StartWith

Inspiration

Most AI marketing tools generate isolated content. I wanted to build something that starts with the product strategy and keeps every output connected to the same hypothesis. Build Week pushed me to take that further by turning Codex into an operator inside the product, not just a tool used to build it.

What it does

StartWith turns a project hypothesis into an approval-ready marketing system. Codex can understand the project, review content angles, and create connected landing pages, blog posts, social content and visuals for human review. How I built it

How I built it

StartWith is built with Next.js, React, TypeScript, Convex, Clerk and Vercel. It uses OpenAI models through the OpenAI SDK and Vercel AI SDK. I also built a private Codex plugin using scoped MCP tools, allowing Codex to safely inspect project context and create drafts without publishing automatically.

Challenges I ran into

The hardest part was giving the agent enough context to make useful decisions without giving it unlimited control. I had to design clear approval boundaries, scoped authentication and a consistent data model so every generated asset stayed connected to the original strategy.

Accomplishments that I'm proud of

Codex can now inspect a real StartWith project, evaluate which content angles are strongest, create draft landing pages, blog posts and social packs, generate supporting visuals, and return everything to the product for review.

What I learned

Agents become much more useful when they have structured product context, clear capabilities and a defined review loop. Good agent design is less about giving the model more freedom and more about giving it the right context and boundaries.

What's next for StartWith

Next, I want to expand the operator into campaigns, email journeys and deeper project memory. The goal is a complete marketing operator that can plan and prepare work across channels while keeping the human in control.

Built With

• axiom
• clerk
• convex
• css
• openai
• playwright
• postmark
• radix
• react
• sentry
• tailwind
• typescript
• vercel
• vitest