extension-object-storage

SKILL.md

Object Storage

Object storage extension for Caffeine AI.

Overview

This skill adds off-chain file/object storage with on-chain references. The MixinObjectStorage mixin provides infrastructure for file operations; you track uploaded files in your own data structures using Storage.ExternalBlob.

Required Setup Checklist

All four steps are mandatory. Skipping any one causes 403 Forbidden: Invalid payload at upload time.

mops dependency — add caffeineai-object-storage to mops.toml under [dependencies].

Mixin invocation — include MixinObjectStorage() in main.mo (imported from "mo:caffeineai-object-storage/Mixin").

Storage.ExternalBlob types — every data field that represents a file MUST use Storage.ExternalBlob, never Text.

Frontend npm package — @caffeineai/object-storage installed and ExternalBlob.fromBytes(bytes, file.type, file.name) used at the call site.

CRITICAL: The frontend package (@caffeineai/object-storage) does NOT work without the backend mops package (caffeineai-object-storage). Installing only the npm package and not the mops package causes silent upload failures (403 from the storage gateway). You MUST install both together.

Backend