination format:
   • When adding to Metadata: credentials is always a string (stringified JSON for MQTT Basic).
   • When adding to Data: credentials is a JSON object for MQTT Basic; plain string for others.
4. Add the two fields to message data or metadata.
5. Route via Success.

State: device has Access Token credentials sm001_token_123.

{ "fetchTo": "METADATA" }

Outgoing metadata (added): { "credentialsType": "ACCESS_TOKEN", "credentials": "sm001_token_123" }

State: device has MQTT Basic credentials clientId=clientId123, userName=username.

{ "fetchTo": "METADATA" }

Outgoing metadata (added): { "credentialsType": "MQTT_BASIC", "credentials": "{\"clientId\":\"clientId123\",\"userName\":\"username\",\"password\":\"password123\"}" }

State: same MQTT Basic device.

{ "fetchTo": "DATA" }

Outgoing data (merged): { ..., "credentialsType": "MQTT_BASIC", "credentials": { "clientId": "clientId123", "userName": "username", "password": "password" } }

State: device has X.509 credentials (public key string).

{ "fetchTo": "DATA" }

Outgoing data (merged): { ..., "credentialsType": "X509_CERTIFICATE", "credentials": "o3Qwq2xq...QDAQAB" }

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "TbFetchDeviceCredentialsNodeConfiguration",
  "type": "object",
  "required": ["fetchTo"],
  "additionalProperties": false,
  "properties": {
    "fetchTo": { "type": "string", "enum": ["DATA", "METADATA"] }
  }
}