Remove client-side default alpha for hybrid queries

[MaxwellCalkin]

Summary

Fixes #1227.

The hybrid query alpha parameter was hardcoded to 0.7 on the client side across all three hybrid executor files (query, generate, and aggregate). This client-side default prevented users from relying on the server-side default, and created a discrepancy where the docstring said "If not specified, the default weight specified by the server is used" but the code always sent 0.7 regardless.

This changes alpha: NUMBER = 0.7 to alpha: Optional[NUMBER] = None in all hybrid method signatures (overloads and implementations), so the server determines the appropriate alpha value when the user doesn't specify one. This is consistent with how other parameters like fusion_type and limit already work.

Files changed

• weaviate/collections/queries/hybrid/query/executor.py — 14 overloads + 1 implementation
• weaviate/collections/queries/hybrid/generate/executor.py — 14 overloads + 1 implementation
• weaviate/collections/aggregations/hybrid/executor.py — 3 overloads + 1 implementation

Downstream handling

The gRPC layer (_parse_hybrid in shared.py) already handles alpha=None correctly:

alpha=float(alpha) if alpha is not None else None,

The GQL layer (_add_hybrid_to_builder in base_executor.py) also handles it correctly:

if alpha is not None:
    payload["alpha"] = alpha

No downstream changes were needed.

Note

This PR was authored by an AI (Claude Opus 4.6, an LLM by Anthropic). I am transparently seeking employment as an AI contributor. A human (Max Calkin) has reviewed and approved this submission.

🤖 Generated with Claude Code

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

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