Cimo is a WordPress media optimizer that converts and compresses files in the browser before WordPress receives them. The free product is instant image → WebP on upload. Premium deepens the same spine with more formats, smart optimize, bulk library rewrite, forms coverage, LQIP, stealth, and license/updates via a lite Freemius layer.
Cimo: The WordPress plugin product (this codebase). Avoid: CMO, WP Cimo (except marketing URLs), Image Optimizer (as the product name)
Upload interception:
Capture-phase listeners that catch drops and file-input changes, run conversion, then re-dispatch a synthetic event with the optimized File so WordPress uploads the optimized bytes.
Avoid: upload hook (PHP sense), interceptor middleware, middleware chain
Converter: A class implementing the shared convert/optimize contract for one media kind (image, video, audio, SVG, or null passthrough). Avoid: optimizer (as the class name), encoder alone, transcoder alone
NullConverter: Passthrough converter that performs no work and signals “do not intercept / no progress UI.” Avoid: skip converter, no-op handler (prefer the type name)
Conversion engine:
The router (getFileConverter) plus abstract Converter contract and registered format converters.
Avoid: conversion service, media pipeline (too vague)
Smart Optimization: Premium image path that searches quality (resemblejs) instead of a fixed WebP quality setting. Avoid: auto quality, perceptual optimize (as the setting name)
Bulk library optimization: Premium client-side rewrite of existing Media Library attachments (original + intermediate sizes) with backup/restore. Distinct from on-upload interception. Avoid: bulk upload, mass optimize (alone), library scan (the list API is only the dataset)
Attachment intelligence: The cluster that records and surfaces per-attachment Cimo meta: metadata queue, Media Library sidebar, Edit Media metabox, and stats. Avoid: media info box (alone), analytics (too broad)
Stealth mode: Premium setting that hides Cimo branding/UI (metabox, sidebar chrome, settings menu surfacing) while optimization continues. Avoid: hide mode, white-label (unless documenting marketing copy)
LQIP: Premium low-quality image placeholder frontend enhancement. Avoid: blur-up (as the product name), lazy placeholder alone
Optimize-all media:
Premium widening of interception locations (including form file inputs and optional * catch-all).
Avoid: global optimize, catch-all uploads (as the setting name)
cimoSettings:
Localized runtime settings object on window used by converters and interception (quality, dimensions, flags, isPremium, disable toggle).
Avoid: cimoAdmin (that is the settings-page localize), options blob
cimo meta:
Per-attachment metadata under the cimo key (upload savings, bulk entries, flags such as smartOptimized).
Avoid: attachment options, cimo_options (site settings)
Metadata queue:
Server transient keyed by filename that bridges browser saveMetadata REST posts to add_attachment matching.
Avoid: meta cache (sidebar upload-notice cache is separate), pending attachments list
Upload notice cache: Client-side cache of just-converted notice/meta for Media Library UI before attachment meta round-trips. Avoid: metadata queue (server)
Freemius lite / FSLite: Premium-only custom license activation and update stack that talks to Freemius APIs without shipping the full Freemius WordPress SDK UI/bloat. Avoid: Freemius SDK (the full product), FS (ambiguous)
CIMO_BUILD:
PHP constant (free | premium) flipped by build scripts; gates loading pro__premium_only/.
Avoid: BUILD_TYPE alone (packaging sibling), isPremium (runtime localize derived from build/plan)
Free: Directory-safe plugin tree: on-upload image WebP, settings for quality/dimensions/thumbnails, stats, sidebar/metabox, bulk upsell + shared list/progress REST. Avoid: lite, basic tier (as the technical name)
Premium:
Code under pro__premium_only/ loaded when CIMO_BUILD === 'premium', gated by Freemius lite plan (premium | agency).
Avoid: pro features sprinkled in the free tree