Write Tech Spec

This generates a TECH.md file that bridges product intent and implementation reality. It forces you to inspect the actual codebase before writing, grounds the spec in real module boundaries and data flow, and maps product behaviors to concrete tests. The structure scales from 40-line plans for focused changes to longer docs for cross-cutting work. What I like here is the Parallelization section: it pushes you to think about sub-agents upfront, with specific worktrees and branch strategies rather than vague concurrency hopes. Use it when the implementation has architectural choices worth reviewing before code lands, or when multiple modules need coordination. Skip it for straightforward fixes where the code is the clearest explanation.

Install to Claude Code

npx -y skills add warpdotdev/common-skills --skill write-tech-spec --agent claude-code