Sparkles

Sparkles is building Lovable for large existing codebases.

Everyone is using coding agents now, but many teams are still stuck relying on outsourced development agencies, and it can take weeks to turn an idea into something live in production.

Sparkles is building the AI workflow for teams shipping changes to existing products. We’re making it possible for product, design, marketing, and ops teams to safely make real changes to production codebases through GitHub-native workflows, reviewable pull requests, and the right guardrails.

Sparkles was founded by Dan, who dropped out of University College London and previously worked with the former CTO of Monzo at Iterate.com. We raised $3.5M, backed by Y Combinator, Moonfire Ventures, and angels from OpenAI, Anthropic, a16z, General Catalyst, Cloudflare, and others.

Sparkles is built for real-time AI agent execution at the edge.

Frontend: TanStack Start, React 19, TypeScript, Tailwind CSS 4, Radix UI, TanStack Router

Backend: Cloudflare Workers, Hono, Cloudflare Durable Objects for real-time WebSocket state

Database: Convex for serverless real-time data, plus Durable Object storage for conversation persistence

AI: Opencode running autonomously in isolated sandboxes, routed through a dual-auth relay worker with per-model token and cost tracking

Sandboxing: Daytona cloud sandboxes with snapshot-based fast startup, Docker containers with s6-overlay, and an in-container daemon (Hono + node-pty) that manages Opencode PTY sessions and streams NDJSON events live

Infra: Cloudflare R2, Stripe + Clerk Billing for credit-based usage, and Sentry + PostHog for monitoring and analytics