Principle:Predibase Lorax Merge Weight Validation

Knowledge Sources	LoRAX Adapter Merging
Domains	API_Design, Validation
Last Updated	2026-02-08 02:00 GMT

Overview

A validation layer that enforces mutual exclusivity between single-adapter and multi-adapter requests, with parameter-level constraint checking for merge configurations.

Description

Merge Weight Validation ensures that inference requests with adapter merge configurations are internally consistent. Key validations:

• Mutual Exclusivity: A request cannot specify both adapter_id (single adapter) and merged_adapters (multi-adapter merge)
• Weight-ID Length Match: The number of weights must equal the number of adapter IDs
• Strategy Validity: The merge strategy must be one of the supported strategies
• Density Bounds: Density must be between 0.0 and 1.0
• Adapter Source Validity: Sources must be one of "hub", "local", "s3", "pbase"

Usage

Applied automatically during request construction. Validation errors are raised immediately when invalid configurations are provided, preventing malformed requests from reaching the server.

Theoretical Basis

Pseudo-code:

# Validation constraints
def validate_request(params):
    assert not (params.adapter_id and params.merged_adapters)
    if params.merged_adapters:
        assert len(ids) == len(weights)
        assert merge_strategy in VALID_STRATEGIES
        assert 0 <= density <= 1.0

Related Pages

Implemented By

• Implementation:Predibase_Lorax_Merged_Adapters_Validators