@daml/ledger

Client side API implementation for a DAML based ledgers. This library implements the JSON API for a DAML ledger.

Usage

The best way to get you started quickly is to look at Create DAML App and to read the Quickstart Guide.

We recommend to use the React framework and the @daml/react library to build frontends for DAML applications. If you choose a different Javascript based framework, please take a look at the source of @daml/react and it's usage of the @daml/ledger library.

The main export of @daml/ledger is the Ledger class. It's constructor takes an authentication token used to communicate with the JSON API, an HTTP base URL and a websocket base URL.

An instance of the Ledger class provides the following methods to communicate with a DAML ledger. Please consult the documentation for their exact signatures.

create

Create a new contract of the given template with given arguments.

archive

Archive a contract identified by its contract id.

archiveByKey

Archive a contract identified by its contract key.

exercise

Exercise a choice on a contract identified by its contract id.

exerciseByKey

Exercise a choice on a contract identified by its contract key.

query

Retrieve contracts for a given template matching a given query. If no query is given, all contracts of that template visible for the submitting party are returned.

streamQuery

Deprecated: prefer streamQueries.

Retrieve a consolidated stream of events for a given template and optional query. The accumulated state is the current set of active contracts matching the query if one was given; if the function was called without a query argument, or the query argument was undefined, the accumulated state will instead contain all of the active contracts for the given template.

streamQueries

Retrieve a consolidated stream of events for a given template and queries. The accumulated state is the current set of active contracts matching at least one of the given queries, or all contracts for the given template if no query is given.

fetch

Fetch a contract identified by its contract id.

fetchByKey

Fetch a contract identified by its contract key.

streamFetchByKey

Deprecated: prefer streamFetchByKeys.

Retrieve a consolidated stream of CreateEvent's for a given template and contract key. The accumulated state is either the CreateEvent for the active contract matching the given key, or null if there is no currently-active contract for the given key.

streamFetchByKeys

Retrieve a consolidated stream of CreateEvent's for a given template and contract keys. The accumulated state is a vector of the same length as the given vector of keys, where each element is the CreateEvent for the current active contract of the corresponding key (element-wise), or null if there is no current active contract for that key.

Note: the given key objects will be compared for (deep) equality with the values returned by the API. As such, they have to be given in the "output" format of the JSON API. See the JSON API docs for details.

Source

https://github.com/digital-asset/daml/tree/master/language-support/ts/daml-ledger

License

Apache-2.0