# Advanced services

The Trusted Twin platform offers a series of advanced services. These services are:

  • the History service (stores historical values of Ledger entries),
  • the Timeseries service (stores structured and multidimensional views of Twin history),
  • the Indexes service (stores structured and multidimensional views of Twin states),
  • the Notifications (publish/notify) service,
  • the Stickers (workflow tags) service.

# 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 created through the create_timeseries_table endpoint. A Timeseries database consists of one or more tables.

On the right-hand side you can find an example of a Timeseries table which 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 created through the create_indexes_table endpoint. An Indexes database consists of one or more tables. An Index can occur only once in a given Twin.

On the right-hand side you can find an example of an Indexes table which 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,
  • value update of a given Ledger Entry,
  • creation of a Sticker (workflow tag) of a given color (name),
  • removal of a Sticker (workflow tag) of a given color (name),
  • expiration of a Sticker (workflow tag) of a given color (name).

# 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.