# Configuring sandbox seeding in 2.5.0

**URL:** <https://forum.canton.network/t/configuring-sandbox-seeding-in-2-5-0/6044>\
**Category:** App Development\
**Tags:** sandbox\
**Created:** [January 31, 2023, 8:27am UTC](https://forum.canton.network/t/configuring-sandbox-seeding-in-2-5-0/6044 "2023-01-31T08:27:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Luciano](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/luciano/32/319_2.png) [@Luciano](https://forum.canton.network/u/Luciano)\
**Post date:** [January 31, 2023, 8:27am UTC](https://forum.canton.network/t/configuring-sandbox-seeding-in-2-5-0/6044/1 "2023-01-31T08:27:14Z")

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Going off these old threads

> [@\`contract-id-seeding=testing-weak\` not effective?](https://discuss.daml.com/t/contract-id-seeding-testing-weak-not-effective/5031):
>
> I start a sandbox with the option to use testing-weak: sandbox-options: - -C=canton.participants.sandbox.parameters.contract-id-seeding=testing-weak Yet I get this warning: WARN c.d.p.a.SeedService$ - Trying to gather entropy from the underlying operating system to initialized the contract ID seeding, but the entropy pool seems empty. WARN c.d.p.a.SeedService$ - In CI environments environment consider using the "testing-weak" mode, that may produce insecure contract IDs but does not block…

and

> [@What became of sandbox option --contract-id-seeding=testing-weak in 2.x.x?](https://discuss.daml.com/t/what-became-of-sandbox-option-contract-id-seeding-testing-weak-in-2-x-x/4382):
>
> Under Daml SDK 1.x.x, I used this clause in the daml.yaml file to make daml start work without failing on waiting to gather entropy: sandbox-options: - --contract-id-seeding=testing-weak After upgrading to 2.1.0, I see the following error message in daml start: ... Created .daml/dist/arbo-ledger-0.0.1.dar Error: Unknown option --contract-id-seeding=testing-weak Canton v2.1.0 Usage: canton [daemon|run|generate] [options] \<…

I’m trying to change the seeding on sandbox 2.5.0. When I run `daml start --sandbox-option -C=canton.participants.sandbox.parameters.contract-id-seeding=testing-weak`, I see

```shell
Waiting for canton sandbox to start.
2023-01-31 09:17:41,237 [main] ERROR c.d.canton.CantonCommunityApp$ - GENERIC_CONFIG_ERROR(8,0): Cannot convert configuration to a config of class com.digitalasset.canton.config.CantonCommunityConfig. Failures are:
  at 'canton.participants.sandbox.parameters.contract-id-seeding':
    - (hardcoded value) Unknown key.
 err-context:{location=CantonConfig.scala:1467} 

```

As you can see it doesn’t recognise that config item. I’ve tried values `no`, `static-weak`, `strong`, none of these appear to work. Any idea what’s wrong? Has this configuration item changed again after the 2.0 release?

---

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**Author:** ![Mate\_Varga](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/mate_varga/32/2308_2.png) [@Mate\_Varga](https://forum.canton.network/u/Mate_Varga)\
**Post date:** [January 31, 2023, 12:04pm UTC](https://forum.canton.network/t/configuring-sandbox-seeding-in-2-5-0/6044/2 "2023-01-31T12:04:36Z")

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Hi @Luciano,

Yes, the parameter placement has changed as part of an improvement.

This should work:  
-C=canton.participants.sandbox.parameters.ledger-api-server-parameters.contract-id-seeding=testing-weak

Kind Regards,  
Mate