agentmods.dev

bug_fix_detection

A rule that recognises when a user is reporting a software defect, error, broken feature, or failing test.

In plain words
What is it for?
Use it when a request includes bug reports, error messages, stack traces, regressions, or test failures.
Why use it?
It helps an agent start the appropriate bug-fixing process and gather details such as affected files, symptoms, and reproduction steps.

Cursor rule for Cursor

2 1mo ago A scan 27 tokens original MIT
View the source file markmhendrickson/foundation
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 rules/markmhendrickson/foundation/bug_fix_detection
Clone the repo
git clone --depth 1 https://github.com/markmhendrickson/foundation

Made for: Cursor.

Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,130 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 $0.00027 $0.01130
Opus 5 $0.00014 $0.00565
Sonnet 5 $0.00005 $0.00226
Haiku 4.5 $0.00003 $0.00113

Measured yesterday against content hash c71906ed271a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

bug_fix_detection 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.

.cursor/rules/bug_fix_detection.mdc · 143 lines

How it starts

The opening of the file, as written. The whole thing — 143 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Bug Fix Detection Rule

Reference: Skill fix-feature-bug — Bug fix workflow (.cursor/skills/fix-feature-bug/SKILL.md or foundation/agent_instructions/cursor_skills/fix-feature-bug/SKILL.md)

Configuration is read from foundation-config.yaml.

Trigger Patterns

When a user mentions any of the following patterns, automatically detect bug fix intent:

  • "bug"
  • "error"
  • "fix"
  • "broken"
  • "not working"
  • "failing"
  • "issue" (in context of problems)
  • "problem" (in context of code/functionality)
  • Error messages or stack traces
  • Test failures
  • "regression"
  • "broken feature"
  • "doesn't work"

Agent Actions

Step 1: Detection and Confirmation

If context suggests a bug (mentions "bug", "error", "fix", "broken", error messages, etc.):

  1. Extract bug information from context:

    • Error messages or stack traces (if provided)
    • Feature/module ID (if mentioned or can be inferred from path/context)
    • Description of the problem
    • Steps to reproduce (if mentioned)

  2. Identify affected feature/module:

    • Check error messages for file paths
    • Check context for feature mentions
    • Check open files for feature references
    • If cannot identify → ask user: "Which feature/module is affected? (identifier or 'unknown')"

  3. Ask for confirmation:

    I see you're reporting a bug. Should I fix this using the bug fix workflow? 
Feature/Module: {identifier} (or 'unknown' if not identified)
(yes/no)

  4. Exception handling:

    • If user says "no" → do not proceed with bug fix workflow
    • If user says "just document it" → document the bug instead

Step 2: Execute Bug Fix Workflow

If user confirms (yes):

  1. Load configuration:

    • Read foundation-config.yaml to get bug fix workflow settings
    • Check if error classification is configured
    • Determine feature unit directory (if feature units enabled)

  2. Load required documents:

    • Skill fix-feature-bug (.cursor/skills/fix-feature-bug/SKILL.md or foundation/agent_instructions/cursor_skills/fix-feature-bug/SKILL.md)
    • Repository navigation guide (if configured)
    • Feature spec and manifest (if feature units enabled and identifier provided)
    • Error classification documentation (if configured)
    • Relevant subsystem/module docs (if configured)

Read the full file on GitHub · 143 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. yesterday First seen · 143 lines · 27 tokens per session scan A c71906ed271a

Subscribe to this mod's changes

bug_fix_detection is a cursor rule published in the GitHub repository markmhendrickson/foundation (2 stars, last pushed 1mo ago), licensed MIT. It adds 27 tokens to every session and 1,130 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 2026-08-31.

DebuggingProductivityTesting
Related

Other cursor rules, from other repositories

angular-20

This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.

angular/angular · 0 tokens

dev-standard

Apache Superset development standards and guidelines for Cursor IDE.

apache/superset · 1,147 tokens

typescript

Changes to these high-fan-out internals can affect every message, delta, element, or rerun. Keep work in them minimal, and benchmark changes with representative stress-test apps.

streamlit/streamlit · 4,669 tokens

coolify-ai-docs

Master reference to all Coolify AI documentation in .ai/ directory.

coollabsio/coolify · 1,426 tokens

python_lib

Tips and guidelines specific to the development of the Streamlit Python library, not applicable to scripts and e2e tests.

streamlit/streamlit · 0 tokens

specs

This directory contains product and tech specs for Streamlit features.

streamlit/streamlit · 0 tokens