Show HN: tweakcc (OSS)–customize Claude Code's system prompt and LSP and /title (github.com)

tweakcc is an open‑source utility showcased on Hacker News that lets developers customize Claude Code’s system prompt and its editor integrations (notably LSP behavior and a /title command). The project positions itself as a small but focused tool for prompt-engineering inside coding workflows: users can apply qualifiers (see documentation) to control how the assistant frames responses, and there’s an active changelog (v3.1.0 → v3.1.1) indicating ongoing development. A minor UI hiccup (“error while loading”) was reported, but the repo appears maintained and responsive to feedback. Why it matters: giving engineers direct, versionable control over a model’s system prompt and LSP hooks makes prompt tuning reproducible, sharable, and automatable across teams and editors. That can improve code-generation consistency, adapt assistants to project conventions, and integrate assistant behavior into editor tooling and CI. From a technical standpoint, tweakcc’s OSS nature enables audits, community contributions, and safer experimentation with qualifiers and templates; it also raises governance questions around misuse and the need for guardrails when altering model instructions. For anyone building tooling around Claude Code or embedding assistant behavior in development environments, tweakcc offers a lightweight, community-driven way to standardize and iterate on assistant policies and editor behaviors.