OpenAPI

Design like Karpathy is watching — Zeke Sikelianos, Replicate

Jul 19, 2025 · 19:26

Zeke Sikelianos of Replicate analyzes Andrej Karpathy's experience building and deploying MenuGen, a vibe-coded web app that turns menu photos into images, to argue that LLMs are now the primary audience for developer tools. He details Replicate's specific failures—rate limiting and outdated docs that blocked Karpathy—and the fixes they implemented: adding LLMs.txt files for Markdown-friendly documentation, promoting curl commands as the LLM-friendly interface, and launching an MCP server built on OpenAPI schemas. Sikelianos advocates for 'boring technology' like SQL and 'good API hygiene' to keep payloads small and information-dense for LLM context windows. He also calls for better payment acceptance and documentation discipline, stressing that unblocking power users like Karpathy (whose CEO intervened) should not require a viral blog post.

The rise of the agentic economy on the shoulders of MCP — Jan Curn, Apify

Jul 18, 2025 · 18:08

Jan Curn, founder of Apify, argues that MCP (Model Context Protocol) enables a future agentic economy where AI agents autonomously discover and purchase tools from other agents or businesses (B2A/A2A). He explains that Apify's marketplace of 5,000 Actors (Docker-based tools) now integrates with MCP, allowing agents to dynamically discover and call any Actor via tool discovery — a key MCP feature. Curn demonstrates this with Claude Desktop, where an agent uses Apify's MCP server to find a venue, scrape Twitter, and even fill a form via a nested MCP server from Browserbase, all without prior configuration. He notes that Apify pays creators over $250,000 monthly, with total Actor revenue exceeding $1.5M/month, and that any developer can publish an Actor to monetize their tools instantly across the ecosystem. The talk closes with open questions about reliability, trust, and whether autonomous agent interaction can lead to AGI.

MCP is all you need — Samuel Colvin, Pydantic

Jul 18, 2025 · 15:24

Samuel Colvin, creator of Pydantic, argues that MCP (Model Context Protocol) is all you need for agent-to-agent communication, simplifying what many are overcomplicating. He explains that MCP's tool calling primitive offers advantages over OpenAPI, such as dynamic tools, logging, and sampling—a mechanism for MCP servers to request LLM calls through the client, enabling nested agentic workflows. Colvin demonstrates a research agent using Pydantic AI that queries the BigQuery public PyPI dataset via an MCP server over stdio, showing how sampling allows the server to generate SQL itself while keeping the main agent's context lean. The demo logs progress to Logfire, an observability platform, and outputs human-readable results. He emphasizes that MCP’s standard I/O mode and extensibility make it ideal for autonomous agents beyond its original desktop coding use case.

Building Reliable Support Agents Using the Effect Typescript Library - Michael Fester

Jun 3, 2025 · 7:22

Michael Fester, co-founder and CTO of Fourteen.ai, explains how his team built production-ready AI support agents using the Effect TypeScript library, arguing it provides strong type safety, composability, and reliability for systems that rely on LLMs. The architecture uses Effect across the entire stack, including Effect RPC, Effect HTTP, Effect SQL, and a custom DSL for agent workflows. Reliability features include fallback between LLM providers (e.g., GPT-4.0 mini to Gemini Flash 2.0), retry policies with state tracking, and duplicated token streams for analytics. Dependency injection allows easy mocking of LLM providers for testing. However, Fester warns of pitfalls like silently losing errors from upstream catches and the steep learning curve. He recommends incremental adoption, starting with a single service.