Codeplain, a startup founded in Ljubljana in early 2025, is betting on spec-driven development as the future of AI-era software. Its core thesis: code should be treated as disposable, regenerated from specs rather than maintained. The company's open-source Plain specification language serves as the single source of truth, and its new plain-forge agentic framework lets coding agents like Claude Code and Codex draft and maintain those specs conversationally. This sidesteps the bottleneck of reviewing AI-generated code by shifting review to human-readable specs that encode intent rather than implementation. The approach also offers economic benefits — spec generation uses 5–10x fewer tokens than direct code generation, and cheaper models handle the code output step. Codeplain has raised $3M and counts Incode among its early customers. The piece also introduces Chad Fowler's 'Phoenix Architecture' philosophy, which frames code as ephemeral and specs as the durable artifact worth preserving, coining the term 'provenance debt' for the lost reasoning behind manual code edits.
