GSD Core fights context rot with fresh-context subagents

Git. Ship. Done. GSD Core is an MIT-licensed framework that drives coding agents through a fixed phase loop, and it exists to solve one specific failure: the quality decay that sets in as an agent's context window fills with the debris of its own work.

What it is

A context-engineering and spec-driven development system that installs into whichever agent you use — Claude Code, OpenCode, Antigravity CLI, Kimi CLI, Kilo, Codex, Copilot, Cursor, Windsurf and more. Each milestone repeats the same five steps: Discuss, Plan, Execute, Verify, Ship.

The names are unremarkable; the enforcement is the product. Discuss captures implementation decisions before planning starts. Verify walks through what was built and fixes it before anything is declared done.

Why it showed up now

v1.10.0 on August 8, pushed daily, three months after the first commit, with documentation organised into tutorials, how-to guides and explanation — the Diátaxis structure, which is a signal about how seriously the project takes being used by strangers.

How it actually works

The mechanism worth taking away is where the work happens. All heavy research, planning and execution runs in fresh-context subagents, while the main session stays lean. Each executor in the Execute phase starts with a clean 200k-token context, and plans are run in parallel waves.

That is a direct structural answer to context rot, and it is the same reason a plan is verified against a fresh context window during the Plan step: if the plan does not fit, it gets decomposed further before anyone starts building. Most agent workflows discover that limit halfway through execution, when the context is already full of half-relevant file contents.

The installer is mandatory rather than optional — the README is explicit that copying files from agents/ or commands/ directly will not work, because cross-runtime compatibility is what the installer produces.

Try it

npx @opengsd/gsd-core@latest

It prompts for your runtime and whether to install globally or locally. Then /gsd-new-project for greenfield work, or /gsd-onboard to bring an existing repository under the loop.

Where it is weak

This is process, and process has a floor cost. Five phases with discussion, planning, verification and archiving is heavy for a one-file fix, and the discipline that pays for itself on a milestone is friction on a typo.

Parallel execution waves with clean 200k contexts each is also not free: fresh context means re-reading, and re-reading means tokens. The README does not publish a cost comparison against running the same work in one session, which is the number a team evaluating this would want.

Eighty-nine issues are open, and supporting nine-plus agent runtimes means every one of them can break the installer independently. As with every prompt-level framework, what you are adopting is a set of instructions whose enforcement depends entirely on the model choosing to follow them.