Documentation

RenderFast generates images by rendering a template — a canvas of text, image, and shape layers you design once in the editor — with per-request layer overrides. Call the authenticated /api/generate endpoint (or the public, no-auth /api/render URL) with a template ID and the fields you want to change, and get back a rendered PNG, JPEG, or WebP.

Everything else — uploads, the TypeScript SDK, programmatic template edits, and rate limits — builds on that same request shape.

Where to go next

• Quickstart — clone a starter template, create an API key, and render your first image
• Generate API — the authenticated /api/generate endpoint, layer override reference, strict validation, and warnings
• Assets — upload your own images and fonts and reference them with asset:<id> and font:<id>
• TypeScript SDK — the typed @renderfast/client package
• Render URLs — the public, no-auth /api/render endpoint for OG images
• Templates API — edit templates programmatically
• Template Guide — layer naming, canvas presets, typography, and testing
• Rate Limits & Usage — plan limits and what doesn’t count against them

Need help?

Questions about the API or template creation?

Contact our support team.