8f75e27554
* feat(#3045): deny an executor dispatch that drops its isolation flag Every isolation gate already resolved correctly. The resolved value then reached the executor through a prose instruction telling the model to substitute it into a call the model composes itself, and nothing verified the substitution. When it was dropped, the executor edited and committed in the user's primary checkout with no consent and no warning. A prose backstop would be the same class of artifact as the defect, so this is a shipped PreToolUse hook on the Agent tool. It fires at the instant of the call rather than being read once at the top of a workflow, which is the only placement the model cannot skip. The guard is inert unless it can positively establish that this is a GSD project, that the project resolves to harness isolation, and that the dispatch targets an executor. A non-GSD repo has no invariant to enforce. Where it cannot read the configuration at all, it denies rather than assuming, with its own reason -- a guard that cannot verify must not answer safe. A malformed payload allows rather than throwing. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * feat(#3045): extend the isolation guard to Cursor Cursor is the second of only two runtimes that resolve harness isolation, so shipping the guard for Claude alone left half the exposed surface unguarded while the changeset implied it was covered. The two runtimes fail differently. On Claude the harness flag is a per-dispatch kwarg the model must copy into a call it composes, and the defect is that it can be dropped. On Cursor the flag is --worktree, which applies to the whole session, and the subagent-start payload carries no isolation field at all. There is no flag to check, so the guard verifies the effective state instead: whether the workspace is genuinely running outside the user's primary checkout. That is a stronger check than the Claude one because it tests reality rather than intent, and it is commented so nobody later rewrites it into a flag check. Isolation is established two ways, either sufficient: the workspace resolves to a linked git worktree, or it sits under the worktree root Cursor manages. The second matters because a directory Cursor placed there is a legitimate isolated session even before it becomes a distinct git worktree, where linkage alone would report no repository. Detecting linkage required a new primitive rather than the existing context resolver. That resolver short-circuits on finding a local .planning directory before it ever compares the git directory to the common one -- and an isolation worktree normally has its own checked-out .planning. Reusing it would have read a correctly isolated session as unisolated and denied it, which is the failure direction that gets a guard switched off. The comparison is now its own shortcut-free function that the resolver delegates to after its own shortcut, so existing behavior is unchanged, and the case that would have broken is pinned. The subagent type is checked before any configuration is read, so an unreadable config cannot deny a dispatch this guard would never have enforced against. The input-schema comment on the Cursor hook documented only the fields common to every event and omitted the ones specific to this one. That omission cost a halt during this work; it now documents both. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(#3045): enforce the resolved dispatch decision, not the host capability The guard keyed on the registry's dispatch.isolation, which says only that a runtime is CAPABLE of harness worktrees. The decision that actually governs a dispatch is the one the workflow resolves after gating, and that legitimately comes out as sequential in three documented cases: a project setting use_worktrees false, a per-plan submodule intersection, and the base-check auto-degrade. The workflow tells the model to omit the flag in exactly those cases, and the guard was denying every one of them. The third case matters most. The preceding fix made the base-check degrade on git timeouts and a missing git binary, where it had previously answered "safe". That correction is right, and it means a transient hang now degrades to sequential far more often than before -- so the two changes composed into a trap where the workflow behaved exactly as designed and the guard blocked it. The workflow already resolves isolation in shell, deterministically, which is what makes it a trustworthy source in a way the model-authored call is not. It now records that resolved value through a dedicated verb, and both guards read it first. A fresh record is authoritative, so sequential dispatches pass untouched. Absent or stale, the guards fall back to the capability check combined with the project's use_worktrees setting, which still covers the case that never reaches the workflow. Also widened the matcher to accept Task alongside Agent, since a host that names the tool Task would otherwise leave the guard silently inert while implying coverage; stopped assuming Claude when no runtime is declared, which is the shipped default and would have demanded a Claude-only argument elsewhere; and made a non-git project inert rather than denied, since advising a worktree session is not actionable without a repository. The original diagnosis never modeled sequential mode as legitimate. That omission is what let this through, and it is now recorded there. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(#3045): record at resolution and bind the record to its dispatch Two independent reviews converged on the same failure: the guard was fail-open in a default install, so it did not catch the defect it exists to catch. A shipped project carries no runtime key, which made "runtime not confidently known" the common case rather than a corner one. A record asserting that isolation was required but carrying no flag then fell through to a capability lookup that answered "none", and the dispatch was allowed. The flag itself only arrived from a second shell block -- the same block a model dropping the argument would also skip. A test had pinned that behavior as intended. The record is now written by the resolver, as an unavoidable consequence of asking for the value, rather than by a step the model is told in prose to go and run. A guard against a prose-carried value cannot itself depend on prose. Mode, flag and identifiers are written together and atomically, so the flagless window is gone, and a record asserting isolation with no resolvable flag now denies instead of degrading. Runtime is also resolved from the installer's own recorded default, which makes confident resolution the normal case. The per-plan submodule gate degrades after the phase-level decision and never re-recorded, so a plan that legitimately ran sequentially was denied against a still-fresh phase record. It now records its own, scoped to the plan. A record also authorized any dispatch for four hours. One phase degrading to sequential could silently license an unisolated dispatch in the next. Records now carry phase and plan, the guards require them to match, and the window is minutes rather than hours -- the resolver rewrites it before every dispatch, so a long window bought nothing and only widened the hole. The flag validator rejected any value beginning with two dashes, which is exactly the form Cursor and Windsurf declare, so their real value could never have been stored. Writer and reader also derived the record path differently and diverged inside a linked worktree without local planning state. The predictable path remains a way to silence the control without leaving a trace in the diff. It grants no access an agent with shell does not already have, so it is documented as accepted rather than redesigned around. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(#3045): correct the staleness boundary and unmask a vacuous parity test The remote runner returned twenty failures. One was a real production defect the boundary case existed to catch: a record whose age exactly equalled the staleness window was treated as fresh, so it stayed authoritative for one tick past its own expiry. Freshness is now strictly inside the window. The parity test meant to stop the two guards' executor lists from drifting could never have failed. Its project fixture was a bare directory rather than a repository, so the non-git inert branch answered before the executor list was ever consulted. It asserted agreement it never actually measured. The fixture is now a real repository, like every sibling in the file. A test also asserted that Windsurf declares the worktree flag. It does not -- Windsurf resolves to no isolation by design, having no named concurrent dispatch to isolate. The test claimed a registry fact that was never true, and a comment in the resolver repeated it. Both corrected, and the test now proves what it should have all along: that the parser accepts any bare flag value, rather than one runtime's supposed value. The new guard was missing from the bundled-hook whitelist, which is the surface that decides what actually ships, and the per-plan gate had gained calls to the launcher without the preamble those calls require. The changeset carried parenthetical product descriptions the purity rule forbids. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * chore(#3045): backfill changeset pr number Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * test(#3045): make the guard tests hold on Windows Two tests redirect HOME to control where the installer-persisted runtime default is read from. Node resolves the home directory from USERPROFILE on Windows and never consults HOME, so both silently read the real runner profile, found no recorded runtime, and asserted against a project the hook had not recognised. The production code was already correct in asking the platform rather than the variable; only the tests were wrong to assume one variable answers everywhere. The helpers now mirror the override onto both. The symlink spoofing test also created a directory symlink unconditionally, which needs elevated privileges on Windows. It survived on this runner, but it would fail on any host without them, so the creation is now attempted and the test skips explicitly when it cannot be done -- a bare return would have counted as a pass and hidden the gap. Skipping alone would have left the platform uncovered, so the behaviour it proves is now also driven in-process through an injected realpath, following the seam already used for the clock. That case no longer depends on privileges at all, and the end-to-end test keeps its original assertions wherever symlinks work. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
GSD Core
Git. Ship. Done.
English · Português · 简体中文 · 日本語 · 한국어
A light-weight meta-prompting, context engineering, and spec-driven development system for Claude Code, OpenCode, Antigravity CLI, Kimi CLI, Kilo, Codex, Copilot, Cursor, Windsurf, and more.
What is GSD Core
GSD Core is a context-engineering and spec-driven development framework that drives AI coding agents (Claude Code, Codex, Antigravity CLI, Kimi CLI, Copilot, Cursor, and more) through a disciplined phase loop. It solves context rot — the quality degradation that accumulates as an AI fills its context window — by running all heavy research, planning, and execution work in fresh-context subagents while keeping your main session lean.
How it works
Each milestone repeats the same five-step loop, one phase at a time:
- Discuss — capture implementation decisions before anything is planned
- Plan — research, decompose, and verify the plan fits a fresh context window
- Execute — run plans in parallel waves; each executor starts with a clean 200k-token context
- Verify — walk through what was built; diagnose and fix before declaring done
- Ship — create the PR, archive the phase, repeat for the next one
Quickstart
npx @opengsd/gsd-core@latest
The installer prompts for your runtime (Claude Code, OpenCode, Antigravity CLI, Kimi CLI, Kilo, Codex, Copilot, Cursor, Windsurf, and more) and whether to install globally or locally. The installer is required for cross-runtime compatibility — do not copy files from agents/ or commands/ directly.
On another runtime or without Node.js? See Install on your runtime.
Once installed, start a new project or onboard an existing repo:
/gsd-new-project # greenfield project
/gsd-onboard # existing codebase
New here? Follow Your first project for a guided walkthrough from install to first shipped phase, or Onboarding an existing codebase for brownfield setup.
Documentation
What's new in 1.7.0 → docs/whats-new-1.7.0.md
Tutorials — learning by doing:
How-to guides — task-focused recipes:
Reference — authoritative facts:
Explanation — concepts and design decisions:
Full index: docs/README.md. Other languages: 日本語 · 한국어 · Português · 简体中文.
Why it works
Most AI-coding setups fail at scale because context bloat silently degrades output quality, there is no shared memory between sessions, and nothing verifies that code actually works. GSD Core solves all three: heavy work runs in fresh subagents, structured artifacts like STATE.md and CONTEXT.md survive session boundaries, and the verify step walks through what was built and generates fix plans before a phase is declared done. See docs/explanation/context-engineering.md for the full reasoning.
Troubleshooting? See docs/how-to/recover-and-troubleshoot.md.
Community
| Project | Platform |
|---|---|
| gsd-opencode | Original OpenCode port |
| Discord | Community support |
Star History
License
MIT License. See LICENSE for details.
Claude Code is powerful. GSD Core makes it reliable.