Canvas LMS — Codebase Overview

Repository

Field	Detail
GitHub	instructure/canvas-lms
Stars	6,478
Forks	2,886
License	AGPL-3.0
Primary Language	Ruby (~45%), JavaScript/TypeScript (~45%)
Created	~2011

Tech Stack

• Backend: Ruby on Rails (one of the largest Rails monoliths in production)
• Database: PostgreSQL (MySQL support dropped years ago)
• Cache / Queue: Redis for caching, sessions, and job queuing
• Job Processing: inst-jobs (Instructure's custom Delayed Jobs fork)
• Analytics Store: Apache Cassandra (optional, for page views / high-write workloads)
• Frontend: React (migrating from legacy jQuery/Backbone), TypeScript (active migration from JS)
• Build: Webpack
• Component Library: Instructure UI (InstUI) — Instructure's open-source React design system
• APIs: Extensive REST API (hundreds of endpoints) + growing GraphQL API
• Standards: LTI 1.1, 1.3, LTI Advantage, SCORM
• Rich Content: Standalone RCE service built on TinyMCE (canvas-rce-api)
• Scaling: Switchman gem for horizontal PostgreSQL sharding; multi-tenant SaaS architecture

Architecture Highlights

• Massive Rails monolith with plugin/engine architecture (gems/plugins/)
• Multi-tenant: a single instance serves many institutions (accounts)
• Key directories: app/ (Rails core), ui/ (frontend React/TS), spec/ (RSpec tests), gems/ (internal gems/plugins), db/migrate/ (thousands of migrations)
• Docker Compose-based development environment
• Some microservice extraction (RCE, Rich Content Service) but core remains monolithic

Release Model

Canvas follows a continuous deployment model for its SaaS product, with production deploys multiple times per week. Open-source/self-hosted releases are tagged as date-based stable releases (e.g., release/2026-03-11.30). There is no semantic versioning.

Canvas publishes release notes through the Canvas Community rather than a traditional CHANGELOG.

Recent Development Activity

The repo sees dozens of commits per day from Instructure engineers, with 80,000–90,000+ lifetime commits. Recent sample commits (February 2026):

• accept icon enum values instead of icon_url in API
• Move coverage-istanbul-loader to devDependencies
• clean up from_user enrollments after merge move
• selenium: bypass rack app for static assets
• allow spaces in login and registration input fields

Active Development Areas

• Frontend modernization: CoffeeScript → JS/TS, jQuery/Backbone → React
• TypeScript adoption: Systematic .js → .ts/.tsx conversion
• InstUI upgrades: Migrating to newer Instructure UI versions
• GraphQL API expansion: Adding queries and mutations
• Accessibility: Continuous WCAG 2.1 AA compliance work
• Performance: Database query optimization, caching improvements

Notable Recent Features & Changes

• Block Editor: New content editor experience for course pages
• New Quizzes: Continued migration from Classic Quizzes to the new assessment engine
• AI features: Instructure has been adding AI-powered tools (some require additional licensing)
• Smart Search: AI-powered search capabilities
• Pace Plans: Self-paced learning features
• Discussion Redesign: Overhauled discussion boards UI
• Canvas Credentials: Verifiable digital credentialing work

Key Technical Migrations

• CoffeeScript removal: Long-running effort, mostly complete
• jQuery/Backbone deprecation: Being replaced by React
• Rails 7.x: Keeping current with Rails versions
• Ruby 3.x: Tracking modern Ruby versions
• Node.js LTS: Current with LTS versions for frontend build

Caveats

• AGPL-3.0 means any modifications deployed as a network service must be open-sourced — more restrictive than MIT/Apache
• The open-source version diverges from the commercial SaaS product (some features are not in the open-source repo)
• Self-hosting is complex and resource-intensive; Instructure provides limited support for self-hosted installations
• Community around self-hosted Canvas is smaller than the commercial user base