sepia

sepia is a portable Agent Skill for Claude Code, Codex, Grok Build, and Antigravity that revises AI-assisted fiction and professional prose at the narrative-architecture and discourse levels, rather than only changing word choice. For fiction, its three-pass protocol addresses narrative architecture, discourse flow, and surface style; its rules cover issues such as overly tidy causality, explained themes, linear time, sparse character networks, uniform emotional rendering, templated paragraph flow, and predictable endings. Professional-writing rules are matched to document venues including release notes, pull-request and issue replies, postmortems, tickets, and technical articles.

The package provides write, review, refactor, and recreate operations, plus a general router. Review diagnoses without editing, refactor makes minimal in-place changes, and recreate rewrites from source facts and intent. It includes a 30-feature diagnosis rubric, model-specific fingerprint corrections, shared professional-prose checks, and research references. The repository distributes the skill as a plugin package with native installation paths for the supported tools and an alternative Skills CLI installation. It is licensed under the MIT License.