# How to fetch a contract from dumlhub Ledger via Java

**URL:** <https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638>\
**Category:** App Development\
**Tags:** daml\
**Created:** [May 29, 2022, 4:27pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638 "2022-05-29T16:27:55Z")\
**Posts on this page:** 13\
**Page:** 2

<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 4, 2022, 6:00am UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/21 "2022-06-04T06:00:54Z")

</div>

Thanks @Leonid_Rozenberg

I indeed performed **damlhub token eyJ0e…**

And got this response but i wonder where the created token is saved so i can use it?

{  
“message”: “Saved Daml Hub token with base domain: [hub.daml.com](http://hub.daml.com)”,  
“success”: true  
}

---

<div class="post-metadata">

**Author:** ![Leonid\_Rozenberg](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/leonid_rozenberg/32/48_2.png) [@Leonid\_Rozenberg](https://forum.canton.network/u/Leonid_Rozenberg)\
**Post date:** [June 4, 2022, 2:53pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/22 "2022-06-04T14:53:32Z")

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@liav Please read my response carefully.

```haskell
damlhub token

```

is the not same as

```haskell
damlhub ledger multipartyToken

```

The latter takes as argument the identity of parties that you want to add to a multiparty JWT. Whereas the former saves your account JWT locally (in the `scratch` folder) for reuse with other commands.

---

<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 4, 2022, 3:30pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/23 "2022-06-04T15:30:22Z")

</div>

Something like that? (sorry, i couldn’t find the manual nor the help entry on the client)

Command:  
**damlhub ledger multipartyToken p4np49dc43hsdza3 Carrier Owner**

Output:

{  
“accessToken”: “eyJ0eXAiOiJKV1QiLCJhbGciOiJSXXXXXXXXXXXXXXX1IiwiaHR0cHM6Ly9kYW1sLmNvbS9sZWRnZXItYXBpIjp7ImFjdEFzIjpbImxlZGdlci1wYXJ0eS04NTRlMwXXXXXXtuhafywLaaVPXmNEqlJS6z2sbSoetYz0KZ1X8G8rIVsP1M-zdw05CSxawMERXm6DJUm5W6raDnvSLUJ3kbh4A5IgJOs”  
}

---

<div class="post-metadata">

**Author:** ![Leonid\_Rozenberg](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/leonid_rozenberg/32/48_2.png) [@Leonid\_Rozenberg](https://forum.canton.network/u/Leonid_Rozenberg)\
**Post date:** [June 4, 2022, 11:29pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/24 "2022-06-04T23:29:30Z")

</div>

I don’t know if you copy and pasted correctly, sure looks like a lot of `X`s 😉 , but yes that’s the right call.

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<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 5, 2022, 12:30pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/25 "2022-06-05T12:30:26Z")

</div>

What am i missing?

The command seemed to work (see earlier posts in this thread but now it fails with 401

Command:  
`damlhub ledger multipartyToken p4np49dc43hsdza3 Carrier Owner`

Output:

```haskell
2022-06-05 15:27:15,982 ERROR [tokens] Tried to compute a URL for .admin, .site; got back //login.hub.daml.com/auth/login which requires the same scope.
Unexpected error: Error: Received a 401 when making a site level API request.
    at TokenManager._this._circularTokenRequirement (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:198:19)
    at TokenManager.refreshToken (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:283:18)
    at TokenManager.<anonymous> (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:237:51)
    at step (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:67:23)
    at Object.next (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:48:53)
    at /Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:42:71
    at new Promise (<anonymous>)
    at __awaiter (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:38:12)
    at TokenManager.getToken (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:228:16)
    at TokenManager.<anonymous> (/Users/le056g/.config/yarn/global/node_modules/damlhub-cli/lib/src/dabl/apiTokens.js:221:51)

```

I assume i need a preliminary login step? I tried running this command just befor the multiParty one but it didn’t help (i used account token):

```haskell
damlhub token eyJ0eXAiOiJKV1QiLCJh....

```

---

<div class="post-metadata">

**Author:** ![Leonid\_Rozenberg](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/leonid_rozenberg/32/48_2.png) [@Leonid\_Rozenberg](https://forum.canton.network/u/Leonid_Rozenberg)\
**Post date:** [June 5, 2022, 2:57pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/26 "2022-06-05T14:57:13Z")

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@liav Maybe your account token has expired?

1. Remove the `scratch/` folder where you’re running this command. This is where your account token is stored.
2. Get the latest account token from when you login into DamlHub.
3. Save it locally with `damlhub token [paste-token-here]`
4. Try running `damlhub ledger multipartyToken`

(@Alex_Matson @dtanabe , I wish there was a better error message here)

---

<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 5, 2022, 8:08pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/27 "2022-06-05T20:08:19Z")

</div>

Thanks @Leonid_Rozenberg it worked as you suggested.

Can you please refer me to the online documentation of the JSON API/gRPC for ExerciseCommand with actAs and readAs additions (to support multiParty submission)

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<div class="post-metadata">

**Author:** ![a\_putkov](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/a_putkov/32/2971_2.png) [@a\_putkov](https://forum.canton.network/u/a_putkov)\
**Post date:** [June 8, 2022, 9:50pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/28 "2022-06-08T21:50:08Z")

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@liav  
When you use HTTP JSON API, the actAs and readAs are taken from the token included in the HTTP request. For multiparty submission you simply need to include the token that contains all the actAs and readAs that you want to use.  
For gRPC the act\_as and read\_as fields are included in the Commands message. You can find the definitions for the [Commands message](https://github.com/digital-asset/daml/blob/944cc3142ad8ed36110c0d518caff2d408aeb10f/ledger-api/grpc-definitions/com/daml/ledger/api/v1/commands.proto) under [Ledger API gRPC definitions](https://github.com/digital-asset/daml/tree/main/ledger-api/grpc-definitions) on GitHub.

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<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 9, 2022, 11:17am UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/29 "2022-06-09T11:17:26Z")

</div>

Thanks @a_putkov ,

I indeed use the gRPC api rather than the JSON API. If you have a link to the documentation of the multi submit via JSON API i would check it also.

For now, with current gRPC implementation - i couldn’t understand your reply: The fact that actAs and readAs lists are part of the message i’m aware of (see code below) but **i wonder if i need to populate them both with same parties**

Code:

```haskell
private void exerciseCommandOnProduct(String contractId, ProductFields productFields, String multiPartyToken) {
        List<String> actAs = Arrays.asList(damlProperties.getOwnerParty(), "DemoParty");
        List<String> readAs = Arrays.asList(damlProperties.getOwnerParty(), "DemoParty");

        ArrayList<DamlRecord.Field> fields = new ArrayList<DamlRecord.Field>();
        fields.add(new DamlRecord.Field(new Party(damlProperties.getOwnerParty())));
        fields.add(new DamlRecord.Field(new Party(productFields.getProductCode())));

        DamlRecord choiceArgument = new DamlRecord(fields);

        ExerciseCommand command = new ExerciseCommand(TEMPLATE_ID, contractId, "CustomerCreatesPolicyRequest", choiceArgument);
        List<Command> commands = Collections.singletonList(command);

        final Single<Empty> emptySingle = client.
                getCommandSubmissionClient().
                submit(WORKFLOW_ID, APPLICATION_ID, UUID.randomUUID().toString(), actAs, readAs, commands, multiPartyToken);

        emptySingle.blockingGet();
    }

```

---

<div class="post-metadata">

**Author:** ![a\_putkov](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/a_putkov/32/2971_2.png) [@a\_putkov](https://forum.canton.network/u/a_putkov)\
**Post date:** [June 9, 2022, 5:19pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/30 "2022-06-09T17:19:36Z")

</div>

@liav  
My apologies, I thought you were asking how to specify actAs and readAs in gRPC message. Now I understand your question to be about the significance of `act_as` and `read_as` fields, right?

`act_as` must include all parties, whose authority is required to execute the transaction, else the transaction will fail according to Daml ledger [authorization rules](https://docs.daml.com/concepts/ledger-model/ledger-integrity.html#authorization-rules).

`read_as` allows you to provide additional parties that may be required for the visibility of contracts involved in the transaction. As stated in the comments for the `read_as` field in the [Commands message](https://github.com/digital-asset/daml/blob/944cc3142ad8ed36110c0d518caff2d408aeb10f/ledger-api/grpc-definitions/com/daml/ledger/api/v1/commands.proto) spec, "A command can only use contracts that are visible to at least one of the parties in `act_as` or `read_as`".

So, if every contract involved in the transaction is visible to at least one party in the `act_as` list, the `read_as` list does not need to be populated. However, if at least one contract involved in the transaction is not visible to any party in the `act_as` list, the transaction will fail unless `read_as` list contains at least one party, for which that contract is visible. An example, where a contract involved in the transaction may not be visible to any party authorizing the transaction, is a fetch action used in a choice, where the fetched contract is not visible to any of the choice controllers.

---

<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 13, 2022, 10:58am UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/31 "2022-06-13T10:58:30Z")

</div>

Thanks @a_putkov ,

I indeed encounter an issue on the exact topic you’re referring to: authentication.

My submitMulti Java implementation was as @Leonid_Rozenberg advised (see code below).

How can i gain access to the logs in order to understand the root cause of below authentication error thrown from the submit command?

The parties are: **Owner2 Public**

code:

multi party token is created via damlhub-cli:

```haskell
damlhub ledger multipartyToken ry3wqxrcdqpkz7xz Owner2 Public

```

submitMulti:

```haskell
private void exerciseCommandOnProduct(String contractId, ProductFields productFields, String multiPartyToken) {
        List<String> actAs = Arrays.asList("Public", "Owner2");
        List<String> readAs = Arrays.asList("Public", "Owner2");

        ArrayList<DamlRecord.Field> fields = new ArrayList<DamlRecord.Field>();
        fields.add(new DamlRecord.Field(new Party("Owner2")));

        DamlRecord choiceArgument = new DamlRecord(fields);

        ExerciseCommand command = new ExerciseCommand(TEMPLATE_ID, contractId, "CustomerCreatesPolicyRequest", choiceArgument);
        List<Command> commands = Collections.singletonList(command);

        final Single<Empty> emptySingle = client.
                getCommandSubmissionClient().
                submit(WORKFLOW_ID, APPLICATION_ID, UUID.randomUUID().toString(), actAs, readAs, commands, multiPartyToken);

        emptySingle.blockingGet();
    }

```

Caused by: io.grpc.StatusRuntimeException: UNAUTHENTICATED: An error occurred. Please contact the operator and inquire about the request   
at io.grpc.Status.asRuntimeException(Status.java:535) ~[grpc-api-1.44.0.jar:1.44.0]  
at io.grpc.stub.ClientCalls$UnaryStreamToFuture.onClose(ClientCalls.java:534) ~[grpc-stub-1.44.0.jar:1.44.0]  
at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:562) ~[grpc-core-1.44.0.jar:1.44.0]  
at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:70) ~[grpc-core-1.44.0.jar:1.44.0]  
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:743) ~[grpc-core-1.44.0.jar:1.44.0]  
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:722) ~[grpc-core-1.44.0.jar:1.44.0]  
at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37) ~[grpc-core-1.44.0.jar:1.44.0]  
at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:133) ~[grpc-core-1.44.0.jar:1.44.0]  
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]  
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]  
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

---

<div class="post-metadata">

**Author:** ![a\_putkov](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/a_putkov/32/2971_2.png) [@a\_putkov](https://forum.canton.network/u/a_putkov)\
**Post date:** [June 13, 2022, 2:09pm UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/32 "2022-06-13T14:09:56Z")

</div>

@liav  
As @dtanabe explained in [this post](https://discuss.daml.com/t/java-binding-exercisecommand-multisubmit-mode/4699/8) on another thread you opened, if you’re en enterprise user, you need to open a support ticket with Digital Asset Support team and provide your ledger ID to have the logs pulled from Daml Hub.

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<div class="post-metadata">

**Author:** ![liav](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/liav/32/3304_2.png) [@liav](https://forum.canton.network/u/liav)\
**Post date:** [June 14, 2022, 5:02am UTC](https://forum.canton.network/t/how-to-fetch-a-contract-from-dumlhub-ledger-via-java/4638/33 "2022-06-14T05:02:37Z")

</div>

@Roy_Silon @cohen.avraham

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