tinify.ai — AI Image Optimization for WordPress

WordPress plugin for tinify.ai — a four-stage AI image optimization pipeline: upscale (Real-ESRGAN), resize, compress (TinyPNG), and auto-generate SEO alt text. Runs in the background via ActionScheduler.

For installation instructions, feature descriptions, and FAQ see the WordPress.org plugin listing (coming soon) or readme.txt.

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Development

Requirements: PHP 8.1+, Composer

composer install   # install dependencies
composer test      # run PHPUnit with --testdox

# Lint
./vendor/bin/phpcs --standard=phpcs.xml.dist src/ uninstall.php

# Auto-fix style
./vendor/bin/phpcbf --standard=phpcs.xml.dist src/ uninstall.php

# Run a single test class
./vendor/bin/phpunit --filter ProcessorTest

# Run a single test method
./vendor/bin/phpunit --filter 'ProcessorTest::test_run_saves_results_on_success'

Tests use PHPUnit 10 + Brain\Monkey (Mockery-backed WordPress function stubs) — no live WordPress install required.

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Architecture

tinify-ai.php bootstraps on plugins_loaded and calls Plugin::init(), the single wiring point for all WordPress hooks. No hooks are registered outside of Plugin.

Processing pipeline

Upload event
  └─ Scheduler::queueOnUpload()            wp_generate_attachment_metadata filter
       └─ ActionScheduler job
            └─ Processor::run()
                 ├─ ApiClient::upload()             → temp_file_id  (3 retries)
                 ├─ ApiClient::process()            → job_id
                 ├─ ApiClient::pollJob()            → polls every 3s, max 5 min
                 ├─ ApiClient::downloadProcessedFile()
                 ├─ Replacer::swap()                → atomic copy+rename, .tinify-orig backup
                 ├─ MetaManager::saveResults()      → _tinify_* meta, status=completed
                 └─ Processor::optimizeThumbnails() → opt-in, non-fatal

Status lifecycle

(none) → pending → processing → completed
                              → failed
                              → paused   (credits exhausted; auto-resumes)

All status is stored in _tinify_* attachment post meta, managed exclusively by MetaManager.

Key gotchas

• Re-entrant guard: Replacer::swap() calls wp_generate_attachment_metadata() to regenerate thumbnails, which re-fires the upload filter. Scheduler::queueOnUpload() returns early if status is already pending, processing, or completed.
• Poll resume: a PollTimeoutException leaves job_id intact so the next Processor::run() call skips upload+process and resumes from polling.
• API key encryption: AES-256-CBC using AUTH_KEY . SECURE_AUTH_KEY as key material; never output in plaintext.

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Debugging

Check the ActionScheduler queue:

/wp-admin/tools.php?page=action-scheduler&s=tinify_ai