Lessons from Building an MCP Server for a SaaS Product in Under a Month

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A developer at Drumbeats, a monitoring SaaS, shared key lessons after shipping a working MCP server in roughly one day, with three weeks of surrounding preparation and refinement proving equally critical. Before writing any MCP-specific code, the team overhauled their core API to support account-scoped keys and per-key permission scopes, ensuring agents could operate with least-privilege access. The developer emphasized identifying a single flagship action — in this case, creating a monitor — as the north star for all subsequent design decisions. Rather than mapping REST endpoints one-to-one to tools, the team merged related endpoints into task-shaped tools to reduce the number of choices an AI agent must make, minimizing model errors. The post positions these pre-coding and design steps as the real playbook for any SaaS team considering an MCP integration.

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