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 skills/juan294/cc-rpi/error-patternsnpx skills add juan294/cc-rpi --skill error-patternsgit clone --depth 1 https://github.com/juan294/cc-rpiWhat 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 | $0.00038 | $0.00876 |
| Opus 5 | $0.00019 | $0.00438 |
| Sonnet 5 | $0.00008 | $0.00175 |
| Haiku 4.5 | $0.00004 | $0.00088 |
Grade A, and why
error-patterns 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.
How it starts
The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Error Patterns -- Top 20
#1: Parallel verification kills siblings --
Chain with ; or &&, never parallel Bash calls.
#2: Worktree cwd resets to main repo --
Prefix EVERY command with cd /absolute/path &&.
#3: Pre-commit hook rejection -- Run typecheck/lint BEFORE committing. Fix first.
#8: Tilde in file paths --
Never use ~ in Read/Write/Edit paths. Full absolute.
#9: Push rejected (non-fast-forward) --
Pull with rebase first: git pull --rebase && git push.
#12: Push and forget CI -- Spawn background agent to monitor CI after every push.
#13: Skipping TDD -- Write the failing test FIRST. Red-Green-Refactor.
#16: Dependencies not installed --
Run pnpm install / uv sync before build/test/lint.
#25: No upstream tracking --
First push: git push -u origin branch-name.
#30: PR create before pushing --
Push branch to remote BEFORE gh pr create.
#33: Pull rebase with dirty tree --
Commit before git pull --rebase (hook enforced).
#44: Push --tags pushes ALL tags --
Push specific: git push origin v1.0.0 or --follow-tags.
#45: Fabricated filesystem paths -- Never guess paths. Use Glob/Grep to find files first.
#48: Commit/push to wrong branch --
Run git branch --show-current before every commit.
#49: Sub-agent git conflicts -- Each sub-agent owns different files. Central commit.
#51: CI explosion from parallel pushes -- Batch pushes. One push triggers one CI run.
#56: Merge to main without topology -- Ask: does merging to main deploy to production?
#58: Deploy without preview verification -- CI passing is NOT sufficient. Verify on preview URL.
#59: Improvised production recovery -- Roll back immediately. Never deploy to diagnose.
#62: Supabase migration without local test --
Always supabase db reset locally before db push.
Error Domains
- Shell & Tools: #1, #2, #8, #16, #17, #22, #24, #36, #45
- Git: #3, #6, #9, #11, #15, #18, #25, #33, #44, #48, #54, #55
- GitHub CLI: #4, #10, #20, #23, #30, #31, #32, #35, #39, #52, #53
- CI & Deployment: #12, #50, #51, #56, #57, #58, #59, #60
- Python/macOS: #21, #26, #29, #37, #38, #40, #41, #42
- Supabase: #61, #62
- Multi-Agent: #19, #49, #63
- Process: #5, #7, #13, #14, #27, #28, #34, #43, #46, #47, #64
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 · 92 lines · 38 tokens per session scan A e00e99cb4ea0
error-patterns is a skill published in the GitHub repository juan294/cc-rpi (5 stars, last pushed 13d ago), licensed MIT. It adds 38 tokens to every session and 876 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.
Other skills, from other repositories
claude-md-review
Audit a CLAUDE.md file for the patterns that actually degrade Claude Code's output — vagueness, unnamed files, stale facts, and bloat. Use when asked to review, audit, improve, shrink, or fix a CLAUDE.md, and when a project's results feel inconsistent or Claude keeps rediscovering the same context.
best-practices
Searchable knowledge base of 152+ programming best practices across 30+ languages and frameworks. BM25-powered search over curated resources from industry leaders (Google, Airbnb, Uber, Mozilla, Shopify, OWASP).
common-exploit-verification
Enforce "No Exploit, No Report" policy with PoC construction standards, false-positive filtering, and evidence collection per vulnerability class across backend, frontend, and mobile. Use when validating security findings, constructing exploit proofs, filtering false positives, or writing pentest findings.
JavaScript Tooling
Development tools, linting, and testing for JavaScript projects.
common-product-requirements
Standardize PRD discovery and drafting for product scope, user outcomes, requirement IDs, and acceptance criteria. Use when creating PRD, product requirements, feature specification, or acceptance criteria plan.
common-security-audit
Probe for hardcoded secrets, injection surfaces, unguarded routes, business logic flaws, and platform-specific weaknesses across backend (Node, Go, Java, Python, Rust), frontend (React, Angular, Vue), and mobile (iOS, Android, Flutter) codebases. Use when performing security audits, vulnerability scans, secrets…