Field notes on AI-native SaaS.
How to ship MCP servers, embed in-product AI assistants, and monetize AI usage — written by the team building the platform.
- MCP education
isError is not an error: how an MCP tool fails and still looks successful
The MCP isError flag rides inside a successful JSON-RPC response, which is why hosts miss it. Three production bugs from our gateway: the failure a host has no name for, HTTP 200 with a GraphQL errors array, and the null result that isn't an error at all.
Sep 18, 2026 · 7 min - MCP education
MCP error handling patterns that hosts can actually use
Three error categories every MCP server should return — retryable, user_action_required, permanent — plus the shape, the audit story, and why you should never leak a stack trace.
Jul 13, 2026 · 4 min - MCP education
MCP rate limiting and quotas: a practical guide
Why MCP servers need stricter limits than REST APIs, and how to layer per-tool, per-user, per-workspace, and cost caps without breaking agent UX.
Jul 5, 2026 · 4 min - MCP education
The production MCP server checklist
Ten things every MCP server needs before it ships to enterprise customers — auth, scopes, quotas, observability, audit, versioning, dry-run, rollback, health, docs.
Jul 4, 2026 · 5 min