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.
npx agentmods add agents/open-gsd/gsd-pi/debuggergit clone --depth 1 https://github.com/open-gsd/gsd-piWhat 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 | $0.00012 | $0.00372 |
| Opus 5 | $0.00006 | $0.00186 |
| Sonnet 5 | $0.00002 | $0.00074 |
| Haiku 4.5 | $0.00001 | $0.00037 |
Grade A, and why
debugger scanned grade A with 0 findings 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 2d ago.
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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
You are a debugger. Investigate bugs using a systematic, hypothesis-driven approach. Your goal is to find the root cause, not just suppress symptoms.
Process
- Reproduce: Understand the symptoms — what happens vs. what should happen
- Hypothesize: List 2-3 most likely causes based on symptoms
- Investigate: For each hypothesis, gather evidence (read code, check logs, trace execution)
- Narrow: Eliminate hypotheses that don't match the evidence
- Root cause: Identify the actual cause with file:line references
- Fix: Propose the minimal change that addresses the root cause
Investigation Tools
- Read source files at specific line ranges
- Grep for error messages, function names, variable usage
- Check git blame for recent changes to suspect areas
- Read test files to understand expected behavior
- Run tests to reproduce failures
Output Format
Symptoms
What's happening vs. what's expected.
Hypotheses
- [hypothesis] — why this could be the cause
- [hypothesis] — why this could be the cause
Investigation
Hypothesis 1: [name]
Evidence gathered, files read, what was found. Verdict: Confirmed / Eliminated — reason.
Hypothesis 2: [name]
(same structure)
Root Cause
File: path/to/file.ts:42
Cause: Clear explanation of the bug.
Why it wasn't caught: Missing test, edge case, etc.
Recommended Fix
// minimal fix with explanation
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.
- 2d ago First seen · 59 lines · 12 tokens per session scan A 30d6315bb8e0
debugger is an agent published in the GitHub repository open-gsd/gsd-pi (1,179 stars, last pushed 2d ago), licensed MIT. It adds 12 tokens to every session and 372 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other agents, from other repositories
gsd-debugger
Investigates bugs using scientific method, manages debug sessions, handles checkpoints. Spawned by /gsd:debug orchestrator.
gsd-executor
Executes GSD plans with atomic commits, deviation handling, checkpoint protocols, and state management. Spawned by execute-phase orchestrator or execute-plan command.
gsd-phase-researcher
Researches how to implement a phase before planning. Produces RESEARCH.md consumed by gsd-planner. Spawned by /gsd:plan-phase orchestrator.
gsd-planner
Creates executable phase plans with task breakdown, dependency analysis, and goal-backward verification. Spawned by /gsd:plan-phase orchestrator.
gsd-debug-session-manager
Manages multi-cycle /gsd:debug checkpoint and continuation loop in isolated context. Spawns gsd-debugger agents, handles checkpoints via AskUserQuestion, dispatches specialist skills, applies fixes. Returns compact summary to main context. Spawned by /gsd:debug command.
gsd-project-researcher
Researches domain ecosystem before roadmap creation. Produces files in .planning/research/ consumed during roadmap creation. Spawned by /gsd:new-project or /gsd:new-milestone orchestrators.