MXBAIEdgeColbert (Core ML)

A Core ML export of mixedbread-ai/mxbai-edge-colbert-v0-32m for on-device ColBERT late-interaction (multi-vector) encoding on Apple platforms.

Base model

• Base model: mixedbread-ai/mxbai-edge-colbert-v0-32m

This repository contains only the compiled Core ML encoder (MXBAIEdgeColbert.mlmodelc). All weights are derived from the base model above; no additional training was performed.

What was exported

The exported program wraps the base transformer plus its three ColBERT Dense projection layers (384 → 768 → 768 → 64, no bias / no activation), producing per-token embeddings that are L2-normalized and masked by the attention mask.

Property	Value
Inputs	input_ids and attention_mask, int32, static shape (1, 256)
Output	token_embeddings (per-token, dim 64, L2-normalized, padding zeroed)
Compute precision	float16
Minimum deployment target	iOS 18 / macOS 15

Tokenization and the ColBERT [Q] / [D] prefixing and skiplist masking are performed by the host application; this model performs encoding only.

Usage

Intended for use as the encoder in an on-device ColBERT/PLAID retrieval pipeline. Load the compiled model with Core ML, feed padded int32 input_ids / attention_mask, and read token_embeddings.

License

Released under the Apache-2.0 license, following the base model.