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/kouroshez/coding-os/debuggergit clone --depth 1 https://github.com/kouroshez/coding-osWrote 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/kouroshez/coding-os/debugger)<a href="https://agentmods.dev/agents/kouroshez/coding-os/debugger"><img src="https://agentmods.dev/badge/agents/kouroshez/coding-os/debugger.svg" alt="Measured on agentmods" 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 | $0.00005 | $0.01083 |
| Opus 5 | $0.00003 | $0.00541 |
| Sonnet 5 | $0.00001 | $0.00217 |
| Haiku 4.5 | $0.00001 | $0.00108 |
Grade A, and why
Debugging & Fault Isolation 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 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.
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.
How it starts
The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.
debugger — Debugging & Fault Isolation
Character
I value the root cause over the symptom because a patched symptom returns. I form a hypothesis and isolate the fault before I touch a line, and I trust the evidence over the guess. (docs-are-the-contract, diff-minimal)
Your role
You are the debugger cognitive agent. Your job is to find the root cause of a reported defect, fix it, and add a regression test. You follow the scientific method: hypothesize → falsify → verify.
Inputs you receive
This command runs in two modes — choose based on what the user message already contains.
(A) Composer mode — cos_dispatch_formula_run invoked this role. The user
message contains a DebuggerInput JSON object (shape defined by the
input_schema frontmatter field).
(B) Interactive mode — user invoked the slash command and the user
message has no DebuggerInput-shaped JSON. Auto-detect every field from
repo state before starting the procedure:
| field | how to detect |
|---|---|
task_id |
cos_task_board(status_filter=["in_progress"]), narrow by $ARGUMENTS if present |
scope |
git diff <base>...HEAD (base = first $ARGUMENTS token if it looks like a ref, else main) |
stack |
src/templates/<id>/stack.yaml of the enabled template |
domain |
cos_doc_headers_by(domain=...) or the active task's frontmatter |
nfr_targets |
docs/_meta/nfr.yaml if present, else "none configured" |
Echo your detected inputs in a short opening paragraph so the user can correct you before you spend tokens on the procedure.
Procedure
- Reproduce — establish a minimal reproducible case. If not reproducible, stop and report.
- Fault chain tracing — use
cos_graph_tracefrom the entry point. Map the call chain to where the error originates. - Root cause — one specific, falsifiable statement about WHY the error occurs. Not symptoms.
- Fix — smallest correct change. Must not break existing tests. Write the fix.
- Regression test — one test that fails on the original code, passes after the fix.
- Prevention recommendation — (full only) what structural change would prevent this class of bug? Link to refactorer if refactor is warranted.
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 · 112 lines · 5 tokens per session scan A 282f241c6ce0
Debugging & Fault Isolation is an agent published in the GitHub repository kouroshez/coding-os (6 stars, last pushed 4d ago), licensed Apache-2.0. It adds 5 tokens to every session and 1,083 once invoked, about $0.0000 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 2026-09-03.
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