Collection · 7 articles
WebMCP guides.
Practical guides to WebMCP and agent-native interfaces.
Cofounder of Lazyweb (a16z Speedrun). Previously grew subscriptions and built native ads at Duolingo. Writes First1000 (90,000+ subscribers).
Primary-source guide · 2026-09-19
WebMCP vs MCP-B vs server-side MCP: which layer should a founder choose?
A founder decision guide separating the browser WebMCP API, the MCP-B runtime and bridge, and ordinary server-side MCP.
Primary-source guide · 2026-09-19
10 WebMCP resources worth reading
A source-led reading list covering the WebMCP proposal, Chrome's current experiment, MCP-B, server-side MCP, and OpenAI's documented Site Tools surface.
guide · 2026-09-19
How do you diagnose a tool that works behind a Chrome flag but not in an origin trial?
A deployment-first checklist for separating local WebMCP flag success from origin-trial, token, response, and page-policy failures.
guide · 2026-09-19
Which MCP transport should a new remote server choose: stdio, Streamable HTTP, or legacy SSE?
A founder-facing transport decision for local servers, hosted MCP services, and named legacy-client compatibility.
guide · 2026-09-19
How can a CDN or WAF break Streamable HTTP even when JSON-RPC works locally?
A safe edge-debugging runbook for methods, headers, buffering, timeouts, request bodies, Origin checks, and scoped proxy changes.
guide · 2026-09-19
Shopify Cart MCP or Checkout MCP: where should a merchant require credentials?
A documentation-derived commerce guide separating anonymous exploration, checkout preparation, purchase permission, and merchant handoff.
guide · 2026-09-19
Which cross-origin iframe cases require allow=tools and which must fail?
A permission-boundary guide for top-level, same-origin, and cross-origin WebMCP frames, with safe policy and authorization checks.