Explore · The library

Every resource founders actually use, in one library.

The essays, videos, podcasts, books and tools behind every answer across eChai's hubs, from starting up to go-to-market, D2C, founder money and AI, each with a note on why it is here.

What founders use most, ranked by how many answers lean on it.

  1. Every question you will have about evals, answered by the field's top teacher. hamel.dev Article · How Founders Use AI LLM Evals: Everything You Need to Know (FAQ) Hamel Husain In 2 answers
  2. The course that trained 2,000+ people, including teams at OpenAI and Anthropic. maven.com Course · How Founders Use AI AI Evals For Engineers & PMs (Maven course) Hamel Husain & Shreya Shankar In 2 answers
  3. The same masterclass in podcast form for the commute. open.spotify.com Podcast · How Founders Use AI Why AI evals are the hottest new skill (audio) Lenny's Podcast In 2 answers
  4. Video · How Founders Use AI Harrison Chase on Deep Agents, LangSmith, and Earning Trust NVIDIA AI Podcast (Harrison Chase) In 2 answers
  5. Sierra's founder on agents as the new front door for every brand. sierra.ai Podcast · How Founders Use AI No Priors Ep. 82: Bret Taylor on company-branded agents No Priors (Bret Taylor) In 2 answers
  6. Why enterprise software's future belongs to vertical agents, per its loudest champion. pigment.com Podcast · How Founders Use AI Vertical AI Agents | Bret Taylor on Perspectives Pigment Perspectives (Bret Taylor) In 2 answers
  7. The unvarnished go-to-market grind behind a vertical agent startup. upstartsmedia.com Podcast · How Founders Use AI Jesse Zhang on sales battles, AI wrapper revenge, and making agents work Upstarts Media (Jesse Zhang) In 2 answers
  8. Patterns from 60+ agent companies distilled into a usable framework. growthunhinged.com Article · How Founders Use AI A new framework for AI agent pricing Kyle Poyar (Growth Unhinged) In 2 answers
  9. Why 95% of AI startups get pricing wrong, from the field's leading advisor. lennysnewsletter.com Podcast · How Founders Use AI Pricing and scaling your AI product | Madhavan Ramanujam Lenny's Podcast (Madhavan Ramanujam) In 2 answers
  10. The evidence that base-plus-usage hybrids outperform pure models. revenuecreator.com Podcast · How Founders Use AI Why hybrid pricing already won the AI era Revenue Creator (Kyle Poyar) In 2 answers
  11. A catalogue of every live agent pricing model with examples. getmonetizely.com Guide · How Founders Use AI The 2026 Guide to SaaS, AI, and Agentic Pricing Models Monetizely In 2 answers
  12. The billing-infrastructure view of metering agents without angering customers. flexprice.io Article · How Founders Use AI Why AI Companies Have Adopted Usage-Based Pricing Flexprice In 2 answers
  13. A quick taxonomy to pick your starting model in an afternoon. pickaxe.co Article · How Founders Use AI AI Agent Pricing Models Explained Pickaxe In 2 answers
  14. Kills the 'wait for GPT-next' excuse; harness engineering is the work. venturebeat.com Article · How Founders Use AI LangChain's CEO: better models alone won't get your agent to production VentureBeat (Harrison Chase) In 2 answers
  15. A founder who beat the failure rate explains what enterprise-grade actually took. podcasts.apple.com Podcast · How Founders Use AI How Decagon Built Human-Level AI Support | Ashwin Sreenivas Startup Project (Ashwin Sreenivas) In 2 answers
  16. The canonical guide: curation beats clever prompting for agents. anthropic.com Guide · How Founders Use AI Effective context engineering for AI agents Anthropic In 2 answers
  17. The write, select, compress, isolate framework every team now uses. langchain.com Article · How Founders Use AI Context Engineering for Agents LangChain In 2 answers
  18. Why context, not model size, unlocks agents that work for hours. sequoiacap.com Podcast · How Founders Use AI Context Engineering Long-Horizon Agents | Harrison Chase Sequoia Training Data (Harrison Chase) In 2 answers
  19. Closes the loop: a prototype only pays off if you put it in front of users, and this shows how. maze.co Guide · How Founders Use AI How to test and validate AI prototypes with users Maze In 2 answers
  20. What to prompt when the tool gets stuck in a loop of broken fixes. blog.techforproduct.com Article · How Founders Use AI How to debug AI prototypes Colin Matthews (Tech for Product) In 2 answers
  21. The foundational YC lesson on extracting truth from user conversations. ycombinator.com Video · How Founders Use AI How to talk to users Y Combinator In 2 answers
  22. The most rigorous framework for when AI research participants are and are not legitimate. nngroup.com Article · How Founders Use AI Synthetic users: if, when, and how to use AI-generated research Nielsen Norman Group In 2 answers
  23. The crispest articulation of the unknown-unknowns problem with AI feedback. radicalproduct.com Article · How Founders Use AI Synthetic users vs real user research: why AI falls short Radical Product Thinking In 2 answers
  24. Feature-by-feature walkthrough aimed at people making commerce and launch assets. shopify.com Guide · How Founders Use AI How to use Canva AI: 10 Magic Studio features Shopify In 2 answers

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The hubs

Starting Up Find an idea, validate it, build, and land your first customers. 1327 questions GTM Go-to-market, from breaking in to how the best teams do it. 379 questions D2C Building a direct-to-consumer brand, India-first. 512 questions Wealth Paying yourself, ESOPs, secondaries, and de-risking founder wealth. 165 questions How Founders Use AI How founders actually put AI to work, mapped topic by topic. 360 questions Glossary Plain-language definitions of the startup and VC terms you'll hit. 425 terms
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