Implementation Gap Check

Structural audit skill invoked against plans prior to execution to resolve missing edge cases.

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/matheusht/redthread/gap-check
Any agent
npx skills add matheusht/redthread --skill gap-check
Clone the repo
git clone --depth 1 https://github.com/matheusht/redthread

Made for: Claude Code, Codex.

Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 194 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 $0.00019 $0.00194
Opus 5 $0.00010 $0.00097
Sonnet 5 $0.00004 $0.00039
Haiku 4.5 $0.00002 $0.00019

Measured today against content hash 5f6b898c6366, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Implementation Gap Check 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 today.

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.

.agent/skills/gap-check/SKILL.md · 19 lines

What it actually says

Gap-Check Skill

Trigger condition:

You should execute this skill prior to submitting a complex implementation_plan.md for human review, or when the user explicitly requests an audit.

Executing the Gap Check:

Evaluate the proposed logic against the foundational models described in docs/AGENT_DECISION_TREE.md:

  1. Security / Red-Teaming Coverage: Does the mechanism rely purely on single-turn evaluation, or does it properly branch (e.g., TAP algorithm)?
  2. Evaluation Metrics: Is there an Auto-CoT JudgeAgent assigned to evaluate the results? If missing, the plan has a gap!
  3. Defense Pipeline: Will this output synthesize into dynamic guardrails, or is the loop artificially broken?

Generate a gap analysis report in the plan's Open Questions section targeting the user.

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. today First seen · 19 lines · 19 tokens per session scan A 5f6b898c6366

Subscribe to this mod's changes

Implementation Gap Check is a skill published in the GitHub repository matheusht/redthread (47 stars, last pushed 10d ago), licensed MIT. It adds 19 tokens to every session and 194 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 2026-09-01.

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