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dfx canister

Reference

Use the dfx canister command with options and subcommands to manage canister operations and interaction with the Internet Computer or the local canister execution environment. In most cases, you use dfx canister subcommands after you compile a program to manage the canister lifecycle and to perform key tasks such as calling program functions.

The basic syntax for running dfx canister commands is:

dfx canister <subcommand> [options]

Depending on the dfx canister subcommand you specify, additional arguments and options might apply or be required. To view usage information for a specific dfx canister subcommand, specify the subcommand and the --help flag. For example, to see usage information for dfx canister call, you can run the following command:

dfx canister call --help

For reference information and examples that illustrate using dfx canister commands, select an appropriate command.

CommandDescription
callCalls a specified method on a deployed canister.
createCreates an empty canister and associates the assigned Canister ID to the canister name.
deleteDeletes a currently stopped canister.
deposit-cyclesDeposit cycles into the specified canister.
helpDisplays usage information message for a specified subcommand.
idDisplays the identifier of a canister.
infoGet the hash of a canister’s Wasm module and its current controller.
installInstalls compiled code in a canister.
logsReturns the logs from a canister.
metadataDisplays metadata in a canister.
request-statusRequests the status of a call to a canister.
sendSend a previously-signed message.
signSign a canister call and generate message file.
startStarts a stopped canister.
statusReturns the current status of a canister as defined here.
stopStops a currently running canister.
uninstall-codeUninstalls a canister, removing its code and state. Does not delete the canister.
update-settingsUpdate one or more of a canister's settings (i.e its controller, compute allocation, or memory allocation.).
urlDisplays the url of a canister.

Overriding the default deployment environment

By default, dfx canister commands run on the local canister execution environment specified in the dfx.json file. If you want to send a dfx canister subcommand to the Internet Computer or a testnet without changing the settings in your dfx.json configuration file, you can explicitly specify the URL to connect to using the --network option.

For example, to register unique canister identifiers for a project on the local canister execution environment, you can run the following command:

dfx canister create --all

If you want to register unique canister identifiers for the same project on the Internet Computer, you can run the following command:

dfx canister create --all --network ic

The SDK comes with an alias of ic, which is configured to point to the Internet Computer. You can also pass a URL as a network option, or you can configure additional aliases in dfx.json under the networks configuration, or in $HOME/.config/dfx/networks.json.

To illustrate, you can call a canister and function running on a testnet using a command similar to the following:

dfx canister call counter get --network http://192.168.3.1:5678

Performing a call through the wallet

By default, most dfx canister commands to the Internet Computer are signed by and sent from your own principal. ( Exceptions are commands that require cycles: dfx canister create and dfx canister deposit-cycles. Those automatically go through the wallet.) Occasionally, you may want to make a call from your wallet, e.g. when only your wallet is allowed to call a certain function. To send a call through your wallet, you can use the --wallet option like this:

dfx canister status <canister name> --wallet <wallet id>

As a concrete example, if you want to request the status of a canister on the ic that is only controlled by your wallet, you would do the following:

dfx identity get-wallet --network ic

This command outputs your wallet's principal (e.g. 22ayq-aiaaa-aaaai-qgmma-cai) on the ic network. Using this id, you can then query the status of the canister (let's assume the canister is called my_canister_name) as follows:

dfx canister status --network ic --wallet 22ayq-aiaaa-aaaai-qgmma-cai

dfx canister call

Use the dfx canister call command to call a specified method on a deployed canister.

Basic usage

dfx canister call [options] <canister_name> <method_name> [argument]

Options

You can use the following options with the dfx canister call command.

OptionDescription
--argument-file <argument-file>Specifies the file from which to read the argument to pass to the method. Stdin may be referred to as -.
--asyncSpecifies not to wait for the result of the call to be returned by polling the replica. Instead return a response ID.
--candid <file.did>Provide the .did file with which to decode the response. Overrides value from dfx.json for project canisters.
--output <output>Specifies the output format to use when displaying a method’s return result. The valid values are idl, 'json', pp and raw. The pp option is equivalent to idl, but is pretty-printed.
--querySends a query request instead of an update request. For information about the difference between query and update calls, see Canisters include both program and state.
--random <random>Specifies the config for generating random arguments.
--type <type>Specifies the data format for the argument when making the call using an argument. The valid values are idl and raw.
--updateSends an update request to a canister. This is the default if the method is not a query method.
--with-cycles <amount>Specifies the amount of cycles to send on the call. Deducted from the wallet. Requires --wallet as an option to dfx canister.

Arguments

You can specify the following arguments for the dfx canister call command.

ArgumentDescription
canister_nameSpecifies the name of the canister to call. The canister name is a required argument and should match the name you have configured for a project in the canisters section of the dfx.json configuration file.
method_nameSpecifies the method name to call on the canister. The canister method is a required argument.
argumentSpecifies the argument to pass to the method

Specifies the argument to pass to the method

Depending on your program logic, the argument can be a required or optional argument. You can specify a data format type using the --type option if you pass an argument to the canister. By default, you can specify arguments using the Candid (idl) syntax for data values. For information about using Candid and its supported types, see Interact with a service in a terminal and supported types. You can use raw as the argument type if you want to pass raw bytes.

Examples

You can use the dfx canister call command to invoke specific methods—with or without arguments—after you have deployed the canister using the dfx canister install command. For example, to invoke the get method for a canister with a canister_name of counter, you can run the following command:

dfx canister call counter get --async

In this example, the command includes the --async option to indicate that you want to make a separate request-status call rather than waiting to poll the local canister execution environment or the Internet Computer for the result. The --async option is useful when processing an operation might take some time to complete. The option enables you to continue performing other operations then check for the result using a separate dfx canister request-status command. The returned result will be displayed as the IDL textual format.

Using the IDL syntax

You can explicitly specify that you are passing arguments using the IDL syntax by running commands similar to the following for a Text data type:

dfx canister call hello greet --type idl '("Lisa")'
("Hello, Lisa!")

dfx canister call hello greet '("Lisa")' --type idl
("Hello, Lisa!")

You can also implicitly use the IDL by running a command similar to the following:

dfx canister call hello greet '("Lisa")'
("Hello, Lisa!")

To specify multiple arguments using the IDL syntax, use commas between the arguments. For example:

dfx canister call contacts insert '("Amy Lu","01 916-335-2042")'

dfx canister call hotel guestroom '("Deluxe Suite",42,true)'

You can pass raw data in bytes by running a command similar to the following:

dfx canister call hello greet --type raw '4449444c00017103e29883'

This example uses the raw data type to pass a hexadecimal to the greet function of the hello canister.

JSON output

The --output json option formats the output as JSON.

Candid types don't map 1:1 to JSON types.

Notably, the following Candid types map to strings rather than numbers: nat, nat64, int, int64.

These are the mappings:

Candid typeJSON type
nullnull
boolboolean
natstring
nat8number
nat16number
nat32number
nat64string
intstring
int8number
int16number
int32number
int64string
float32float or "NaN"
float64float or "NaN"
textstring
optarray with 0 or 1 elements
vecarray
recordobject
variantobject
blobarray of numbers

dfx canister create

Use the dfx canister create command to register one or more canister identifiers without compiled code. The new canister principals are then recorded in canister_ids.json for non-local networks. You must be connected to the local canister execution environment or the Internet Computer to run this command.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister create [options] [--all | canister_name]

Options

You can use the following options with the dfx canister create command.

OptionDescription
-c, --compute-allocation <allocation>Specifies the canister's compute allocation. This should be a percent in the range [0..100].
--controller <principal>Specifies the identity name or the principal of the new controller.
--created-at-time <timestamp>Transaction timestamp, in nanoseconds, for use in controlling transaction deduplication, default is system time. https://internetcomputer.org/docs/current/developer-docs/integrations/icrc-1/#transaction-deduplication-
--from-subaccount <subaccount>Subaccount of the selected identity to spend cycles from.
--memory-allocation <memory>Specifies how much memory the canister is allowed to use in total. This should be a value in the range [0..12 GiB]. A setting of 0 means the canister will have access to memory on a “best-effort” basis: It will only be charged for the memory it uses, but at any point in time may stop running if it tries to allocate more memory when there isn’t space available on the subnet.
--reserved-cycles-limit <limit>Specifies the upper limit for the canister's reserved cycles.
--wasm-memory-limit <limit>Specifies a soft upper limit for the canister's heap memory.
--log-visibility <visibility>Specifies who is allowed to read the canister's logs. Can be either "controllers" or "public".
--no-walletPerforms the call with the user Identity as the Sender of messages. Bypasses the Wallet canister. Enabled by default.
--with-cycles <number-of-cycles>Specifies the initial cycle balance to deposit into the newly created canister. The specified amount needs to take the canister create fee into account. This amount is deducted from the wallet's cycle balance.
--specified-id <PRINCIPAL>Attempts to create the canister with this Canister ID
--subnet-type <subnet-type>Specify the subnet type to create the canister on. If no subnet type is provided, the canister will be created on a random default application subnet.
--subnet <subnet-principal>Specify the subnet to create the canister on. If no subnet is provided, the canister will be created on a random default application subnet.
--next-to <canister-principal>Create canisters on the same subnet as this canister.

Arguments

You can use the following argument with the dfx canister create command.

ArgumentDescription
--allEnables you to create multiple canister identifiers at once if you have a project dfx.json file that defines multiple canisters. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister for which you want to register an identifier. If you are not using the --all option, the canister name is a required argument and must match at least one name that you have configured in the canisters section of the dfx.json configuration file for your project.

Examples

You can use the dfx canister create command to register canister identifiers without first compiling any code. For example, if you want to create the canister identifier for the project my_counter before writing the program, you can run the following command:

dfx canister create my_counter

You can use the dfx canister create command with the --with-cycles option to specify the initial balance upon the creation of one canister or all canisters in a project. For example, to specify an initial balance of 8000000000000 cycles for all canisters, run the following command:

dfx canister create --with-cycles 8000000000000 --all

Allocating message processing

The --compute-allocation options allows you to allocate computing resources as a percentage in the range of 0 to 100 to indicate how often your canister should be scheduled for execution.

For example, assume you run the following command:

dfx canister create --all --compute-allocation 50

With this setting, all of the canisters in the current projects are assigned a 50% allocation. When canisters in the project receive input messages to process, the messages are scheduled for execution. Over 100 execution cycles, each canister’s messages will be scheduled for processing at least 50 times.

The default value for this option is 0—indicating that no specific allocation or scheduling is in effect. If all of your canisters use the default setting, processing occurs in a round-robin fashion.

dfx canister delete

Use the dfx canister delete command to delete a stopped canister from the local canister execution environment or the Internet Computer. By default, this withdraws remaining cycles to your wallet before deleting the canister.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister delete [options] [--all | canister_name]

Options

You can use the following options with the dfx canister delete command.

OptionDescription
--no-withdrawalDo not withdrawal cycles, just delete the canister.
--initial-margin <cycles>Leave this many cycles in the canister when withdrawing cycles.
--to-subaccountSubaccount of the selected identity to deposit cycles to.
--withdraw-cycles-to-dankWithdraw cycles to dank with the current principal.
--withdraw-cycles-to-canister <principal>Withdraw cycles from canister(s) to the specified canister/wallet before deleting.
--withdraw-cycles-to-dank-principal <principal>Withdraw cycles to dank with the given principal.
-y, --yesAuto-confirm deletion for a non-stopped canister

Arguments

You can use the following arguments with the dfx canister delete command.

ArgumentDescription
--allDeletes all of the canisters configured in the dfx.json file. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister you want to delete. Note that you must specify either a canister name or the --all option.

Examples

You can use the dfx canister delete command to delete a specific canister or all canisters.

To delete the hello_world canister, you can run the following command:

dfx canister delete hello_world

To delete all of the canisters you have deployed on the ic Internet Computer and configured in your dfx.json, you can run the following command:

dfx canister delete --all --network=ic

dfx canister deposit-cycles

Use the dfx canister deposit-cycles command to deposit cycles from your configured wallet into a canister.

Note that you must have your cycles wallet configured for this to work.

Basic usage

dfx canister deposit-cycles <cycles> [--all | canister_name]

Arguments

You can use the following arguments with the dfx canister deposit-cycles command.

ArgumentDescription
--allDeposits the specified amount of cycles into all canisters configured in dfx.json. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister you want to deposit cycles into. Note that you must specify either a canister name or the --all option.

Options

You can use the following options with the dfx canister deposit-cycles command.

OptionDescription
--created-at-time <timestamp>Transaction timestamp, in nanoseconds, for use in controlling transaction deduplication, default is system time. https://internetcomputer.org/docs/current/developer-docs/integrations/icrc-1/#transaction-deduplication-
--from-subaccount <subaccount>Subaccount of the selected identity to spend cycles from.

Examples

You can use the dfx canister deposit-cycles command to add cycles to a specific canister or all canisters.

To add 1T cycles to the canister called hello, you can run the following command:

dfx canister deposit-cycles 1000000000000 hello

To add 2T cycles to each individual canister specified in dfx.json, you can run the following command:

dfx canister deposit-cycles 2000000000000 --all

dfx canister id

Use the dfx canister id command to output the canister identifier/principal for a specific canister name.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

If the canister has been deployed by the local user, the locally stored canister ID will be provided.

If a canister has been deployed by a third party, the user may set the .canisters[$CANISTER_NAME].remote[$NETWORK] entry in dfx.json to the canister ID. In this case, the third party is responsible for maintaining the canister and the local user must ensure that they have the correct canister ID. dfx will return the provided canister ID with no further checks.

If a canister is typically deployed to the same canister ID on mainnet and all testnets, the user may set a remote canister ID for the __default network. In this case, dfx canister id $CANISTER_NAME will return the default canister ID for all networks that don't have a dedicated entry.

Basic usage

dfx canister id <canister_name>

Arguments

You can use the following argument with the dfx canister id command.

ArgumentDescription
canister_nameSpecifies the name of the canister for which you want to display an identifier.

Examples

You can use the dfx canister id command to display the canister identifier for a specific canister name.

To display the canister identifier for the hello_world canister, you can run the following command:

dfx canister id hello_world

The command displays output similar to the following:

75hes-oqbaa-aaaaa-aaaaa-aaaaa-aaaaa-aaaaa-q

dfx canister info

Use the dfx canister info command to output a canister's controller and installed Wasm module hash.

Basic usage

dfx canister info <canister>

Arguments

You can use the following argument with the dfx canister info command.

ArgumentDescription
canisterSpecifies the name or id of the canister for which you want to display data.

Examples

You can use the dfx canister info command to display the canister controller and installed Wasm module.

To the data about the hello_world canister, you can run the following command:

dfx canister info hello_world

The command displays output similar to the following:

Controllers: owdog-wiaaa-aaaad-qaaaq-cai
Module hash: 0x2cfb6f216fd6ab367364c02960afbbc5c444f5481225ee676992ac9058fd41e3

dfx canister install

Use the dfx canister install command to install compiled code as a canister on the Internet Computer or on the local canister execution environment.

Basic usage

dfx canister install [option] [--all | canister_name]

Options

You can use the following options with the dfx canister install command.

OptionDescription
--argument <argument>Specifies an argument to pass to the canister during installation.
--argument-type <argument-type>Specifies the data type for the argument when making the call using an argument [possible values: idl, raw]
--argument-file <argument-file>Specifies the file from which to read the argument to pass to the init method. Stdin may be referred to as -.
--async-callEnables you to continue without waiting for the result of the installation to be returned by polling the Internet Computer or the local canister execution environment.
-m, --mode <mode>Specifies whether you want to install, reinstall, or upgrade canisters. Defaults to install. For more information about installation modes and canister management, see managing canisters.
--no-walletPerforms the call with the user Identity as the Sender of messages. Bypasses the Wallet canister. Enabled by default.
--no-asset-upgradeSkips upgrading the asset canister, to only install the assets themselves.
--upgrade-unchangedUpgrade the canister even if the .wasm did not change.
--wasm <file.wasm>Specifies a particular Wasm file to install, bypassing the dfx.json project settings.

Specifies the argument to pass to the init entrypoint

With --argument-type, you can specify the data format for the argument when you install using the --argument option. The valid values are idl and raw. By default, you can specify arguments using the Candid (idl) syntax for data values. For information about using Candid and its supported types, see Interact with a service in a terminal and Supported types. You can use raw as the argument type if you want to pass raw bytes to a canister.

Arguments

You can use the following arguments with the dfx canister install command.

ArgumentDescription
--allEnables you to install multiple canisters at once if you have a project dfx.json file that includes multiple canisters. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister to deploy. If you are not using the --all option, the canister name is a required argument and should match the name you have configured for a project in the canisters section of the dfx.json configuration file.

Examples

You can use the dfx canister install command to deploy WebAssembly you have compiled using the dfx build command as a canister on the Internet Computer or on the local canister execution environment. The most common use case is to install all of the canisters by running the following command:

dfx canister install --all

Installing a specific canister

You can also use the dfx canister install command to deploy a specific canister instead of all of the canisters in your project. For example, if you have a project with a hello_world_backend canister and a hello_world_frontend canister but only want to deploy the hello_world_backend canister, you can deploy just that the canister by running the following command:

dfx canister install hello_world_backend

Sending an asynchronous request

If you want to submit a request to install the canister and return a request identifier to check on the status of your request later instead of waiting for the command to complete, you can run a command similar to the following:

dfx canister install hello_world_backend --async

This command submits a request to install the canister and returns a request identifier similar to the following:

0x58d08e785445dcab4ff090463b9e8b12565a67bf436251d13e308b32b5058608

You can then use the request identifier to check the status of the request at a later time, much like a tracking number if you were shipping a package.

Overriding the default deployment options

If you want to deploy a canister on a testnet without changing the settings in your dfx.json configuration file, you can explicitly specify the testnet you want to connect to by using the --network option.

For example, you can specify a testnet URL by running a command similar to the following:

dfx canister install --all --network http://192.168.3.1:5678

dfx canister logs

Use the dfx canister logs command to display the logs from a canister.

Basic usage

dfx canister logs <canister-name>

Examples

To display the logs from the hello_world canister, you can run the following command:

dfx canister logs hello_world

The command displays output similar to the following:

[42. 2021-05-06T19:17:10.000000001Z]: Some text message
[43. 2021-05-06T19:17:10.000000002Z]: (bytes) 0xc0ffee

dfx canister metadata

Use the dfx canister metadata command to display metadata stored in a canister's Wasm module.

Basic usage

dfx canister metadata <canister-name> <metadata-name>

Arguments

You can use the following argument with the dfx canister metadata command.

ArgumentDescription
canisterSpecifies the name or id of the canister for which you want to display metadata.
metadata-nameSpecifies the name of the metadata which you want to display.

Examples

To display the candid service metadata for the hello_world canister, you can run the following command:

dfx canister metadata hello_world candid:service

The command displays output similar to the following:

service : {
greet: (text) -> (text);
}

dfx canister request-status

Use the dfx canister request-status command to request the status of a specified call to a canister. This command requires you to specify the request identifier you received after invoking a method on the canister. The request identifier is an hexadecimal string starting with 0x.

Basic usage

dfx canister request-status [options] <request-id> <canister>

Options

You can use the following options with the dfx canister request-status command.

OptionDescription
--output <output>Specifies the format for displaying the method's return result. Possible values are idl, raw and pp, where pp is equivalent to idl, but is pretty-printed.

Arguments

You can specify the following argument for the dfx canister request-status command.

ArgumentDescription
request_idSpecifies the hexadecimal string returned in response to a dfx canister call or dfx canister install command. This identifier is an hexadecimal string starting with 0x.
canisterSpecifies the name or id of the canister onto which the request was made. If the request was made to the Management canister, specify the id of the canister it is updating/querying. If the call was proxied by the wallet, i.e. a dfx canister call --async --wallet=<ID> flag, specify the wallet canister id.

Examples

You can use the dfx canister request-status command to check on the status of a canister state change or to verify that a call was not rejected by running a command similar to the following:

dfx canister request-status 0x58d08e785445dcab4ff090463b9e8b12565a67bf436251d13e308b32b5058608 backend

This command displays an error message if the request identifier is invalid or refused by the canister.

dfx canister send

Use the dfx canister send command after signing a message with the dfx canister sign command when you want to separate these steps, rather than using the single dfx canister call command. Using separate calls can add security to the transaction.

For example, when creating your neuron stake, you might want to use the dfx canister sign command to create a signed message.json file using an air-gapped computer, then use the dfx canister send command to deliver the signed message.

Basic usage

dfx canister send [options] <file_name>

Options

You can use the following options with the dfx canister request-status command.

OptionDescription
--statusSend the signed request-status call in the message.

Arguments

You can specify the following argument for the dfx canister send command.

ArgumentDescription
file_nameSpecifies the file name of the message.

Examples

Use the dfx canister send command to send a signed message created using the dfx canister sign command to the genesis token canister (GTC) to create a neuron on your behalf by running the following command:

dfx canister send message.json

dfx canister sign

Use the dfx canister sign command before sending a message with the dfx canister send command when you want to separate these steps, rather than using the single dfx canister call command. Using separate calls can add security to the transaction. For example, when creating your neuron stake, you might want to use the dfx canister sign command to create a signed message.json file using an air-gapped computer, then use the dfx canister send command to deliver the signed message from a computer connected to the Internet Computer.

Basic usage

dfx canister sign [options] <canister-name> <method-name> [argument]

Options

You can specify the following options for the dfx canister sign command.

OptionDescription
--argument-file <file>Specifies the file from which to read the argument to pass to the method. Stdin may be referred to as -.
--expire-after <seconds>Specifies how long the message will be valid before it expires and cannot be sent. Specify in seconds. If not defined, the default is 300s (5m).
--file <output>Specifies the output file name. The default is message.json.
--querySends a query request to a canister.
--random <random>Specifies the configuration for generating random arguments.
--type <type>Specifies the data type for the argument when making a call using an argument. Possible values are idl and raw.
--updateSends an update request to the canister. This is the default method if the --query method is not used.

Arguments

You can specify the following arguments for the dfx canister sign command.

ArgumentDescription
canister_nameSpecifies the name of the canister to call. The canister name is a required argument and should match the name you have configured for a project in the canisters section of the dfx.json configuration file.
method_nameSpecifies the method name to call on the canister. The canister method is a required argument.
argumentSpecifies the argument to pass to the method

Specifies the argument to pass to the method

Depending on your program logic, the argument can be a required or optional argument. You can specify a data format type using the --type option if you pass an argument to the canister. By default, you can specify arguments using the Candid (idl) syntax for data values. For information about using Candid and its supported types, see Interact with a service in a terminal and supported types. You can use raw as the argument type if you want to pass raw bytes.

Examples

Use the dfx canister sign command to create a signed message.json file using the selected identity by running a command similar to the following:

dfx canister sign --network=ic --expire-after=1h rno2w-sqaaa-aaaaa-aaacq-cai create_neurons ‘(“PUBLIC_KEY”)’

This command illustrates how to creates a message.json file to create neurons on the Internet Computer specified by the ic alias, that is signed using your principal identifier as the message sender and with an expiration window that ends in one hour.

Note that the time allotted to send a signed message is a fixed 5-minute window. The --expire-after option enables you to specify the point in time when the 5-minute window for sending the signed message should end. For example, if you set the --expire-after option to one hour (1h), you must wait at least 55 minutes before you send the generated message and the signature for the message is only valid during the 5-minute window ending in the 60th minute.

In this example, therefore, you would need to send the message after 55 minutes and before 60 minutes for the message to be recognized as valid.

If you don’t specify the --expire-after option, the default expiration is five minutes.

Send the signed message to the genesis token canister (GTC) to create a neuron on your behalf by running the following command:

dfx canister send message.json

dfx canister start

Use the dfx canister start command to restart a stopped canister on the Internet Computer or the local canister execution environment.

In most cases, you run this command after you have stopped a canister to properly terminate any pending requests as a prerequisite to upgrading the canister.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister start [--all | canister_name]

Arguments

You can use the following arguments with the dfx canister start command.

ArgumentDescription
--allStarts all of the canisters configured in the dfx.json file. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister you want to start. Note that you must specify either a canister name or the --all option.

Examples

You can use the dfx canister start command to start a specific canister or all canisters.

To start the hello_world canister, you can run the following command:

dfx canister start hello_world

To start all of the canisters you have deployed on the ic Internet Computer, you can run the following command:

dfx canister start --all --network=ic

dfx canister status

Use the dfx canister status command to check whether a canister is currently running, in the process of stopping, or currently stopped on the Internet Computer or on the local canister execution environment.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister status [--all | canister_name]

Arguments

You can use the following arguments with the dfx canister status command.

ArgumentDescription
--allReturns status information for all of the canisters configured in the dfx.json file. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister you want to return information for. Note that you must specify either a canister name or the --all option.

Examples

You can use the dfx canister status command to check the status of a specific canister or all canisters.

To check the status of the hello_world canister, you can run the following command:

dfx canister status hello_world

To check the status for all of the canisters you have deployed on the ic Internet Computer, you can run the following command:

dfx canister status --all --network=ic

dfx canister stop

Use the dfx canister stop command to stop a canister that is currently running on the Internet Computer or on the local canister execution environment.

In most cases, you run this command to properly terminate any pending requests as a prerequisite to upgrading the canister.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister stop [--all | canister_name]

Arguments

You can use the following arguments with the dfx canister stop command.

ArgumentDescription
--allStops all of the canisters configured in the dfx.json file. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister you want to stop. Note that you must specify either a canister name or the --all option.

Examples

You can use the dfx canister stop command to stop a specific canister or all canisters.

To stop the hello_world canister, you can run the following command:

dfx canister stop hello_world

To stop all of the canisters you have deployed on the ic Internet Computer, you can run the following command:

dfx canister stop --all --network=ic

dfx canister uninstall-code

Use the dfx canister uninstall-code command to uninstall the code that a canister that is currently running on the Internet Computer or on the local canister execution environment.

This method removes a canister’s code and state, making the canister empty again. Only the controller of the canister can uninstall code. Uninstalling a canister’s code will reject all calls that the canister has not yet responded to, and drop the canister’s code and state. Outstanding responses to the canister will not be processed, even if they arrive after code has been installed again. The canister is now empty.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister uninstall-code [--all | canister_name]

Arguments

You can use the following arguments with the dfx canister uninstall-code command.

ArgumentDescription
--allUninstalls all of the canisters configured in the dfx.json file. Note that you must specify --all or an individual canister name.
canister_nameSpecifies the name of the canister you want to uninstall. Note that you must specify either a canister name or the --all option.

Examples

You can use the dfx canister uninstall-code command to uninstall a specific canister or all canisters.

To uninstall the hello_world canister, you can run the following command:

dfx canister uninstall-code hello_world

To uninstall all of the canisters you have deployed on the ic Internet Computer, you can run the following command:

dfx canister uninstall-code --all --network=ic

dfx canister update-settings

Use the dfx canister update-settings command to update the settings of a canister running in the local execution environment.

In most cases, you run this command to tune the amount of resources allocated to your canister.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

Basic usage

dfx canister update-settings [options] [canister_name | --all]

Options

You can specify the following options for the dfx canister update-settings command.

OptionDescription
--add-controller <principal>Add a principal to the list of controllers of the canister.
-c, --compute-allocation <allocation>Specifies the canister's compute allocation. This should be a percent in the range [0..100].
--confirm-very-long-freezing-thresholdFreezing thresholds above ~1.5 years require this option as confirmation.
--set-controller <principal>Specifies the identity name or the principal of the new controller. Can be specified more than once, indicating the canister will have multiple controllers. If any controllers are set with this parameter, any other controllers will be removed.
--memory-allocation <allocation>Specifies how much memory the canister is allowed to use in total. This should be a value in the range [0..12 GiB]. A setting of 0 means the canister will have access to memory on a “best-effort” basis: It will only be charged for the memory it uses, but at any point in time may stop running if it tries to allocate more memory when there isn’t space available on the subnet.
--reserved-cycles-limit <limit>Specifies the upper limit of the canister's reserved cycles.
--wasm-memory-limit <limit>Specifies a soft upper limit for the canister's heap memory.
--log-visibility <visibility>Specifies who is allowed to read the canister's logs. Can be either "controllers" or "public".
--remove-controller <principal>Removes a principal from the list of controllers of the canister.
--freezing-threshold <seconds>Set the freezing threshold in seconds for a canister. This should be a value in the range [0..2^64^-1]. Very long thresholds require the --confirm-very-long-freezing-threshold option.
-y, --yesSkips yes/no checks by answering 'yes'. Such checks can result in loss of control, so this is not recommended outside of CI.

Arguments

You can use the following arguments with the dfx canister update-settings command.

ArgumentDescription
--allUpdates all canisters you have specified in dfx.json. You must specify either canister name/id or the --all option.
canister_nameSpecifies the name of the canister you want to update. You must specify either canister name/id or the --all option.

Examples

You can use the dfx canister update-settings command to update settings of a specific canister.

To update the settings of the hello_world canister, you can run the following command:

dfx canister update-settings --freezing-threshold 2592000 --compute-allocation 99 hello_world

dfx canister url

Use the dfx canister url command to output the canister url for a specific canister.

Note that you can only run this command from within the project directory structure. For example, if your project name is hello_world, your current working directory must be the hello_world top-level project directory or one of its subdirectories.

If the canister has been deployed by the local user, the locally stored canister ID will be provided within the url. You can check the .dfx/local/canister_ids.json file in the project directory for details.

If a canister has been deployed by a third party, the user may set the .canisters[$CANISTER_NAME].remote[$NETWORK] entry in dfx.json to the canister ID. In this case, the third party is responsible for maintaining the canister and the local user must ensure that they have the correct canister ID. dfx will use the provided canister ID with no further checks.

Basic usage

dfx canister url <canister>

Arguments

You can use the following argument with the dfx canister url command.

ArgumentDescription
canisterSpecifies the name or id of the canister for which you want to display the url.

Examples

To display the canister url for the hello_world_backend canister, you can run the following command:

dfx canister url hello_world_backend

The command displays output similar to the following:

http://127.0.0.1:4943/?canisterId=br5f7-7uaaa-aaaaa-qaaca-cai&id=bkyz2-fmaaa-aaaaa-qaaaq-cai

The br5f7-7uaaa-aaaaa-qaaca-cai is the local canister id for __Candid_UI canister. You need to run dfx deploy to generate the local __Candid_UI entry in .dfx/local/canister_ids.json first.

If you run:

dfx canister url hello_world_backend --network ic

The command displays output similar to the following:

https://a4gq6-oaaaa-aaaab-qaa4q-cai.raw.icp0.io/?id=bkyz2-fmaaa-aaaaa-qaaaq-cai

The a4gq6-oaaaa-aaaab-qaa4q-cai is the canister id for __Candid_UI canister on the IC mainnet.