ThirdLayer
Building Dex, the AI Browser Copilot
If you are part of ThirdLayer (or you are a YC founder who looks at ThirdLayer and thinks that is the kind of business I run), you probably do not have time for a six-month SEO agency contract. Seoable was built for that. Audit your site, queue 100 ready-to-publish posts, and run it all from your AI assistant.
About ThirdLayer
ThirdLayer is an applied research and product lab building the next interface for human–AI collaboration. Our first product is Dex, an AI copilot for the browser. Think Cursor for knowledge work, optimized for speed and embedded directly where you work. Most web agents are built for set-and-forget tasks. But real work is fluid and messy—spread across tabs, tools, and evolving decisions. Dex transforms your browser into an intelligent, multimodal workspace that understands your intent through voice, text, and action. It enhances familiar interfaces, automates tedious steps, and removes the friction of handoffs. Beneath the surface, Dex is more than a browser agent — it’s a foundation for: ● Long-term, cross-modal memory grounded in real workflows ● A new interaction layer to replace static UI with a collaborative canvas ● Personalization: understanding how individuals approach tasks and navigate software We're building the infrastructure for adaptive, intent-aware systems that work the way you do.
Quick facts
- YC Batch
- Winter 2025
- Founded
- 2025
- Headquarters
- San Francisco
- Team size
- 2
- Industry
- B2B • B2B -> Analytics
- Tags
- artificial-intelligence, generative-ai, productivity, consumer-products, ai
- Website
- thirdlayer.inc
Founders
Why founders like ThirdLayer use Seoable
- Ship without an agency. Audit your site and queue 100 posts in one afternoon. No briefs to write, no calls to take.
- Drive it from Claude or Cursor. Seoable is MCP-first. Your assistant can run audits, queue posts, and pull reports without you opening a dashboard.
- Pay per piece, not per seat. Credits instead of monthly seats. Buy what you need, when you need it.
- SEO that includes AI engines. Our audits check what ChatGPT, Claude, Perplexity, Gemini, DeepSeek, and Grok already say about you, not just Google.