Code Reconnaissance

Code Reconnaissance is a skill for Claude Code from ralfyishere/rules-with-receipts. It costs 101 tokens per session (1,322 once invoked), scanned A, original, MIT.

A set of steps for understanding an existing codebase before changing it, including its conventions, related code, callers, and the possible impact of an edit.

In plain words
What is it for?
Use it before adding a feature, fixing a bug, refactoring, integrating with existing code, or deciding where a change belongs.
Why use it?
It helps avoid duplicating existing helpers, placing code in the wrong area, or breaking parts of the application that were not obvious at first.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

Good fit Use it before adding a feature, fixing a bug, refactoring, integrating with…

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Install with agentmods
npx agentmods add skills/ralfyishere/rules-with-receipts/code-reconnaissance
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.

Any agent
npx skills add ralfyishere/rules-with-receipts --skill code-reconnaissance
Clone the repo
git clone --depth 1 https://github.com/ralfyishere/rules-with-receipts

Made for: Claude Code.

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 Code Reconnaissance

README.md
[![agentmods](https://agentmods.dev/badge/skills/ralfyishere/rules-with-receipts/code-reconnaissance.svg)](https://agentmods.dev/skills/ralfyishere/rules-with-receipts/code-reconnaissance)
Your own site
<a href="https://agentmods.dev/skills/ralfyishere/rules-with-receipts/code-reconnaissance"><img src="https://agentmods.dev/badge/skills/ralfyishere/rules-with-receipts/code-reconnaissance.svg" alt="Measured on agentmods" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,322 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00101 $0.01322
Opus 5 $0.00051 $0.00661
Sonnet 5 $0.00020 $0.00264
Haiku 4.5 $0.00010 $0.00132

Measured 6d ago against content hash a3840889a65d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

Code Reconnaissance 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.

.claude/skills/code-reconnaissance/SKILL.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Reconnaissance

Purpose

Code written without reconnaissance is foreign tissue: it duplicates helpers that already exist, violates conventions the rest of the codebase follows, and breaks callers the author never saw. Fifteen minutes of directed reading turns a plausible change into a native one. This is the comprehension strategy that runs before any plan for changing existing code — live-state-truth says "read before you edit"; this skill says what to read and what to extract from it.

When to use this skill

  • Before implementing anything in a codebase not written in this session.
  • Before choosing where new code should live ("where does this belong?" is a recon question, not a taste question).
  • Before editing any function/module whose callers you can't name.
  • When the task says "do it the way the rest of the app does it" — explicitly or implicitly (it's always implicit).

When NOT to use this skill

  • Greenfield code with no surrounding conventions to honor.
  • Code you wrote or fully mapped earlier in this session and haven't been away from (see memory-hygiene for when that expires).
  • Don't let recon become stalling: the checklist below is minutes of reading, not a full codebase audit. Depth follows effort-calibration.

Operating procedure

1 — Locate the territory. Search by the feature's vocabulary (user-facing terms, route names, domain nouns) to find where this concern already lives. Entry points first: routes, CLI commands, main modules, exported APIs.

2 — Find an exemplar. Locate one existing implementation of the same kind of thing you're about to build (another endpoint, another validator, another migration). This is the single highest-value recon artifact — it answers naming, structure, error handling, and test placement in one read.

3 — Check for prior art before writing anything new. The helper you're about to write probably exists. Search for it by behavior, not just name (utils, shared libs, an existing dependency that does it). Writing a second formatDate is how codebases rot.

Read the full file on GitHub · 70 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 · 70 lines · 0 tokens per session scan A a3840889a65d

Subscribe to this mod's changes

Code Reconnaissance is a skill published in the GitHub repository ralfyishere/rules-with-receipts (2 stars, last pushed 1mo ago), licensed MIT. It adds 101 tokens to every session and 1,322 once invoked, about $0.0005 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.

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