Content Easy — Lightning-fast template-based image generation in Rust
Render carousel, OG images, and marketing visuals from JSON + SVG templates at ~50ms/slide. No browser. No Chromium. Single binary.
| Canva | Bannerbear | Cosy | |
|---|---|---|---|
| Speed | Manual | 2-5s/render | ~50ms/render |
| Dependency | Browser/App | Browser-based | None (pure Rust) |
| Scriptable | No | Yes (API) | Yes (CLI + API) |
| Self-hosted | No | No | Yes |
| Price | $15/mo | $49-149/mo | TBD |
Template (SVG + JSON schema) → minijinja token replacement → resvg render → PNG
- Define a template: SVG file + JSON schema (brand fields + slide fields)
- Fill the template: JSON data input (brand info + per-slide content)
- Render: Cosy renders PNG in ~50ms per slide
# Build
cargo build --release
# List templates
cosy templates
# Render single image
cosy render --template stat-card --data input.json --output cover.png --scale 2
# Output defaults to 2x (retina) — pass --scale 1 for exact template dimensions.# Images (bg_image, logo) accept local paths or https URLs (SSRF-guarded in cosy serve).# Render with inline JSON
cosy render --template stat-card --json '{"brand":{"brand_name":"CodeCora"},"slides":[{"stat_number":"127%","stat_label":"Revenue Growth"}]}' --output cover.png
# Start HTTP API server (open, no auth — dev only)
cosy serve --port 3000
# Start with bearer token auth
cosy serve --port 3000 --token mysecretkey
# or: COSY_API_KEY=mysecretkey cosy serve --port 3000# Health check (always public)
curl http://localhost:3000/api/health
# List templates (requires auth if token is set)
curl -H "Authorization: Bearer mysecretkey" \
http://localhost:3000/api/templates
# Render via API (requires auth if token is set)
curl -o output.png -X POST http://localhost:3000/api/render \
-H "Content-Type: application/json" \
-H "Authorization: Bearer mysecretkey" \
-d '{"template":"stat-card","scale":2,"data":{"brand":{"brand_name":"CodeCora"},"slides":[{"stat_number":"127%","stat_label":"Revenue Growth"}]}}'When COSY_API_KEY is set (via env var or --token flag), all API endpoints except /api/health require an Authorization: Bearer <token> header. Requests without a valid token receive 401 Unauthorized. If no key is configured, auth is disabled (development mode).
# Pull from GHCR
docker pull ghcr.io/codecoradev/cosy:latest
# Run with auth
docker run -d \
-p 3000:3000 \
-e COSY_API_KEY=mysecretkey \
--name cosy \
ghcr.io/codecoradev/cosy:latest
# Or use docker-compose
cp .env.example .env # edit COSY_API_KEY
docker compose up -dtemplates/
├── stat-card/
│ ├── template.svg # SVG with {{ tokens }}
│ └── schema.json # Field definitions
├── twitter-quote/
│ ├── template.svg
│ └── schema.json
└── ... # 18 templates included
- Template Authoring Guide — How to create custom templates
- Changelog — Release history
| Template | Size | Use Case |
|---|---|---|
| stat-card | 1080×1080 | Single statistic highlight |
| twitter-quote | 1200×675 | Twitter/X quote card |
| linkedin-card | 1200×627 | LinkedIn post image |
| dev-quote | 1080×1080 | Developer quote (code snippet) |
| instagram-story | 1080×1920 | Instagram/Snapchat story |
| youtube-thumb | 1280×720 | YouTube thumbnail |
| github-readme | 800×600 | GitHub README banner |
| tiktok-quote | 1080×1200 | TikTok quote card |
| newsletter-header | 1200×400 | Email newsletter header |
| podcast-cover | 1080×1080 | Podcast episode cover |
| event-banner | 1920×1080 | Event/webinar banner |
| testimonial | 1080×1350 | Customer testimonial |
| checklist | 1080×1350 | Tips/checklist carousel |
| comparison | 1080×1350 | Before/after comparison |
| announcement | 1200×630 | Product announcement |
| carousel-default | 1080×1350 | Generic carousel slide |
| og-image | 1200×630 | Open Graph meta image |
| social-quote | 1080×1080 | General social media quote |
Business Source License 1.1 (BSL-1.1). See LICENSE.
Copyright © 2026 PT Azfirazka Digital Kreatif