design-an-interface
Generate multiple radically different interface designs for a module using parallel sub-agents. Use when user wants to design an API, explore interface options, compare module shapes, or mentions "design it twice".
Install
With your agent
Install OMGSkills skill "mattpocock/skills:design-an-interface" into this agent's normal skills directory: call the OMGSkills MCP get_install_plan tool for your agent and run the script it returns (it installs only the pinned commit and verifies SKILL.md), and stop if MCP or the pin is unavailable. Do not overwrite or change existing skills without asking me.
Manual command
git clone https://github.com/mattpocock/skills /tmp/skills && ln -s /tmp/skills/skills/deprecated/design-an-interface ~/.claude/skills/design-an-interfaceFrom README
Design an Interface Based on "Design It Twice" from "A Philosophy of Software Design": your first idea is unlikely to be the best. Generate multiple radically different designs, then compare. Workflow Gather Requirements Before designing, understand: [ ] What problem does this module solve? [ ] Who are the callers? (other modules, external users, tests) [ ] What are the key operations? [ ] Any constraints? (performance, compatibility, existing patterns) [ ] What should be hidden inside vs exposed? Ask: "What does this module need to do? Who will use it?" Generate Designs (Parallel Sub-Agents) Spawn 3+ sub-agents simultaneously using Task tool. Each must produce a radically different approach. Present Designs Show each design with: Interface signature - types, methods, params examples - how callers actually use it in practice What it hides - complexity kept internal Present designs sequentially so user can absorb each approach before comparison.