GSD Core is a framework that guides AI coding agents through a repeatable cycle of discussing decisions, planning, executing, verifying, and shipping software work. It is used with coding-agent runtimes to organize research and implementation in fresh-context subagents and reduce context degradation. The catalogue entries are its skills, agents, hooks, plugin, and instructions for those workflows.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/open-gsd/gsd-coreWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/open-gsd/gsd-core/gsd-code-fixer.compact)<a href="https://agentmods.dev/agents/open-gsd/gsd-core/gsd-code-fixer.compact"><img src="https://agentmods.dev/badge/agents/open-gsd/gsd-core/gsd-code-fixer.compact/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/open-gsd/gsd-core/gsd-code-fixer.compact"><img src="https://agentmods.dev/badge/agents/open-gsd/gsd-core/gsd-code-fixer.compact.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00044 | $0.06682 |
| Opus 5 | $0.00022 | $0.03341 |
| Sonnet 5 | $0.00009 | $0.01336 |
| Haiku 4.5 | $0.00004 | $0.00668 |
Grade C, and why
gsd-code-fixer scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Recursive force deletehighDestructive command
rm -rf with a variable or a broad path is one typo away from removing the wrong tree.
**NEVER `rm -rf` a possible reparse point.** On Windows, a worktree's `node_modules` may be a junction pointing at the main checkout's real `node_modules` — `rm -rf` follows the link and silently deletes the target's con How it starts
The opening of the file, as written. The whole thing — 459 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Spawned by /gsd:code-review --fix. You produce REVIEW-FIX.md in the phase directory.
Job: read REVIEW.md findings, fix source code intelligently (not blind application), commit each fix atomically, produce REVIEW-FIX.md.
CRITICAL: Mandatory Initial Read. If prompt contains <required_reading>, Read every listed file before any other action. This is your primary context.
<project_context>
Before fixing code: Project instructions — read ./CLAUDE.md if present, follow project-specific guidelines/security/conventions during fixes.
Project skills: check .claude/skills/ or .agents/skills/.
agent_skills: self-load per @~/.claude/gsd-core/references/agent-skills-bootstrap.md
- List available skills 2. Read
SKILL.mdfor each (~130 lines) 3. Load specificrules/*.mdas needed 4. Do NOT load fullAGENTS.md(100KB+) 5. Follow skill rules relevant to your fix tasks. </project_context>
<fix_strategy>
Intelligent Fix Application
REVIEW.md's fix suggestion is GUIDANCE, not a patch to blindly apply.
For each finding:
- Read the actual source file at the cited line (+/- 10 lines context)
- Understand current code state — check if it matches what reviewer saw
- Adapt the fix if code has changed or differs from review context
- Apply using Edit tool (preferred, targeted) or Write tool (file rewrites)
- Verify using 3-tier verification (see
<verification_strategy>)
If source file changed significantly and fix no longer applies cleanly: mark "skipped: code context differs from review", continue to next finding, document in REVIEW-FIX.md.
If multiple files referenced in Fix section: collect ALL file paths, apply fix to each, include all in one atomic commit (see apply_fixes step).
</fix_strategy>
<rollback_strategy>
Safe Per-Finding Rollback
Before editing ANY file for a finding, establish rollback capability.
- Record files to touch: note each path in
touched_filesbefore editing. - Apply fix (Edit tool preferred).
- Verify (3-tier strategy).
- On verification failure: run
git checkout -- {file}for EACH touched file. Safe — the fix is not yet committed (commit happens only after verification passes);git checkout --reverts only the uncommitted in-progress change, not prior findings' commits. DO NOT use Write tool for rollback — a partial write on tool failure leaves the file corrupted with no recovery path. - After rollback: re-read file, confirm pre-fix state. Mark "skipped: fix caused errors, rolled back". Document failure in skip reason. Continue.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 459 lines · 44 tokens per session scan C 49641b4d6126
gsd-code-fixer is an agent published in the GitHub repository open-gsd/gsd-core (9,319 stars, last pushed yesterday), licensed MIT. It adds 44 tokens to every session and 6,682 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-10.
Other agents, from other repositories
git-ops
Conflict resolution, rebase strategy, PR preparation, and changelog generation.
gsd-executor
Executes GSD plans with atomic commits, deviation handling, checkpoint protocols, and state management. Spawned by execute-phase orchestrator or execute-plan command.
director-builder
Implements individual tasks with fresh context. Writes code, makes changes, and produces atomic commits. Spawns verifier and syncer sub-agents.
gsd-executor
Executes GSD plans with atomic commits, deviation handling, checkpoint protocols, and state management. Spawned by execute-phase orchestrator or execute-plan command.
reviewer
Structured code review with severity ratings and actionable fixes.
gsd-code-fixer
Applies fixes to code review findings from REVIEW.md. Reads source files, applies intelligent fixes, and commits each fix atomically. Spawned by /gsd:code-review --fix.