debug

A router for choosing between two debugging workflows: one that verifies narrow code fixes automatically and one that has the user verify deeper or visual issues.

In plain words
What is it for?
Use it when debugging logic bugs, race conditions, UI problems, known reproduction steps, or issues caused by outdated project specifications.
Why use it?
It matches the debugging process to the problem, including whether project specifications may need updating after the fix.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/blake-simpson/belmont/debug
Any agent
npx skills add blake-simpson/belmont --skill debug
Clone the repo
git clone --depth 1 https://github.com/blake-simpson/belmont

Made for: Claude Code, Codex.

Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 628 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00033 $0.00628
Opus 5 $0.00016 $0.00314
Sonnet 5 $0.00007 $0.00126
Haiku 4.5 $0.00003 $0.00063

Measured 2d ago against content hash aef8aba92ddc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

debug 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.

plugin/skills/debug/SKILL.md · 47 lines

How it starts

The opening of the file, as written. The whole thing — 47 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Belmont: Debug

This is the debug router. It directs you to the appropriate debug sub-workflow.

Two Modes

Mode Skill Verification Best for
Auto /belmont:debug-auto Verification agent checks each fix Complex logic bugs, race conditions, issues needing automated testing, narrow code-only fixes
Manual /belmont:debug-manual User checks each fix (adds debug logs); deep Belmont context + in-place spec reconciliation after the fix UI bugs, visual issues, known repro steps, bugs that exist because the spec drifted from reality, multi-feature debugging

The two modes diverge sharply after the fix is confirmed:

  • Auto commits the code change and ends. The PRD, TECH_PLAN, NOTES stay as they are.
  • Manual runs a Spec Reconciliation phase that walks the loaded specs, identifies drift, presents diffs for user approval, and commits code + spec edits atomically. This is how Belmont's memory gets corrected so future sessions don't operate on stale truth.

Route Decision

Check the user's invocation text for mode hints:

Route to /belmont:debug-auto if the user mentions:

  • "auto", "automatic", "full verification", "run tests", "agent verify"
  • "just the code", "narrow fix", "don't touch specs"
  • Complex or hard-to-reproduce issues where agent-driven iteration beats user-in-the-loop

Route to /belmont:debug-manual if the user mentions:

  • "manual", "I'll check", "I'll verify", "I can test", "quick", "fast"
  • "debug logs", "console.log", "logging"
  • UI bugs, visual issues, styling problems
  • "I know how to reproduce"
  • "spec is wrong", "PRD is stale", "TECH_PLAN doesn't match", "fix the docs too", "reconcile specs"
  • "across two features", "multi-feature", "spans X and Y"

If unclear, ask the user:

Which debug mode?

  • Auto (/belmont:debug-auto) — dispatches a verification agent to check each fix. Narrow code-only fix. More thorough but slower.
  • Manual (/belmont:debug-manual) — you verify each fix yourself. Loads deep Belmont context (master PR_FAQ + master/feature PRD + TECH_PLAN + NOTES + latest MILESTONE.done). After the fix, walks the loaded specs and offers diffs to reconcile drift in place. Best for bugs that may have a spec-level root cause.

Read the full file on GitHub · 47 lines

Changes

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.

  1. 2d ago First seen · 47 lines · 33 tokens per session scan A aef8aba92ddc

Subscribe to this mod's changes

debug is a skill published in the GitHub repository blake-simpson/belmont (4 stars, last pushed 14d ago), licensed Apache-2.0. It adds 33 tokens to every session and 628 once invoked, about $0.0002 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 2026-08-31.