blindspot

blindspot is a skill for Claude Code, Codex from yologdev/yoyo-evolve. It costs 25 tokens per session (2,137 once invoked), scanned A, original, MIT.

A structured review for finding hidden problems in code, system design, APIs, and deployment setups. It looks beyond syntax and formatting issues to risks that may appear later.

In plain words
What is it for?
Use it before modifying unfamiliar code, after finishing a feature, or when investigating a reported class of issue. It can review a file, directory, module, or specific concept.
Why use it?
It helps expose problems that are easy to miss when you are familiar with the code, such as slow behavior at larger scale or changes that could break users.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

About the project

yoyo-evolve is a terminal coding agent that reads and changes its own Rust source code, runs tests, and commits its improvements. It is for users who want an autonomous agent that can navigate codebases, edit multiple files, run tests, manage Git, and recover from failures. The catalogue entries are skills for working with this coding agent.

yologdev/yoyo-evolve · 1,870 stars · on GitHub · yoyo.yolog.dev

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/yologdev/yoyo-evolve/blindspot
Any agent
npx skills add yologdev/yoyo-evolve --skill blindspot
Clone the repo
git clone --depth 1 https://github.com/yologdev/yoyo-evolve

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for blindspot

README.md
[![agentmods](https://agentmods.dev/badge/skills/yologdev/yoyo-evolve/blindspot.svg)](https://agentmods.dev/skills/yologdev/yoyo-evolve/blindspot)
Your own site
<a href="https://agentmods.dev/skills/yologdev/yoyo-evolve/blindspot"><img src="https://agentmods.dev/badge/skills/yologdev/yoyo-evolve/blindspot.svg" alt="Measured on agentmods" height="20"></a>
Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,137 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 5.1 $0.00025 $0.02137
Opus 5 $0.00013 $0.01069
Sonnet 5 $0.00005 $0.00427
Haiku 4.5 $0.00003 $0.00214

Measured 6d ago against content hash 7617e6c70993, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

blindspot 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 6d 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.

skills/blindspot/SKILL.md · 223 lines

How it starts

The opening of the file, as written. The whole thing — 223 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Blindspot

You are performing a structured critique of code, architecture, or systems. Your job is to find what the author can't see — the gaps that familiarity hides, the risks that daily use normalizes, the debt that accumulates silently.

This is not a linter. Linters catch syntax and style. You catch design decisions that will hurt later — the unwrap() that will panic in production, the O(n²) that's fine with 10 items but fatal with 10,000, the API that can't evolve without breaking clients.

When to use

  • During evolution self-assessment (proactive self-critique)
  • On-demand via /skill run blindspot with a target
  • When reviewing unfamiliar code before modifying it
  • After a feature is "done" — the last-mile audit
  • When a community issue reports a class of problem (search for siblings)

When NOT to use

  • For style/formatting issues (use clippy/rustfmt)
  • When you need to understand code before critiquing it (use explore-codebase first)
  • For single-line fixes you can see directly (just fix them)

Parameters

Target

What to analyze. One of:

  • A file path: src/tools.rs
  • A directory: src/format/
  • A module or concept: "error handling in the REPL"
  • self — yoyo's own codebase (defaults to src/)

Roast level

Controls the threshold for reporting:

  • gentle — Critical and Warning only. For when you want actionable items without noise.
  • standard (default) — Critical + Warning + Smell. The balanced default.
  • brutal — Everything, including nitpicks. For when you want the full picture.

Analysis Dimensions

Examine the target through these lenses:

1. Error handling gaps

  • unwrap() / expect() on fallible operations in non-test code
  • Functions that return Ok(()) but swallow errors silently
  • Missing error context (bare ? without .context() or .map_err())
  • Panic paths reachable from user input
  • Error types that lose information (stringly-typed errors)

2. Security blind spots

  • Hardcoded secrets, tokens, or credentials
  • User input passed to shell commands without sanitization
  • Path traversal vulnerabilities (unchecked ../)
  • Unsafe blocks without safety comments
  • Dependencies with known vulnerabilities

Read the full file on GitHub · 223 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. 6d ago First seen · 223 lines · 25 tokens per session scan A 7617e6c70993

Subscribe to this mod's changes

blindspot is a skill published in the GitHub repository yologdev/yoyo-evolve (1,870 stars, last pushed today), licensed MIT. It adds 25 tokens to every session and 2,137 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 2026-08-30.

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