[AI Bundle] Qdrant store: Invalid constructor argument with missing optional parameters

[jvancoillie]

When configuring a Qdrant store under ai.store.qdrant, optional parameters (dimensions, distance, async) are conditionally added to the service arguments.

If some options like dimensions and distance are not defined but async is present (or defaults to false), the container generates a sparse argument array, for example:

[0 => ..., 1 => ..., 2 => ..., 3 => ..., 6 => false]

This results in a container compilation error:

"Invalid constructor argument X: argument Y must be defined before."

Expected behavior: the service should compile without errors even when optional parameters are omitted.

Steps to reproduce:

1. Configure a Qdrant store with endpoint, api_key, and collection_name, but leave out dimensions and distance.
2. Run bin/console cache:clear.

Minimal reproducer: configure any Qdrant store with only required options as above.

[OskarStark]

friendly ping @Guikingone

[Guikingone]

Hum, this one's strange, I'm using the store locally and I'm not facing an issue, could it be related to #834? 🤔

[Guikingone]

@jvancoillie Could you test locally by adding ? before the three latest arguments types?

I bet this is related to the fact that we're requiring the arguments no matter the fact that previous ones are defined 🤔

[Guikingone]

I pushed a fix via a PR, @OskarStark if you have time to check it, @jvancoillie I can confirm the issue, if arguments are not optionals, the build phase fails.

[jvancoillie]

@Guikingone I tested adding ? to make the last three constructor arguments nullable, but the error still occurs:

Invalid constructor argument 7 for service "ai.store.qdrant.symfonycon": argument 5 must be defined before.

The issue persists because the problem is not about PHP accepting null, but about the container receiving a non-contiguous argument array imho. Symfony requires all previous arguments to be defined, so sparse arrays still trigger this error, no ?

I also tested removing the defaultFalse() for the async option in the configuration:

->booleanNode('async')->end()

With this change, the container no longer generates a sparse array and the service builds successfully.

This confirms that the error is caused by async always being set, creating “holes” in the argument array when previous optional parameters (dimensions, distance) are not defined.

[Guikingone]

Hum, got it, didn't noticed the defaultFalse, I'll remove it via #843

[jvancoillie]

Even if removing defaultFalse() for async allows the container to build when no async is configured, the issue still occurs if async is set without defining dimensions or distance, for example:

store:
    qdrant:
        symfonycon:
            collection_name: 'symfony_blog'
            endpoint: 'http://qdrant:6333'
            api_key: '%env(QDRANT_API_KEY)%'
            async: true

In this case, the argument array becomes sparse again:

[0 => http_client, 1 => endpoint, 2 => api_key, 3 => collectionName, 6 => true]

Symfony requires all constructor arguments to be defined in order, so sparse arrays still trigger the error.

I think the robust solution would be to always provide a value for every optional constructor argument, using either the value from configuration or the default defined in the constructor, for example:

$arguments = [
    new Reference('http_client'),
    $store['endpoint'],
    $store['api_key'],
    $store['collection_name'],
    $store['dimensions'] ?? 1536,
    $store['distance'] ?? 'Cosine',
    $store['async'] ?? false,
];

This ensures there are no “holes” in the argument array, Symfony builds succeed, and default values are applied consistently.

[Guikingone]

Weird behavior, other stores are using the same approach and no errors 🤔

[jvancoillie]

Are you able to reproduce this on your side? Is there any difference in my setup that could explain why I’m seeing this issue?

[jvancoillie]

I also tested this with another store (Typesense) and the same issue occurs. As soon as an optional configuration creates a “hole” in the arguments array (e.g., dimensions set but vector_field missing), Symfony throws the same error

  Invalid constructor argument 6 for service "ai.store.typesense.symfonycon": argument 5 must be defined before. Check your service definition.  

This shows that the problem is not specific to Qdrant, but affects any store where optional arguments are appended conditionally using numeric indexes.

[chr-hertel]

Weird behavior, other stores are using the same approach and no errors 🤔

we don't have tests to proof that this is only a qdrant issue, i'm afraid