Advanced services

The Trusted Twin platform offers a series of advanced services.

Advanced service	Description
History	The History service stores historical values of Ledger Entries.
Timeseries	The Timeseries database service stores structured and multidimensional views of Twin history.
Indexes	The Indexes database service stores structured and multidimensional views of Twin states.
Notifications (publish/notify)	The Notifications service allows to automatically invoke external services via publish/notify service (e.g., webhooks).
Stickers (workflow tags)	The Stickers (workflow tags) service facilitates workflow processes.

History

The History service lets you store historical values of Entries of a Ledger with a timestamp denoting when the value was changed.

The historical values, as well as the current value of the Entry, can be viewed at any time by sending a request to the get_twin_ledger_entry_history endpoint. The response returns a list of Entries with the history of Entry value changes in form of key-value pairs:

Timeseries

A Timeseries database on the Trusted Twin platform stores structured and multidimensional views of Twin history in form of user-defined tables. A Timeseries database consists of one or more tables.

Below you can find an example of a Timeseries table. It contains a timestamp column (added automatically by the system), one dimension ("city") and three measurements ("temperature", "ozone", "relative_humidity"):

A Timeseries table is automatically updated each time an Entry with a "timeseries" attribute for the given Timeseries table is being changed.

The Timeseries database service needs to be enabled for your account. Please contact hello@trustedtwin.com for more details.

_timestamp	city	temperature	ozone	relative_humidity
21 Apr 2022 2022, 15:00:00	Gdańsk	12	29	55
21 Apr 2022 2022, 15:00:00	Wrocław	12	29	55
21 Apr 2022 2022, 16:00:00	Gdańsk	13	30	56
21 Apr 2022 2022, 16:00:00	Wrocław	12	29	55
21 Apr 2022 2022, 17:00:00	Gdańsk	12	29	54
21 Apr 2022 2022, 17:00:00	Wrocław	12	29	55
21 Apr 2022 2022, 18:00:00	Gdańsk	10	30	54
21 Apr 2022 2022, 18:00:00	Wrocław	12	29	55

Indexes

Indexes* allow you to efficiently access Ledger records and are especially helpful if you manage a large number of Twins within your account. The Indexes database on the Trusted Twin platform stores structured and multidimensional views of Twin states in form of user-defined tables. An Indexes database consists of one or more tables. An Index can occur only once in a given Twin.

Below you can find an example of an Indexes table. It contains a Twin column (stating the UUID of the Twin where the index occurs), a timestamp column stating when the index was last changed (added automatically by the system), and three properties ("gdansk_temperature", "gdansk_ozone", "gdansk_relative_humidity").

The Indexes service needs to be enabled for your account. Please contact hello@trustedtwin.com for more details.

_twin	_timestamp	gdansk_temperature	gdansk_ozone	gdansk_relative_humidity
ca12b80e-045a-4c93-9e9b-2fc407fc5f2f	18 May 2022, 11:36:39	21	29	55
b27289ba-da39-4232-a9d7-7bef299d548c	18 May 2022, 12:00:00	20	29	56

Notifications

Notifications allow to automatically invoke external services via publish/notify service (e.g., webhooks). Notifications can be triggered by the following events:

• creation of a Ledger Entry of a given name,
• change of value of a Ledger Entry,
• deletion of a Ledger Entry,
• creation of a Sticker (workflow tag),
• removal of a Sticker (workflow tag),
• expiration of a Sticker (workflow tag).

Stickers

Stickers (workflow tags) are a functionality designed to facilitate workflow processes. They support passing ownership of workflow items (e.g., tasks to be done) between multiple users.