Daml

Daml Shell

Daml Shell is a component that enables you to interactively query ledger data made available in the Participant Query Store (PQS) PostgreSQL database.

Overview

Daml Shell provides an interactive terminal session to examine the current and historical state of the ledger by querying ledger transactions and associated events (creates and exercises/archives) stored in a PostgreSQL database by an active PQS deployment.

With Daml Shell you can do the following:

Find a specific contract and display it. For example, if you have a contract ID, you can use Daml Shell to inspect the corresponding contract using the contract command.
Find all events related to a transaction ID. A transaction is displayed as a series of ledger events (creates, archives, and exercises).
Auto-completion for identifiers such as contract IDs, fully qualified names, and package names.
List active, inactive, or all contracts for a template using a template FQN.
Apply queries and filters to commands to manage the output.
Use the compare-contracts command to highlight the delta between two contract IDs for the same template.
Query between a range of offset values.

The diagram below illustrates where Daml Shell sits within the overall architecture of a Canton ledger and how it interacts with PQS’s database:

        flowchart LR
  PQS  --> |"Ledger API<br>(gRPC)"| Participant["Canton<br>Participant"]
  PQS["PQS"] --> |"DML<br>(JDBC)"| PG
  Shell["Daml Shell<br>(daml-shell.jar)"] -.-> |"SQL<br>(JDBC)"| PG["PostgreSQL"]

Compatibility

Daml Shell is compatible with multiple versions of PQS:

Dependency	Versions
PQS	>= 0.4.11
postgres-document.schema	>= 014

Download

Daml Shell is only available to enterprise customers. Daml Shell is available as both a Java jar file and a Docker container image.

Source	Location
Browse UI	https://console.cloud.google.com/artifacts/docker/da-images/europe/public/docker%2Fdaml-shell
Docker Registry	`europe-docker.pkg.dev/da-images/public/docker/daml-shell`

Configure

Daml Shell ascertains its configuration from the following sources, in order of priority:

HOCON configuration files (--config argument)
Command-line arguments
Java system properties (-D arguments to java command)
Environment variables
Interactively via set command once running

Note

While Daml Shell’s configuration is read at start up many of the values can be adjusted interactively. Please consult the Interactive configuration section.

Consult Configuration options for all available configuration options.

Secure

Daml Shell is a client to PostgreSQL database as such it needs to respect security settings mandated by those services - TLS and authentication:

TLS

Your server-side components (PostgreSQL) may require TLS to be used. Please refer to their documentation for instructions:

for PostgreSQL see [1]

Once configured, use appropriate values for dedicated parameters:

$ ./daml-shell.jar \
     --postgres-tls-cert /path/to/postgres.crt \
     --postgres-tls-key /path/to/postgres.der \
     --postgres-tls-cafile /path/to/postgres.crt \
     --postgres-tls-mode VerifyFull

Operate

Pre-requisites

To run Daml Shell you need the following:

PQS deployment with Populated PostgreSQL database

Daml Shell application jar or Docker image

Run Daml Shell

Daml Shell is an interactive client and requires a PQS database.

Start Daml Shell with a downloaded jar file:

$ ./daml-shell.jar

Note

You will need to ensure you have a suitable Java Runtime Environment (17+) installed on your host to run the .jar artifact

Docker image considerations

Due to Daml Shell being an interactive terminal application please ensure your docker run command has the interactive (-i / --interactive) and TTY (-t / --tty) arguments set as a TTY is required.

$ docker run --interactive --tty \
    europe-docker.pkg.dev/da-images/docker/daml-shell:<version-tag>

Note

If using container orchestration tooling such as Docker Compose or Kubernetes, please consult the respective documentation for enabling TTY and interactivity for Daml Shell

Get help

Exploring configuration options is easiest via the –help argument:

$ ./daml-shell.jar --help
   Usage: daml-shell [options]

     -h, --help               prints this usage text
     --config <file>          HOCON config file with settings as key-value pairs
     -v, --version            Print the version of Daml Shell
     --wildcard-char <char>   wildcard character used to abbreviate identifiers. Default: "…"
     --identifier-hash-length <length>
                              Number of characters to render for hashes inside identifiers. Default: 20
     --full-identifiers       Disable identifier shortening.
     --identifier-trim-location <leading|middle|trailing>
                              Where to trim long identifiers. Default: "trailing"
     --completion-query-items <count>
                              How many completions to show unprompted. Default: 100
     --disable-color          Disable ANSI colored output.
     --postgres-host <host>   Postgres host to connect to. Implies --connect. Default: "localhost"
     --postgres-port <port>   Postgres port to connect to. Implies --connect. Default: 5432
     --postgres-username <username>
                              Postgres username to connect with. Implies --connect. Default: "postgres"
     --postgres-password <password>
                              Postgres password to connect with. Implies --connect. Default: none
     --postgres-database <name>
                              Postgres database to connect to. Implies --connect. Default: "postgres"
     --postgres-schema <schema>
                              Postgres schema to connect to. Implies --connect. Default: "public"
     --postgres-tls-mode <Disable|VerifyCA|VerifyFull|Require>
                              TLS mode for Postgres connection. Implies --connect. Default: "Disable"
     --postgres-tls-cafile <path>
                              Path to the TLS CA file for Postgres connection. Implies --connect. Default: none
     --postgres-tls-cert <path>
                              Path to the TLS certificate file for Postgres connection. Implies --connect. Default: none
     --postgres-tls-key <path>
                              Path to the TLS key file for Postgres connection. Implies --connect. Default: none
     --connect                Auto-connect to the database on startup.

Troubleshoot

Why don’t I see any archived contracts?

If you don’t see any archived contracts, PQS might be configured to seed the database from the latest available ACS, which does not include historical events.

To see pre-existing archived contracts, seed the database from the Transaction Stream or Transaction Tree Stream.

To ingest as much history as possible, set --pipeline-ledger-start to Genesis when running PQS for the first time, refer to the PQS documentation.

Why don’t I see any choices?

Choices are only visible on the Ledger API’s Transaction Tree Stream. Set --pipeline-datasource to TransactionTreeStream when running PQS, refer to the PQS documentation.

If you still don’t see choices, see Why don’t I see any archived contracts?

Why don’t I see any interface views?

Interfaces are only visible on the Ledger API’s Transaction Stream or ACS (not the Transaction Tree Stream).

Set --pipeline-datasource to TransactionStream when running PQS, refer to the PQS documentation.

Why do all contracts show the same ledger offset?

See Why don’t I see any archived contracts?

Contribute

Please, visit https://discuss.daml.com/tag/daml-shell to ask questions and raise feature requests.

References

Configuration options

./daml-shell.jar parameters

Parameter	Description
`--config <file>`	Path to configuration overrides via an external HOCON file (optional) + Environment variable: `DAML_SHELL_CONFIG` System property: `config`
`--wildcard-char <char>`	Wildcard character used to abbreviate identifiers. (default: `…`) Environment variable: `DAML_SHELL_WILDCARD_CHAR` System property: `wildcard-char`
`--identifier-hash-length <length>`	Number of characters to render for hashes inside identifiers. (default: `20`) Environment variable: `DAML_SHELL_IDENTIFIER_HASH_LENGTH` System property: `identifier-hash-length`
`--full-identifiers`	Disable identifier shortening. Environment variable: `DAML_SHELL_FULL_INDENTIFIERS` System property: full-identifiers
`--identifier-trim-location <enum>`	Where to trim long identifiers. (default: `trailing`) Environment variable: `DAML_SHELL_IDENTIFIER_TRIM_LOCATION` System property: `identifier-trim-location` Enumeration values: `leading`, `middle`, `trailing`
`--completion-query-items <count>`	How many completions to show unprompted. (default: `100`) Environment variable: `DAML_SHELL_COMPLETION_QUERY_ITEMS` System property: `completion-query-items`
`--disable-color`	Disable ANSI colored output (optional) Environment variable: `DAML_SHELL_DISABLE_COLOR` System property: `disable-color`
`--postgres-host <host>`	Postgres host to connect to. Implies –connect. (default: `localhost`) Environment variable: `DAML_SHELL_POSTGRES_HOST` System property: `postgres-host`
`--postgres-port <port>`	Postgres port to connect to. Implies –connect. (default: `5432`) Environment variable: `DAML_SHELL_POSTGRES_PORT` System property: `postgres-port`
`--postgres-username <username>`	Postgres username to connect with. Implies –connect. (default: `postgres`) Environment variable: `DAML_SHELL_POSTGRES_USERNAME` System property: `postgres-username`
`--postgres-password <password>`	Postgres password to connect with. Implies –connect. (default: `none`) Environment variable: `DAML_SHELL_POSTGRES_PASSWORD` System property: `postgres-password`
`--postgres-database <name>`	Postgres database to connect to. Implies –connect. (default: `postgres`) Environment variable: `DAML_SHELL_POSTGRES_DATABASE` System property: `postgres-database`
`--postgres-schema <name>`	Postgres schema to connect to. Implies –connect. (default: `public`) Environment variable: `DAML_SHELL_POSTGRES_SCHEMA` System property: `postgres-schema`
`--postgres-tls-mode <enum>`	TLS mode for Postgres connection. Implies –connect. (default: `Disable`) Environment variable: `DAML_SHELL_POSTGRES_TLS_MODE` System property: `postgres-tls-mode` Enumeration values: `Disable`, `VerifyCA`, `VerifyFull`, `Require`
`--postgres-tls-cafile <path>`	Path to the TLS CA file for Postgres connection. Implies –connect. (default: `none`) Environment variable: `DAML_SHELL_POSTGRES_TLS_CAFILE` System property: `postgres-tls-cafile`
`--postgres-tls-cert <path>`	Path to the TLS certificate file for Postgres connection. Implies –connect. (default: `none`) Environment variable: `DAML_SHELL_POSTGRES_TLS_CERT` System property: `postgres-tls-cert`
`--postgres-tls-key <path>`	Path to the TLS key file for Postgres connection. Implies –connect. (default: `none`) Environment variable: `DAML_SHELL_POSTGRES_TLS_KEY` System property: `postgres-tls-key`
`--connect`	Auto-connect to the database on startup. Environment variable: `DAML_SHELL_CONNECT` System property: `connect`

Interactive configuration

You can set or adjust configuration values interactively using the set command once Daml Shell has been started.

Change the length of the identifier hash:

> set identifier-hash-length full
Disabled identifier shortening

Type help set or help set <setting> to learn more about specific settings:

> help set
NAME
    set - configure application settings

SYNOPSIS
    set [<command>]

DESCRIPTION
    Available settings:
      * postgres-database <database> - PostgreSQL database
      * oldest <start|offset> - lower offset bound
      * postgres-tls-key <path> - PostgreSQL TLS key file
      * postgres-username <username> - PostgreSQL username
      * postgres-port <port> - PostgreSQL port
      * latest <end|previous|next|offset> - upper offset bound
      * identifier-hash-length <length|full> - identifier length
      * postgres-host <host> - PostgreSQL host
      * disable-color  - disable color output
      * postgres-password <password> - PostgreSQL password
      * postgres-tls-cafile <path> - PostgreSQL TLS CA file
      * postgres-tls-cert <path> - PostgreSQL TLS cert file
      * identifier-trim-location <leading|middle|trailing> - identifier trim location
      * postgres-tls-mode <mode> - PostgreSQL TLS mode
      * wildcard-char <char> - identifier wildcard
      * enable-color  - enable color output
      * completion-query-items <count> - completion count

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