56a5c6404c
* test(#1959): add failing-first SBFL contract + Ochiai correctness tests Epic #1957 Phase 1B. Source-text-is-the-product contract tests (Ochiai formula documented, Tarantula fallback, top-N seeding, no-coverage skip logged, ranking->Evidence, Bohrbug gating) plus a behavioral Ochiai formula-correctness section: bound [0,1], max-score invariant, a known-fault fixture proving the fault ranks #1 (criterion 2), clean degradation on zero failing tests, and two fast-check properties. Failing-first: reference file and agent routing do not yet exist. * feat(#1959): add spectrum-based fault localization (Ochiai) pre-filter to gsd-debugger Epic #1957 Phase 1B. When a runnable test suite with per-test coverage exists (>=1 failing AND >=1 passing test), the debugger computes an Ochiai suspiciousness ranking over the coverage spectrum and seeds the top-N suspicious locations into Evidence as first-class hypothesis candidates, narrowing the search space deterministically before LLM reasoning. Tarantula documented as fallback. Degrades cleanly (logged, never silent) when there is no test suite, no failing tests, or no per-test coverage, and is explicitly not trusted on flaky/Heisenbug spectra (pairs with Phase 2B bug-taxonomy). Full rules extracted to gsd-core/references/debugger-sbfl.md (slim Phase 1.25 routing kept in the agent to respect the size cap). No new coverage framework — reuses the project's existing test/coverage runner. INVENTORY + manifest + agent-size baseline + install-parity goldens + AGENTS.md updated. * test(#1959): bound property generators to valid coverage counts The [0,1] property generated failedExec independently of totalFailed, but Ochiai's score is only bounded by 1 under the coverage invariant failedExec <= totalFailed (a failing test that executed s is one of the totalFailed failing tests). Out-of-domain inputs (failedExec=100, totalFailed=5) make the formula correctly return >1. Bound failedExec by totalFailed via fc.chain so the property tests the real domain. Also cleaned up the ranking property (removed dead code). * fix(#1959): address orthogonal review (monotonicity property, degradation row, coverage bounding) - Replace vacuous ranking property (true-by-sort-construction) with a non-trivial monotonicity property: holding totalFailed + passedExec fixed, ochiai is non-decreasing in failedExec. An inverted formula would fail it. - Add the missing 'no passing tests' degradation row (preconditions require >=1 passing test; Tarantula would divide by totalPassed=0). - Bound the coverage subprocess (CLAUDE.md gauntlet): cap the coverage run, degrade-to-skip on timeout, never hang the debug session. - Reword 'discard the ranking' -> 'mark the Evidence entry as revoked (do not delete)' per Kernighan auditability. * test(#1959): bound monotonicity-property generator to valid coverage (failedExecA <= totalFailed) * chore(#1959): backfill changeset pr number (PR #2403)
GSD Core
Git. Ship. Done.
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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.